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auto serv¡ceand repair SER VIC ¡N G, LOC A TIN G TR OU B LE , R EP AIR IN GMOD E R NA U TOMOBLE T S, BASICKNOW-HOW APPLICABLE TO AL L MA K E SA , LL MOD E LS
oy M A R TINW .S TOC K E L Industri alE ducat¡on C onsul tant
South Hollond, lllinois
THEGOODHEART-WILLCOX COMPANY, INC. Publishers
INTRODUCTION This Repair
text
M oder n
to all models AUTO courages
Tells
and Shows How to Serviee,
Aut om obi l e s .
of all makes SERVI CE
is profusely
SERVICE illustrated.
Trouble,
is basic, andis
and
applicable
of cars.
AND
the Devel0pment
AUTO
The information
Locate
R E 'A I R
teaches
of Good work
AND
REPAIR
Essential
Habits.
is
skiils:
It Emphasizes
comprehensive,
Many of the drawings
En-
safety.
detailed,
and
were prepared
especialv
instruction
as recom-
for use in this text. AUTO
sERVicE
AND
mended by the standards
REPAIR
for Automotive
provides
serviee Instructionin
It is intended
for
fundamentals;
also those now engaged in automotive
beginners
who want to increase
their
who need a sound, thorough
skills
and step up their
schools.
foundation
service earnings.
in
and reoair
CONTENTS BASICHAND TOOLS
2
PRECISION MEASURING TOOLS
25
3
FASTENE RS, TOROUEWRENCHES
39
4
GASKETS,SEALANTS,SEALS
59
5
TUBINGAND HOSE
73
6
WIRE AND W¡RING
93
7
JACKS,LIFTS,PULLERS,PRESSES, HOLD¡NGFIXTURES
107
SOLDERING,BRAZING,WELDINGCRACK DETECTIONAND REPAIR
119
CLEANINGEOUIPMENTAND TECHNIOUES
139
8
"E$-
7
1
9
19, FRICTIONBEARINGS
149
11, ANTIFRICTIONBEARINGS
163
12 TENGINEREMOVAL
179
1 s,. i'
,13T -r+'-tr CYLINDERHEAD,VALVE AND } VALVE TRAIN SERVICE 14: CRANKSHAFT,MAIN BEARING, FLYWHEELSERVICE
185 ,....225
15. CAMSHAFT,TIMING GEAR,CHAIN SERVICE
243
16t SERVICINGENGINEBLOCKS,CYLINDERS,R¡NGS, coNNECTtNGRODS
261
::> - ,
17) ENGTNELUBRICATION,VENTILATIONSYSTEMS
295
18
ENGINEASSEMBLY,INSTALLATION,BREAK-IN
311
19
COOLINGSYSTEMSERVICE
319
2A
FUEL SYS TEMSERVICE
71
¡GNITIONSYSTEMSERVICE
22
BATTERY,GENERATOR,REGULATOR, STARTERSERVICE
431
23
TUNE-UP,ENGINESYSTEMSPROBLEMDIAGNOS]S
485
24
CLUTCHSERVICE
517
25
OVERDRIVE, MANUAL TRANSMISSION, DRIVE SERVICE FOUR-WHEEL
535
26
AUTOMATICTRANSMISSIONSEBVICE
575
27
PROPELLER SHA FT,UNIVERSALJO¡NTSERVICE
599
28
DIFFERENTIAL,AXLE, SEAL, HOUSINGSERVICE
615
29
BRAKESERVICE
647
30
WHEELS,BEARINGS,TIR ES
689
31
SYSTEMSSERVICE STEERING.SUSPENSION
719
32
AIR coNDITIONINGSYSTEMSERVICE
763
33
EXHAUSTAND EMISSIONCONTROLSERVICE. . . . .
789t:
34
IN AUTOMOTIVEFIELD CAREEROPPOR TUNITIES
817
35
METRICTABLES
821
36
GLOSSARYOF TERMS
829
37
INDEX
851
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Chapter1
BASICHANDTOOLS PROPERCARE IS ESSENTIAL
I-:-:s chapter will c over the identification *,mri :se of basic hand tools. There are many ¡r:e: :ools of a rnore specialized nature which a:e :::ed by' auto meehanics. These willbe illustra;:j ard discussed in the chapters dealing with i5e ;e:r:ce procedures in which they are used.
Fast, efficient work and confusion cannot exist together. Keep your tools clean, orderly type of cabinet, in and near at hand. A roll with a tool chest and "tote'l,tray combination (a small tray, containing a few selected tools, that may be placed right at the job) will provide proper storage and accessibility. See Fig. 1-1.
TMLS ARE IMPORTANT =.T:ng available for use when needed, awide saej:,::-oof quality tools will make your work not rmir -ore effective, but faster. The tools will perform eumrle you to quickly any of the great jobs ¡r-t,..e- of encountered by the mechanics. l1¡e cost of labor is high, and in fairness to [,m.-.: c:slomer and garage, a mechanic cannot a-ff:r: :o waste time working with an inadequate $ei*e:c4 of tools.
EiliJNT TOP OUALITY TOOLS li ¡c: are, or plan to become a professionatr m*::¿:-:c, rule out inferior tools. The cheaper ,g":ai:s and made of poor material, "re usually a-¡e -5ek and thus cumbersome to handle. They m':-' i='l sooner, slow down your work and, due i,r ;,:,:r i:rlshing, will be harder to clean. T:'c qrality tools are made of alloy steel *,md s:e carefully heat treated to impart great wl"lre:::h a¡rd long wear. They will be less bulky mri r:1] have a smooth finish that makes them e*É-r 3n :he hands and quick to clean. The work:mlg s-:rfaces will be made to eloser tolerances. fr,s¡¡e:r parts and facilities will be available and tine :oois ¡ri.ll be guaranteed. that lAe:e are a number of manufacturers prr"scnee excellent tools. Selection of a specific lfirrs:lÉ r:st mechanic. be left to the individual good $'Flm}[BER: tools of The initial cost pride of ownership, ¡m,nr'l'e high but considering úe-mldablüty, life span and ease of use and ciÉ¡.:iqg, they are, in the end, less expensive rfosr= :ools of low quality.
Fi g. l -1. A good w ay to store rool s..(foo/s ore sfi ow n arronged lor disploy; normolly they Íit neotly into drowers.) (Snop-On fools Corp.)
Place delicate measuring tools in proteetive cases. Separate cutting tools such as files, ehisels, drills, etc., topreventdamage tocutting
7
Auto Service ond Repqir
edges. Tools subject to rusting should be lightly oiled. Place heavy tools by themselves and in general, atiempt to keep the most frequently used tools handy. Keep sets such as sockets, open end, and box end wrenches together. REMEMBER: THE LITTLE TIME IT TAKES TO KEEP YOUR TOOLS CLEAN AND ORDERLY WILL BE GREATLY OFFSET BY THE TIME SAVED ON THE JOBJ HA M M E R S Ball peen, plastic tipped, brass and lead hammers should be included in everymechanicrs selection. Various sizes of each are desirable. The ball peen is used for.general striking, riveting, gasket cutting, etc., and the plastic, lead and brass hammers are used to prevent marring part surfaces. When using a hammer, grasp the handle firmly, hand near to the handle end, and strike so the face of the hammer engages the work squarely, Fig. 1-2.
4
Fi g. l -3. C fi i se/s. 1-H ol l round. 2-D i amond, 3-C ope. 4-Fl ot.
it as far from the top as practieal. This will protect your fingers somewhat if the hammer slips from the chisel head. For heavy hammering, a chisel holder should be used, Fig. 1-4.
Fi g. l -4. C hi sel hol de¡. l n use tñe handl e s houl d be k ept ti ght.
!
Keep the cutting edge sharp and the top chamfered (edges tapered) to reduce the possibility of small chisel segments breaking off and flying outward. WEAR GOGGLES WHEN USING A C H IS E L, Fi g. 1-5. PUNCHES Starting, drift and pin punches are essential. A few sections of round brass stock in varying
F i g . l- 2 . Ha m m e r s. Bo ll p e e n .Plo stic fípped. 8ross.
DANGER.I USE A HAMMER WITH CARE. DO NOT SWING IT IN A DIRECTiON THAT WOULD ALLOW IT TO STRIKE SOMEONE IF IT SLIPPED FROM YOUR GRASP. MAKE CERTAIN THE HANDLE IS TIGHT IN THE HEAD AND THAT THE HANDLE IS CLEAN ANDDRY. CHI S EL S Chisels are used for jobs such as eutting off rivet heads, bolts and rusted nuts, Flat, cape, diamond, half-round and rrrivet bustertt ehisels should be available, Fig. 1'3. Hold a chisel seeurely yet not tightly. Grasp
SHARP EN ED
F i s . l - 5 . Clrisel or left is dangerous fo use. Some cfiisel, ofter chamfering and shorpening, is sfiown ot ri ght.
Bosic Hqnd Tools
diameters are useful in driving parts that may be damaged with steel punches. punch is used to start driving A starting rivets, bolts, etc., from the hole. Due to its taper, it may fill the hole before the part is out. If it does, the job is completed with a drift punch. A pin punch is similar to a drift punch but has a smaller diameter driving shank. Pin punehes are useful in removing small pins, bolts, ete., F ig. 1 -6.
Fi g. I-7A . A l i gni ng punch. A -R un punch throughhol es os f o¡ os possi bl e. B -P ul l punch upri ght and Íorce i nto hol es. Thi s w i l l couse ports to shilt into olignment,
F ig. l- 6 . P u n c l r e s . l - s to r tin g p u n ch . 2 - Dr ilt p u n "h . 3 - Pin pur.h.
A center punch is neededtomark workbefore drilling. The small V-shaped hole will align the drill bit. The center punch is also useful for marking parts so that they will be assembled in their original position, Fig. 1-7.
punches. Grind slowly, keeping correct angles, and quench (dip in cold water) often to prevent drawing the temper (overheating, turning the metal blue thus rendering it soft). WEAR-GOGGLES WIIEN GRINDINGJ FILE S The most frequently used files are the flat miLl, round, square, triangular and "point" files. Many other special shapes are made, Fig. 1-8.
s c3 '3 Fi g. l -8. Fi l e shopes, l -K ni l e. 2-H ol l ¡ound, 3-R ound. 4 tFl ot, 5-Triangle. 6-5Iitting. 7-Pilla¡. 8-Sguore.
Fig. l:7. Center puncfi. A-Workmo¡kedlor drilling. B-Drill aligned with pvnch mork,
The aligni.ng punch is very helpful in shifting parts so that the holes line up, Fig..1-7A. U s e ear e whe n s h a rp e n i n g c h i s e l s and
One determination of file cut indicates the relative size and number of cutting edges per inch. In general, the softerthe metalthe coarser the cut needed. Three popular cuts - bastard, second cut and smooth, are shown in Fig. 1-9. A file may be either singl.e cut (a single row of diagonal cutting edges alL at the same angle),
+,
Auto Service ond Repcir
Control the file to prevent roeking (unless round stock). It takes a great deal of filing practice to become expert at filing. A file, in the hands of a professi.onal, can do amazingly aecurate work. Keep the file clean and free of oil. Use a file eard (special wire brush) occasionally to clean chalk may be blackboard the . teeth. Regular prevent clogging. rubbed into the file to help
Fig . 1 - 9 . T h r e e d ilfe r e n t file cu ts - b ostord, s eco n d cu f, o n d sm o o fh . lsim o n d s F i l e C o')
F ER R U LE
!:¡ {¡ I
r
,j
ii
Fi g. l -l l ,
Fíg. l-10. File cufs. l-Single cut. 2-Dovblecuf. 3'Rosp cut. Co.) 4-Curvecut. (N¡cholson
Typtcol si ngl e cut ni l l (¡l e.
Use a cut suitable for the work. Coarse cuts are best for soft metals (aluminum, brass, lead) and the finer euts work well for use on steel. Your choice will also depend upon the finish desired.
or double cut (two rows of diagonalcuttingedges that cross each other at anangle). Files may also be ra sp and c ur v e eut , Fig. 1- 10. A typical single cut mill file is pictured in Fig. 1-11. Note the handlej BE SURE THE FILE AI.. WITII A HANDLE - FIRMLY IS FITTED IT. USING BEFORE TANG, TO THE FIXED This will provide a firm grip and will eliminate the hand, the danger of the tang piercing
ru @."-,@
Fig.1 -11 .
USINGTHE FILE Grasp the file handle with the right hand (for right-handed persons), holding the tip with the fingers of the Left. On the forward stroke, bear down with enough presaure to produce good cutting. On the return stroke, raise the file to avoid damaging the cutting edges.
IN VER TED CONE
BALL Fi g. l -l l A .
t0
R otory fi l es
Bqsic HqndTools
ROTARYFILES The rotary file is chucked hand dril1. It is very handy for recesses where a regular file Se ve ral u se ful s hapes ar e s hown
in an electric blind holes or will not work. in Fig. 1 - 1 1 A . R IN D IN GWH E E L
GRINDERS Fi g. l J3A .
The a uto mec hanic will of t enhav e need t o u s e a g rind er to s har pen t ools , r ewor k par t s , e t c . Grinding, like all shop operations, requires skill and careful handling. Several types of grinders are found in most garag es. Yo u s hould be f am iliar wit hallof them.
H ond pow er yi nder.
(A l bertson ond Co.)
BENCHOR PEDESTALGRINDER This grinder is commonly used to sharpen tools and remove stock from various parts. It is often fÍtted with a grinding wheel onone side, and a wire wheel for cleaning, on the other. If rr.rounted on a beneh, it is referred to as a bench grinder. If mounted on a stand, it is called a pede sta l g rind er , Fig. 1- 12.
Fig. l-138. Discsonder. e t e . , a r e a l s o f o u n d i n a u t o s h o p s . T h e u se o f t h e s e t o o l s w i l l b e d í s c u s s e d i n t h e c h a p te r s reLating to the work they are designed to perform.
EYESHIEL D
SAFETY RULES FOR GRINDERS, SANDERS,AND WIRE WHEELS Grinders, improperly u s e d , a r e d a n ge r o u s a n d a r e r e s p o n s i b l e f o r m a n y s e r i o u s a n d l a sti n g injuries t o t h e e y e s , h a n d s a n d f a c e . R e a l i zi n g t h i s , t h e c o m p e t e n t m e c h a n i c w i l l A L WA Y S o b serve the following safety rules: 1. ALWAYS WEAR GOGGLES. 2. KEEP ABRAS]VE S T O N E S T I G H T , CL EAN
A N D TR U E . A LLOW TH E GR IN D E R TO R E A C H FULL R P M B E FOR E U S IN G, S TA N D TOON E SI DE U N TIL FU LL W H E E L S P E E D IS R E A CHED. ^ K E E P TH E TOOL R E S T, W H E R E USED, A S C LOS E TO TH E W H E E L A S P OS SI BLE. STAND TO ONE SIDE OF THE STONE AS MU C H A S FE A S IB LE . 6 KEEP P E R S ON S W ITH OU T GOGGLES AWAY FROM THE TOOL YOU ARE USING. 7. H OLD S MA LL OB JE C TS W ITH V IS E - G RI P PLIERS RATHER THAN BY HAND TO AVOID GRINDING YOUR FINGERS OR HAV]NG THE OBJECT SEIZED BY THE WHEEL AND THROWN VIOLENTLY. B . FOR HEAVY GRINDING, WEAR LEATHER GLOV E S .
F ig . l- 1 2 . Be n ch g r in d e r .
HAND POWERGRINDERAND SANDER These tools include grindstones, wire wheels and abrasive discs. They are used in body and fender work, carbon and rust removal, smoothing and eleaning welds, porting, relieving, etc. F igs. 1 -13 A an d 1- 138.
OTHER GRINDERS Other t¡pes brake grinders,
of specialized grinders such as valve grinders, crank grinders,
11
C LEAR AN C EAN
o
BE CAREFUL NEVER TO STRIKE A GRINDING WHEEL WHILE REVOLVING . IT MAY SHATTER AND LITERALLY EXPLODE. t 0 PROTECT YOUR EYES BY WEARING AN OR F AC E SH IE LD A P P R O V ED -T YP E GOGGLES. 11 AVOID GRINDING IN THE PRESENCE OF EXPLOSIVE VAPORS . GASOLINE, PAINT THINNER, BATTERIES, ETC. 12. WHEN INSTALLING A NEW STONE MAKE CERTAIN IT IS DESIGNED FOR TITE RPM OF THE GRINDER. 13. WHENEVER POSSIBLE, HAVE THE GRIND. ING WHEEL GUARD IN PLACE TO MINIMI.ZE THE DANGER OF FLYING PARTS. A N D W IR E 14. RE ME M BE R , G R IN D ER S TOOLS BE DANGEROUS WHEELS CAN USE THEM WITH CARE - ALWAYS:
-f-,t I2 D EG.
I2 D EG .
point.{Angle purpose Fig. I-15. Drill lip ongles.A ond B-Generol slrownin B is for cleoronce.)D-Fo¡cost ironond oluminum.ERubber,wood, F-Hord, fough stee/. Nofe fhot the "bock roke" ongles onglesorefhe somein all excep!F' Cleorcnce or cleoronce ore shownin block;lip onglesin colo¡.
3 / B in . o r l a r g e r , Now select an old drill, (goggles on, safety shield in start the grinder place) and try sharpening the drill. Remember to start at the eutting edge and finish at the heel. Both cutting lips should be the same length and angle. The 12 deg. angle, formed between The the cutting 1ip and heel, is very important. to for the drill in order heel must be lower F i g . cut. 1-15. Although drill lip angles are varied forwork in different metals, the angle s shown in Fig. 1 - 1 5 will produce good all-around eutting. Grind s1ow1y and frequently quench the drill, by dipping it into cold water. Avoidoverheating, Use a with the carbon steel drills. especially simple drill gauge to help you get the proper angles, Fig.1-16.
DRI LLS The mechanic has many uses for twist drills. The better quality drills, made of high-speed steel, will do a good job of drilling on most parts of the car and can be readily ground without drawing their temper. Carbon steel twist drills are cheaper but require frequent sharpening and lose their temper if slightly overheated. A s e t o f fra c ti o n a l s i z e d ri l l s from 1/16 to t lz ¡ n. (2 9 d ri l l s to th e s e t), a s et of number dr it ls f r o m 1 to 6 0 , p l u s 9 /1 6 ,5 /8 and 3/4 i n. drills, will handle just about any requirements. A t y p i c a l tw i s t d ri l l i s i l l u s tra te d i n Fi g. 1-14.
- D R ILL
G AU G E
59 DEG
F ig . l- 1 4 . T yp ico l twist d r ill
SHARPENINGDRILLS Select a new 1 I 2 ín. drill and without starting place the cutting edge of the lip the grinder, either on the side or on the face of the wheel. Keep the shank lower than the tip. With a slight pivoting motion, eause the drill 1ip rocking, surface to slide across the wheel. Always start at the cutting edge and end at the heel. Keep trying this until you can go throughthe sharpening motion keeping the lip in proper contact at all times.
Fi g. I-16. l l si ng o dri l l gouge. TÁ ís si mp/e go uge w i l l c hec k ongl es ond |ength. Li p l engfhs A ond B mu s t 6e fhe s ome.
l2
Bqsic Hqnd Tools
S A FE TY R U LE S FOR TH E U S E OF D R ILLS
If you have sharpened the drill correctl¡ it will cut quickly and smoothly. Both lips will be cutting and an equal amount of chip or curl will b e e vid en t, Fig. 1- 17.
1. UNPLUG THE CORD BEFORE INSERTING OR REMOVING A DRILL FROM THE CHUCK. (If the drill starts while you are holding the chuck wrench in the chuck, it might rip your hand badly.) 2. KEEP LOOSE CLOTHING, SLEEVES, TIES, PANT LEGS, ETC., AWAY FROM THE DRILL. 3. MAKE CERTAIN THE DRILL IS PROPERLY E LE C TR IC DRI LLS GR OU N D E D .... A LL PRESENT DANGER OF SHOCK. 4. NEVER USE POWÉR TOOLS OF ANY KIND WHILE STANDING IN WATER OR ON WET GROI'ND. 5. SECI]RE THE WORK TO BE DRILLED. (If the drill grabs and the work is loose, it can begin to spin with a vieious cutting force.) 6. WEAR GOGGLES WHEN GRINDING DRILLS. 7. DO NOT USE ANY POWER TOOL IN THE PRESENCE OF EXPLOSIVE VAPORS.
F i g . l - 1 7 . D r i l l c uttin g p r o p e r ly. Il th e d ¡ ill is slr o rpenedcorr e c t l y , e a c h lip will p to d u ce a sim ilo r ly size d chi p.
U S ¡ NG DRI LL S Center punch the spot to be drilled. Chuck the drill tightly. When drilling cast iron, pot metal, aluminum and thin body metal, cutting oil is not neeessary. When drilling steel, a small quantity of cutting oil will be helpful. Keep the drill at the proper angle and apply enough pressure to produee good cutting. Just before the drill breaks through, ease up on the pressure to prevent grabbing. Securely fasten the piece to be drilled. On thin stock, be careful to hold it down as it has a tendency to climb up the flutes. Fig. 1- 18 pictures a t J 4 in. elee tri c h a n d d ri l l . T h e 3 /8 in. hand drill is handy with medium size drills, while the tl2 in. size will handle heavy drilling,turni ng c y linder h o n e s , e tc . S e e F i g . 1 -1 8 .
R E A ME R S Reamers are used to enlarge, shape or smooth holes. They produce a finish that is much smoother and more accurate than that produeed by drilling. Some reamers may be adjusted and others are of a fixed size. Both straight and tapered reamers are needed. They may use ei ther strai ght f lut es, or spi ral Fi g.1-19. Use cutting oil when reaming. Turn the reamer in a CLOCKWISE direction only - both on entering and leaving the hole. Take small cuts (.001 -.002). R eamers are very har d and the cutting edges chip readily. Wipe down with oil and keep them in a protective container. TA P S A N D D IE S
F i g . I - 1 8 . Ele ctr ic h o n d d r ill.
Taps are used for cutting internal threads. Dies are used to cut external threads on bolts, screws, pipe, etc. The mechanic should have a set of taps and diescoveringthe UnifiedNational Fine and the Unified National Coarse threads (these are fully covered in the chapter on fasteners). This set would have machine screw sizes 1 through 12, plus the ll4 through 5/8 by si xteenths, pl us a 314, ?/8 and 1 i n. size. There are many kinds of taps butforgeneral garage use the taper, plug, bottoming and pipe taps will do nicely. The taper tap has a long
( Sktl T o o ls,l
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AutoServiceond Repoir tl
The pipe tap is tapered over the full length (about 314 in. per ft.) and is used to tap holes for pipe fittings. Taper, plug, bottoming and machine screw taps are illustrated in Fig. 1-20. TA P P IN G
\
determine exactly the number of First, threads per inch and the diameter of the screw that will enter the hole. Referring to a tap drill si ze chart (Fl g. 1-21), sel ect the pr oper t ap size drill.
OR K
f-E it
ct
:
--l
TAP DRIIJÍJ SIZES
I
R€oñh.¡dd
¡MENICAN
t
NTTION¡L
COARSE STÁNDARD THREID
I
lor
SCRTW
(N. C.)
TTIREID
PITICHES
SPECIIL
THRETD
N. S.)
:it 2
56 ,18 40 4 ,¡O 5 32 32 I 24 l0 24 t2 r 14 20 s/r6 ¡ 8 318 l6 7116 t4 r12 ¡3 9/16 s/8 ll 314 l 0 718 9 I I a l - r /8 r-r 14 7
Fig. t-19. Reomers. A-Enlorged seclion sfiowing rcamer looth consfrucfion. B-Reomer tooth removing stock. C-Nonodiustoble, spirol (lute reome¡. D-Nonodiustable, straight llute ¡eamer. EÁd¡ustoble stroight reomer. l, is opened ond closed by removing th e o d iu stin g n u ts. chamfer
(about
10
threads)
that
allows
it
to
start easily. It cannot, however, be usedinblind holes where the thread must run almost to the bottom. The plug tap has a shorter chamfer (about 5 threads) and with care, can be started successfully. It is useful for open holes and for blind holes. The bottoming tap has a short chamfer (about 1 thread) and is used in blind holes to finish the thread to the bottom of the hole. The plug tap shoutd be used first and when it strikes bottom, the bottoming tap should be . us ed.
.66 .099 .l l 2 .125 .138 .164 .190 .216 .zfi .31?5 .3?5 .{3?5 .500 .5623 .625 .?50 .875 l .@ 1.t25 t.250
FINE STANDARD
s 50 a7 43 38 36 a I t6 7
0.üm 0.0?8!t 0.(E90 0.1013 0.1(b5 0.t360 0.t495 0.17?0 0.2010 r 0.2570 5/16 0.3125 U 0.3680 27lA 0.{2r9 3t/6{ 0.48€ r7l& 0.33r2 2r 132 0.656¿ 4916Á 0.?636 718 0.8?5 63/6{ 0.9843 r-7t64 Ll0s3
THRETT.D (N. F.)
1ir:lii' 0 I 2
{
80 72 6,1 s6 ¡t8
{{
40 36 32 I I r 14 5/r6 2{ 24 3/8 7116 20 r12 20 9/16 l 8 l8 s/8 314 l6 718 l { l{ r - r /8 l 2 t2 l-v4
ó
l0 t2
i--+re TAPER
.060 J?3 .086 .099 .l l2
st 50
0.0t¡95 0.07(x) 0.0820 0.0935 0.10,|() .ls 0.1130 .16{ 0.t360 0.1590 .190 0.¡820 .216 0.2130 .250 o.2720 .3125 0.3it20 .3?S o .4:l?5 2s161 0.3906 .sm ?9164 0.4cll .56¿5 0.8062 0.506? 0.5687 0.5687 .?50 r r /16 0.68?5 .875 0.80m 0.8@o 1.000 o.gna o.9271 r-3/64 ¡.0468 l .125 ¡.2S0 l-l ¡/64 t.1718 4S 12 37 3i¡ A 2l ta 3
¡
Fig. l-21 . Top &ill
{l {l
el
el
t0 12 l{ t{ !/16 3le r18
I 36 36 ao l 30 l &
m
A 64 t8 |0 32 38
ste sl9 3/r6 u 3/r6 3[¡ 713¿ 2l 719 9, rl l u rll 27 rl a 3¿l 5/16 6 s1r6 n 5/r6 3a 3/8 m 3/8 2t ?/16 2l 7lr8 ?:I t12 t2 r12 2a r12 27 9/16 27 3/8 t2 sl8 27 r¡/16 u rt/16 t6 t2 3lr 314 n 7le 12 7le t8 718 n I I
size chart.
tz n
0.@0 . t t m {5 0.@ .1t20 aa 0.ll!0 .t380 3{ .teo n 0.ta{E qr',o .tgm a .2td) l3 0.18c) 0.t935 .Hin t0 .zan 7 0.2010 .0623 3/6r 0.0a6¡ .09t¡8 a9 0.üno .12!n 38 0.10t3 .lsgt l/8 0.t230 0.t285 .tsdt 30 .18?5 I 0.t470 .18?3 2 0.t$r0 .2r88 t6 0.ri?o .2188 t2 0.1890 0.2G0 .2to .29! 3 0.2¡30 713¿ 0.2t8? .250 .3123 17lil 0.2656 o.zno .3t25 ,t 913¿ o .m 2 .3125 2rls 0.3281 .3?5 0.9$0 .3?3 R 0.3970 .43?S x 0.(x0 .$75 Y nlEa 0.{2t9 .s00 .s00 ?€rc1 0.¡1531 r3l9 0.{68:t .3oo ru9 0.sitl2 .56¿5 35/64 0.3469 .625 rs13¿ 0.$:¡7 .62tt .68?3 r9l3z 0.3git7 s/8 0.6350 .68?5 43l6¡ 0.6?19 .nn alu 0.?18? .750 3r/64 0.7969 .8?5 53/8{ 0.828¡ .8?3 2713¿0.8¡13? .875 39/64 0.92t9 ¡-000 3rlu 0.9687 l.(m
{
(South Bend Loth)
For example, say that you desire a threaded hole for a 7 116 in. screw with 20 threads per inch. Looking at the ehart, you will find that a 7lt6 in., 20 threads per inch, is a Unified National Fine size. Going directly across from the 7116 in. UNF, you will notice a column marked "Tap Drill Size." In this case, the tap dri l l si ze for a ?/16 i n. x 20 i sa25 l64 in. dr ill. What would be the correct tap size drill to use for a serew 3/8 in. in diameter with 16
PLUG
BOTTOMING
MACHINESCREW Fig. l-20. Typicol tops. AmountoÍ chomlervo¡ies with eocñtype.
l4
F ig . 1 - 2 2 . A ssorted tops ond di es.
threads per inch? Checking the chart, you will f ind it t o be 5 /1 6 i n , Drill the hole with a tap size drill (holes over I 14 in. should be drilled in at least two operations - start with a small pilot drillabout an 1/B in. in diameter, and work up to the tap drill). Using a suitable tap wreneh, carefully start the tap. Cutting oil wilL help when tapping steel. After running the tap in for one or two turns, back the tap up about one-half turn to break the chip. Repeat this proeess until fully tapped. Remember that taps are very brittle. Donot strain them and be sure to keep the hole from clogging with chips. The die is used much like the tap. After selecting a die of the correct size, place it in a die stock (handle), apply cutting oil to the bolt and start the die. Use the same turn and back method used for tapping. Dies are often adjustable so the thread fit can be ehanged. Adjust so that the nut will turn on smoothly with finger pressure. Keeptaps and dies clean, oiled, and in a box. There are many special purpose taps and
TENSI O N ADJ USTE
Fig. l-23. Hocksow lrome.
Fig. l-24. "Jab"
(S nop-Onfool s)
dies, Fig. 1-22 shows a number of them: A -. external rethreading set, B - internal thread r eD -axle restorer, restorer, C -thread threader which is opened up and placed around the good threads and backed off, E and F - nut dies that can be operated with aboxend wrench, G and H - spark plug hole thread restorers very handy for removing rust and carbon, J combination tap and die set for tube fittings, K - tap and die set with taphandle anddie stock.
HACKSAWS A hacksaw is used to cut tubing, bolts, etc. The mechanic should have blades with 18,24, and32teethper i nch. The 1B -tooth bl ade is used for cutting thick metal, the 24-tooth formedium thickness, and the 32-tooth blade for thin sheet metal and tubing. The blades should be of high quality steel as they will cut faster and longer than low quality blades. Fig. l-23, illustrates a typicat hacksaw frame. For very thick work, use a 14-tooth blade.
OTHERHACKSAWS t'iab saw,rr will A special hacksaw, termed a facilitate eutting in tight quarters. A hole saw, driven with an electric drill, is handy for cutting large holes in sheet metal. See Figs. 1-24 and 1-244.
(Owottono Tool (orp.)
sow, o handy tool in right qeoilerc.
Fig. l-24A. Hole sow. Cutters oÍ vo¡ious sizes ore ovoiloble. (Snop-On fools)
SCREWDRIVERS The mechanie should own several different sizes of screwdrivers of the standard, Reed & Prince, Phillips and Clutch types; Fig. 1-2?. The offset screwdriver shown in Fig. 1-27, is useful in tight quarters where evenattstubbytt cannot be used.
/ñ
0 u l\lV t:
F ig . l- 2 5 . T yp ico l b e n cfi vise .
VISE
A
A vise suitable for automotive work is pic t ur ed i n F i g . 1 -2 5 . K e e p th e v i s e cl ean, use c opper ja w e o v e rs fo r w o rk th a tma ybemarred, oil the working parts and avoid hammering on the handle or on other surfaees.
!t
PH ILLIPS
\t¡l
!-7
R EED AN D PR IN C E
C LU T C H
-
Fig. l-27, Screwdriver fypes. Wren usíng screwdrivers, selecf the ri ght type ond si ze, A good ossortmenfis es s enti ol .
CLE A NI N G T OOL S H A N D LIN G S C R E W D R IV E R S A number of useful cleaning tools are illust r at ed in F i g . 1 -2 6 . H a v i n g a s e l e cti on speeds up cleaning work. The wire wheel and power cleaning brushes are mounted in an eleetric drill. USE GOGGLES WHEN OPERATING THE WIRE WHEEL AND ALSO WHEN CLEANING WITH CAUSTIC (WILL BURN SKIN AND EYES) SOLUTIONS.I
Use a screwdriver in keeping with the job. Avoid prying with or hammering on the screwdriver. (Some verylarge screwdrivers are made so that minor prying and hammering will not harm them.) When grinding a new tip on the standard tip screwdriver, maintain the original taper. Do not grind to a sharp point or to a steep taper as the tip will either twist off or climb out of the slot. Avoid overheating. See Fig. 1-28. CAUTIONj WHEN HOLDING SMALL I]NITS IN THE HAND, DO NOT SHOVE DOWN ON THE SCREWDRIVER HANDLE AS IT MAY SLIP AND A
I F i g . l - 2 6 . Cle a n in g ¡ o o ls. l- Ho llo w co r b o n b r u s h. 2-l l i ¡e b¡ush. 3-Wire wáeel. 4-Flexible scroper. S-Twisted strond wire b¡ush. 6-Bristle head. 7-Rigid scraper. 8-Cor6on b¡ush. 9-B¡is¡le 6rush o n d h o l d e r . l0 - A¡ b o ¡ fo r wi¡ e wh e e l. Il- Cie o n in g brush w i th nylon 6ríst/es. l2-Hond wire scrofcfi brusñ,
B
c
D
E
II
F
ü
Fig. l-28. Correcf sfiorpening is importon¡. A and B-F¡ont ond side view of co¡¡ect sfiope. C-Too sfeep ond sñorp. D-Correct toper ond size. E-Steep angle will "climb our" of screw slot. F. ' Screwd¡iver ground too thin; it will twist o|l.
t6
PIERCE YOUR HAND. IF WORKING ON ELEC. TRICAL EQUIPMENT, SHUT OFF THE CURRENT, USE AN INSULATED (FULL LENGTH) SCREWDRIVER AND KEEP YOUR HANDS FREE OF ANY WIRES WHERE IT IS IMPOSSIBLE TO SHUT OFF THE CURRENT. IF. YOU MUST WORK AWAY FROM AN OPEN SWITCIT, TAG IT SO THAT SOMEONE WILL NOT ACCiDENTALLY TURN IT ONJ P LI E RS Pliers are used for cutting wire, holding parts, crimping connections, bending cotter pins, etc. The combination slip joint, vise-grip, adjustable rib joint, battery, pump, ignition, Long nose, needle nose, diagonal and side cutter pliers are most often used. Other, more specialized pliers such as the snap ring, hose-clamp,brake spring, will be covered in later chapters. Avoid cutting hardened objects and never use pliers to turn nuts, bolts or tubing fittings, Fig. 1-29.
Fi g. l -30, 8ox end w ¡encñes. A -D oubl e ofl set. B -1S -deo.offs er.
er swing while the 6-point provides superior holding power. One design uses a double offset to give more handle clearance while another uses the popular 15-deg. offset. Differentlengths plus a complete range of opening sizes are needed, Fl gs. 1-30 and 1-31.
q.
Fi g. l -31. B ox end w ¡ench. Slrown is o lS-deg. oflsef, short l ength type. (J. H . Wi l l i ons)
FLARENUTIIEAD TU B IN GS LIP STH R OU GH Fig. l-32. Combina¡ion ilore nut and open end wrench.
F L A RENUTWRE NCH The flare nut wrench is quite similar to the box end wrench but has a section cut out so that it may be slipped around tubing and dropped over the tubing nut. This wrench has either 6-point or 12-point opening. The flare nut wrenchis amust for carburetor, vacuum, brakes, etc., fittings, Fi g.1-32. R A TC H E T B OX E N D F i g . l - 2 9 . U s e l u l p lie r s. l- Ne e d le n o se . 2 - Ch a in n o se. 3-E l ect ri c i o n . 4 - D i o g o n o l. 5 - Rí6 io in t. 6 - lg n iiio n . 7 - Co n b in oti on sl i p j o i n r . 8 - "Vise - g r ip " o r p lie r wr e n ch . (Utico ond Proto fools)
BOXEN DWR ENCHE S Box end wrenches are available with 12-point or 6-point openings. The 12-point allows a short-
This is a ratcheting tool using a box end design. It is fast to use andhas many applications, Fi g. 1.-33.
O P E NE NDWRE NCH The open end úrench grasps the nut on only two flats. Unless it fits well, it is apt to slip and round off the nut. There are many places,
F i g . l - 33.
Rotcáef
6ox end wr ench. 7o rev e¡ s e ¡ ofc her ( J. H. V ti l l i ons ) f lip wr ench over .
h o w e v e r , w h e r e t h e y m a y b e u se d sa ti sfa cto r i l y. Wh e n e v e r p o s s i b l e , u s e a b o x e n d o r so cke t i n preference to the open end. Open end wrenches have the head set at an angle. In tight quarters where the handle swing is limited, pul1 the handle as far as it will go, flip the wrench over and replace on the nut. By t h i s m e t h o d , t h e o p e n e n d c a n op e r a te i n a sw i n g of 30 deg., Fig. 1-34.
oc ti on,
COMBINATIONBOX AND OPEN END WRENCH
F ig . l- 3 4 . Op e ne n d wr ench.
This tool has a box end on one end and an open end on the other. Both ends are of the same size, Fig. 1-35. Fig.
A
l- 35.
Com binolion
SOCKETWRENCHES
box ond open end w ¡ enc h.
c
T h e s o c k e t i s o n e o f t h e f a s t esta n d m o st co n venient of all the wrenches. Sockets are available i n 6 - p o i n t a n d 1 2 - p o i n t o p e n i n g s a n d i n Il 4 ,3 l B, ll2, 3 / 4 i n . a n d l a r g e r d r i v e s . D r i ve si ze i n d i cates the size of the square driving hole in the base of the socket. The mechanic should have a ll4 in. drivefor small fasteners, a 3 l B i n . d r i ve to h a n d l e th e medium size s and a I 12 and B I 4 in. drive for the remainder of the work. Sockets come in two depths - standard and deep. Standard sockets will handle the bulk of the work, while the extra reach of the deep s o c k e t i s o c e a s i o n a l l y n e e d e d , Fi g . 1 - 8 6 .
D
S WI V E LS O CK E T
F i g . l -3 6 . Vo ¡ io u s so cke ts. A- 1 2 - 2 o in td e ep socker. B -t2-poi nt s t o n d o r d so cke,f C- 6 - p o in td e e p so i/< e t.,D-ó-poi nf stondordsockef. ( Sn o p - Onfo o /s Co ¡ p ,)
T h e s w i v e l s o c k e t a l l o w s th e u se r to tu r n fasteners at an angle and as a result is handy for many jobs, Fig. 1-3?.
Fi g.1-38. S ocket speed hondl e. (J. H . l ti l ti ons )
F ig . l- 3 7 . 6 a n d l2 - p o in t swive / sockets.
Fi g. l -39. S ocker fl ex hondl e. (Ow ottono Tool C o¡p.)
t8
G
ü¡' )OCKET HANDLES The Se ve ral diffe r ent dr iv e handles ar eus ed. ha nd le is us ed whenev er pos s ible a s i t . ::ed -=:, be turn ed r aPidlY, Fig. 1- 38. Flex handles of different lengthprovide heavy : -::,rng le ve rag e and m ay be us ed at m any a n g l e s ,
Fi g. l -43. S ocket rotchefi ng odopter' (J' H ' l l íl l i ons )
.
:. 1-3 9. The sliding T-handle has some applicatíons =,'..i sh ou ld be i nc luded in a s oc k et s et , Fig. 1 - 4 0 ' Sp inn er h an dles ar e us ed m uc h as s c r e w .,-ers and will accept all the socket attach-: : :--:nts, Fig , 1-4 1. The ratchet handle allows both heavyturning : ::ce a nd spe ed. The f as t ener c an be t ur n e d i n a lever on the ratchet. The _: out by flicking ra:ch et is a lso us ef ul wher e a lim it ed s w i n g i s Fig . l- 42. : :cessa ry, \ ratcheting adapter can be used with a flex :.=:d le, T-ha nd le, et c . , t hus m ak ing t hem q u i t e ' .':rsa tlIe, .r1 9, r - + J . at driving joint will permit The universal :riferent angles with the various sockethandles,
Fi g. l -44. S ocket uni verso/ i oi nf.
r '-g. L -44 . drive size can be Sockets of one particular another by using from handles the with ':rned an ad ap ter, Fig. 1- 45.
CTHER SOCKETATTACHMENTS drag link and crowfoot socket Screwdriver, are a few of the many offered, =:tachments |
Fi g, I -45. S ockef odoP fer'
- 4h
F i q . l - 4 0 . So cke t slid in q T - h o n d le '
Fis.
l - 46,
O ¡ her s oc k el ol foc hm ents . l - Sc r ew dti v er ' ( EonneY T ool s / 3- C r ow l oof.
2 -D ro g l i n k '
F i g. 1 - 41. Sockel sPínner hondle'
Fi g. 1-46A . S ockef exl ensi on bors'
( Owo tto n o T o ol C orP ') F i q . l - 4 2 . S ocke f r o fch e f h o n d le .
19
(J' H ' Y l i l l i ons )
Auto Service ond Repoir
SOCK E TE X T.E NS IONS The long, medium and short extensions allow the user to extend the reach ofhis set. They may b e used s ingly or s napped t oget he r i f s o d e s i r e d , Fio 1 - 46A
1i rli
.f
FLEX-HEAD WRENCH The flex-head wrench is a valuable addition to the tool box as it can be used through various an gle s and in c r am ped quar t er s , F i g . 1 - 4 7 .
Fig, l-48. Stud wrencfi. ll¡enc/r is droppedover stud ond the locking wedge is slroved in bore uniil if confocfs s¡ud. llhen wrench i s turned, w edge w i l l ¡om ogoi nst stud. To remov e s tud, i ns ert wedge os slrown. fo instoll stud, insert wedge lrom opposife side.
F ig . l- 4 7 . F le x- h e o d wr e n ch . ( Snop-Onfool s)
1r
F i g - l - 4 8 A. Stu d w¡ e n c/rtyp e s. A- T h r e e io w. B -Wedgerype si mi l or to Fi g. 1-48. C -R orori ng l ock w heel . D -l l edge ty pe l or ti ght quo' rers . (Snop-On foo/s Corp.)
STUDWRENCH Several types of stud wrenches are manufactured. With any of them, be careful not to damage the threads on the stud, Figs. 1-48, an d 1- 484.
Fi g. l -49. A dj ustobl e w renc fi .
F ig . I- 5 0 . Pi pe w renches, A -Oursi de pi pe w rench. 8-fnsi de pi pe w rench.
20
Bqsic HqndTools
&
#
ñ ''CRESCENT''OR ADJUSTABLEWRENCH
P RO B I NG TOOLS
The adjustable wrench is a useful toolinthat its size may be readily adapted to that of the fastener. However, it is prone to loosening and slipping. When other wrenches are available use the m, Fig. 1 - 49.
Mechanical fingers, extension magnets and mirror d e v i c e s h e l p t h e m e c h a n i c t o r e t r i e ve parts and to see in blind areas, Fig. 1-52.
PIPE WRENCHES
( a i r ) i m p a ct An electric, or pneumatic wreneh, used in conjunctionwith sockets, speeds up the job a significant amount. Most shops are now using them, Fig. 1-53.
Th e pip e wrenc h is us ed t o gr as p ir r egu l a r or round surfaces. It provides great gripping power. Both inside and outside pipe wrenches should be available, Fig. 1-50.
POWEROR IMPACT WRENCHES
AL L ENAN DFLUTE DWRE NCHE S T hes e wr enc h e s a re u s e d to tu rn s e ts c r ew s, ca p s c r ews , et c . , F i g . 1 -5 1 .
F i g . l - 5 1 . AIle n o n d llu te d wr e n ch e s. Fi g. l -53. E l ectri c i mpoct w rench. (A l bertson C o. )
BE W A RE J WHEN USING ANY WRENCH, MAKE CERTAiN THE WRENCH IS THE CORRECT SIZE AND IS SECURELY ENGAGED, PULL, DO NOT PUSH. IF PUSHING IS ABSOLUTELY NECES. SARY, OPEN THE HAND AND PUSH WITHTHE PALM. BE CAREFUL, IF A WRENCH SLIPS, YOU CAN GET A SERIOUS CUT:
O T HE RST O F O L L O W As mentioned earlier, many other more s p e e i a l i z e d t o o l s w i l l b e d i s c u s s e d i n t h i s te xt. When, in your reading, you come across one, pay particular attention to the name and how it is used. Many jobs in the shop can be made either time consuming and difficult or fast and easy, depending on an intelligent selection of tools. REMEMBER: PROPER T O O L S E L EC . L E AR N TION ANDUSEISVERYIMPORTANT ALL YOU CAN ABOUT THEMJ
S UG G E S T EADCT I V I T I E S
Fig. l - 5 2 . P r o h i n g t o o ls. A- M e ch o n ico l fin g e r p icku p . B-Tel es c o p i n g mo g n e t. C- T e le sco p in g m ir r o r .
Wrrte to a number of tool manufacturers and ask for a copy of their tool catalog, and any informative brochure s they may offer concerning their products. You may find their names and addresses by looking in automotive trade prye-rs. After ¡rou have received your material, btudy Learn the names and suggésted it carefully. uses of as rnany as you ean. Flick through the
'# %"
i
@
peen hommer'.3'R eedond,P ri ncesc¡ew dri verheod' 4' c o¡¡e¡ F ig , 1 - 5 4 . l- M e d iu n le n g ilr so cke t extensi on. 2-C ross offset box.end' 8A -C ombi nori onbox ondopen end. 7-srondord-l ength,doubl e p in p u lle r .S- sto n d o r dt"r ".ir ]".r . socket' l J'S ocke¡ d¡i ve odoptet 1/ 2 i n' to 6-poi nt 1}-R egui or hondl e. rctch* fio .k"t Re g u lo r 1 2 - p o in t "o "k.r . hornmer. I5-Job sow n l 6'A l i gni ng bo¡ w i ¡h 3 /g ¡ n . l2 - So td e r in g ir o n . l3 - p h ilti ps heod screw dri r.r.i 4-B otl 'peen sockel exfensi on. 20'socker u ni v e¡s ol l 9-Long ti p. r o lle r h e o d , I7 - Scr e wd r ive r .o cker,' l 8-srondord screw dri ver reomer' 24'S¡ud w¡ench' 25-Socker 23-Acliuslobte screwdriver. 22-S¡ondord socker. flex driue ioínt. 21-12-point speed hondle' 30-Topered puller' 29'sockef 28'G"a' b'ush' carbon wire (lex hondle. 26-Drcg link socket. 27'Smott re.gulor lip screw' 34-Srubhy homme¡' tip 33'Plostic mollet' reome¡. 31-Clutch type screwdriver típ. 32-Rubber l 5-de9' 6ox end w rench' 38-P tri l l íps screw dri v er 37'S hort extensi on' socket 3 6 Short w¡ e n ch . e n d 3 5 Op e n d r ive r . P h¡tt¡P ssc¡ew dri ver' 42'l nternolpi pe w rencfi ' 43-S oc k ' tip . 3 9 - F to t n ítl lile . ¿ O- li- i.¡ ^ ¡ de"p ,orkut. ^4t-S fu66y e tslid in g T - t,o ,¿ t..( Bo ,,.y,S nop-on,ow ol fono,|Jti co,Y l i l ton,P roto,andA rmstrongTool s)
.r-q
i
'ii
u 1i
¡,
Fig. 1-55' 44-Point Íile. Ai-Flex socket. 46-Rotcfiet 6ox end. 47-Hose clomp plier. Ai-Ratchet open end. 49-Ccii6on scroper. Sl'Linemon plier. 51-Adiustoble wrench. S2-Hacksow lro^e, ii-F.ele¡ gouge, S¿-Cot¿cñisel. 55I /4 in. elec¡ric drill. 56-Torque w¡encá. 57-Pipe die. 58-Rtb ioint plier. 59-Center puncfr-.60-Needle nose p/ier. 6 l - C l e a n i n g b r u sh . 6 2 - Stip io in t p lie r . 6 3 - Cr o wÍoot otl ochment, 64-P i pe w rench.'65-D i ogonot pl i er. 66-OÍl set screwd¡íver. 67-Allen w¡encfi. 68-Broke spring plier. 69-6-point óox end. 7l-Choin nose p/ier. Tl -Storting punch. 7 2 ' C l u ¡ c h t i p scr e wd r ive r . 7 3 - 1 2 - p o in ttu b in g wrench. 74-Y i se yi p pl i er.7S -B attery pl i er. 76-Tw i s, d¡¡1. 7l -C clonp. 78'Drih punch. 79-Cylinder heod wrench, 80-Rin9 compressor. 8 I -S/ide hommer puller. 82-5[eer neto/ sn jps. ( B o n ne y,Sn o p .On ,Owo lto n o , Utica , Vlilton, P roto, A rmstrong,V l i l l i ons, Tho¡ ond gurtevont foo/s)
23
I
1. :i
Auto Seryice ond Repoir
pages and see how manyyou can identifycorrectly. You will be amazed at the number of automotive tools that are available.
18. A used to cleanfiles. -_-is 19. When grinding, never let the tool rest get close to the wheel. True or False? 20. Give ten important safety rules for the use of grinders. 21. Better quality drills are made of _
MARKYOURTOOLS As you procure your tools, mark them with your name. An electric marking pencil or a vibrating tool will do a good job. Mark the tools in an area that willbedifficultto grind off.
22. What are the drill iip angles for general purpose cuttingr 23. Give five important safety rules for the use of electric drills. 24. A reamer should remove about_of stock each cut. 25. Always turn a reamer in a.direction. 26. D i es are used to cut _threads. 27. Name four kinds of taps. 28. Referring to your tap drill size chartinthis ehapter, what is the correct tap drill size for a cap screw 5/B di ame t er wit h llt hr eads per i nch? 29. An 1B-tooth hacksaw blade is excellent for cutting tubing. True or False? 30. The teeth on a hacksaw blade should alwavs face the handle. True or False? 31. Name four cleaning tools. 32. What four kinds of screwdrivers would vou need ? 33. Pliers are useful to tighten tubing fittings. True or False ? 34. Name six kinds of plier:s. 35. Describe briefly a box end, open end and adjustable wrench. 36. Flare nut wrenches should be used on ,j fittings. _
OUIZ - ChopterI 1 . C h i s e l s , fi l e s , d ri l l s , e tc., areveryhardand as a result can all be piled together for storage. True or False? 2 Present day tools are all rustproof. True or False ? 3. Explain how YOU will store YOUR tools. 4. Three types of useful hammers would be th e _ ,_ , a n d the_. 5. Give two safety preeautions for the use of hammers. 6. A diamond point chisel is ideal for cutting off rivets. True or False? ?. Name three other important chisels. 8. For heavy hammering, hold the chisel very tightly with the hand. True or False ? 9. Drawing the temper from a tool wilt soften it. True or False? 10. A pin puneh is ideal to start a rivet from a hole. True or False? 11. Before drilling a hoIe,_ _the spot where the drill will start. 12. When grinding tools,_often to prevent overheating. 13. N a m e fo u r fi l e s h a p e s u s e dbythemechani c. 14. A fil.e with one row of parallel cuttingedges is known as a
37. What advantage does a 6-point opening have over a l2-point? The l2-point over the 6 -point ? 38. Sockets are either of the-or the _Iength. 39. Name five socket handles. 40. An impact wrench will speed up your work a eonsiderable amount. True or False ? 41. How many of the tools can you identify in Fi gs. 1-54, and 1-55?
file.
15. Keep files lightly oiled. True or False? 16. You would use a BASTARD, SECOND CUT, SMOOTH CUT, to rough file a piece of alur¡inum. (Select one.) 17. From a safety standpoint, why should a file always be used with a handle ?
24
Chapter2
PRECISION MEASURING TOOLS The auto mechanic mustbe thoroughlyfamiliar with the precision measuring tools used in his trade. Many of the jobs he is ca1led upon to perform involve checking sizes, clearances and alignments. 'i -A eareless or inaccurate measurement can be eostly, both in money and customer relations to say nothing of damaging the mechanicrs reputation.
After each use, wipe the tool down with a lightly oiled, lint-free, clean cloth. Never dip a precision measuring tool i.n solvent (unless it is being completely dismantled) or use an airhose for cleaning it.
H A N D LIN G When using a measuring tool, place it in a clean spot from which it will not fal1 or be struck by other tools. Never pry, hammer or force the tools. REMEMBER: They are PRECISION tools - keep them that way,l
O U AL ITYTO OLSIMP ORTA NT When selecting measui'ing tools that will be used for a period of years, it pays to buy top quality tools. The initial cost will obviously be higher but considering the importance of accuracy, and the longer life span of superior tools, the extra cost is easily justified.
CHE CKF O RA CCURA CY It is good practice to occasionally check precision tools for accuracy. They may be checked against a tool of known accuraey or by using special gauges provided for that purpose. If a tool is accidentally dropped or struckby some object, immediately check itfor accuracy. Adjustments for wear or veryminordamage are provided on many measuring tools. Follow the manufacturer t s instructions.
STORAGE It is advisable to keep your measuring tools in a protective case, in an area that will not be subjected to excessive moisture or heavy usage, Fi g . 2- 1.
(outsidel MICROMETER The outside micrometer (mike) is used to check the diameter ofpistons, pins, crankshafts, etc. The most commonl yusedmi crometer r eads in one thousandths of an inch. Withthis micrometer it is easy:]o estimate as close as onequarter thousandth. It is possible to obtain micrometers that can produce measurements to within one ten-thousandth of an i nch. Thi stypeusesaverni er scale. A cut-away view of atypical outside micrometer is shown in Fig. 2-2. Be sure to learn the names of the parts and their relationship to the operation.
Fig . 2 - 1 . f h i s m í c r o me fe rco se p r o vid e s e xce //e n t p r o te cl ¡on Ío¡ the tools. (L. S. Sro¡¡efi)
25
",
Auto Service ond RePoir
MICROMETERRANGE is designed to micrometer Each individual produce readings over a range of one fu1l inch' a set Ideally, the auto mechanic should obtain
Fig. 2- 2.
They (twenty-five thousandths inch) markings' ( z e r o i n ch ) ' to o n e will read from .000 to 1.000, twentyhas The tapered end of the thimble 0' five lines marked around it. They will read co m p l e te o n e I n t h a t 2 5 . etc., up to !, 2, 3,4,
Cut- owoy view ol on oufs i de m i c r om el er '
edge moves the thimble of the thimble turn the sleeve' '.025, the on or one mark exactly readby determined distance between marks is
sizes 0- 1 iri" covering of six micrometers 5-6 in' Fig' in. , 4- 5in' , and in. , 3- 4 1-2 in . , 2- 3 m icrorneters t welv e 2 -3 shows a c as ed s et of co ve ring 0- 12 in. It wáuld be less expensive to purchase only a 0- 4 in. and a 4 - 6 i n ', b o t h two m ic r om et er s , anvils. However, the multiwith interchangeable more bulky and is less is micrometer range convenient
Leor n the nom es oÍ the v or i ous por l s '
to use, Fí9. 2-4-
READINGTHE MICROMETER Micrometers are made so that every turn of
the thimble will move the spindle.025 in' You will notice that the sleeve is marked with a series of line s . Ea c h o f th e s e l i n e s represents ' 025' Every fourth one of these .025 markings is ? , B , o r 9' These sl eeve m ar k e d 1 ,2 ,3 ,4 ,5 ,6 , (onenum b e rs i n d i c a te .1 0 0 , .2 0 0 , . 300; etc" micrometer The hundred thousandths, etc.). sleeve then is marked out for one inch in '025
N ofe the 6ox of Fi g.2-3. C ssed sef ol 12 outsi de mi crom efers ' "míke'" of eocfr occurocy lhe checking slondords lor
26
Precision MeosuringTools
ing the thimble line that is even with the long line drawn the length of the sleeve markings. E a c h l i n e o n t h e t h i m b l e e d g e r e p r e s e n t s .0 0 1 (one thousandth of an inch), Fig. 2-44. Look at the markings on the micrometer section in Fig. 2-5. How many numbers are v i s i b l e o n t h e s l e e v e ? T h e r e a r e t h r e e . T h is 3 i n d i c a t e s t h a t t h e m i k e i s o p e n a t l e a s t .3 0 0 (three hundred thousandths of an inch). you can see that the thimble edge is actually past the . 3 0 0 b u t n o t t o t h e . 4 0 0 m a r k . B y e a r e f u l s tu d y you will see that the thimble edge has moved exactly two additional marks past the .300. This
ti l i p l e
ro n ge micr ometer . By using the pr oper a nv i l ..o me te r cove¡ s o r onge ol lr om 0 in, to 4 in, ( Lulkin)
L OC KN U T ANVIL
SP IN D L E
\
THIMBLE S LE E V E MA R K S THIMBLE N U MB E R S
al
ur
l¿ Nts. , 1 .0 1 1 1 3 .0 9 l? ' 5 ,1 5 6 ¿
50 : 75 ilü 25 875 l 6 ¿55 i 8 7:' 5 .Jt¿ 2 5 .43 ¡-
SLEEVE LONG LINE
7 2187 / 9,e81¿ 11.343? 13 .4Ó5 ¿ 15.468? '---'r&;; 1?.5311 .i 19.593? Tlu, s.!l¡ dF' ' l Co. 31.656? .' ArHür,t¡e!s. *1.4. 23 .7 r &7 ,,' ü¡nt ts u.5.¡.
5g
11
6$75
2 9 .9 U 1 3 .8 1 2 5 1 5 .9 3 7 5 J1 .9 6 8 ?
F ig . 2 - 4 A. 0 - l in . o u ¡ sid em icromel er.Studythe morkings ondport nomes.
means that the thimble edge is lined up two marks past the .300. As each sleeve mark represents .025, it is obvj.ous that theedgeis actually s t o p p e d a t . 3 0 0 p l u s . 0 5 0 , o r . 3 5 0 ( t h r e e h u n d r ed and fifty thousandths of an inch). In that the thimble edge 0 marking is aligned with the long s l e e v e 1 i n e , t h e m i k e i s s e t e x a c t l y o n . 3 5 0 . Th e reading then, if this were a one inch mike (reads from 0-1 in.) wouldbe.3S0.Ifthiswere a 2-3 in. mike, the actual reading would be two inches plus .350 or 2.350. In Fig. 2-6, the micrometer h a s b e e n o p e ne d to a wider measurement. You will see that the thimble edge is no longer on a sleeve marking but is somewhere in between. How many numbers are visible on the sleeve ? There are five or.500 (five hundredthousandths). The thimble edge has movedthree marks or.0?5
S L E E V E LONG LINE SLEEvE
THIMBLE EDGE
" j. . l i l ¡ e t h i n b l e e d ge ñ o sm o ve d o c¡ o ss fh e s/e e ve u p to t he 3 - r " : _ s i w o m o ¡ es / e eve m o r ks( ,0 5 0 ) . T h e r h in b le 0 m o r kis i n '. r c ' - e s / e . " e / o n g l in e so t/r e r e o d in g is,.3 0 0 + .0 5 0 + 0 = .j 50.
27
012
3 4 5
seven thousandths of an inch). If this were a 3-4 in. micrometer, the actuaL measurement w oul .dbe 3.58?. Study the readings shown in Fig.2-74. Compare your answers with those shown. Make your readings in four steps. See Fig. 2-?. 1. Read the largest sleeve numberthatisvisible - each one i ndi cates .100. , Count the number of full sleeve marks past thi s number - each one i ndi cat es. 025. 3. Count the number of thimble marks past this last sleeve number. Each one indicates .001. If the thimble marks are not quite aligned with the sleeve long line, estimate the fraction of a mark. 4. Add the readings in steps 1, 2 and 3. The total is the correct micrometer reading. Add this reading to the starting size of the micrometer being used. If the mike range was 1-2 in., add the total reading to 1.000 (one inch), F'íg.2-7.
F i g . 2 - 6 . T h in b le e d g e h o s m o ve d u p to ffte 5 (.500) pl us three m o ¡ e s l ee ve n o ¡ ks ( .0 7 5 ) p lu s l2 lh in b le no¡ks ('012) resul ti ng in a totol reading ol .587.
1
ill i
past the .500 mark. This makes a total of .575. The thimble edge has movedpastthethirdmark. In that the fourth mark is notvisible, u¡e know it is somewhere between the third and fourth mark, Fig. 2-6. By examining the thimble edge marks, Fig. 2-6, you will see that the twelfthmarkis aligned with the sleeve long line. This means that the thimble edge has moved twelve thimble marks past the third sleeve mark. In that each thimble mark equals .001 (one thousandth of an inch) the thimble has actualtry moved .012 (twelve thousandths of an inch) past the third sleeve mark. Your reading then would be .500 0argest sleeve number visible) PLUS .075 (three sleeve marks past sleeve number) PLUS.012 (twelve thimble marks past the third sleeve mark) making a total reading of .587 (five hundred and eighty-
RR A D U A T E D RE A DI NG A MI CRO ME T EG OF AN ¡NCH I N T E N T HO US A NDT HS The same reading technique as that just described is used to read this type of micrometer. Instead, however, of estimating fractions of a thousandth between thimble marks, a VERNIER scale on the sleeve makes it possible to accu-
I I I
l+.:oo*l F ig .2 - l.
.oso --l l+
t+
.012+l
I
secondreodi ng i nB =.050,th i rdreadfh r e e sfe p s in r e o d ing ffi emi c¡omefer.Fhstreodi ngi nA =.300, ing in C = .Ot2 = o totol reoding ol ,362 (Three hund¡ed and sixty-two tfrousonds).
0 L2345
F ig .2 - 7 A.¡ = .t7 5 ,8 = .5 9 9 ,C= .2 4 2y2or.2425.N otef[ofi nC rñel ¡octi oni none-fhousondtñi sesti motedos indicoted by rhe thimblé mark.
28
PrecisionMeosuringToofs rately divide each thousandth into ten parts or one ten-thousandth of an inch. The vernier consists of elevel.l thin tines scribed parallel to the sleeve long line. They are roarked 0-10. Whenever the thimble marks donot fall in line with the long sleeve line thus indicating a fraction of one-thousandth ineh, carelully examine the vernierlines. One of the vernier lines will be aligned with one of the thimble ¡oarks. When you have diseovered the specific r¡ernier line that is aligned with athimble mark, :he number of that particular vernier line will :ndicate the number of tenthousandthtobe added
Fig, 2-9, ln A, vernier /ine No. 5 is oligned with o thimble mo*; readi ngw oul d be .075 + ,005 + .0005 = .O¿OSl n . B , verni erl i ne N o. 4 i s al i gned; reodi ngw ovl d be .200 + .025 + ,012'+ .0004 = .2374,
thumb and forefinger unti.l the spindle engages the object. Do not clamp the micrometertight use only enough pressure on the thimble to cause the work to ju-El fit between the anvil and spindle. Slip the objeet inandoutof the micrometer while giving the thimble a final adjustment. The work must slip throughthe micrometerwith a qy ljght force. When satisfied that your adjustment is correct, read the micrometer setting. BE CAREFUL THAT YOU DO NOT MOVE THEADJUSTMENT, Fi g. 2- 10.
o----J_
(o ----_r
__r co ___r
{
,¿', ----+-20
F- F
(,-F N ---aÉ -------L_
'o futs --lrlTE Fig.2-8, Vernie¡ /ines ore sñown in colo¡. Note táot vernier line Í{o. 3 is the only one exactly in line with a thimble mork, your
'adins wouldthen6e .100+
:1tr=-.;:li.-
.0003(¡hreetenthou-
:o vour initial thimble reading, Fig. 2-g. Examine the readings shown in Fig. 2-9. In both instances a fraction of a thousandth is obnous by examining the thimble marks. By check'rg the vernier, you can see that one of the ver::er lines is in ali!.nment with a thimble mark -l'¡s indicating the number of ten thousandth over --be thimble thousandth reading. Compare your :eadings with those shown, Fig. 2-g.
LIHENUSINGANY MEASURING TOOL Always thoroughly clean the work to be "easured. This assures you of accurate work ¡nd reduces wear on the workingtips ofthe tool.
LIs¡NG OUTSIDEMICROMETER
Fig. 2J0. Miking a small hole gauge. The heel o{ ¡he ñond supporfs tlre mic¡omete¡ frome while the ¡humb ond lorelinger turn rfie r[in6le. lL. S. Srorrer)
\\'tren measuring small objects, grasp the *'erometer in the right hand, and at the same :¡ae insert the object to be measured between :¡e anvil and spindle end While holding the work e€ainst the anvil, turn the thimble with the
To measure larger objects, grasp the frame of the micrometer and slip the micrometerover the work while adjusting the thimble. Slip the mike back and forth over the work until verv light resistance is fett, Fig. 2-10A.
29
F ig . 2 -10A . Mi ki ng o c¡onkshol t.N oti ce how the mi ke i s hel d.
2 ,!
a' t F h,',
i,
t I'
I I I
J
Some micrometers have a ratchet clutch knob on the end of the thimble to allow the user to bring the splndle down against the work with the same amount of tension each time. As the micrometer is slipped back and forth over the work, it should be rocked from side to side a trifle to make certain the spindle cannot b e clo s ed an addit ional am ount , F i g . 2 - 1 1 .
PRACTICEIS NECESSARY Measure objects of a known diameter until you have mastered the feel of using a micrometer. Keep practicing until you are completely confident of your readings. REMEMBER - A MECHANIC MUST BE ABLE TO MAKE ACCURATE MICROMETER READINGS. HANDLE THE MICROMETER WITH CARE. NEVER STORE A MIKE WITH THE ANVIL AND SPINDLE TIP TOUCHING (this encourages rusting between the tips). CLEAN YOUR WORK BEFORE MEASURING.
I
\
I I
\
I I
IN S ID E MIC R OME TE R
I
The inside micrometer is used for making measurements in cylinder bores, brake drums, l arge bushi ngs, etc., Fi g.2-L2.
F i g . 2 - l l . ln A, m iu o m e te r is slip p e d b o ck ond l orth over obj ect. ln B, micrometer is rocked from side to side lo moke certoin the s m o l l esf d io m e te ris { o u n d . Ro ckin g is o ctuol l y very sl i ght.
Fis. 2-12.l nsi de mi crometu. B y chongi ng ro ds , thi s sure hom 2 to 8 in,
30
lL. S. Sto¡refi)
s et w i l l meo-
Precision MeosuringTools
It is read in the same manner as the outside =Licrometer and the same feel is required. When :neasurin g, rock t he ins ide m ik e f r om s i d e t o side at the same time keeping the anvil firmly against one side of the bore. While the free end :s be ing ro cked , it m us t als o be t ipped i n a n d out. The rocking allows you to locate the widest :art o f th e bo re while t he t ipping as s ur es y o u :hat the micrometer is at right angles to the :or e , Fig .2-1 3. An extension handle permits the use of an in a bor e t oo s m all t o h a n d -nsid e micro mete r :o1d the tool.
E, g . 2 - 1 3 . l n s i d e m i cr o m e r e rm u st 6 e r o cke d fr o m sid e fo si de os - A , w h i l e o l f h e s o m e fim e it m u st b e fip p e d o s sfio wn i n 8. B o l h m o ve m e n tso r e r e lo tive ly slig h t.
M IC R OM ETER DE P THGA UGE This
is a handy tool for reading the depth of sp line s, c ou nt e r b o r e s , ho1es , e t c . , -.-ots, .' -2,. 2 -t4.
'j:\
ii'
,.,.$r 2 - 1 4 , M i c r o n e t e r d e p th g o u g e . T h e to n g e co n 6 e ín c¡eosed b y u sin g lo n g e r r o d s,
To use, the base is pressed against the work (after cleaning) and the spindle is run down into the hole to be measured. It is read líke an outside micrometer, th e only difference being that the sleeve marks run in a reverse direction, Fig. 2-15.
Fi g.2-15. U si ng the mi crometerdepth gouge. The 6ose i s he/d l i rnl y ogoi nst the w ork ond the thi mbl e ¡urned unti l l he r od c on. focl s fhe shou/der.
DI A L G A UG EO R I NDI CA T O R The dial indicator is a precision tool designed to measure movements in thousandths of an inch. Some common uses are cheeking end p l a y i n s h a f t s , b a c k l a s h b e t w e e n g e a r s , va l ve Iift, shaft run-out, taper in cylinders, etc. Use care in the handling of this tool as it is sensitive and easily damaged. When not in use keep in a protective case. Dial indicator faces are calibrated in thousandths of an ineh. Various type dial markings are available. Ranges (distance over which the indicator can be used) vary also depending on the instrument, Fig. 2-16. Various mounting arms, swivels and adapters are provided so that the indicator can be used on various setups. When using a dial indicator, be certain that it is firmly mounted and that the standard
Auto Service ond Repoir
anticipated. Ranges usually run from around .200, to 1.000 (one i nch) depending on t he instrurnent. Fi gs. 2-18, 2-184,2-1B B illust r at e t lpical di al i ndi cator setups.
DIAL INDICATOR
CLAMP BASE
Fig. 2J6,
Diol in¿icotor ond holdi ng ( L. S. 5to¡ ¡ ett)
ottoc hm enl s .
(act uat ing r od) is par allelt ot he plane (direction) , m eas ur ed, I . i g. 2-I7. of m ov em ent t o be Place the rod end against the work to be toward the measured, and force the indicator work causing the indicator needle to travel far enough around the dial so that movement in either direction can be read. The dial face can then be turned to line the 0 mark with the indicator needle. Be sure that the indicator range . (limit will the movement cover of travel)
Fi g.2-18. C hecki ng ti mi ng geor 6oc/
IN D IC AT O R
----t
l*'*l F i g . 2 - 1 7 . ln d ico ¡ o rI se f u p is NOT p o r ol l el to movementol shol t. W h e n sh o lt m o ve s d isfo n ce A, in d ico tor rod moves dístonce C , g i v i n g a h lse r e o d in g Ío r sh o lt e n d p loy, Indi cotor 2 l S porol l el a n d sh o lt m o ve m e n tA co u se s in d ico to ¡ rod to move di stonce B , p r o d u cin g o n o ccu r o le reodi ng'
Fi s. 2-18A . U si ng o di ol indicotor lo detetmine center. ( P & G M l g .C o ')
32
pislon
top deod
Precision MeosuringTools
F i g . 2 - 1 8 8 . C h e c k i n g co m sh o lt !o h e t¡ ft w¡ r h o ¿ io l i ndi cotor, ( Ch e vr o le t) Fi g.2-20. C yl i nder gouge. Onl y o sho¡f secl i on ol the hondl e i s show n. l L. 5. S torre*)
OTHER DIAL INDICATORTOOLS INSIDEAND OUTSIDECALIPERS Two other valuable measuring toolsutilizing d ial ind ica tor as par t of t heir c ons t r uc t iona r e :re out-of-roundness and cylinder gauges. The : :t - of-roundne s s gauge is used to check connect-:g rod big end bores. This can be done with an -rsid e mike bu t t his s pec ial gauge m ak es t h e j o b : asie r an d faster , Fig. 2- 19.
T h e s e a r e u s e f u l t o o L s f o r q u i c k m e asu r e ments when aecuracy is not critical . I.í9. 2-21, illustrates a pair of outside calipers.
ADJUST sF ORDIF F ERENTSIZE S
Fig. 2-21. Oursidecoliper. gouge. F ig. 2-l 9. Oul-ol-roundness Fig. 2-22, shows the inside caliper. The ins i d e c a l i p e r i s u s e d t o m e a s u r e t h e d i a m e te r o f To determine hold the holes. the reading, on an accurate steel rule. Careful calipers
gauge makes the checking of The cylinder e¡'Iinder bore size, taper and out-of-roundness quick a nd a ccur at e, Fig. 2- 20.
OTHER USEFUL MEASURINGTOOLS In addition to the precision tools that have 'ceen discussed, there are a number of other tools as described by the following paragraphs, that a mechanic should own. Keep in mind that :n your work as an auto mechanic a number of rreasurements varying from a few thousandths :o several feet will be required.
F i g. 2-22. l nsi de co/i per.
33
Auto Serv¡ce qnd Repq¡r
measuring across the points (very light touch) with an outside micrometer will give a more ac c u ra te re a d i n g , F i g . 2 -2 2 . DIV ID E R S Dividers are somewhat like calipers but have straight shanks and pointed ends. Theyare handy for making circles, taking surface meas u re m e n ts , e tc . F i g . 2 -2 3 , i l l ustrates a pai r of divide rs.
Fi g. 2-25. l l i re gouge sef for check i ng s poú pl ug gop.
WI REG A UG E The w i re gauge i s i neffect at hicknessgauge, but i.nstead of a thin flat strip of steel, wires of varying diameter make up the typical set. It is excellent for checking spark plug gap, distributor poi nt gap, etc., Fi g. 2-25.
S CRE WP I T CHG A UG E This is a handy tool for determining the number of threads per inch on bolts, screws and studs, I.i g.2-26.
F ig .2 - 2 3 . Divíd e ¡ s. Po in fs musl óe shorp.
FE E LE RGA UGE S Feeler or thickness gauges are thin strips of specially hardened and ground steel, with the thickness marked in thousandths ofaninch. They a re us ed t o c hec k c lear anc es b e t w e e n t w o p a r t s sueh as valve gap, piston ring side and end gap clearance, etc. They are available in sets as shown in Fig. 2-24, and also in 12 in. or longer lengths.
Fi g.2-26. S crew pi fcá gouge, The fi ¡st o¡ s mol l numberi ndi c otes the numher ol threods per inch. Iñe second number indicates the douhle depth ol ¡he threads.
ffry*'***''* F ig ,2 - 2 4 . F e e /e r g o u g e se f.
Fis. 2-27. Tel escopi ng gouges. The gouges s /row n w i l l c ov e¡
( Ow ottono Tool s)
range lrom 1/2 ro 2-1/2 in.
34
(L. S. Srorref)
Precision MeosuringTools
TELESCO PING GA UGE The tele scop ing
hook rule with a sliding steel head, marked in 32nds. and 64ths., a combination square made up of a steel rule, protractor head, center head and square; and a ten foot pocket tape rule. See Fig. 2-28, and 2-284.
gauge is an ac c ur at et oo l f o r
measuring inside bores of connecting rods, main bearings, etc. To use this too1, the plungers are
HEAD PROTRACTOR SQUARE HEAD C E N T E RH E A D
Fig. 2-28. Combinotion squore with cenfer heod ond protroctor. (L. S . S ror¡etr)
compressed and locked by turning the knurled screw on the handle. The gauge is placed inside the bore, and the plungers are released until t hey con tact the bor e walls . They ar et henloc k e d and the tool is removed. An outside mierometer
l
K HE A D
SPRINGSCALE T w o s p r i n g s c a l e s , o n e r e a d i n g i n o u n c e sth e other in pounds, are a "must." These are needed puII on to determine contact point pressure, feeler strips whenfitti.ngpistons, etc.,Fig. 2-29.
RULE
-rX
Fi g.2-29. S pri ng scol e' A must i n every tool ki t.
S T E E LS T RA I G HT E DG E
Fi g . 2 - 2 8 A . 6 i n . h o o k r u le wi¡ h slid in g d e p th a n d o n gl e heod.
An accurate steel straightedge longenoughto span the length of an engine block or head is essential for checking these parts for warpage. Be eareful when handling and storing a straightedge so it is not damaged, Fig. 2-30.
is used to measure across the plungers for an aceurate checking of bore size. Telescoping gauges have different ranges and may be purehased in sets. The proper feel for using this tool will be the same as that used with the insi de m ier om et e r, F i g . 2 -2 7 .
TE MP E R A TU R E IS IMP OR TA N T Many specifications for measurements will state room temperature, an exact temperature, engine at normal running temperature, etc. Remember that all metals contract and expand in
STEELRUL ES Other measuring tools that can be used to good advantage include a thin six inch steel
35
r-
W ü
AutoServiceond RePoir
I
f:--rW
i ll ryi 1iri 1i
E . Check the run-out on a camshaft by using a dial indicator. F . Measure the inside diameter of a wrist pin bore using a telescoping gauge and an outside micrometer. G. Check the accuracy of an outside micrometer by using a STANDARD (measuring rod of exact length) furnished for this purpose. H. Check the accuracy of aninside mikebyusing the outside micrometer youhave just checked with the standard. I. Check the gap between spark plugelectrodes by using a wire gauge. J . Determine the number of threads per inch on a bolt by using a screw pitch gauge. K. Determine the tension on a set of distributor contact points by using a spring scale. L. With a straightedge, check the surfaee of a cylinder block for warpage.
ll
!l
t,**-1
ü'$
- 'l¡' r .ii ii
*-J
-
i:,
I
-;;
"*
m#bffiffi
J -"'-'"ttt*c
Fie.2-30. Steel stroigtrtedge. A-sguore edge. 8-Bevel edge. C' Bevel and ruled edge. These ore ovailable in diÍÍerent lengths.
direct proportion to their temperature. This makes it imperative that temperature specifications be followed when making precision measurements and settings. Your measuring tools themselves can be affeeted by extremes of heat and cold. If your tools must be used when very cold or very hot, eheck them for accuracy before using.
ACTIVITIES SUGGESTED 1. Place a wrist pin in thefreezereompartment When thoroughly cold, reof a refrigerator. move, wipe, and quickly measure both the diameter and length using an outside micrometer. (Hold the wrist pin with a cloth.) Write down your readings. Now place the wrist pin in boiling water. When hot, remove, dry and quickly recheck diameter and length. Was there adifference? If so, how much? What does this indicate? 2. Explain how to read a micrometer toafriend that does not know how. Have himtrya reading and continue to help him until he does it correctly. By doing this you will reinforce your own knowledge.
S UM MA R Y
lii
l$ ',.i
.il i
".|
The abitity to select and correctly use the proper measuring tools to secure highly accurate measurements, is a MUST -for all auto mechanics. Preeision tools require cleanliness, careful handling and proper storage. The mechanic should own, or have available, micrometer outside and inside micrometers, depth gauge, dial indicator setup, inside and outside calipers, dividers, feeler gauges, wire gauge¡ screw pitch gauge, telescoping gauge, steel rules, straightedge and spring scales. Other specialized measuring tools may be acquired as the need dictates.
OUIZ - ChoPter2 1. When using a micrometer, make surethatthe tool is clamped around the worktightly. True or False ? 2. Measuring tools are rustproof. True or False ? should be checked 3. A micrometer if accidentally dropPed. is read in the same 4. An inside micrometer fashion as the outside micrometer. True or Fa1se? 5. To measure an object 3.500 in diameter, you with a range of would use a micrometer to
SUGGESTED PRACTICEJOBS A.'Practice reading a micrometer until youcan make a correct reading everY time. B. Use an outside micrometer to measure several objects of known size. C. Measure the inside diameter of a cylinder of a cylinder of a known size with your inside micrometer. D. Using a depth gauge, measure the distance from the surface of a cylinder head to the top of a valve guide. fValve-in-head engine.)
36
Precision MeosuringTools
5. Name the best tool to handle each one of the following measurements : a. Diameter of a wrist pin. b. Diameter of a cylinder bore. c. Distance from face of head to valve guide top. d. End play in crankshaft. e. Diameter of wrist pin bore in a piston. f. Connecting rod big end bore diameter. g. L ash (free m ov dm ent or play ) bet ween t w o g ea rs. h. Teeth per inch on a bolt. i Clearance between the valve stem and rocker. (Valve-in-head engi.ne.) i Diameter of an exhaust pipe. k. Spark plug gap. point contact 1. Tension on the distributor arm. m. Length of a muffler. n. Distance between the fan blades and radiator. o. Engine block surface for warpage. 1. Select the correct deeimal readings for the following a - i. (Some are incorrect.) Two inc hes , t hr ee hundr ed andt w e n t y --a. five thousandths. Eight hundred and seventy-eight and _b. one-half thousandths. Four inches, six hundred andthirteen _ c. and one quarter thousandths. Three and one-half inches. _d . One ten-thousandth of an ineh. One thousandth of an inch. One hundredth of an inch. _9. One tenth of an inch. _h.
r.
One inch. 2 .3 2 5 1 .00 0 4.6 t3 2 5 .0 0 1 4 .6 1 3 0 2 5 .8785 . 0 0 01 .1 0 0 0 2 .3 0 0 25 .010 3 .0 0 5 .100 3 .5 0 0 .0 1 0 1 0 Select the correct (some are wrong) readings f or t he f ollow i n g mi c ro me te r s e tti n g s . 0-1i n. micrometer.
_i.
a
.359 .376
.349 .286
.3001 .243
.3003 .242
.2994 .299L
WHA TI S Y O URO P I NI O N? A person has just applied for a job as a mechanic at a garage withareputationfor excellent
-E
37
. +4ís.1:
Aqidservice ond Repoir work. The owner is interested; there is an opening;.ihe pay is good. So the owner introduces th*e.app$.icantto you, who, as shop supervisor, will be expected to evaluate thispersonts worth as a mechanic. You walk to a nearby service bench, open your tool chest and lay out a selection of measuring tools. You indicate a specific cylinder bore you would like miked, and inform the applicant to choose the tools and make the measurement. The applicant picks up an inside caliper and a six inch steel rule, adjusts the caliper in the bore, then plaees the caliper on the face of
the six inch rule and, after some squinting, informs you that the bore diameter is "iust a whisker over four inches." The actual bore diameter is 4.030. What do you think of the applicantfs ability? Will you recommend hiring this person? If ,not, why? R E ME MB E R : No one can be termed a top-notch mechanic who is not fámiliar withandcompetentinthe use of measuring tools used in the trade. youcan be proud of your ability to make precision measurements - it is the mark of a fine mechanic,l
SlendardTorque Spec¡fical¡onsend CapscrewMarkingsChert SAEGRAOE1 or 2 (Us6dlf,íisqu€ñtly)
A CAPSCFEW HEADMANKINGS
CAPSCBEW BOOYSrZE Inches- Thrۇd
Torque
I /4-20
{l "t
-ú
r.avtY)
3/a'16 . -24 7/16-14 | '24
SAEs
l3 20
37.9629 40.6745
.7/¿=13 -20
3S
rrr9:]i
5l
5/8-1 1 -18 3/4-10 .. -16
83 95
I
SAESor?
IGM 260-M)
6,7791 8.13€ 14.9f40 17.6256 24.4047 27.1164
5./16-18
dto saEGfsdo5. 4¡r'+rÉ¡
SAElor2
5
.{GM 28O-M)
Ft.Lb
t0
7 9 31 35 49
23.0449 25.7605 42.0304 47.4536
r 60 175 235 250
318.6130 338 9500
590 660
(cM 290-M}
Ft- L b .
0 .4 4 6 5 3 .5 5 8 2
75 85 110 r20 150 170 270 295
customary (¡nch) bolts - tdentif¡cat¡onmarks correspondto bott ,t."ngt¡'rn"r"áing nu.b"" represent¡ncreasingstrength.
fvletr¡cBolts - ldent¡ficat¡onclassnumberscorrespondto bolt strength- Increasingnumbersrepresent¡ncreas¡ng strength.
I
34
66,.435I 74.5700
Nm
T,o fq u e
Nm
FI.L b
r 3.5582
t2
25.7605
24 27
16.2698 18.9815 32.5396 36 6071
4 6 .0 9 7 8
74.5100
49 10
66.4351 ro5.7538
01.6863 15.2445 49.1380 62.6960 203.3700 230.4860 366.0660 399.9610 535.541 0 589.7730 7993220 894.8280
(cM 3OO_M}
SAE GR AOE 8 (Uséd Ffsquoñtly)
Torque
Nm
I 10
52.8769 55.5885 69.1467 74.51ú 112.5329 128.8027 r42.3609 r55.9170 216.9280 231.2650
r05 115
SAE GR AD E 6 o r 7 ( U s€ d .tfi m o s)
Torque
Nm
FI- L b il¡nuladu6r's má¡ks may v¡ry Tñrcelina ma.kings on h6ads.
SAEGRADE5 (Us6dFr6auontlv)
85
1 1 5.2445
120
162.6960
161
226.4186
2AO
3t9.6240
440
596.5520
660
8 9 4 .8 2 8 0
r42.36@ 162.6960 210.1490 230.4860
105 120 170 2r0 244 420 605 675
284.7180 325.3920 508.4250 569.4360 820.2590 915.1650
990
l 2 3 3 .7tAQ | 342.2420
_6.* *b STRENGTH l[tiT tDENTlFlcATloN
I
ID EN T IF IC AT IO N M AR KS ( 4}
fig .3 - A. Clr o ¡ f sh o ws t ypi col torgue for cop screw s w i th ¡hreods cl eon ond dry, R educe torque by l0 percent il threods ore oiled; reduce by 20 percent i( new, ploted fosleners ore used lo¡ vorisus lo sr e n e r sr o d e s. AL WA Y S FOLLOW MA N U FA C .TU R E R 'SIOR QU E S P E C IFIC A TION SFOR TH E EXACT JOB AT HAND. A -C op screw s, 6ol ts ctd nul s dre morked w i th ei ffi er /i nes or numbetsto in d iccir e th e i¡ r e lo tive strength. B -C usl omory (i nchl bol t morki ngs. N ote trrot the strength (gro de) co r r e sp o n d s to th e n u mbe¡ of l i nes. fhere ore ol w ays tw o /i nes l ess ¡hon the octuol grade. Q,M e ¡ ¡ ic b o lr .m a r kin g s.fh e hi gher.thegrode (cusl omory)or number(mel ri c), the greoteri he sl ren gl h. (A meri con Motors - Generol Mofors)
38
'li.
Chapfer3
FASTEN ERS, TORQUE WRENCHES
) ¡
INCREASINGIMPORTANCE ¡
another. When drawn up, the two parts are then held in firm contact. Fig. 3-1, illustrates the use of a cap screw (machine screw with a hexagonal head). There are many different types of machine screw s and screw heads. Fi g. g-Z sh ows a number of those i n common use.
In th e mod er n c ar , ev er iner eas ing h o r s e power and road speeds subject the various components to heavy loads, high frequency vibration and severe stress. As a result, fastener (nuts, boLts, screws, etc.) design, material and torque settings, once of relatively small interest to the mechanic, have assumed a position of major importance. It is important that the mechanic familiarize himself with the various t¡pes, materials used in their construction, uses, and proper installation.
ooooooo
HHHHHóo
R E A D CA RE F U L L Y
H EX
Be sure to read this chapter carefully. Study the various fasteners, their markings and uses until you can recognize them immediately. Pay particular attention to the section on toroue w r enc hes .
FLA T
OV A L FILLIS TE RR OU N D C LU TC H FLU TE D
Fi s.3-2.Typi col
mehi ne screw s. Four heods at ri ght i l l us trate vori ous openi ngsl or l urni ng tool s,
PAN H EAO
R O U N DH EAD
,,_.'f-, ,.'A HE
M A CHI NE S CR E WS Machine screú'S are used without nuts. They are passed through one part and threaded into
EF
=
CLEARANCEHOLE
Fi g. 3-3, Typi col sÁ eet mefol screw s.
A
SELF-TAPPINGOR SHEET METAL SCREWS
TH READ ED u^t
E
B Siireet metal screws are used to fasten thin met¿. parts together and for attaehing various items to ¡ireet metal. They are much faster and less expensive than bolts, Fig. 3-3.
F ig . 3 - l , C o p s c r e w . Co p scr e w is p o sse d th r o u g h cle o r ancehol e in port A and threoded into part B,
39
Auto Service ond Repoir
,rl
I
To use a sheet metal serew, a hole, that is slightly smaller than the minor diameter (diamet er of th e s c re w i fth e th re a d s w e re ground off), is either drilled or punched through a piece of metal. The punched hole provides more threading area and when the screw is drawn up, the hole attempts to close thus providing greater grippi.ng power. Fig. 3-4. 5CR EW
Fis' 3-5' studthreadednin"':":
r rt
Ei
rl ,¡
':"'i¿;'::':;!over
..ii l {e ri
¡i tfj
I¡
lr
stud'nvtptoced
F i g . 3 - 4 , Scr e w p o sse s Ír e e ly th r o u g h A o n d cuts threods i n punched hole in B. Wñensc¡ew tightens, punched metol draws up o n d in , p r o vid in g o sé cu ¡ e g r ip, C .
BOLT A bolt is a metal rod that has a head at one end and a screw thread to take a nut at the other. The bolt is passed through the parts to be joined then the nut is installed and drawn up, thus holding the parts together, Fig. 3-4A.
and a nut is turned down on the stud to seeure the part. Studs are available in many lengths and diameters. Some have a coarse thread on one end and a fine thread on the other..Others have the same thread on both ends and in some eases, this thread may run the full length of the stud, Fi g. 3-5. A stud wrench should be used to install or remove studs. Re careful not to damage the threads. If no stud wrench is available, plaee two nuts on the stud and "j"*t' them together (turn the top one clockwise, the bottomcounterclockwise until they eome together). place a wreneh on the lower nut to remove the stud, on the upper.nut to install, Fig. 3-6.
REMOVING BROKENSTUDSOR SCREWS
NUf -
There are several methods that mav be employed. If a fair portion of the stud projects
- BOLT
Fig. 3-4A. Using o bol¡ to hold two ports together,
STUDS A stud iS a metal rod, threaded onboth ends. The stud is turned ínto a threaded hole in a part. The other part is slipped over the stud
Fi g.3-6. l Jsi ng i om nuts ond w renchto remov e s fud.
40
FostenersqndTorqueWrenches above the work, it may be gripped with vise_ grip pliers, or a small pipe wrench and backed out. Where the portion protruding is not sufficient to grasp with pliers or wrench, flat surfaces may be filed to take a wrench, or a slot may be eut to allow the use ofa screwdriver, Fig. 3_64 Detail A.
^fu I B
ñ,-Q \--2
-----1 .
EXTRACTOR
,Or-ffi
/
g
€
a trifle smaller than the stud minor diameter. Lightly tap the extractor into the shell that remains and back it out with a wrench. The sharp edges on the flutes will grip the shell. Do not exert enough force on the extractor to break it as removal of the extractor segmenr coul d present a real probl em, Fi g. 8- 6A, Detail D. In the event the methods previously de_ scribed fail, select the proper tap size drill and after running it through the stub shell, care_ fully tap out the hole. If done properl¡ the tap will remove the shell threads leaving the original threads in the hole undamaged, Fig. 3-64, D etai l E . When drilling, drilt through the stub only. Do not drill beyond as you may damage some part. If working on a setup where metal ehips may fall into a housing, eoat the drill and tap with a heawy eoat of sticky grease so that the chips will adhere to the tools.
US EP E NE T RA T I NG OIL
Fíg.3-6A. Merñodsusedin ¡emovingbrokenstud. A_Srudsrorred w f iled llot. B-Nut weldedon. C-punchr".d ro Á"r.w broken piece. D-Screwextroctor. E-lJsingo top to removeshell. -\nother method is to drill a hole in a,section of f,lat steel, pLace it over the broken stud and ineld the strip to the stud. A nut large enough to fit over the stud can also be welded on. ,,r,-HEti WELDING, BE CAREFUL OF FIRE AND D-{IÍ-{GE TO PARTS. The arc welder does the job quickly and with a minimal amount of heat_ ing, Fig. 3-6,4', Detail B. When the stud is broken off flush or slight_ lv below the surface, you may use a thin and sharp pointed punch and try driving the broken seetion in a counterclockwise direetion. Some_ times the stub will turn out easily. If you are not getting results - stop and try another method, Fig. 3-64, Detail C. A screw extractor can often be used with good results. Center puneh in theEXACTcenter of the stub. Drill through the stub with a small diameter drill then run a drill through that is
Regardless of the method of removal, it is a good idea to apply penetrating oil (a special Iight oil with high penetrating powers used to free rusty and dirty parts) to the area and give it a few minutes to work in. If heat is noiin_ jurious to the part, an applicatíon of heat will also help. Use caution not to overheat. If in doubt as to the effects - do hot apply heat. NEVER USE A TORCH NEAR A GAS TANK, BATTERY OR OTHER FLAMMABLE MATERIALS. R E P A ¡R IN G TH R E A D S Occasionally threads, both external and internal, are only partially stripped. In such cases they can be readily cleaned up through the use of a thread die or atap, Fig. B-BA. When threads in holes are damaged beyond repair, one of three things can be done: 1. The hole may be drilled and tapped to the next suitable oversize and a larger diameter cap screw or stud installed. Use a chart to determine the proper size (tap size) to use. A clearance or body drill (a drill the size of the bolts major diameter) must be passed through the attaching part to al1ow an oversi ze cap screw to be used, Fi g. 3-68. 2. The hole may be drilled and tapped to accepr a threaded plug. The plug should also be
4l
T HREADSSTRIPPED
NUTS
Fig,3-68.
drilled A
Nuts are manufactured in a variety of sizes and styles. Nuts for automotive use are generally hexagonal in shape (six sided). They are used on bolts and on studs and obviously must be of the correct diameter and thread pitch (threads per i nch), Fi g. 3-7.
Re p o ir in g str ip p e d r h r e o d b y d r ill i ng ond |crppi ngto n e xf o ve r size .
a n d ta p p e d
s p e cia l
to th e
se lf- ta p p in g
o r ig in al
p lu g
a lr eady
screw
si ze.
threaded
to the original size may be used. you merely drill a hole to the specified size, run the threaded plug into the hole by using a cap serew and jam nut. When fully seated, the ja m nut is loos ened and t he c a p s c r e w r e moved, Fig. 3- 6C.
+CAP
SCREW
_
LOCK OR J AM N U T
rffir \t_J
E2w -| -l W IN GN U T
F i g . 3 - 6 C. In se r tin g¡ h ¡ e o d e dp lu g to r e p o ir stri ppedrfi reods.
B O L T A NDS CRE W T E RMI NO L O G Y
3. Another method makes use of a patented
Bolts and screws may be identified by type, length, major diameter, pitch (threads per inch), Iength of thread, class or fit, material, tensi l e strength, and w rench size needed, Fi g. 3-8.
coil wire insert called a Heli-Coil. The hole is drilled then tapped with a speeial tap. A Heli-Coil is then inserted. This brings the hole back to its original diameter andthread, F igs . 3 -6 D a n d 3 -4 0 .
j
l^*l¡*l F i g . 3 - 6 D. Re p o ir in g str ip p e d th r e o d s by.usíng o He li- Co il in sto llo tio n , ( Ch r ysl er)
_T -Y
ll BC YI
REM EMB E R Whenever removing a broken screw or repairing stripped threads, proceed carefully. A frantic or careless attempt at repair can often cause serious and costly trouble.
t
SPEEDN U T
Fig. 3-7. Common nuts. fhe wing nut is insrol/ed ond removed wirh the Íingers. Ilre speed nut js used in lastening sáeef mefo/ or other pdús not requiring the strength ol the regulor nut,
DRILLED AN D T APPED
f
I
I
THREAD EDPLU G
t
S L O TTE D H E X
H EX
Fig. 3-8. Bol¡ and sc¡ew fermino/ogy. A-Pitch. B-Minor diometer. C-Moior diometer. D-Threod lengtfi. E-Screw length. F-Th¡eods per inch. G-Heod size measured ocross táé f/ots.
42
Fqstenersond TorqueWrenches
H EADM AR KINGS Steel bolts and ¡i the same quality :he same. Current --re bolt and screw
cap screws are not all made rnaterial nor is the tempering practice utilizes markings on heads to indicate the tensile ::rength of the fastener. Learn what these impor:alt marks means, Fig. 3-A on page 38.
R ETH READING ñtE
fine thread in these materials will strip more -¡ easily. practice is to use the coarse The current thread mcre widely than in the past. The coarse thread has a larger and less critical shoulder bearing area, screws in and out more quickly and is less subject to stripping and gatling. Galling occurs when the threads ri.p particles
HHÉ INTERNAL THREAD CHASE R5
r_ L
HANDT AP F i g . 3 { .A. Sd m e ffir e o d r e sfo r in g to o r s. (Deere & Co.)
Fig. 3-88. Using o threod-pitch gouge to defe¡míne the numberol threods per inch.
UAJOR DIAMETER
of metal from each other, therebydamagingboth threads and, in severe cases, causing the fastener to stick tightly. As a bolt diameter lncreases, the size and pitch of the thread becomes greater. For example: UNC threads on a Ll4 in. diameter bolt are smaller and there are more threads per inch than UNC threads on a 1/2 in. bolt.
Th is is th e . wides t diam et er as m ea s u r e d ::o:n the top or crest of the threads on one : -de to the cre st of t hos e on t he ot her , Fig. 3 - 8 .
TilINORDIAMETER This diameter is determined by measuring :::n the bottom of the threads on one side to ti: bottom of the threads on the other. If you ;m'-::e to remove all traces of the threads, the '-=-neter ' -aine ter,
of the portion Fig. 3- B.
O T HE RT HRE A DS E RI E S Less commonly used are the UNEF (Unified National Extra Fine) and the B, 12, and 16-thread s eries. The UNEF is a finer thread than the UNF w h i l e t h e B , 1 2 , a n d 1 6 - t h r e a d s e r i e s a r e c o a r se threads for large bolts. For example: all bolts in the 8-thread series, regardless of diameter,
left would be the minor
PfTCH pitch is the distance between the Thread :rest of one thread to the same spot on the crest :j :he next thread. The smaller the pitch, the sreater number of threads per inch. The pitch :: number per inch can best be of threads gauge, Figs. by using a thread-pitch 'e:ermined 1- 3 B a nd 3-8 C.
. ] TH R EAD SER IE S Two series of threads in common use are (UNC - Unified .National Coarse) coarse (UNF the fine - Unified National Fine). The '-d :3arse thread is generally used when screws -:e threaded into cast iron and aluminum as a úe
gouge being number o{ threads per i nc h.
Fis. 3-8C. Ihreod-pitch
43
used to check nut lo¡ (Dee¡e E Co.)
Auto Service and Repoir have 8 threads per inch. The 12-thread series bolts have 12 threads per inch, etc. Study the chart in Fig. 3-9. Note that screws under Ll4 in. in diameter are designated by number instead of fractional size.
I
I.l
iii
C LA S S OR FIT Thread class indicates the operating clear_ ance between the nut internal threads and the bolt external threads. Classes are divided i.nto
Recommended for AIIERICAIII NATIONAL scREw THREAD PITCHES c(,ARsE STANDARD THREAD (N. C.) SPECTALTHREAD (N. S.) Formerly U. S. Standard Thread
I
lr
Slta.
l
I
2 3
.l li
4 5 6 8 't0 12 Vl Xt ,l ,rí
iii
Kt
+t
Tt 7h 1 1Vs 1V1
Inllact ?.. l¡cñ
64 56 48 40 40 32 32 24 24 20 18 16 14 't3 '12 11 10 I 8 7 7
oul¡¡da D¡tn!aat rl Scr.t
frD Dr¡ll SlrG
.utó 53 .086 50 .099 47 .112 43 .125 38 .138 36 .164 29 .190 25 .216 16 .250 7 .3125 F .375 4, .4375 U n4 .500 3l/ .5625 tu trÁ2 .625 ,N2 .750 a9/ .875 /u 7ti 1.000 't.125 9(, 1.250 1t1,
I orc|nd I Eqo¡rrl.nt LdDrt'l
0.0595 0.0700 0.0785 0.0890 0.1015 0.1065 0.1360 0.1495 o.1770 0.2010 0.2570 0.3125 0.3680 0.4219 0.4843 0.5312 0.6562 0.7656 0.875 0.9843 1.t093
slt.!
1 4 4 6 I 10 12 14 14
X,
Yn h Yt Yt Xt Xt
,1,
,r, V1 1/t
F|NE STANDARD THREAD (N. F.) Formerly S.A.E. Thread Slt..
0 1 2
ó
4 5 6 8 10. 12 V1
:i:lta
4a th
,/
r¿-ti
46
V2 %t YB V¿ t/a 1 1 Vs 11/t
ii
if
{l
1l
Pat Inch
72 54 56 48 44 40 36 32 2A 28 24 24 20 20 18 18 16 14 14 12 '12
Vt Xt Xt Xi ,l ,b ,r(,
Equ¡r.lanl ol Drlll
at
.060 .073 .086 .099 .112 .'125 .138 .164 .190 .2r6 .250 .3125 .375 .4375 .500 .5625 .625 .750 .875 .000 .125 .250
/u 53 50 45 42 37 33 29 21 14 ?
I
o '7ú 2l/
0.5062 0.5687 ll,í
0.8020 0.9274 1lu l rY u
0.0595 0.0700 0.0820 0.0935 0.1040 0.1130 0.1360 0.1590 0.1820 0.2130 o,2720 0.3320 0.3906 0.4531 0.s062 0.5687 0.6875 0.8020 0.9274 1.0468 1.17 t8
'rl¿ f2 V2 y2
X, 5h
Y. tXt tXt Yt Yt r/¿ ,h ,h
1 I
r¡.aaúr Pü Inch
56 32 36 36 40 30 32 20 24 64 48 40 32 36 24 32 24 32 24 27 32 20 27 32 20 27 24 27 12 24 27 27 12 27 11 16 't2 27 12 18 27 12| 27
gut¡tgt Olrñttat rl Sc..r
TIP Drlll Slras
54 | .0730 45 1.1120 44 1.r120 | .1380 34 .1640 28 I | .1900 22 | .2160 13 10 | .2420 7 | .2420 yu | .0625 | .0e38 49 I .12s0 38 Vs | .1563 | .1563 30 | .187s 26 | .1875 22 I .2188 't6 .2188 12 .250 4 .250 3 ,r(, .250 D4 .3125 .3125 J .3125 4 2l/ .375 .u 1 .375 R 1 .4375 x I 1 .4375 n4 1 .500 2% 1 .500 'á2 1 .500 I'A 1 .5625 |Yu .625 1 tb: 1 .625 t162 | .6875 % | .6,875 ry | .750 ,9r, 1 .750 tt/ .u 1 .875 v 1 .875 ,r& .875 I tt^ 1.000 tlli 11.000
Daclmrl Equlrrla¡t ot Orlll
0.0550 0.0820 0.0860 0.1110 0.1405 0.1570 0.1850 0.1935 0.2010 0.0469 0.0730 0.1015 0.1250 0.1285 0.1470 0.1570 0.1770 0.1890 0.2090 0.2130 0.2187 0.2656 0.2770 o.2812 0.3281 0.3390 0.3970 0.4040 0.4219 0.4531 0.4687 0.5312 0.5469 0.5937 0.5937 0.6250 0.6719 0.7187 0.7969 0.8281 0.8437 0.9219 0.9687
Fi g.3-9. Typi cal screw tfi reod l op si ze chort. (Peere E f,o.)
NUTS
six categories, 1A, LB, ZA, 28, 3A, and 3I!. The letter A indicates external threads (bolts, studs, screws) and the letter B indicates internal threads (nuts, threaded holes). This in effect, gives three cLasses. Number I class is a relatively loose fit and would be used for ease of assemblyanddisassemblyunder adverse conditions. Class 2 provides a fairly
I
Nuts used on bolts which are hexagonal in shape, have a corresponding number of threads per inch and with the same major thread diameter. Wrench size (rneasured across flats) is very much standardized but does varv for special applications, Fig. 3-10.
4
Fostenersond TorqueWrenches accurate fit with only a small amount of cleara:rce, and is the class commonly used for autonotive fasteners. Class B is an extremelyclose i:t and is used where utmost accuracv is e s sential. T OP V IE W
II
t
passes through the nut, it spreads the segments apart thus producing a locking action. Detail C shows a single slotinthe side of the nut. The slot may be forced open or closed during manufacture thus destorting upper thread. This will create a jamming effect when bolt threads pull nut threads back into alignment. A crimped nut is shown in Fig. B-40.
cRosssEcTtoN
I
S E LF-LOC K IN G S C R E W S Some cap screws have heads that are designed to spring under pressure of tightening to produce a self-locking effect. Occasionally the threaded end of a cap screw will be split and the halves slightly bent outward. When threaded into a hole, the halves are forced together this creating friction between the threads.
Erg . 3 - 1 0 . T y p i c o l n uf. A- Size o cr o ss flo fs. B.T h r e o d moj or di omefe¡. C-ffireod mino¡ diometet.
LOC K W A S H E R S A lock washer is used under the nut and grips both the nut and the part surface. The three basic designs are the internal, external and the p1ain.
L }NI F I E D The word UNIFIED, as used in Unified lfational Coarse and UnifiedNational Fine, indi:ates that this thread eonforms with thread s--andards as used in the United States, Canada =-i E ngland.
ffiffiffi
I]-OCKING DEVICES !
- \ " s c r ews , b o l ts , n u ts , e tc ., a re s u b j e c t edto r:nration, expansion and contraction, theytend to w'srk loose. To prevent this, numerous locking ieciices have been developed. These maybe an inrcgral part of the screw or nut, or may be a part :-aced under, through or aroundthe screw or nut. I?c:ry cement is sometimes used.
SLO T T EDAN D PIN C H ED
D IST OR T EDT H RE A D
ABc
5E¡.F-LOCKING NUTS
Fi g.3-l l . S el f-l ocki ng nurs. A -S ofr col l or type. B -Top s ec ri on slotted and pinched together. C-Stor ro distoii upper thieod areo.
Some nuts are designed to be self-locking. Th:s is accomplished in various ways but all share the same principle, that being the cres:iql of friction between the threads of the bolt rr stud and the nut, Fig. B-11. In Fig. 3-11, nut A utilizes a collar of soft =etal, fiber or plastic. As the bolt threads pass :p through the nut, they must foree their way :hrough the collar. This jams the collar material tightly into the threads thus loeking the nut in place. In B, the nut upper section is slotted and the segments are forced together. When the bolt
When using lock washers, especially the plain, with die cast or aluminum parts, a plain steel non-locking washer is frequently used under the lock washer, to prevent damaging the part, Fi g. 3-12.
P A L NUT The palnut locking device is constructed of thin stamped steel and is designed to bind against the threads of the bolt when installed. In
45
Auto Service ond Repq¡r use, t he palnut is s pun downint o c o n t a c t w i t h the regular nut (open side of palnut away from the regular nut) with the fingers. Once firmly in contact with the nut, it is given one-half turn. Do not t ight en bey ond O NE- HA L F TURN as the EXTERNAL
PLATN
ltl
IN T ER N AL
wl @
rrppeo ¡oée
Fig.3-14. Usesofcotfe¡ pin. A-Linkoge.B-C/evispin. C_Cosrle nut. D-Typicolcotterpin.
/- - \
\='É/ F i g . 3- 1 2 . T yp ico l lo ckwo sñ e ¡ s. No t illustroted i s onol her type l l r o t use s b o th in te r n o l o n d e xte r n o l { in gers, Ti pped edges provid e g r ip p in g p o we r in lh e "o { 1" di ¡ecti on.
end movement is present. Splines will allow, when desired, longitudinal movement while stil1 c a u s i n g t h e p a r t s t o r o t a t e to g e th e r . In so m e c a s e s p i n s a r e u s e d t o f i x s h afts i n h o u si n g s to p r e v e n t e n d m o v e m e n t a n d r o ta ti o n , Fi g . 3_15.
L O CK I NG P L A T E SA NDS A F ET YP t N S j
t
¡i ,
ii
effectiveness of the palnut will be destroyed. The one- half t ur n dr aws t he s t ee l f i n g e r s t o w a r d s th e nut c aus ing t hem t o jam i n t o t h e t h r e a d s , Fig. 3- 13.
Locking plates are made of thin sheet metal. T h e p l a t e i s g e n e r a l l y a r r a n g e d so th a r tw o or m o r e s c r e w s p a s s t h r o u g h i t . T h e m e ta l e d g e o r tab is then bent up snugly against the bolt. Various patterns are used. Occasionally screws w i l l b e l o cke d w i th s a f e t y w i r e ( s o f t o r d u c t i l e w i r e ) . Th e w i r e i s p a s s e d f r o m s c r e w t o s c r e w i n su ch a m a n n e r as to exert a clockwise pull.
SPRINGSTEEL F IN GER
F i g . 3- 1 3 , Po ln u t. Ho ll- tu r n fo m s sfe e l li ngers ogoi nst tá¡eods.
C OTTE RK E YOR P tN Cotter pins are used both with slotted and castle nuts as well as on clevis pins, linkage en ds, et c . Us e as t hic k a c ot t er p i n a s p o s s i b l e . Cut off the surplus length and bend the ends as shown. If necessar¡r, they may be bent around the sides of the nut. Make certain that the bent en ds will not int er f er e wit h s om e p a r t , F i g . 3 - 1 4 .
KEY s,S P LTNEASNDP |NS SPLIN E
Thes e ar e us ed t o at t ac h gea r s , p u l l e y s , e t c . , to shafts so that they witl rotate as units. When a key or pin is used, the unit being attached to the shaft is generally fixed so that no end to
l,i
?--
F i s . 3 - 1 5 . K ey, sp/i ne ond pi n. N ote fñot the s p/i ne al l ow s end m O v em ent, The pin fixes the sholt ¡o the housing, ollowing no m ov em ent. The key is commonly reler¡ed to os o woodrulÍ key,
ol so a hol {-moon kev .
46
LOC KIN GPLAT E
Never reuse safety wire and always dispose cf locking plates on which the tabs are fatigued /rea dy to crack ) , Fig. 3- 16.
5NAP RINGS Sna p rin gs ar e us ed t o pos it ion s haf t s , b e a r -::g s, ge ars, et c . Ther e ar e bot h int er na l a n d external snap rings of numerous sizes and shap es. The snap ring is made of spring steel and =ust either be expanded or contracted, depend-ng on the type, in order tg be removed or in=-talled. Special snap ring pliers are used. Be careful when installin! or removing snap rings because overexpansion or eontractionwill drstort and ruin them. If a snap ring is sprung cut of shape - throw it away. NEVER atterrrpi :o pound one back into shape. Never compress cr expand snap rings any more than necessary. -ibove a1l, do not pry one end free of the groove and slide it along the shaft, as this may ruin :he ring , Fig. 3 - 17.
I, I SAF ET Y W IR E
Fi g. 3-16. Lockíng pl ote ond sol ety w i re. Ioós musr be bentl i rnIy ogoi nst cop screw Íl a! l o prevent ¡otal i on.
S ETSCREWS Setscre ws ar e us ed t o bot h loc k and po s i t i o n ¡.:lleys and other parts to shafts. The setscrew --c hardened and is available with different tios and drive heads. Keep in mind that setscrews are poordriving deviees because they often slip on the shaft. -rihen used in conjunction with a woodruff key, :hey merely position the unit. As a general rule, do not install any unit without a woodruff key. When a setscrew is used, the shaft will usualXy have a f1a,4 sqot to take the screw tip. Make certain this 5po/ is aligned before running the screw up , Fig. 3- 18.
G R O O VE
Fi g.3-17. S nopri ngs. A -Fl ot i nternol type. B -E xrernol . C -R ound exte¡nol . There o¡e mony shopes cnd si zes ol ri ngs .
ALLEN H EAD
v/ --< 1.---1
: RIVETS
PO IN T ED
F LAT O N S H A FT
-Z
Rivets are made of various metals, including brass, aluminum, soft steel, etc., and find many applications on an automobile. They are installed cold so that there is no contraction that would allow side movement between the parrs. F ig. 3-1 9, sho ws s ev er al t y pes of r iv et s . When using rivets, there are several important considerations. The two parts to be joined must be held tightly together before and during riveting. The rivet should fit the hole snugly. The rivet material must be in i
Fi g.3-18. Typi col setscrew s. S efscrew s ore hordenedond they shou/d óe run up very tightly.
ti^t \.
A.
couNrERsuNK
WWWTY -/
H O LLO IVOR T U BU LAR
'SO L¡ D
SPLIT
Fi g. 3-19. S everol fypes of ri vefs.
47
Fis. 3-208.pop Riveroo/in use.
tr
?
:ri,
,f
:,il
.f l l
,i f i
;ii ; lri t:
i,'i
Íl
+ii
' $ll
correct
typ e
( fla t
b e se t with
head, a to o l
o v;r !, e tc.) and the ri vet ( r ive t set) desi gned for
t he pu rp o s e . F i g . 3 -2 0 , i l l u s tra tes the setti ng of a solid and a tubular rivet. P O P R IVE T S When one side of the work to be riveted is inaccessible, pop rivets may be used. They can be set from the outside and thus make the use of blind rivets practical. Fig. 3-20A illustrates the use of one form of pop rivet.
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Y
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;
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3 - 2 0 8 ) i s p l a c e d o v e r t h e r i v e t a n vi l p i n , and when the handles are closed, the anvil pin is pulled outward. As the anvil is drawn outward, the rivet head is forced against the work and t h e h o l l o w s t e m i s s e t . T h e se tti n g p r o ce ss draws the two parts tightly together. Further pressure on the tool handles causes the anvil pin to snap off just ahead of the anvil. The anvil remains in the set area. F i g . 3 - 2 0 B s h o w s a p o p R i v e to o l b e i n g u se d to attach seat back trim.
F i g . 3 - 20 . Se tlin g r ive ts. A- Pie ce s b r o u ght togerher ond ri vet s e o f e d . 8 - Rive t b u lg e d . C- Rive r cr o wn e dond seJ. D -S et used fo¡ t u b ulo ¡ ¡ ive t, E- Se f lo r ce d d o wn , cr o wn ing ¡i vef os sñow n.
should
PfNsNAp s
O T HE RF A S T E NE RS In addition to fasteners already discussed, there are numerous other specialized type fasteners such as hose clamps, C washers, clevis pins, spring lock pins, etc. Many types are pictured in Fig. B-40.
ln IU
F A S T E NE RS S HO UL D B E T O RO U E D
r
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rii i.
ilt :l I
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ii
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ilil ,ili
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THIN AREA
r
To better understand the reason for, and the proper application of, controlled torque, the meehanie should be familiar with several important terms. Read the definitions which fo11ow earefully as these terms will be used a great deal in this section.
TORQUE: Torque is a turning or twisting force exerted upon an object - in this case, the fastener. It is measured in inch_grams, inch_ ounces, i nch-pounds and foot_pounds, Fig. 3_21. TENSION; Tension is a pulling force. When screw is tightened, it actually stretehes 9 ""p (about.001 per 90,000 l bs. of tensioó duet o t he tension being applied, Fig. 3-22. ELASTIC LIMIT: The amount or disrance an object can be distorted (compressed, bent,
n rv e rs e f AN YIL R EM AIN S
F i g . 3 - 2 0 A, In sto llin g d p o p r ive ¡ . A_ p o p ¡i vet i n pl oce. B 'lRivetool" hos pu|Ied or"it' pin our*o,i,'oíU,ri'irr)r" rlsethet, sefiing rivet and snopping off pin,
The pop rivet is inserted through the parts to be joined, a hand-operatecl setting tool (Fig.
ifl i'i
1l]i $1i ¡ll
.,'.1.",
48
Fqsteners ond TorqueWrenches
stre tch ed ) an d s t ill r et ur nt ot he s am e dim e n s i o n whe n the force is r em ov ed, Fig. 3- 23. DISTORTION: The normal shape or configuration of an object being changed or altered due to the application of some force or forces, Fig . 3 -24 . TENSILE STRENGTH: The amount of pull an o bje ct will with s t and bef or e br eak ing, Fig . 3 - 2 5 . RESIDUAL TENSION: The stress remaining
C A P S CR E W
in an elastic object that h a s b e e n d i s t o r te d a n d not allowed to return to its original dimension, Fig. 3-26.
O
WRENCH
Fi g. 3-24. D i s.torti on.A -H ydroul i c rom oboulto engoger ounds teel ri ng. B -P ressu¡el rom ¡am óends o¡ di storts ri ng.
F i g . 3 - 2 1 , T o r q u e . To r q u e o t o twistin g lo r ce b e in g a p pl i ed to o cop screw with o box end wrench.
\rrr
illtr/
ro*
\\IZ 7/t1rFi g.3-25. Tensi l e strength. A -B sr ol steel i n o test moc ñi ne. B -H eovy tensi on oppl i ed exceedi ng el osti c l i mi t, covsi ng bor to sf¡elch. C-lnc¡eosed pull {inolly snops óor os fensjon exceeds tensi l e strength. Fi g . 3 - 2 2 . f e n s i o n . A- Sr e e l 6 o ¡ p lo ce din io ws o l o fe sf mocfi i ne. B - J o w s m o v i n g o p o r t, cr e o l¡ n go p u ll o r fe n sio n o n the bar.
\^z*n¡'-
\4
B2
Y8 3
4
Fi g . 3 - 2 3 . E l o s ¡ i c Lin it. Bo r s in Al o n d BI o ¡ r e st. No fe thot they te oligned with the black dot. ln A2 ¡he hor is bent within elosfic l¡n¡t and when pressure is ¡emoved it springs 6ock to its no¡ml (43) positíon. Bo¡ in 82 is bent beyond its elosfic limi¡ ond rlren pressure ís removed, the bor springs only part woy 6ock os in 8 3 .
Fi g.3-26. R esíduol tensi on. A -R u66er band ot Íest,' no res i duol lension. B-Bond being pulled (distorted) out to engagespring sfeel fiook. C-8ond ottempls to rcturn to originol dimensions, creating o pull (residuol tension) ond bending the hook. Ylithin its elostic limit, steel is more elosfic than ¡ubber,
49
r
Auto Service ond RePoir
l¡
The ability of an object to ELASTICITY: shape to its original distortion, after return, force has once the distortive and dimensions b ee n re m ov ed, Fig. 3- 27.
B Fig.3-29. Cold {low. ln A, the nul is nof tight ond fáe¡e is no compressíve lo¡ce on gos/
ti ¿. ¡ ; t-
HIGH PRESSURE LUBRICANT: A lubricant that continues to reduce friction between two objects even when they are forced together under heavy pressure.
i 5
l
l
Fig. 3-27. Elasticity. A-Originol position o{ ho¡. B-Bor deÍlected by pressure, C-No pressure, and ba¡ ¡eturns to original posifion.
TOROUEFASTENERS NECESSITY To understand of the VITAL torquing, we should first establish what we want to accomplish by tightening fasteners. O¡rcethis is clear, the reason for the use of a torque wrench become s obvious. We tighten fasteners to hold parts together. On the surface this seems like a simple statement but there is more here than meets the eye. When we say to hold parts together, we are in effect saying that once together, the parts should remain that way. When drawn together the parts
-l -l
-t
0 L b s.
Lbs. 0
Fig.3-28, Compression. A-Obiect ot rest. 8-Object under compression as ¡am builds uP ptessure.
I
2 3 -0
COMPRESSION: A force tending to compress or squeeze an object, Fig. 3-28. COLD FLOW: This refers to the tendency of an object under compression to expand outward thus reducing its thickness in the direction of c om pr e s s i o n , F i g . 3 -2 9 . HOOKE'S LAW: This law states that the amount of distortion (lengthening, shortening, bending, twisting, etc.), as long as it is kept within the elastic limits of the material, will be directly proportional to the applied force. This forms the basis for spring scales' torque wr enc h e s , e tc ., F i g . 3 -3 0 .
-2 -0 _l
2
3 Fig. 3-30. Hooke's low. Nofe fñot os fÁe weight on the spring bor is increosed, táe¡e ís o ptoportionole movemenl on tfte scole. T]rís would conlinue until the bor wos dellec¡ed Posl its eloslic limit.
50
Fqsteners qnd TorqueWrenches should not be distorted; that the fasteners should not be overtightened to the. point they will fail in service; that they have been tightened enough to prevent them fromworkingloose, andperhaps being sheared or pounded apart; andthatoil,gas and water leaks will not occur. Letts assume that a t'greenhornrt mechanic has just completeJ.y assembled an engine with a "guess and by goshrr method of tightening. Here is what COULD HAppEN to the engine: 1. Cylinders out-of-round. 2. Connecting rod and mainbearings egg shaped. 3. Cylinder head warped. 4. Valve guides forced out of alignment. 5. Camshaft bearing centerline out. 6. Crankshaft centerline out. 7. All engine components affected to some extent. In addition, blown head gaskets, oil, water and air leaks, broken connecting rods, etc. can plague the job. Obviously, the amount of distortion willvary depending on the stresses set up within the assembly but even at best, ring, piston, valve, and bearing wear will be accelerated and the job will fail in service long before it should.
use a.quality at least equal to that originally used. You will find that the more critical the (main bearing, connecting rod, etc.) application the better the quality.
HOW FASTENERTOROUEIS MEASURED To secure recommended torque, a measuring tool called a TOReUE WRENCH is a "must." The torque wrench will measure the toroue (twisting force) that is bei.ng applied to ihe fastener. Singte round beam, double roundbeam, and single taperedbeamtype oftorque wrenches, are shown in Fíg. 3-31. Handle
Drive
Squaró Beam
or Measuring
Element
@ Rouwoeeeu Head
Pivoted
Pointer
Handle
Double Beam or Measuring Element
FROPER FASTENERTENSION
@ noual e
Force
or Pull
R ouN D B E A M
Pointer
The first thing to keep in mind is that all car manufaeturers publish torque specifications and that they should be followed. Each company bas spent a great deal of time and money de:ermining the fastener torque for theirproducts '}rat will give the bestresults. Whenusingrorque eharts make sure they pertain tothe jobat hand. It has been found that for the vast majority cf applications a fastener should be tightened -¡¡til it has built up a tension within itself that :s around 50 to 60 percent of its elastic limit. When the fastener has been drawn up to this roint, it will not be twisted off. It will retain enough residual tension to continue to exert sressure on the parts and will resist loosening. Steel bolts and eap screws will stretch about .001 for each 30,000 pounds of tension. Like a rubber band, the tendency to return to their normal length provides continuous clamping effect.
Drive
Square
,
Beam
or Measuring
Element
@ reenaeo BEAM wRENcH Fi g,3-31. forgue w rencfi es. fñese ore ol l beom type w renc hes , oll widely used, durcble, ond occurote.
HOWA TOROUEWRENCHWORKS \
torque wrench uses Hookers law in its lttr" c\onstruction, (bending) a steel By deflecting beam (in some cases a eoil spring), the re-
lationship between the puLl onthe handle (torque) and the amount of beam deflection is readilv e stablished When the head is attached to the fastener and the handle is pulled, the flexible beam is bent. The pointer rod, being attached to the solid wrench head, is not bent. Since the scale is attached to the handle element, it follows the flexible beam thus moving the scale under the pointer end. The scale is calibrated so that the operator can see how much torque is being applied.
FASTEN ER MA TE RIA L As previously mentioned, most bolts and screws have radial tines on the head that indicate tensil.e strength. Whenreplaeing afastener,
5l
Auto Serviceond Repoir If the center of pull on the handle is exactly one foot from the center ofthe head, a one pound pul1 on the handle would be ONE FOOT-POUND. One foot-pound is twelve inch-pounds. Torque wrenches are available witha sensing device in addition to the sca1e. This warns the
pounds. For general automotive use, the inchpound and foot-pound torque wrenches are in common use. R E ME MB E R : To conver t f oot pounds to inch-pounds, multiply the foot-pounds by 12. To convert inch-pounds to foot-pounds, divide inch-pounds by 12.
i] l
FOOI.POUND SCAIE
FUTT WRENCH.I,:NGTH ADAP'ER ,\AULIIPTIES IEADINGS 3Y 2 HAI.F-I.CNGTH ADAPTEP MutilPuEs nEAD|NGS 8y lt,/2 OUATTE¡.TTNGfH ADAPTER IiUI.TIPTIES ¡EADINGS BY I'¿ SIANOARD 50cKEf5
OPEN END ,a\
gOX END
IYCID
Effective
Lengfh
of Assembly
(L + A)
\ \-a=
L = t8 ,t
\
Fig. 3-314. Torque wrench odoplers, (Populor Science Monthly ond P. A. Sfurfevonr Co.)
J. ;l
t
.
1
\rser that a preset torque has been reached. Various t¡pes of sensing devices suchas alight, audible click, etc., are employed so that the user can tell when the correct torque has been reached without having to read the scale. \4¡hen a torque wrench must be used in a position that makes reading the scale difficult or impossible, the sensing device is mighty handy.
TOROUEWRENCHRANGE .'Torque wrenches are made indifferentsizes or ranges as well as in different calibrations. Ideally, the mechanie should have a 0-200 inchpound, a 0-50 foot-pound, a0-100 foot-poundand a 150 foot-pound torque wrench. A torque wrench will produce BEST results if it is used somewhere near the middle half of its range. For example, a 0-100 foot-pound .wrench would give the most aecurate readings from around 25 to ?5 foot-pounds. By having several ranges of wrenches the meehanie will
TOROUEWRENCH CALIBRATION Torque recommendations can range from inch-grams, ineh-ounces, inch-pounds to foot-
52
Fqsteners ond Torque Wrenches
also find that this will offerhimseverallengths. The shorter ones can be useful in restricted quarters.
RANG ECANB E A LTE RE D B Y USINGAN A DA P TE R Say you have a 0-100 foot-pound wrench available and the torque recommendation is 150 foot-pounds. This is obviously beyond the range of the wrench. It ean stillbe used however through the use of an adapter to lengthen the effective range. If the lever lenlth (distance from the center of wrench head to pivot point on the handle) is 19 in. and you used an adapter bar of equal length, the torque being applied would be double that s hown ont h e s e a l e . If th e l e v e rw a s 9 - 1/2 i n. or half as long as the lever length, the torque would be one and one-half times that shown on the scale. A handy formula to determine applied torque when using an adapter or extension is as follows:
and to the area where the nut orcap serew head contacts the part.. N ever-seez, Fel -P ro C -5, Mol ykot e or a similar high strength lubricant is suitable. The use of this lubricant will prevent or reduce the possibility of galling, seizing (sticking) or stripping, and will assure that the fastener torque has created the proper tension. It should be mentioned that the lubricant, while making the fasteners easier to remove at some future date, will not (if torqued properly) cause them to loosen i.n service. Tothe contrary, the increased tensioning for the same torque reading will actually cause the fastener to remain more secure.
US EP RO P E RL O CK I NG DE V I CE Unless a self-Iocking nut or cap screw is being used, make certai.n the recommendedlock washer is in place. When running a fastener up against the softer metals, the use of a plain, flat washer between the Lockwasher andthe part,
Dial reading x (L + A) = --t!!- Torque applied to fastener' L (L) rs the length j.n inches from the center of the handle pivot to the center of the wrench head. (A) ¡^ ID the length in inches from the center of the wrench head to the end of the adapter. Must b e measured parallel to the centerline of the wrench. i.s often specified. This prevents the part from being "chewed'r up and allows proper"torquing without crushing the part.
Fig. 3-31A, shows three adapter setups. Notice that the effective length (L+A) is always measured parallel to the centerline of the wrench. REMEMBER: When using adapters or extensions, be certain of their exact length. Do no\ forget that length and torque are directly r 3, lr dt ed,F ig. 3 -3 1 A.
CHECKFASTENERS Be careful to check fasteners for correct diameter, threads per inch and length. When installing cap screws, make certain they will not bottom (strike bottom of a threaded hole), in a blind hol.e hole not drilled clear through part), nor in a through hole protrude into the housing and damage a part of the unit. R E ME MB E R : S tri pped threads, br oken screws, loose parts and damaged units can result. Be carefuli In A , Fi g. 3-32, the screw hasbottomedleaving the part loose. Continuedtorquing could twist off the screw. In B, the screw protruded into case and damaged gear. In C, coarse thread screw, jammed into hole with fine threads, cracked part, Fig. 3-32. If any fasteners serve an additionalpurpose, such as a head bolt or cap screu/ that may be drilled for passage of oil, or a cap screw with
USINGTOROUEWRENCH After determining the proper torque and selecting a suitable range torque wrench, you are ready to proceed. Be sure to observe the following: THREADS MUST BE CLEAN: The threads on the boLt or screw as well as those in the nut or hole, must be absolutely clean. Rust, carbon, dirt, etc., will cause galling and improper tension. An accurate torque reading with dirty threads is impossible. USE HIGH TEMPERATURE LUBRICANT: Unless the use of a lubricant is specificallyforbidden (due to the possibility of area contamination or the need of a special sealant) always apply a high pressure Iubricant to the threads
53
S¡ .
w It
Auto Serviceond Repoir
't.. \'.\.
J!
t" l, ID
If I
I ¡S
_-----.- - -- 1r' <--/ -_
,r' uu
/
,a
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F i g. 3- 34. H eod bol t ti ghteni ng s eguenc e w h e n n o s p e c i o l m endoti on i s ov oi l oól e. ( Vi c tor G o s k e r C o . )
re c o m-
set up throughout, at the same time, allowing t h e p a r t s t o b e d r a w n t o g e t h e r so th a t th e i r m a t i n g s u r f a c e s w i l l c o n t a c t , F i g. 3 - 3 5 .
FOLLOW RECOMMENDEDSEOUENCE
f
t-
:
a thre aded hole in t he head t o w h i c h a n o t h e r asse mbly is at t ac hed, be c ar ef ul t o i n s e r t t h e m in th e c or r ec t plac e.
ld
t.
a
F i g .3 -3 2 . Check fostener s/ M oke cer toin thot fos tener s o¡ e of l h e co rrecl diometer , length ond with sullicient th¡ eod ol tfr e c o¡ r ect num ber o{ tee¡ h oe¡ inc h.
Wh er e a num ber of f as t ener s a r e u s e d t o secure a par t ( s uc h as a c y llnder h e a d ) t h e p r o p e r seq ue nc e ( or der ) of t ight ening s hou l d b e f o l l o w e d . trig . 3- 33 illus t r at es t he head b o l t t i g h t e n i n g seq ue nc e f or one m odel engine. A l w a y s f o l l o w eoe nig. 3_33. th e ma nuf aCt ur er Sr gnenif ior iinnq
r i,
ln
It I
o@o@oc oo@o@o @ @o
@__@_@
Fi g. 3-35. Ti ghteni ng bol ts i n..írr.rl s
s equenc e.
@oooilo ooo@o@ FRONT Fig,3-33. Cylinderheodbolt tighteningseguence. (AmericanMofo¡s)
Fig. 3-36. lfrongseguence in tighleningfosleners.Ihis seguence wouldproduceo very poorlit!
If no s equenc e c har t c an be o b t a i n e d , i t i s usually advisable to start in the center and work ou t toth e ends . The c har t inFig. 3- 3 4 , i l l u s t r a t e s this technique. On s om e as s em blies , it is ad v i s a b l e r o u s e a crissc r os s s equenc e. Alway s a v o i d s t a r t i n g in one spot and tightening one after another in a row. Remember that the object is to tighten the pa rts i n s uc h a m anner t hat an e v e n s t r e s s i s
Would a good fit be acquired if you followed the sequence shown in Fig. 3-36? Quite obviously if this sequence is followed, the two ends would be clamped down first and when the center bolts were tightened the part could not flatten out. In order to flatten, it must spread outward and in order to do this, the ends must be free.
54
Fqstenersond TorqueWrenches You witt find that when a fastener has stuck, the torque required to start lt moving fureakaway torque), is much higher than that required to keep it moving thus indicating that break-away torque is not a true picture of actual fastener torque. When sticking occurs, run the fastener in an off-direction (about one-half turn) until it breaks
TO RO UE I N F O U R ST E PS Always run the fasteners up snug (do not overtighten) with a regular wrench and then abserve the following four steps. i. Run each fastener, in the proper sequence, up to one-third of the recommended torque setting. !. Repeat the process running up to two-thirds of the setting. 3. Repeat, running every fastener up to full torque. 4. This is a very importantandfrequentlyoverlooked step - often to the embarrassment of the meehanic when the unit fails. REPEAT STEP THREE TO BE POSITIVE YOU HAVE NOT MISSED A FASTENER:
[n\
n\ rrrn
+)F1 p
tf+ur7
te\l
;\(
All
RIGHT
RIGHT
:\l
HOLDING THE TOROUEWRENCH
S)*=dtr.) *
W R ON G
Where possible (it saves skinned knuckles) PULL on the wrench. Keep your hand on the handle and if using a pivoted handle, keep the handle from tipping in against the wrench. This :s important as the pivot is where the pull should be for exact readings. Items A and B, :n Fig. 3-3?, show the correct hand position. In C, the mechanic has placed his hand on one end of the handle tipping it and causing interference sith wrench action; D shows an extension in place on the handle. This should never be done'
rflva,
D
'\
|
WR O N G
Fig.3-37. Grosp táe lorque wrench properly.
free, then, with a smooth and steady pull, sweep the wrench handle around in a tightening directi on. S TOP w hen' the requi red tor que is reached.
P ULLI NG T HE WR EN C H When using a beam-type torque wreneh, especially the single round beam, be careful to the beam is bent only in -¡u11in such a way that :he direction of travel. If the wrench is bent up or down while pulling, the indicator point can* drag on the scale thus impairing the reading. Plaee the palm of the left hand on the head of the wrench to counterbalance the pull on the handle. Allow yolrr palm to turnwiththewrench. Fig. 3-38, illustrates the use of the lefthand f or balanc e. I n th i s c a s e ,b o th a n a d a p te ra nd extension are being used.
Fig. 3-38.-'Use the polm ol the hond on the heod ol the wrench to bolonce the pull on the hondle. (P. A. Srurrevonr Co.)
TOROUE RUN-DOWN Self-locking nuts, slightly damaged threads material will cause the fastener to foreign or turn with some degree of resistance before it begins drawing parts together. This is called run-down torque. If at all noticeable, add this run-downtorque to the recommended torque. Determine rundown torque only during the last one or two turns
STICKING Quite often when nearing full torque value, you will hear a popping sound and the fastener will seem to stick and stop turning. If you increase pressure on the wrench, it mayrunup to full torque without moving the fastener.
55
Auto Service ond Repoir
IF
of the fastener. When a fastener is first started, it may show considerable resistance but by the time it reaches bottom, this may have Iessened or disappeared. CAUTION: Whenever a fastener shows undue resistance - remove it and make sure it is the right length, diameter, and has the proper num_ ber of threads per inch.
-t
RE T O RO UI NG O n s o m e a s s e m b l i e s , s u c h a s cyl i n d e r h e a d s, manifolds, etó., all fasteners should be torqued after a certain period of operation. Cases such as these, and the proper, interval, will be dis_ c u s s e d i n t h e s e c t i o n s ''c o v e r i n g u n i ts to w h i ch they apply.
WHENTOROUERECOMMENDATTONS AR E NOTA V A ILA B LE
SUMMARY The expert mechanic is vitally concerned with fastener design, applieation and torque. He r e a l i z e s t h a t t o a g r e a t e x t e n t, th e su e ce ss o r failure of his work depends upon the proper use of fasteners. There are many types of fasteners; screws that thread into a part, bolts that pass through the parts and require nuts, studs that thread into the part and also use a nut, and sheet metal scréws that cut their own threads. The Unified National Coarse and the Unified N a t i o n a l F i n e t h r e a d s e r i e s a r e co m m o n l yu se d . Threaded fasteners are identified by material, thread pitch, diameter, length of ttrread, type, etc. Steel bolts and screws use radial markings on the head to indicate material and tensile strength. The removal of broken fasteners can cause difficulty unless done properly. Various methods are used. When threads in a hole are damaged beyond repair, the hole may be drilled and tappedf----=) 1. To the next suitable oversize , nyg), "r,ácap screw installed. 2. To accept a threaded plug. 3. To accept a patented coil wire inserr. rings, rivets, clevis pins, keys and -.Srap are nonthreaded splines fasteners. Fasteners tend to loosen in service. Self_ locking nuts, various lock washers, safetywire, locking plates and cotter pins are some of the most used methods. of keeping fasteners tight. Fastener. tension is important to prevent distortion, to keep fasteneis tight and to pre_ vent fastener faifure. To provide proper ten_ sion, fasteners should be torqued. Several types of torque wrenches are avail_ abie for this purpose. They mr,rst be used prcgierly.
The mechanic should make every endeavor to secure the car manufacturerrs recommended torque for the specific job. If, however, itis not available it is wise to consult a chart such as the one in Fig. 3-3g, to determíne the tensile strength of the fasteners being used. you will note that by using the head markings and diam_ eter, an approximate torque setting may be de_ termined. Keep in mind that if the fastener is threaded into aluminum, brass or thin metal, the torque figures rnay have to be reduced to prevent stripping, Figs. SA and 3-S9.
BOITTOROUE Size
FL Lbs.
neurton metres
Ft Lbs.
newton metres
Ll4-28 95 ln. Lbs. 10.733575 150In. Lbs. 16.947750 5/16-18200In. Lbs. 22.597 270ln. Lbs. 31.207950 5116-24 20 27.tL64 25 33.8955 3/8-16 30 40.6745 40 54.2327 318-24 35 47.4536 45 61.0118 7lI6-t4 50 67.7%9 65 88.12E2 7116-20 55 74.5700 70 94.9073 U2-13 75 101.6864 100 135.582 Ll2-20 85 tL5.2441 110 t49.L40 9ll6-t2 105 142.3611 135 183.0351 9/16-18 115 i55.9191 150 203.373 5/8-11 150 203.373 195 2U.3841 5/8-18 160 216.931 2t0 284.722 314-16 175 237.268I 225 305.0591 sAE CIASSI F ICA GRADE 5
GRADE8 M ARKINGS F OUND ON T OP OF BOIT HEAD INDICAÍE GRADE
Use high pressure lubricant on the threads and under the head or under the nut area on fasteners. Be certain the fastener is of the correct length, diameter and has the proper number of threads per inch.
Fig.3-39. (fiort sfrows torque volues lo¡ Grode S ond Grode g fo sfe n e r s. Je e _ p ig . 3 - A .Ío r o d d itio r ol ,.oJi ng". lDodse) '
,i .:.
"'..*t$,s, 56
Fosteners ond Torque Wrenches
The proper sequence of tightening is very follow the manufacturerrs Always :mportant. :ecommended torque and sequenee.
ITIE S S UG GESTEACTIV D i
,
Take a sheet of paper, wad it intoa bal1, pull it back out and lay it onthe table. If you were to try'to press it out flat, where would you place your hands (fastener) first. In what direction (sequence) would you move them' Try it. How does this compare to tightening sequence. Using a regular wrench, turn up severar 3/8 in. screws to what you would guess to be 15 foot-pounds of torque. Take a torque wrench and break themloose. Watchthe scale carefully to determine the toique requiredto start them. Even though this will be different than true torque, how even were they? W as it c lose to 1 5 fo o t-Po u n d s ?
3. Place two 1 l4 in. bolts, (one with six radial lines on the head and the other with none) of equal length in a vise. Keep them about two and with the same amount of apart inches jaws. Run the vise up tightly' in the material torque wrench, turn eachbolt a suitable With to untit it snaps. Watch the scale earefully torque at-the moment of failure' determine Was the reading fihe ]ame? If not, why? You much effort wiII also note that\doesnottake to sn ap a 1/ 4 in. bolt .
WRENCH? WOULDYOUUSEA TOROUE Le t's sup po s e y ou ar e t obe c ar r ied a l o f t 2 0 stories on a small steel platform. The platform is attached to the cable with ONE bolt' This bolt MUST be torqued to 150 FOOT-POUNDS' and break in mid-air -\t 160 foot-pounds it will a for Anybody slip. will i.t foot-pounds at 140 torq ue wre nch?????
ñeMpt\tenR: MECHANIC CAN THE GROUND. RECOMMENDED WRENCH:
AS A YouR REPUTATIoN WELL BE 20 STORIES OFF KEEP IT SAFE. FOLLOW TORQUE ANDUSE ATORQUE
i s c o n s i d e r e d s u p e r i o r t o p u n ch i n g 3. Drilling h o l e s i n w h i c h s h e e t m e t a l s c r e w s a r e to be inserted. True or False? 4. A stud has-on -ends. Tr u e 5. Studs are beét installed with pliers. or False ? 6 . N a m e f o u r m e t h o d s t h a t m a y b e u s e d to r e move broken screws or studs. ? . H o w c a n a s t r i p p e d h o l e b e r e p a i r e d ? Tw o methods. indiB. Three radial lines on the headofabolt strength tensile greater has it cate that than a bolt with six radial lines. True or False ? 9. Define the term major diámeter. 10. How can the number of threads per inch on a screw be determined? 11. Define the term minor diameter. 12. Name the two popular thread series. to thread class, a 2A would 1 3 . Wh e n r e f e r r i n g nut with a fairly accuthreaded apply to a rate fit. True or False ? 14. The class 2 fit is-usedforautomobile fasteners. 1 5 . D e s c r i b e t w o k i n d s o f s e l f - l o c k i n g nu ts' 1 6 . N a m e t h e t h r e e b a s i c t y p e s o f l o c k w a sh e r s' 1?. To use the palnut, run it down to the nut, open side away, and then give it 18. All fasteners have threads. True or False? 19. A spline. and a woodruff key bÓth act as a True or or device. mechanism driving False ? 20. What is a lock Plate? 21. Snap rings should NEVER be reused' True :' or False ? 22. A setscrew usually has a hexagonal head' True or False ? 23. When a rivet is used, the rivet should be in the hole, the Parts must and a--should -together be used. 24. Torque and tension are one and the same' True
or False?
.,r:':
2' DisTorque' 4. Strength. Tensile 3. tortion. 6. Residual Tension. 7. Com5. Tension. L aw' 9- Hookers 8.. Elasticity. pression. 10. High Pressure Lubricant. fastener for proper reasons three 26. List tension. 27. Proper tension is best,achieved bY using a
25. Define the followirig: 1. Elastic Limit.
OUIZ - ChoPter3 True or t he us e of . nut s ' 1. Scre ws r equir e Fa lse ? 2. Sheet metal screws should be threaded into a hole about the size of their major diameter. True or False?
to tighten fasteü"ers. 28. Why use lubricant on fastener threads? steps' 90 should be in three initial Torquing
57
AutoServiceond Repoir
30. 31.
32. 33.
tl jti i :i
Fasteners drawn up to_of reeommended torque then to-and finally to-torque. What is the important fourth step in torquing ? Indicate your choice of the following range torque wrenches that you would use totighten a bolt to 50 foot-pounds. 1. 0-200 inchpound, 0-50 foot-pound, 0-100 foot-pound. What effect will an adapter have on atorque wrench reading? Describe how sticking during the final torquing should be handled.
34. To allow the user to torque fasteners when the position makes seeing the scale impossible, a_device is used. 35. Always PUSH a torque wrench. True or Fal se ? 36. Once fasteners have been properly torqued, they will never need to be torqued again. True or False ? 37. What is a torque chart? 38. Torque, for automotive use, is measured in and in
-H
,.-)
'11r ,: I I f
ir ¡l 1! :it
@ @
{iiii 'l l,
4" N
@^@ i' I
1 r l, r:¡
: 'I
i li
Fig.340. An osso¡tment of losfene¡s. llthough terminology con vory somewñof, tfiese ore commonly u se d d e scr ip fívé n o m e si l -Fl angeJock nut. 2-Fi l l i srer heod machi ne sc¡ew . 3-B orrel prong nut. 4lling nut. 5-Cop sc¡ew. 6-Pol nut. 7-Co¡¡ioge bol¡. &-Sp¡ing nut. 9-12-point heod bol¡. l?-Round h e o d m o ch in e scr e w. ll- Ask¿w -heod bol ¡. l 2-S i ngl e thread nut. I3-Fl onged nut. l 4-C ap screw , 15Ancho¡ nut. l6-Ploin fiex nuf. l7-Hex flange screw. l8-Acorn (cop) nut. I9-Flo¡ heod screw. 20(ec . Sm a ll lla t lr e o d scr e w. 2l -S peed nut.22-S heet mel ol screw . 23-Locki ng nut.24-K ey.2í-Ol l set centric) stud. 26-Thin nut. 27-Cotte¡ pin. 28-$ocke¡ head bolt. 29-Locking nut. 30-lling nut. 3lSpeciolry nut. 32-Toothed /ock wosñe¡s. 33-Thunbscrew.. 34-Stud. 35-Snop ringi 36-gpring lock pin. 37-Cross heod mochine screw.38-Ponel nut. 39-Flonged hex slotted freod screw. 4O-gp/it loc/< wosfier. 4 l- He x so cke t fie o d b o l t. 42-l l el ded nut. 43-P l ow bol ¡. 44-C l evi s pi n. 4s-Open top ocom nut. 46Closed rop ocorn nut. 47-Squa¡e fieod cop screw. 48-WoodruÍ( key. 49-Sell+opping screw, 50-Serrored n u t.5 l- Sio tte d nut. 52-S ef screw . 53-C ostl e nut. 54-Fl of w oshe¡. 55-C oi rl e nur.
58
Chapter4
SEALANTS, GASKETS, SEALS ANDW IDE LYUS E D I MPO R TANT Gaskets and seals are used throughout the car. They confine gas, oil, water and other Íluids, in addition to air and vacuum, to specific :mits or areas. They exclude the entry of dust, dirt, water and other foreign materials into rarious parts and they play an important part i¡ the proper functioning and service life of all components. Unfortunately, the importance of the proper selection, preparation and installation of gaskets and seals is not always clearly understood. In addition to their basic duties as mentioned, they effect torque and tensibn, part alignment and elearance, temperature, compression ratios, lubrication. REMEMBER: TIIE FAILURE, PARTLAL OR COMPLETE, OF AGASKET ORSEAL CAN CAUSE EXTENSIVE DAMAGE AND EXPENSE. STUDY THE MATERIAL IN THIS CHAPTER CAREFULLY AND APPLY THE INFORTLA.TION TO YOUR WORK:
a seal and yet excessive compressibility will cause the gaskettoextrude (coldflow - literally reducing thickness in the direction of compression and flowing outward) or reduce its thickness beyond a specified point. G ASKET
\ *.ol L
\
A
Fig.4-1. Goskefstops leoks.Assemblyin A has no gosket'Ir,"o,rlailli.r on pdrl mot¡nqsurfoces ollow leokage.ln B, same o"f..6l) is sñiwn -but lnh o goskef. lrreguloritiesote litled ond the leok is stopped' --/ selected will depend on The gasket material t¡pe of temperature, application, the specifie fluid to be confined, smoothness of matingparts, of confined fluid, pressure tension, fastener of mating parts, used in construction material
G ASKET A gasket is a piece of material placed between two or more parts so that when drawn (warped spots, any irregularities together, by the dents, etc.) will be filled scratches, a leakproof producing thus gasket material joint, Fig. 4-1 .
AN D C O L D /,H e,Af
Q,*essu" S enosrox coR R osl oN
oor*rr/
MOIS TU R E
G ASKETM ATERIA LS Many materials are used in gasket construction. Steel, aluminum, copper, asbestos, cork, rubber (synthetic), paper, felt, etc. The materials can be used singly or in combination. Gasket material eompressibility (how easily it flattens under pressure) varies widely. The gasket must compress to some extent to effect
Fi g.4-2. Goskef musf w i thsl ond mony l orces' fhe des r' uc l i ' e forces slrown, in oddition lo ofhers not illustroted, ore constontly attempling to destroy tñe gos/
part affect
59
cl earance the
choice
rel ati onshi p, of gasket
etcmaterial
A II and
of
thes e
design.
Auto Service qnd Repd¡r
p l a c e d b e t w e e n t w o s h e e t s of steel or copper. Note that the edges are rolled to produce a grommet effect.
or selecting gaskets, give When constructing careful thought to these factors and choose wisesome of the destructive ly. Fig. 4-2, illustrates forces that the gasket must resist in order to function properly.
GA S K E TCONS TRUCT!ON Some gaskets are of very simple construction. The engine top water outlet, for example, treated, us es a m edium t hic k nes s , c h e m i c a l l y paper gasket. Unit loading (pressurp'\ fibrous mating parts) is light, temperatufe-' between low and the coolant medium, coolant pressure p r es ent s only m ild pr oblem s , F i g . 4 - 3 . As the sealing task becomes more difficult,
; I i, J ir
. Tn ir
Fí g. 4- 3. Sim plepopergo s k e t .T h e p o per is soff, toughond wote¡resistont. EXHA U S TP I P E
l ri ,
.!
Ii il,
#:'ff : :i],
! jll
i i fi iI li
E*
f
EXH AU STPIPE
gasket construction becomes more involved. The exhaust manifold to exhaust pipe gasket, where uséd, is sorrlbwhat more complex. Unit loading pressure is hilher with corrosive flames, gases attempting to destroythe and high temperatures ga s k et . This gas k et , in t wo b a s i c t y p e s , u s e s asbes t os and s t eel in it s c ons t r u e t i o n , F i g . 4 '4 . gasket in Perhaps the most eomplicated terms of materials used and construction techniques, is the cylinder head gasket. Unit prescombustion \emperatures sure is tremendous, are very high and the gasket and pressures
A 5 B E 5 TO 5A N D S TE E L W I R E
F i g. 4- 4. Ex hous f noni Íol d gos k ets . Th e g o s k e t í n A h o s o n o s bes fos c enl er w i th o thi n s l ee/ oul er l o y e r. N o t e h o w f h e i n n e ¡ edge ís pr otec fed w i th o s teel gr om m e t . Th e g o s k e t i n B i s mo d e up ol os bes fos ond s tee/ w i r e. A thi n sl e e l o u l e r ri n g c o n o l s o b e used lor odditionol
sfrengffi.
The single layer beaded or corrugated type of gasket shown in C, Fig. 4-5, is popular on engines. A single sheet of high compression steel, around .020 thick, is stamped to produce a beaded edge around combustion chamber and one is given an fluid openings. This particular aluminum coating, about .001thiek, onboth sides to assist in sealing, and to prevent corrosion, This type of gasket requires accurate and smooth coated surfaces. The aluminum block-to-head steel gasket will withstand high temperatures In addition, quite successfully. and pressures it will not produce torque loss (gasketbecoming
oil and corrosive must seal against coolant, g as es . There are several basic designs in common steel, copper 7ñ-d.1ubber may use. Asbestos, ) be used in their construction. \ gasketis shownin One type of multiple-layer A, Fig. 4- 5. A s t eel c ent er c o r e , p e r f o r a t e d t o produce tiny gripping hooks, is placed between two sheets of specially prepared asbestos. Steel (the material placed around or copper grommets the edges of an opening to help strengthen or to protect the object passing through the hole from sealing) a br as ion, or as in t his c as e, t o a s s i s t i n and placed chamber the around combustiorr are gasket is then openings, The entire coolant formed into a one-piece uhit. I n B, Fig. 4- 5, an as best o s c e n t e r c o r e i s
thinner
under eontinued fastener tension therebolt tension and toreue). ¡,
by reducing
UNI TL O A DI N G L O CA L I Z E D To produce higher.unit loading around the combustion chambers, or any other opening, a copper wire can be inserted between the top and bottom layers - near the edge. The re-
ó0
ASBESTOS
GROMMET
W I RE CO PPER
CORRUGATED
GROMMET
(V ícto¡) F ig . 4 - 5 . So m eo f ¡ h e d i$ e r e n t metfi odsenpl oyed i n ñeod gosket constructi on.
gaskets
necessary in doing a complete engine c a r b u r e to r , overhaul). Sets for transmission, are available separately. differential, etc.,
main de r of the gas k et t ends t o c om pr es s m o r e t he des ir ed pr e s s u r e rea dily thu s c r eat ing a rou nd th e o pe ning, D, Fig. 4- 5. Ano the r tec hnique us ed t o pr oduc e loc a l i z e d u nit pre ssure o r loading is s howninE, Fig . 4 - 5 . This type uses a copper or soft iron grommet around the rolled edges. Coolant and oil openings are sometimes pla c ing s pec ial r ubber or ne o p r e n e se ale d by gro mmets in t he gas k et openings . Thes e a r e highly resilient and maintain constant pressure arou nd th e op enings , F, Fig. 4- 5.
G ASKETS O FT E NCOMEIN S E TS Gaske ts a re of t en or der ed in s et s . For e n g i n e gaskets are .available in a HEAD SET work, ( includ es all gas k et s nec es s ar y t o r em o v e a n d repla ce th e he ad or heads ) , VALVE G RI N D S E T ( includ es a I1 g as k et s nec es s ar y in doing a v a l v e SET ( inc lud e s a l l grin d job ) a nd O VERHAUL T ERIAL - 7
gosketsef. ffiis set is for o Chev¡olet Fiq. 4-58. Engíneoverhoul six cvlinder. (V¡ctor)
Single gaskets for some specific parts are also G a s k e t s e t s a l s o i n c l u d e n e ce ssa r y available. oil seal replacements.
ST EEL AND A S B E S TOS T OGE TH ER
G A S K E TI NS T A L A T I O NT E CHNI O UE S After deciding just what a specific gasketing situation will call for in the line of gasket maand construction, there are a few important -terial of the Regardless ihstallation considerations. suitability of the gasket, if not properly installed, fail. it will ultimately
S P E C I A LA S B E S T O SS H EET
CLO RE P E R FORATED.ITEE SHEET SPECIALASBESTOS
NE V E RRE US EA G A S K E T Onee a gasket has been in service, it will and when Ioose a great deal of its resiliency, removed will not return to its original thick-
F i g . 4 - 5 A . O n e typ e o Í h e o d g o ske t co n str u ctio n . (McC ord)
6l
AutoServiceond RePoir
seal ne ss. I f r eus ed, it will f ail t oc om p r e s s a n d part and to related as cosj* Gasket properly. meprofessional the and smaú is labor costs, using old gaskets' chanic does not ever\consider how the use of old 4-6, demonstra\es Fig. gaskets will
F :
Produce leaks-
run
may notice that the gasket coolant openings may be slightly large-r or smaller than the ports in the block or head. This gasket may be designed to fit several models or it may be so arranged to restrict or improve coolant circulation. Check out these situations carefullY. Head gaskets for the left and right bank on some V-8 engines are interchangeable - others
r¡rff
N
A
I I
?,
r
0
F i g . 4- 6 , Use d g o ske ts will n o t wo r k! A u s ed goskef i s posi ti oned ¡n i. lVlr"n tlre porls ore lightened, B, the old, hordened goske! c o n n ot co m p r e s' s a n d líll in e g u lo r itie s. The ¡esul ts: LE A K S I
f
F
i
C H ECKMA TINGS URFA CE S After thorough cleaning, inspect both part mating surfaces to detect any nicks, dents, pieces of old gasket or sealer, burrs, dirt, warpage, etc., that may make proper sealing impossible, Éig. +'l .
CHE CKTHE GA S K E TFORP RO P E RF I T Place the gasket on the part to determine if it fits properly. On the more complicated setups such as cylinder head gaskets, make certain the gasket is right side up, proper end forward and that bolt, coolant and other openings are clear and in proper alignment. Oceasionallyyou
;ii
-'. , , ! j il
Fig.4-7. Check moting surfoce' Nofice tfiof the cylinder blocL surfoce ís cleon, smooth ond ¡hot all openings ore cleon' (Chevrolet)
HEADBOLTHOLE PUSIIRODOPEHIilGS
t;. rl:
proper li¡. The dowel pins hold the fieod gosket in ploce ond align the cyl' ' Fig,4-8. Cfiec/<íngo freod gos/
62
T
Goskets,Seolonts, Seols or paper gasket usually does not render it useless, but when checking head gaskets BEWARE of ALL creeses. If bent sharply, do not attempt to straighten it, as the inner layer may be separated and cause failure. A gentle bend will not ruin the gasket - sharp kinks and creases will. Fig. 4-10, illustrates what happens when a multiple-layer head gasket is creased andthen straightened.
are not. Many head gaskets have the word TOP and occasionally the word FRONT stamped on the g aske t, Fig. 4- 8.
SOMEGASKETS TENDTO SHRIN K O R EX P A ND Paper and cork type gaskets that have been stored for some time tend to either lose of pick :rp moisture depending on storage conditions. i-oss of moisture ean cause them to shrink, n,hile excess moisture can expandthem. In either case, when checking for proper fit, they will show signs of misalignment. This condition can be corrected by soaking shrunken gaskets in water for a few minutes or by placing expanded gaskets in a warm (not o v er 150- 200 d e g re e F .) s p o t. C h e c k them occasionally to prevent overdoing the treatment, Fi e. 4- 9.
l I I
ll
,//t$\ Fi g. 4-10. C ¡eosed gosket. A -Mul ti pl e-l oyerl reod gosket. Gos k et hos 6een creosed, B, ond the cenfer pocking pulled oport, Gasket stuoi ghtened, C , produci ngvoi d. D -Gos/
MA K I NGA G A S K E T
F i g . 4 - 9 . P o n g o s k e t fio s sh ¡ u n k. T h e g a ske t ñ o s d ¡ ie d out, pto& t c i n g s h r i n k o g e .N o te in A h o w scr e w h o le s lo il lo m o fch. S ooki n g will so lvo g e fá is g o ske t.
A simple paper or combination cork and rubber gasket can be made either by tracing and cutting with scissors or by layingthe gasket material on the part and gently tappingalongthe edges with a brass hammer. Screw holes can also be tapped lightly with the peen end of the ball peen hammer. Do not tap hard enough to damage the threads. Gasket punches can alsobe used to make neat screw holes. It will help hold the material in place if you tap¡'out the corner holes and start these screws before tapping around the edges, Fig. 4-10.A..
CHAM FERING S CRE WHOLE S M AY BE NECE S S A RY When installing head gaskets, examine the serew holes in the block. Ifthe threads run right up to the very top, it is a good idea to chamfer :hem lightly and then run the proper size tap in and out of the hoLes. The chamfer prevents the :op thread from being pulled above the block surface. Blow out the holes with compressed air. WHEN USING AN AIR HOSE FOR CLEAN:\G, ALWAYS WEAR GOGGLES. SMALL PARTICLES CAN BE THROWN WITH GREAT ¡O RCE - B E C AR EF U L J
/
HA NDL EG A f f E T S WI T HCA RE \
Gaskets sh-óuld be stored flat, in their containers and in an area where they will not be bent or struck with some objeet. Storage space should not be subjected to extremes of temperature or humidity. Handle gaskets earefully. Do not attempt to force them to fit. If a gasket is accidentally cracked or torn - throw it away.
EACHGASKETSHOULDB'ECHECKED Carefully inspect the gasket itself for dents, dirt, cracks or folds. A minor crease in a cork
63
Auto Service ond Repoir
B RASS HAMM ER
not all are highly resistant to oil, water, gas, grease, antifreeze, mild acid and salt solutions. Resistance to heat and cold vary, butingeneral, most sealers are adequate in this respect for all uses other than exhaust applications. The mechanic should be thoroughly familiar w i th seal ers and thei r properti es anduses. The chart, Fi g. 4-11, l i sts vari ous s ealant s, pr oper ties and recommended uses for one line of products. Sealant manufacturers will be happy to provide the mechanic with specific recommendations for using their products. The use of too much sealer is generally worse than using none at all. Excess sealer is squeezed out of the joint and canclogwater, gas and oil passages. A THIN coat is ample. On some oil pan gaskets with corners difficult to seal, a small dab where the gaskets meet is permissible. In general, a nonhardening, flexible sealer will produce the desired results. Some parts with extremely small holes or ports, such as carburetors, automatic transmi ssi on val ve. bodi es, etc., can be r ender ed useless if ANY sealant is squeezed into the openings. In cases such as this, do not use a sealant.
t
É
i F
trl
s; ,
s:
F i g . 4 - 1 0 A. M o kin g o g o ske r . 7 [e lo u r corne¡ screw s [o/d ráe g o s k e l m o te r io l in p lo ce wh ile to p p in g . A bol l peen hommeri s u se d lo r th e fio /e s.
USE OF SEALANTS
il
* ',r ¡ :il i - lr i l1:' :. ,r'ii 'l
A new gas k et , pr oper ly inst a l l e d . b e t w e e n accurate qating surfaces will usually produce a leakproof joint. However, mating surfaces are not always true, present corners problems, torque loss can reduce pressure on the gasket surface, gaskets often shrink slightlyand minute part shifting can break the sea1. For these re ason s it is gener ally c ons ider ed g o o d p r a c t i c e to use a sealant on MOST gaskets. The addition of a sealant helps hold the gaskets in place during assembly and small cracks, indentations and cornervoids are sealed. In short, the use of a good sealant provides additional assurance that the ioint will be leakproof. REMEMBER: A small amount of oil seepage will, due to engine heat, spread over a large area. This produces a messy looking job and is certain to deposit oil dribbLes onthe customer'rs garage floor for - hardly a good advertisement any shop.
I-n-aqy specific
&6 manufacturerr
application, be sure to follow s rec ommendations.
US I NGRUB B E RG A S K E T S Rubber gaskets are highly resilíent andwill, in most cases, do a good job of sealing without the addition of a sealer. In fact, rúbber gaskets tend to extrude (squeeze out) under pressure when a sealer is used. Unless a sealant is specifically recommended, gasket a rubber should be installed without a sealer.
HO L DT NG G A S K E TDURT NG A{SEMBLY Where a sealant is used, the gasket will usually stay in place during assembly. If seal?nt is not being used and the gasket tends to gasket can be held in place {ip, lhe with a thin\óat of grease. On rubber gaskets use grease or sealant only at a few small spots. Some parts, such as oil pans, eanbedifficutt to assemble without disturbing gasket position. In some cases, in addition to using a sealant, it is advisable totiethe gasketwiththin soft string. The parts may be tightened with the string ir place. Patented gasket holders are also avail. able and work well.
SEALA NT Gasket sealer or sealant, is a liquid or semiliquid material that is sprayed, brushed or spread on the gasket surface. Various t¡4pes, having different properties, are available. Some set up hard and others remain pliable. Most, but
64
I
l
J
Gqskets, Seolqnts,Seqls
I
iaxcE tfl?. (DCOTEE3 F.) AXD PNODUCT FORI{'ASTETC llo. I I¡1. Spc. Typ. I r|rL.S45l80 (Ord.)
TY'E OF AP"L!C^llo0a Spraada¡
c.p.
or 3Dfuh mch¡nical 3Dnadar.
FORT{'ASIGÍO La2
Spraadar
U¡|. SpG fyp. ll rrL.s45l80 (ord.)
mÉhrnic!l rpra¡dar.
AYIATION FOiL{4 llc 3
SrETc
c.p. spltula or Bru3h or Gun
rnÉ33utc t ltcE
n€st3T3
-65 to ¡l0o 5O0Op¡¡
a3sambl¡ca, c Pcrmanant un' p!¡. 3¡¡lrts, tiltint¡, con' tñnad avcn sull¡c6, battcr¡6. n.ct¡oñs, crlckad
lvai.r, ¡t.rm, k.ro¡!n., 3raolin., o¡1, troas, m¡ld ac¡d, .lkal¡ and sall solut¡on¡, ant¡.lrcza m¡x' aliDhat¡c hydcrrbon¡. tun3.
F¡3t
/lo0 -65 to 5OOOe¡¡
fa¡¡¡lmbly Slmi!f,manant wo.l. Cwat Dttta3, thro.dad c6nCCl¡On3. tnd hG!
W l tar , ¡ i ar m , k .r o¡ ana, ¡ a¡ ol ¡ na, ol l , troa¡!. mild &id, rllal¡ and ¡alt solut¡on¡. m¡¡hydrocarüon3, antl-fr..¡. turc3. -l¡phrt¡c
Slow
Wrtar, rt.am, ktro3.n., 3a3olinc, o¡1, mild ¡cid, rlklli and srlt slut¡on3, !rau, m¡¡rntl.lruzt hydre.rbon¡, tunr. -lioh.t¡c
Slry
G¡elina, l.roaana. arar3at. o¡13, w.tar, ant¡.lm:a m¡¡tura¡.
Slow
-65 to 4OO 50(xlp3i
Sarllni ot clos! titt¡na Patt¡. oñ ¡rt!3u1.? E!3/lo.¡pply
¡l¡1. Spc. Typ! lll (Ord.) HlL.S45l8{,
GAISIGÍ CETENT
Brush
DRYS 3Ef3 soLYElfl
USES
-65 to 35o V¡ri¡bl.
3c¡l¡ ¡urtac! La33 ¡r..lula. wo.k Gan!.tl ¡n a3$mbly wor¡. rs3añbly
H!rd Alcohol
Fl!¡¡blr Alcohol
Fl.x¡bl. Alcohol
Hard Alcohol
IIDIAN HEAD e^srEf sHELI¡c
Bru3h
A¡I Pi'RPIOSE CEIEI{f
Tuba
- 65 to 35O V.ri.bl.
wo.l and t3iGmbly Grnc.al talt ol P!P.r, on t!¡kat3 .ubbcr ¡nd mtt¡|. c..dbo¡rd.
Gasl¡na, k.rcsna, 3r.at.¡, ani¡.trcza m¡¡turet.
Gl ¡ i ¡ to ¡ l a3r . a!¡ ¡ 3 to m c tal , Sl !a3 to r ubbar .
hta.,
o¡la, w!t!r,
Slow Hrrd A|cohbl
-40 to 225
pol¡¡h.t
and claan.6.
Fa¡t H¡rd Toluan.
JOINf GOIPIOUND 'IPE l.o 5r
SIJPER'3OU FIORTd{ASIGTO
STICK.NSEALO
BrushablC, v¡scous liqu¡d
Irush or Gun
Brush or Gun
-65 to ¡too 50OOp3i - 65 to ,125 5OOOp3i
-¿tO to 20O as an !dhca¡v! io 40Oo .i ¡ saalant
Hot ¡nd cold watar, ¡t.¡m, ¡llum¡ñ.t¡n8 ta¡, tual o¡13, tc.otcnr, lubr¡crt¡n¡ oil¡, óc tr ol c un bt¡ . hy dr aul i c l l u¡ d¡ , !nt¡ ' fr r az a m ¡ ¡ tu." 3.
Sld
work on h¡
o¡l¡ tnd lubr¡ctnt3. ict turl3' H¡¿ct.EGnt loota, m¡ld 3¡lt o¡lr, glycol¡ hG.t tr.ñslat hydrc' ¡lGam, ¡l¡ph¡l¡c wttcr, ¡orut¡on¡, ani¡'trcaza carbon¡. d¡G3tGi lubr¡cant¡, m¡xturG¡, patrolaum ba¡a hydtrulic lluid3' .vi.t'io€-tuCl¡.
Slow
rubba. to rubbar, rubS..l hysllin8 bcr to mrt.l, ¡nd t.an3m¡43¡on dr¡ulic o¡lr. corl to ñat¡1.
G.soliña. tr.asG, bonr. ant¡ircc:G holr.
llrnSc¡. litt¡n¡¡. Thrcadcd Crn br appl¡cd ov!? oil rnd 8.ca3a t¡lm.
hydrc.r' o¡13, sl¡ph.t¡c llcc mixtur?¡. Glycol¡,
V.r¡ablC
St¡ff Brush or Spetulr
- 60 to IOOO
c¡bla Thrqadsd cmn6tion3, nuts manifold¡, lubr¡c.t¡on, rñd bolt!, 3liding mctal 3urd¡3whrr3 facc¡ rspéially P.a. mcct. s¡m¡l¡. mGtals and $izuta. vant¡ a¡llin¡ 3t"31. Erc.ll.nt on st.inla$
43.ñt¡' d.r¡8n.d Ptiñ.ril, W.t.r, ¡te.m. cómPound, ¡n¿ anti€orroa¡on ¡¡oc¡ág
sfAr¡NT t2E2
Sp.tula or mGch¿n¡cal ggrcadar.
- 50 to eoo p¡¡ 5()OO
l¡n"s (.ot c..tyin3 C@llnt w.ta¡) a¡r cond¡tionc.3, trcczcrS.
IOO*, chlor¡nated EitGrs, glycols -hydro' tt@n, sulphur diox¡dc, áii¡oá¡.-a;,mmon¡¡, nonll.m' rcl.¡g?r.nt5. ¡ndu3!.ia¡ ¡¡cohol. hydro' fluidr, arom.iic hvd..ulic m.bl. -kctonc, ph6phata ast!r5. c¡¡bons.
Seolont cñort.
{#; -GUIDE
Fl.¡lbh A|coñol
fr3t Flc¡¡blc Mcthyl Ethyl K.tonc lnd Toulana
arfir-sEtzE oorFoultD rrL-T.5544A (ASG)
Fig. 4-Il.
Fl.¡¡bl. Alcohol
Flcx¡blt Kcro¡anc tnd l¡sht lsbr¡cat¡n8 o¡l Slow H.rd Watcr
(Permatex)
Make certain the gasket is correctly installed and that it remains in alignment during assb.fnbly. S ee Fi g. 4-12. a. \,
PIN
USEPROPERsEO-UENCE WRENCH ANDTOROUE
After running all fasteners up snug, tighten them in the proper sequence as recommended in the chapter on fasteners. Firsttightentoonethird torque, second to two-thirds torque, third to full torque. Improper sequence and torque, in addition
Fóg.1-12. Holding goskel in ploce. It ii importont tfiof gcskets be held in olignmen! during ossembly.
In other iñstances, such as cylinder head :qstal.lation, guide pins are used to hold the gasket in alignment.
65
r
AutoServiceond Repair to snapping fasteners and parts, producing distortion, etc., will very likely cause the gasket to fail to seaI. Excessive torque ean place the gasket under too much pressure and cause ittoextrude badly. Fig. 4-13 shows the results of improper tightening procedures as related to gasket sealing.
RE ME MB E R T HE S ES T E P SI N P R O P E R G A S K E TI NS T A L L A T I O N 1. Clean parts, fasteners and threaded holes. 2. Remove any burrs, bent edges or excessive warpage and check for dents, scratches, ete. 3. Select a new gasket of the correct size and fype. 4. Check the gasket for fit. 5. Where sealant is used, spread a THIN coat of the correct sealant on one side of the gasket. Place the gasket withthecoatedside against the part. Spread a THIN coat on the uncoated side. Do not slop sealantintoparts. Wipe off excess. 6. If alignment difficulty is anticipated during assembly, secure the gasket by additionat means. 7. Carefully place mating part in place. 8. Coat threads of fasteners with anti-sieze (unless prohibited), instal.l intheir PROPER location and run up snug. 9. Torque fasteners in proper seouence. 10. If necessary, retorque after a specified length of time. (These instances will be covered in later ehapters.)
H ri
;1 H *F
TOO TIGHT.W AR PEDPAN
A NA L Y Z EG. A S K E TF A I L URE F i g . 4 - 1 3 , Ove r tig h te n in gwíll co u se d o m a ge, A -P roper l ostener fension. B-Excessive tightening hos split cork pon gos/
When a gasket fails in service, there has to be a reason for the failure. If you do not detect the reason, your own installation mightfail a1so. The following simple steps will hetp you find the underlying cause of the failure: 1. Ask the owner about any unusual conditions. Try to determine if the gasket failed suddenly or over a period of time. 2. Before tear-down, cheek fastenertorque with a torque wrench. You can loosen each one and notice the reading at break-away. This will be somewhat less than true torque. Another method is to carefully mark the position of the head of the screw or nut in relationship to the part (use a sharp scribe). Backthe nut off about one-quarter turn and carefully retighten untj.'Ltlle scryibed lines are exactly in alignment.llf properly, this will give you /one a fair indlCation of torque at the time of failure. If the torque is significantly below that specified, this eould well be the cause of fail.ure. If torque varies from fastener to fastener, this too could be the cause. ALWAYS ALLOW AN ENGINE TO COOL BEFORE REMOVAL OF A CYLINDER HEAD.
STAMP E D P A RTSRE OUIRE E XT RACA RE Relatively thin stamped parts such as rocker arm covers, oil pans, some timing covers¡ etc., if bent along the engagingedge, mustbe straightened before installation, Place the part edge on a smooth, solid metal surface and gently tap to straighten the bent seetions. When installing do not overtighten as the parts will be bent again, F ig. 4 -1 4 .
Fig. 4-14. Stroighten warped Ílange. llorped edges couse leoks. Stroigfrten them belore instollotion.
66
Goskets, Seolonts,Seols
(A cylinder head can be warped to the point of ruin by removing it when too hot.) 3. Following tear-down, carefully blot off any grease, oil, dirt, carbon, etc., from the gasket. Do not rub or wash the gasket immediately, as this may remove tell-tale signs. Inspect the gasket for signs of uneven pressure, burning, corrosion, cracks, voids, etc., that could have caused the failure. Check to determine if the gasket is of the correctmaterial and type for the job. 4. Inspect the mating parts for warpage, burrs, etc. ALWAYS TRY Tp FIND THE CAUSE OF GASKET FAILURE SO YOU MAY EFFECT A CORRECTION WHEN INSTALLING A NEW GASKET.
S E A LIN GE I.E ME N T
"*"19
Fig. 4-15. Typicoloi/ seol consrrucrion.(Victor) In the rubber oil seal, the sealing element is bonded to the case. The element rubs against the shaft, the case holds it inplace and in alignm e n t a n d t h e g a r t e r s p r i n g f o r c e s t h e s e al l i p to conform to minor shaft run-out (wobble) while at the same time maintaining constant and cont r o l l e d p r e s s u r e o n t h e l i p . F i g . 4 - 1 5 , i l l u str a te s typical oil seal construetion.
R ETO R OUE Constant fastener tension and the expansion ard contraction of parts will tend to further :ompress a gasket. This willleavethe fasteners :elow proper torque, and in acritical application s:ch as a head gasket, can cause gasket failure :nlsss the fasteners are retorqued after aperiod ¡f time. Situations requiring retorque will be üscussed in later chapters.
V A RI O US DE S I G NS A RE US E D Many different element and lip shapes are p r o v i d e d . E a c h r e p r e s e n t s a n e n d e a v o r to p r o vide the best seal for a specific task. Fig. 4-16, shows several designs. Notice,-that m^ore than one lip can be used and that the foutsi de diilneter, or one edge, may be coated wr\h-lubber ro provide better OD (outside diameter) sealine.
OIL SEALS -{n oil seal can be used to confine fluids, prevent the entry of foreign materials, and ceparate two different fluids. -ln oil seal is secured to one part while the sealing lip allows the other part to rotate or (move). :eciprocate
SH OULD ER SEAL
Oil seals are used throughoutthemeehanical parts of the car. Engine, transmission, drive t'ne, differential, wheels, steering, brakes, aceessories, (use) seals in etc., all embody :heir construction.
G AR T ER SPR ING
I
O IL SEALCO NS TRUCTION A NDMA TE RI A L S IN N ER LIP
Seals are made up of three basic parts. A metal container or case, the sealing element and a small spiral spring called the GARTER spring. Sealing elements are usually made of synüetie rubber or leather. Synthetic rubber seals are displacing leathei in most applications. The r.rbber seal can be made to close tolerances, can be given special configurations (shapes) and specific wear and heat resistant properties can be imparted.
OU T E R
Fi g. 4-16. Oi / seol desi gns A .S i ngl e l i p. B -D oubl e Ii p w i th rubber sl roul de¡ seol , l nne¡ l i o contro/s oil ond outer lip keeps out dust, water, 'efc. C-Dou6le l i o. B ol h l i ps confro/ oi l . D -D oubl e Iip with ¡ubber outer cool to ossis, oulside diomefe- seoliag.
67
ilr
il
O I L S E A LRE MO V A L
t;
Seals may be removed by prying¡driving, or pulling, depending on the location. 7 Before removal, notice the deptfttowhiehthe seal was installed. As with . g."t inspectthe seal after removal for any signs "\ ofunusual wear o-r hardening. DO NOT REUSE SEALS, WHEN IINITS ARE DOWN FOR SERVICE, REPIJACE TH E S E A LS . S ee Fi g. 4_18.
F
t
S E A L I NS T A L L A T I O N I N N E RC ASE O l r . Oth e ¡ se o l t- yp e s.A_ M o in b e o r in g( r eor) seol madeol l:1. Both upper ond /o*e, /ro-l"es tit-into :-":i:t:;-¡v,i1rn,e. s,oo"." r n e o r o c k o n d co p . B- T yp ico l g r e o se se o / u s i ng 'n o Íert'seori ng 'É ¿¡ r i n g . C - S y nth e tic r u b b e r n o in b J.o r in g ,¡ ilJ. er O ri ngs (not shown) o¡e used ,, r¡.y'"^-",i^pt. ,ouíd ::;;::,,,"^,:1.".
OTHERTY P E SOF OIL A NDGRE AS E SEALS Engine rear main bearing oil seals are constructed in two halves, they may be rnade of graphite impregnated asbestos wicking or sJmthetic rubber. Some grease (not oil) sJals use a felt sealing element. Occasionally a combination will use an inner rubber seal and a felt outer s eal, F ig. 4 -1 2 .
After removing the old seal, carefully clean .. the seal recess or counterbore. Inspect for nicks or burrs. Compare the old seal with the new one to make certain you have the proper replacement. The OD must be the same. The ID (inside diameter) may be a trifle smaller in the new seal as it has notbeenspread and worn. The width can vary a titile.
CO A TWI T HNO NHA RDE NI NG SEALER Coat the inside of the seal counte?\ore with a THIN coat of nonhardening sealer. If there is too much sealer, the seal may/dcrape it off as enlerS, eausing the surplus (to arlp down on il the shaft and sealing lip. Thiñan áuse seal fai l ure, Fi g. 4-19. H OU SIN G
SLID E H AM M ER PULLER
>
SEAL DRIVER
H EAVY C OAT OF SEALER
E xcE sssE A LER B
Fi g.4-19,. A ppl y seal er spori ngl y! A -S eo/ counre r[o¡e ¡os 6een given o.heovy coo! of seo/er. lihen ¡he into the cou,nterb,ore, ";l;;-'ei;", B, fáe excess seoler will t. ¡or..¿ oito the shol¡ cnd seol l i ps. l n addi ti on to rui n.i ng ""i fáe,seo/, i i ¡" c l og s ome opening in the mechonism. "."U F i g , 4 - 1 8 , S e o/ r e r n o vo /. A- SIid e h o m m e r p u lle r jow s ore pus/red t h r o u g h t h e s e o l o n d th e n e xp o n d e d .Op e r o tin g siide homner will pull seol out. B-A sea! driver con ohen 6e used. C-Mony seols con be "popped out" wirh o smoll pinch hor. Wfien o seo/ musf be removed, while o sfioft is present, a hollow th¡eaded cone ís th¡caded into fhe seol. 7[e cone, ofioched to o s/ide hommer, will wi¡ h d ¡ o w fle se o /.
DRI V I NGT HES E A LWI T H NOS HA F TP RE S E NT Afte¡ preparing the seal counterbore, place .. against rhe opening WTTH THE 1T.:"1:Ouarely SEAL LIP FACING INWARD ON TOIVEND THE
ó8
Gcskets, Seolants,Seols
AREA IN WHICH THE FLUID IS BEING CONFIIIED. If the lip faces the other way it will probably leak, Fig. 4-20.
sure the ends are square. If a hammer i7used to start the seal, followed up with a drift,funch. Be very careful to strike at differen\ spots (near the outer edge) each time. If the seál begins to tip, strike the high side. REMEMBER: A SEAL IS EASILY DAMAGED THROUGII IMPROPER INSTALLATION - BE CAREFUL:
2
!t
DRI V ES E A LT O P RO P E RDE P T H If a locating shoulder is used, drive the seal snugly against it. This is espeeially important if the seal inner edge has a rubber sealing compound designed to flatten against the shoulder. See B, Fig. 4-16. When no shoulder is used, keep the seal square and stop at the specifi.ed depth. If you dri ve i t i n toofar,youmayrui ni t w hi l e att em pt ing to pull it back.
WHE NS E A LL I P MUS TS L I DEO V E R S HA F TDURI NGI NS T A L L A T I O N
Fig. 4-20, Seol lip musl foce Íluid! Seol ín A hos 6een ínstolled ,hoctwords. Lip foces owoy lrom Íluid cousing Íluid I to force seol Lip hon shoh, cousing leokoge, Seol in I is correcfly installed with lip Íocing lluid. Pressure ot 2 Ío¡ces seol ogoinsf shoÍt, preventing o leok.
\ When driving a seal that must slip oüer a shaft, use care to see that the seafñ$lip is not nicked or abraded. \ If a plain shaft (no keyway, splineb-or holes) is involved, check the shaft carefull.y for burrs, nicks, etc. If any are found remove them by polishing (shoe shine motion) with CROCUS cloth (a very fine abrasive). Examine the shaft surface where the sealing lips will operate. It must be smooth at this point. If the end of the shaft is chamfered (beveled), polish the chamfered area and if the chamfer is too steep (30 aeg. about maximum) either reduce it or use a mounting bullet or thimble. See Fi g. 4-23. Once the shaft is chamfered and free of scratches, etc., wipe it CLEAN and apply afilm of oil to the full length. Place a small amóunt of oil or soft grease on the seal lip and inner face. With the seal lip facing toward the fluid to be eonfined (counterbore with a thin coat ofsealer) carefully slip the sealing lips over the chamfer onto the shaft. Slide the sealalongthe shaft until it engages the counterbore. Using a suitable driver, seat the seal, Fig. 4-22.
USESUITAB LEDR¡V E R The driver should be just a little smaller fabout .020) than the seal OD when the seal will be driven below the surface. If the seal is to be driven flush (even with surface), the driver can be somewhat wider. In any case, the driver should eontact the seal near the outer edge only. SEVER STRIKE THE INNER PORTION OF A SEAL. This might bend the flange inward and d!stort the sealing el.ement, Fig. 4-21. If a seal driving setis not available, a section d pipe of the correct diameter canbe used. Make
MO UNT I NG SLEEVES A NDB UL L E T S When driving a seal that must first slide over a keyway, drilled hole or splines, start on shaft with a square end, etc., a mounting sleeve or bullet should ALWAYS be used. This will pre-
Fig.4-21, Donoged seol..Seol cose 6odly dislorted 6y coreless iastollation. Punch struck cose ot A. AII drivíng Íorce should be opplied ot B. This seol would leok bodly.
69
F'
vent damage to the seal lip. Fig. 4-23, illusfrates the proper setup. The OD of themounting sleeve should not be much over tlZZ in. larger than the shaft or the seal lips will be spread excessivelY. C O U N T ER BO R E SEAL DRIVER LIP FACES IN
BGULLET LLE T MOU M OU NNTTIN IN GBU S TOC O C KK S HIM SH IMST
Fi g. 4-24, S fi i m stock movnti ngsl eeve. l -S leev e l ormed ond s ol ' deied. 2-Edge sonded smootñ. 3-Sleeve ins¡olled ond leoding edge crimped. All edges musf 6e smooffi'
F i g . 4 - 2 2. !n sto llin g o se o l o ve r o p lo in sh a lt' Ihe seol w i l l sl orf shoit end withoul damoge.Sfioft must 6e smoofh, o"ir.ho^ler.d cle o n o n d o ile d '
3. 4. 5. 6.
GROOVESAN D SPLINE
SHAF
?.
with CROCUS cloth. Pay particular attention to the area where the seal lfp¡'{X operate. Check the new seal for correct )size andtype' Lube the sealing element anQ;;Zraft. If needed, install mounting tool on shaft. Push seal, LIP EDGE TOWARD FLUID, up to counterbore. Using a suitable driver, seattheseal,making certain it is inthe proper depth, andis square with the bore.
IMP OR TA N T The seal must be a drive fit in the counterbore. A seal that slides in easily will leak. When the housing has air vents to relieve pressure build up, make sure they are open. If clogged, pressure within the housing will force the lubricant past the best of seals. If the shaft is installed after the seal, observe the same precautions against seal damage. Cleanliness here, as in all automotive ser-
F i g . 4 - 2 3 . ln sto llin g se o / u sin g m o u n tin g.b ul l et' B ul l .etor sl eeve 'is'ploced or., shoil ond seol con lhen 6e insrolled without lip domoge bY sPline edges'
In the one
may
event be
no mounting
quickly
made
tools by
ar:e available,
using
shirn
stock
(thin brass sheets in various thicknesses);' Wrap the stock tightly around the shaft (one wrap with a small lap) and trim off. Tin the lap with a soldering iron. File the lapped edge after soldering and then smooth/with abrasive cloth. Bend the leading edge inward and it is ready to use, Fig. 4-24. ,..-'
vice, is important. If a new seal is improperly installed and must be removed - throw it away; and use another new seal. Further specific instructions regarding gaskets, sealants and seals willbe giveninchapters to which they aPPIY.
THE S ES TE P SIN R EME MB E R SEA LINS TA LLA T¡ON
SUMMARY
1. Clean seal counterbo?e, remove nicks,burrs, etc., and coat with a VERY THIN layer of nonhardening sealer. 2. Inspect shaft, polish burrs, scratches, etc',
Gaskets and seals are used throughout the car. Their selection, preparation and installation can be of critical importance.
79
Goskets, Seolonts,Seols
Gaskets provide leakproof joints. They are :nade of paper, cork, rubber, asbestos, steel, copper, etc. Different materials or combinations of materials are needed for specific applications. Gaskets are of single layer and multiplelavs¡ so¡gtruction. Many use steel or copper uter layers with asbestos center. The si.ngle laver, beaded steel head gasket is popular on -::gh compression engines. Gaskets may have =.Cditional material around the sealing edges to ::-crease unit loading at these points. Gaskets, once used, shouldbe di.searded. Be¡are of kinked multiple-layer gaskets. \tr/here sealant use is recommended, use sparingly. Sealants of many kinds are available :: both hardening and nonhardeningtypes. Select --::e proper type for the job at hand. \\¡hen a gasket has failed, try to determine xhy, so you can correct the condition. Oil seals are used to confine fluids, prevent ::e entry of foreign material and often, to separate two fluids. Seals are generally constructed in three !."rts - steel case, sealing element and garter s:ring. Some specialized seals use asbestos ;r:cking or sections of synthetic rubber. Seals use both leather and synthetic rubber seal-ing elements. Many different seal lip des:gns are used. \\hen installing seals, the shaft must be s-ooth, the counterbore lightly coated withnon,Lardening sealer, and the seal driven to the ::oper depth. The seal lip should face toward r:e fluid to be confined. Protect seal lip when :-stalling by chamfering or using special mount::g tools. A1ways use a suítable driver. Lubricate :eal and shaft before installing the seal. Cleanli:ess must be observed at all times.
had happened during service. Whatparteould the gaskets have playedinthistorque change? 5. Check this same car for oil, gas and water leaks. Do not overlookthe transmission, rear end and brake lines. Is the car free of leaks? If leaks are present, what could be the major cause ? 6. Inspect some used oil seals that have failed in service. What shape are they in? Whathad happened to them? Discount damage thatmay have incurred during removal.
5 0 WHA T ' SA L I T T L E L E A K You might ask why a chapter is devoted to such t'trifles" as gaskets and seals. It might seem that they are so simple that a passing mention would be enough. Surely they are not that important and if some part leaks a trifle, well - so what¡s a little leakj The facts are that proper gasket and seal selection and installations are actually VERY IMPORTANT. Every repair job is made up of a series of steps or operations - some large including the and some small. All operations little thi.ngs are very important. Leaks are not only messy and ereat{pogr relations, they cause part failure''ahd customer plus real damage to the expensive comebacks, reputation of both garage and mechanic. In fact, even a minor leak may cost someoners life! Letts take the case of mechanic 'lX" (unfortunately, there are too many mechanics of this to a brake job, this service type). Assigned technician had replaced the master cylinder and repai.red the front calirear wheel cylinders, inpers, turned the rear drums and frontdiscs, stalled new brake shoes and pads and replaced front wheel seals and rear axle seals. Upon comp.letion, the technician bled and adjusted the brakes, checked for fluid leaks and, after road testing, declaredthe job complete. The customer, a sales rep::esentative, took delivery. was Several weeks later, the representative road was dark. r.eturning home. The mountain in the glare of the Its wet surface shimmered headlights. Rounding a curve, a rock slide loomed out of the night. The representative didnotpanic. The carrs speed was not excessive and thoughit to stop. there was time would be touchy, Considering the slippery blacktop, the driver pres sed hard on the brake pedal, but not too hard. The The car began to slow, andthenithappened. left rear wheel grabbed, Iocked up tight, lost traction and sent the carintoaviolentslide.
SUGGESTED ACTIVIT¡ES
T
¿
Determine how many separate gaskets are :-rsed on a V-B engine. List the materials used in their construction. \Iake a gasket by placing the gasket material over the part and tapping_.,around the edges an d h ole s. Secure a head gasket that has BLOWN (failed). Examine it carefully and see if you can determine the cause. List some of the possible eauses of head gasket failure. (following \\-ith a torque wrench, specifications), go over the fasteners on an engine that has been in service for some time. Were :hey torqued to specifications ? If not, what
7l
l
i
r
r Auto Service qnd Repqir
l The driver released the brake pedal, cut the wheel, stopped the skid and reapplied the brakes. Another lockup, another terrifyi.ng skid, but now it was too late. The car struck the corner of the rock slide with a sickening thud, bounced high in an arcing skid and plunged off the highway. The driver was lucky and lived through the crash. Subsequent study by a safety investigator disclosed that mechanic t'Xt' had driven the left rear axle seal in so that it was cocked to one side. The axle lube had worked through and fouled the brake lining. Being a mechanic takes intelligence, trainitg, technical knowledge, skill and attention to details. If you ever hear someone sá¡r, "So whatrs a little 1eak,r' - ]IOU TELL THEM:
,j 1
ir
#l t¡ ;
El,h
In ¡. É:¡ . E f 't
r,,
OUIZ - Chopter4
t
1. Define the word GASKET. Give two important reasons for installing gaskets. 3. List seven materials that are usedingasket construction. 4. Name four factors that influence the service life of a gasket. 5. Gaskets are of either_layer or layer construction. 6. A gasket that must resist great heat will often use_in its constructj.on. 7. Define the term UNIT LOADING. 8. The beaded steel head gasket is used on 2
14. A sharp crease in a multiple-Iayer gasket, if it is straightened out, will not harm the gasket. True or False? 15. Of what value is a gasket sealer? 16. S eal ers are of the_or_rype. 1?. When applying sealer, always use a liberal amount. True or False ? 18. Sealer should ALWAYS BE USED. True or Fal se ? 19. N ame three w ays of hol di ngagasket inplace during part assembly. 20. What effect will improper torque and se_ quence have on the gasket sealing proper_ ti es ? 21. Bent mating surfaces on steel stampings should be before_. 22. List seven important steps in proper gasket installation. 23. Why should the mechanic try to determine the reason for gasket failure ? 24. The typical oil seal is madein--parrs. 25. These parts are the_ - ihc and the
26. Leather sealing elements are more widely used than synthetic rubber. True or False? 27. D raw a cross secti on of asi ng lelipoil seal. 28. All oil seal.s are of one piece constr{rgiion. '// True or False ? 29. Describe three methods ot ,.*o/ng an oil seal. 30. Place a small quantity of nonhardening sealer on the tips of each seal before in_ stalling. True or False ? 31. Oil seal lip should face the fluid to be con_ fined. True or False ? 32. Describe a suitable oil seal driver. 33. Nicks ánd scratches on a shaft should be removed by polishing with 34. How are seal lips protected when the seal must slide over a splined, keyed, or drilled shaft ? 35. Give seven important steps in proper seal installation. 36. Once a part has been torqued, the pressure wil.1 always remain constant. True or False ?
-engines. 9. What features in gasket construction provide higher localized unit toading? 10. If you plan a complete engine repair jobyou would order an_set. 11. Old gaskets generally can be reused with s uc c e s s . T ru e o r F a l s e ? L2. Always clean and check both _surfaces before installing a gasket. 13. A gasket that has shrunk can oftenbe brought bac k to s i z e b y _ i n _ .
72
{r
Chapfer5
TU BING A N DH O S E Tubing and hose are used in many parts of the car. Brake systems, fuel delivery, vacuum applic ati on s, air c onditioning, trans mi s si on fluid cooling, engine cooling, heating, power steering, lubrication, instrumentation, etc., all utilize either tubing or hose, and in some instances, both. Selecting, using and working with tubing is a part of most repair jobs. It is imperative that the mechanic be thoroughly familiar with the different types, their application and proper installation.
vacuum lines, lubrícation lines and for other low pressure applications. Copper is subject to work (the material hardening becoming hard and brittle from bending) and should therefore be protected from excessive vibration. NEVER USE COPPER TUBING FOR BRAKEORPOWER STEERING WORKJ
S T E E LT UB I NG When properly coated to prevent rust, steel tubing is suitable for almost all automotive applications. When used for high pressure sys_ tems such as brakes, the steel tubing should be of the double wrapped, brazed and tin_plated
TU BIN GM ATERIA L Annealed (soft) copper, half-hard copper, stee1, aluminum, plastic and stainless steel are some of the materials used inthe manufacturing of tubing. Although alt of these are found in the automotive field, the most commonly usedt¡pes are steel and copper. Copper is more easily bent than steel but is not as strong. Fig. b-1, shows the amount of pressure various kinds of 3/16 in. OD (outside diameter) tubing with a wall thickness of arouñd .020 in. will withstand. These are considered safe working pressures when a safety factor of five to one (material five times stronger than anticipated working pressure) is desired. After studying Fig. b-1, it becomes obvious that the mechanic must KNOW what material is used in the tubing he is working with. He must also have a fairly accurate knowledge of the pressures and temperature produced in the system on which the tubing will be used. Keep in mind that both the power steeringandbraking systems can develop pressure in excess of 1 0 0 0 p ounds .
MA TE RIAL
O.D
Pol y ethy l ene * N y l on 35 A l um i num 5250 A l um i num Anneol ed C opper H ol f- hor d C opper D oubl e W r op, Br oz ed Steel 'l0l 0 Sree I Anneol ed Stoi nl es s Steel 4130 Sr eel
l ,/4 tN . 3/l ó tN .
WA LL PRESSURE TH IC K N E S S LB S. .062 .023 .0t8 .0¡8 .020 .020 .020 .020 .020 .018
200 300 500 | ,00 0 t.000 2,000 2,000 2,000 3.000 5,000
' = AT 70 D EG. F .
Fig. 5-1. Pressurecáorf.Note lhe vo¡iotionin sofe wor/
P L A S T I CT UB I NG Polyethylene and nylon are two of the materials used in the construction ofplastic tubing. Soft plastic tubing has the advantage of flexibility, resistance to corrosion andworkhardening. It will not, however, stand high pressures\ and excess heat. It can be used for fuel, vaeuum I
C O PPERTUBING Copper tubing i.s rustproof, easy to bend and forms good joints. It can be used for gas lines,
73
Auto Serviceond Repoir and some lubrícation lines. Special inserrs are needed to attach the soft plastic to conventional tube fittings.
REAMER BLADE
HANDLINGTUBING When removing tubing from a roll, place the
ro ll on a c lean benc h inanupr ight pos it i o n . Hold the free end of the tube with one hand while ro_ tating the roll over the bench with the other. Never lay the roll fiat and pull the tubing upward as it will be t wis t ed, Fig. 5- 1A.
'CUTT|NG ROLLERS tVHEEL Fig. 5-3, Tube cutter.Note reomerblodein t/re closedposirion. (lnperiolMÍg, Co,) Although a fine-tooth hacksaw can be usedto cut tubing, a faster and better method is to use a tube cutter, Fig. 5-3. The cutter is placed around the tube, the cutter wheel is brought into firm contactandthe cutter is revolved around the tubing. After each complete revolution, the cutter wheel is tight_ ened. DO NOT OVERTIGHTEN,I Repeat this process until the tubing is cut off, Fig. b_4.
,/<\
Fig, 5-IA. Propernethodol removing tubínglromroll. Avoid working (bending) the tubingmorethan necessary. Store tubing where no heavy tools or parts are liable to cause dents. Keep the open end taped to prevent the entry of foreign material.
C U TTl N GTUB ING Tubing, especially when the ends are to be flared, must be cut off SQUA3,ELY. Any burrs, either on the outside or inside, mustbe "L-olrea, F ig. 5- 2.
Fis.s-4. ,,n^r.:":,
wheét A by turnins handte B.
REMOVEBURRS After cutting, you will probably notice a burred edge, especially on the inside. Remove the burr by using the reamer blade onthe cutter tool. Ream only long enough to removetheburr. Excessive reaming will ruin the end forflaring, B, Fig. 5-2. When reaming HOLD THE END OF THE TUBING DOWNWARD SO THAT THE CHIPS WILL FALL FREE. See Fig. b-b. CIT AM F ER
\.c u r
TUBINGCONNECTIONS
or¡
S QU AR ELY
There nections the PIPE. commonly
F i g . 5 - 2 . A - T u b in g cu t o t o n o n g le a n d h e o vily burred. B _C ír squorely b u t ¡ e o m e de xce ssive ly. C- Cu t sq u á r el y ond ¡eomed p r o p e r ly.
74
are three 'basic types of tube con_ the FLARE, the COMPRESSION, and All have variations in design and are use.d.
Tubing qnd Hose
F 'L AR ETYPECONNE CTION In the flare connection, the end of the tubi.ng :s spread (flared) outward at an ang1e. The tube :':tting securely grasps both sides of the flare :bus producing joint. a leakproof Fig. b-bA, :l-lustrates one type of flare connection.
Tw o (l ore onsl es. A -J.l .C . 37 deg. B -S A E 4 5 deg.
Fi s.5-6,
F L A T R E A MER
\
a r ' r , wr L L F AL L FR E E
Fig. 5-5, Removing bu¡¡s with c, reomer,
FITTINGBODY
F LARE Fig. 5-7. A-Sing/e-/op. B-Doob.le-lapÍlore. U N EVEN
C O C KED
d
\
r------1\
Li-l\ F LAR E SH O U LD ER
Fig . 5 - 5 4 . S A E 4 5 d e g , llo r e co n n e cfio n . No r ice fio w Íl ore is pinched 6etween (itting body ond nut.
\
There are two flare angles - B? and 4b you
determine
the
O .K .
-f,1 --..-¿ hjlJ L.--}.J
|,m C O N T AC T
FI.ARE ANGLES Cegrees. Be certain : eed ed , Fig . 5-6 .
SPLIT
F U LL C ON T AC T
F LAR E T O O LAR GE
one
Fi g.5-8. Fl ore must 6e sguore w i ¡h the tu6e cenfer l i ne , ond ol l he correcl si ze.
FLAR ETYPE
w eak
The flare may be SINGLE or DOUBLE-LAP :ype. WHEN FLARING DOUBLE-WRAPPED, BR..{ZED STEEL TUBING, ALWAYS USE A DOUBLE-LAP FLARE. This type of tubing, if a single-lap is used, will SpLITI See Fig. b_?.
and
uneven
fl ares.
These
will
LEAKI When a flare is made incorrecily, off and form a new one, Fig. 5-g.
al w ay s
cut it
F O RMI NG A DO UB L E -L A PF L A RE After cutting, reaming, and determining the proper flare angle, insert the tubing in a flaring tool. The tool shown in Fig. 5-g, wiII produce either a single or double-lap flare. Although you should always follow instructions provided by the manufacturer of the tool
FLAR EM U STBE A CCURA TE LY FORME D The flare must be smooth and square with :he centerline of the tubing. Careless cutting or :rrproper use of the flaring tool will produce
75
F EED SC R EWT IGH T EN EO
fS i l tt*
F0R cE D .
PTERS
"-/'
.{-3
Fi g. 5-l l . F i g . 5 - 9 . On e typ e o l llo r in g ¡ o o l. T h is ¡ o ol w i l l produce both sin g le o n d d o u b le - lo p llo r es.
B el l i ng tube end. Ti ghten cone feed s c rew (l ) un¡íl odopter sfri kes gri pper bl ock (2).
F IN IS H E DFL A R E
you are using, you will find that in general, the actual forming process is similar for all t1pes. Fig . 5 - 9 , a r r a n g e To us e t he t oolillus t r at edin the gripping blocks sothatthe correct size tubing hole is directly beneath the flaring cone. Rotate the adapter plate until the correct size adapter is beneath the cone. Shove the tubingthroughthe gripper blocks until it strikes the adapter. Tighten the block securely so the tubing cannot be pressure, downwar d under f lar ing forced
3->-
Fig .5-1 0.
CONE FEED SCREW
Fi g. 5-12. Fi ni shed fl ore. A daptersw ung osi de (2) ond c one fo¡c ed (I) i n¡o bel l ed end.
Turn the flaring cone back, swingthe adapter out of the way, and run the cone tightly down into the belled tubins. This willformthe finished fl are, Fi g.5-12. REMEMBER - ALWAYS SLIDE THE FITTING NUT ONTHE TUBINGBEFORE FLARING, Fi g.5-13.
GR IP PER B L OCK
CL E A NT UB I NG
SERRATIONS
I
Wtren all cutting, been accomplished,
I
reaming and flaring have air and use compressed
Fig. 5-10. lnserting tubing. Push rubing (l ) in until odopter strikes odopter plote (2). T¡ghten gripper blocks (3).
Run the flaring cone down until it forces the adapter against the gripping blcick. This causes the adapter to BELL the end of the tubing. This step in doing a double-lap flare, is the first
NUT
Fig .5-1 1.
Fig.
76
5-13. Slide nuf on tuhe be(ore Íloring.
Tubing ond Hose
blow out the line to remove any chips or other Place the tubing in a clean foreign material. spot until ready to install. If, duringinstallation, there is any chance of dirt or grease being jammed into the ends, cover the ends with masking tape. AMOUNT REMEMBER - THE SLIGHTEST RUIN THE MAY MATERIAL OF FOREIGN JOB - KEEP THE TUBING SPOTLESS:
BENDIN G TU BING steel tubing in the Soft copper and thin-wall used sizes can be bent by more commonly slipping a bending spring over the tubing then forming the bend with the hands. When using a make sure it is the correct bending spring, size. Bend the tubing a trifle more than needed. When it is bent back to the exact shape, the spr ing can the n be r eadily r em ov ed, Fig. 5 - 1 5 .
Fi g. 5-16. Tubi ng i nsertedi n mechoni calbender .
B EN DING SP RIN G
F i g.5- 17.
Fig. 5-15. Usingo springtubebender. Stiffer tubing may be handled with a levertype bender. This tool will make uniformbends. When appearance is important, it is often used on softer tubing also. Fig. 5-16, shows tubing marked inserted in the tool. Note that thetoolis in degrees to assist in controlling the amount of
N U T F U LLY R ELEASED
F IT T ING C O N NEC T EO
\
ben d, Fig. 5-1 6. In Fig . 5-1 ?, t he handles hav e been cl o s e d and the tubing bent. The mechanic has opened the handles, loosened the holding foot, and is removing the tubing. It is often advisable to bend tubing prior to However, if the bend must be close to flaring. the flare, make the flare first so the bend will with the flaring tool. To facilitate not interfere never start the bend too close to the assembly, flare. Allow about twice the length of the nut,
l * rw o
ST AR T BEND H E R E
_+ l N U rr-excrxs
Fi g. 5-18. A Il ow enough spoce befw een fi tti ng ond 6en d s o thof the nut w i l l s/i de 6oc/
F ig .5-1 8. TUBING, BENDING REMEMBER - WHEN AND KINKS TO AVOID CAREFUL BE VERY FLAT SPOTS: Once kinked or flattened, the flow and lead to trouble. restrict tubing will ALWAYS USE A SUITABLE BENDING DEVICEJ F ig.
Bend c om pl eted, hondl es open, l ubi ng beíng re mo v e d . ( l nper i ol Br os s M fg. C o.,)
ññ F LAT T EN ED
Fis. 5-18A.Whenbendi ng,
5- 1 BA.
77
ov oi d k i nk i ng or l l ol teni ng
o'K'
lubing.
Auto Service qnd RePqir
INSTALLINGTUBlNG
AVOIDSTRAIGHT RUNS
Tubing directions
Straight runs, especially if short, wiII not work well as the slightest shifting between the two units will impose a strain on the connections. They are also difficult to install or remove, Fi g. 5-19.
must- usually be bent ln one or more to provide a proper flt. In order to
S U P P OR T LON G R U N S Tubing can fail if subjected to excessive vibration. Secure long runs with clips or holddowns. Junction or distribution blocks and other heavy units must be supported, Fig. 5-20.
T UB I NGE NDSS HO UL D A L I G NWI T HF I T T I NG S To prevent cross-threading
(threads sta
and turned in a cocked position thus ruining threads) and leaks, as well as to facilitate inmake sure tubi.ng ends are Ín stallation, The tubing should NOT have with the fitting. be sprung into alignment. Fittings should sta
and run up several turns with finger pressu only. If they start hard, check for dam threads, alignment and size. DO NOT CROSSTHREAD THE FITTING. See Fig. 5-21.
DETOURAROUND HOTSPOTS Never run tubing too close to the exhau system. Keep it as far away as possible and a heat baffle or insulate necessary, instl[ tubing, Fíg. 5"22.
A S S E MB L B E O T HE NDSB E F O RE F I NA LT ¡G HT E NI NG
Fig.5-19. Avoidstroightruns - A, B, C, by instollingtubingas shownin A-l , B-l ond C-l.
Connect the tubing long leg end first. Lea the fitting loose so that the other end can' moved enough to make the connection.
insure satisfactory service, a- few important rules should be kept in mind prior to actual bending.
BOTH connections are made, tighten. Use dis-
M OU N T IN GBOLT
SHUT OFF C O C K
-
-
l,touH rtxccl te Y D IST R IEU T ION BLOC K
Fig. 5-20. Long tubing ¡uns ond reloted units musf 6e supporfed with mounting clips ond 6olrs.
78
Tubing qnd Hose
::etion
when tightening. If torque values are "".-ailable, use them. This chapter will give you instruetions i:neral on the amount of tightening -¡eda¡l
REMEMBER: MANY FITTINGS ARE EASY TO TWIST OFF - BE CAREFUL.SeeFie.S-23.
F
xur trrLL LIN EuP
F¡TTINGS Proper selection of fittings is important. The :orrect choice will speed up the job and insure :roper operation. Fittings are designed tomake ::ther a flared, compression, or pipe connection. The flare fitting just discussed can be of the Sin type, type, Fig. 5-25, or the INVERTED 5 -26 . -' -9.
Fig. 5-23.Assembletubinglongleg endlirst os in A. l( sho¡tend (irst, otherendwill be diÍlicul¡ to connec|,B. is ossemó/ed
W HENTO USEFLA REFITTINGS
Flared fittings MUST be lend itself to flaring. used on high pressure automotíve applications such as the brakes and power steering.
Flared fittings CAN be used on any type of ::'ring (copper, aluminum, steeI, etc.) that will
ASSEMBLINGFLARED FITTINGS Slide the nut, long or short dependingonuse, on the tubing. Flare the tubing making certain
TUBING
€
NUT
--CONNECTOR
ffire@
WRONG F i g . 5 -2 1 , Pr o p e r o lig n m e n !is im p o r t o n t , T h e n u t in A wo u ld c¡ o ss- th ¡ e o d .
:00 cLosE : U B I N GI SH O T
Fi g. 5-25. S A E 45 deg. (l are l i tti ng. The nut th¡eads over the l i ¡ting body. (lleotherheod Co.)
N U T ( SH OR T
a o tta t\
k)
ry r" @
EX HA U S TP IP E
il4
*'mrd---r| ñJm[r,L
llutttt{.,,1 lE¡¡¡tl{q:
Fi g. 5-26. Inverl ed 45 deg. f[are (i tti ng. The nut l hreods i nto fhe Íitting body.
Fig. 5-22. Protect tubing lrom heoting A by either instolling o heot bo # le B o r r e r o u tin g C.
79
tr 'I
ll
Auto Service ond Repoir
SLEEVE PINCHÉSTUBING
-A ffiAIil ffii{iil \-J
ilm||tt
ffirrl'r$si
(itting. NoficeÁowupon Fig.5-27. Seporote sleevecompression tightening,tfie sleevepincfiesthe tubing. Fig.5-28.
Double compression fitting. Vlhen tightened, tfie nose ol the nut is fo¡ced ogoinst ihe tubing.
the flare is of the correct angle and width. Double-flare aI1 brazed steel tubing, thin-wall tubing and all high-pressure applications. Align the tubing with the fitting. Shove the flare against the fitting seat and run the nut up finger tight. Using a flare nut wrench, bring the nut up solidly at which point you will feel a firm metal-to-metal contact (flare securely pinched between nut and fitting body). At this point, give the nut an additional 1 /6 turn.
tubing - one and three-quarter turn and for all si zes 3/8 to f-i n., tw o and one-qua r t er t ur ns. WHILE TIGHTENING, HOLD THE TUBING IN THE FITTING: The foregoing tightening procedure applies only to new compression fittings. When assembling USED fittings, bring the nut up firmlywith no additional ,turns.
FLARELESSCOMPRESSION TYPE FITTINGS
P LA S T¡C TU B IN G C OMP R E S S ION FI TTI NG S
A sleeve, either a separate unit or designed as part ofthe nut, is used in compression fittings. When the fitting and nut are drawn together, the sleeve is compressed against the tubing, fitting and nut. The separate sleeve-type compression fitting is pictured in Fig. 5-27. The DOUBLE COMPRESSION type, usingthe nose of the nut as the sleeve, is shown in F ig. 5- 28.
When RIGID plastic tubing is used, a regular separate sleeve compression fittingwill suffice. However, if the tubing is SOFT, a specialinsert is placed in the end so the sleeve will not crush the tube, Fi g. 5-29.
WHENTO USECOMPRESSION FITTINGS
i 1
lr
Compression fittings may be used on lowpressure applications sueh as vacuum, fuel and lubrication lines. Since no flaring is required, connections are quick and easy to make. DO NOT USE ON BRAKE AND POWER STEERING SYSTEMS.
Fig.5-29.
Fitting br soft plostic tubing. The inse¡f is needed to prevent sleeve from crushing tubing,
A S S EM B L IN G C O MP R E SS IO N F IT T ¡NGS
li
t
Slide the nut, followed by the sleeve, on the tubing. When the tubing is aligned with the fitting, insert the tubing as far asitwillgo. While holding the tubing in, run up the nut finger tight. Using a flare nut wrench, bring the nut up until the sleeve just grasps the tubing. For tubing size 1/8, 3/16 and tl4-ín., give the nutan additional one and one-quarter turn. For 5/16-in.
Fig. 5-30. Flexible compression fiffing. fñe composífion sleeve ollows heovy vibration without imposing on undue sfroin on lñe tubing.
ir I
Ii
80
Tubing ond Hose
OTHERSPECIA LIZE COMP D RE sS ION TY P E S
PIPE FITTINGS
One type of compression fitting, designed for resistance to extreme vibration, is shown in Fig. 5-3 0. I ns t ead of t he c onv ent ional m e t a l sle eve, a co mpos it ion s leev e m at er ial is u s e d . Note how the tube can flex without bending. This fittin g is for low - pr es s ur e us e. Th e Erme to is a c om pr es s ion t y pe f i t t i n g design ed to wi t hs t and high pr es s ur e. Heavy, difficult to flare tubing may be handled withthis desig n, Fig .5-3 1.
The pipe fitting uses a tapered thread that when fully tightened will produce leakproof joints. A d e v e l o p m e n t i n p i p e t h r e a d s , ca l l e d
Fi g, 5-33, C ompressi ontype uníon usi ng stondord l ength nut
F i g . 5 - 3 1 . E r m e to h ig h - p r e ssu r eco m p ¡ e ssio n Íitting. ( ln p e r io l Br o ss M lg . Co .)
Fi g. 5-34. C ompressi ontype uni on usi ng the l ong l ength nut.
the DRYSEAL PIPE THREAD, produces leak_ proof joints without undue turning force. Thisis accomplished by a difference in the truncation (cutoff point) of the thread root and crest. As the fitting is drawn together, the root (bottom) and crest (top) of the threads come in contact b e f o r e t h e f l a n k s ( s i d e s ) . F i n a l t i g h t e n i n g c a u se s metal-to-metal c o n t a c t b e t w e e n r o o t , c r e st a n d flank. Fig. 5-36, shows a secti.on of steel pipe joined to a hex NIPPLE by using a COUpLING. Note the tapered threads.
Another compression type fitting that wiiL han dle h igh p res s ur e is s hown in Fig. 5- 32 .
N UT L EN GTH Nuts for both flare and compression fittings are a va ilab le in bot h s t andar dandlongv er s ion s . Where the installation is subjected to heavy
(itting is designedfor highpressure. Fig. 5-32, fhis compression vibration, use the long nut. This will tend to support the tubing a greater distance from the act ual co nn ee tion . Fig. b- 33, illus t r at es a compression-type UNION using the standard nut. The long nut, on a similar union is used in F ig.5 -34 .
fI
Il t#l llililllullilil '"'t"'t= L+g=tilillltl= Fi g. 5-36. P i pe Íi tti ng. N ofe ropered th¡eods. (WeoráerheodC o.)
81
Auto Service qnd Repqir
rerñr¡r¡ \_/vv\_/
T-FITTIN GS This is a handy fitting to use where branch lines are necessary. The two common t¡pesare the BRANCH-T and the RUN-T. MaIe andfemale types are available, Fig. 5-41.
Fig. 5-37. Acluol OD lor pipe Íitting ends lor tuhing sizes ot sÁ-own
P IP E FITTIN GS Common pipe fittings are illustrated in Fig. 5-42. Note that all connections are threaded. No flare or compression sleeves are needed.
PIPET HRE A DS IZE Fig. 5-3?, shows the actual diameter pipe thread ends used on tubing fittings.
of the
ASSEMBLINGPIPE FITTINGS
;
.i
ii ,ii ii
il,
providing the firm hand tightening, After about three threads are clean, give the fitting additional turns. This wilL lock the threads and tightening beyond this point will be of no value and could even split the fitting. Thread sealing compound (a type compatible with the system) shouldbe used on critical applications. Use sparingly.
MW ffi lllHF--l+--'-t i----+-l--J w% W¿a MALE
MALE
lilHHhtf--i
We
FEM AL E
Fi g. 5-38. Typi cal connecfors.(C ompres s i onty pe.)
FITTING DESIGN There are a number of various shaped fittings The designed to handle all types ofinstallations. with the foll.owing should be familiar mechanie b asic d es í gns and t heir us e. S TR AIGH T
CONNECTORS Connectors are used to attach the tubing to a unit such as acarburetor, fuelPumP, oil filter, et c . T h e y c a n a l s o b e u s e d to c o n n e ctthe threaded end of a pipe to a flare or compression fitting, F ig. 5- 3 8 .
BULKHEAD
UNI O N S
cRoss
90 DEG.ELBOW
Fi g, 5-39. Typi col uni ons. (C ompres s i onty pe.,l
A union is designed to connect two or more sections of tubing. It can be disassembled without turning the tubing, Fig. 5-39.
ELBOWS When a line must leave the unit at an angle, male or female elbows are 90 or 4S-degree used. Female refers to a fitting with aninternal thread whereas the Male fitting has an external th rea d, Fig. 5- 40.
90 DEG. FEMALE
Ww 90 DEG. MALE
45 DEG. MALE
90 DEG. D OU BL E
Fig. 5-40. Typical elAows. (Compression type.)
82
Tubing qnd Hose
sIryIVELFITTINGS ,il ,ll
One end of this type fitting utilizes a swivel :r¡'1. These are available in straight connectors, €lbow s, tee s, etc., Fig. 5- 43.
trl i{ I
Fi g. 5-44. O R i ng connecto¡.N ofe strai ght (not pi pe) t/rreods .
O R ING F I T T I NG
,ri ;,í í E
S .A .E . O R IN G B OS S D E S IGN
The O ring fitting uses straight threads and rh::s depends on an O ring to prevent leaks. A s:raight O ring connector is shown in Fig.5-44. Ite elbow design, Fig. 5-45, makes it possible lto position the elbow at any angle. It is held at MALE BRANCH
ME TA L B A C K .U P WASHER
FEMALEBRANCH
IOC K N U T .O' R IN G BOSS
Fig.5-45. 90 deg. O ring odiustobleelbow. the selected angle and the lock nut tightened. This crushes the O ring and seals the fitting, Figs. 5-44 and 5-45.
J UNCT I O N O R DI S T RI B UT I OBNL O CK S FEMALERUN
MALE RUN
When several branch lines are served by a single feeder line, a DISTRIBUTION BLOCK can be used. A distributionblockis usuallvfitted with a mounting bracket, Fig. 5-46.
F i g . 5 - 4 1 . T - l i t t i n g s. ( Co m p r e ssio nr yp e .)
90 DEG. E LBOW
4 5 DEG . STREET ELBOW
45 DEG . ELBO W
90 DEG . STREET ELBO W
M OU N T IN GBR AC KET
gffiulwiltrrx C P LUG
TEE
HEX NI PPLE BUSHI NG
Fig, 5-42. Pipe littinss, Fi g. 5-46. Typi col di stri buti on bl ocks.
S HUT O F F A NDDRA I NCO CK S The SHUTOFF COCK is used to stop flow through a line. A DRAIN COCK is used to draw off the contents. When using thesefittings - always install so that when in the off position the
Fig. 5-43. Elbow wirh swivel nut.
83
i¡
il-
threadsfluid flow is against the seatandnotthe in radiator espeeially threads, prevents the This diffiand corroded becoming from cocks, drain cult to turn, Figs. 5-47, 5-47 A. EK RUBBER P LY
Fis. 5-484.Section of single ply, molded radioto¡ hose. (Gores R u66er C o.)
F ig .5 - 4 7 . Sh u ¡ o llo n d d ¡ o in cocks.
R U B B E R S TE E LW IR E
Fis. 5-488.Secrionof t,"i!,,:
ing) types. It often has a built-in spiral of wire to prevent collapse. The bottom radiator hose is particularly susceptible to collapse duetothe vacuum created by the water PumP. Figs. 5-48A, and 5-488, illustrate the typicamoulded and flexible radiator hose. Fig. 5-49, an enlarged cutaway, shows the fabric ply and spiral wire construction.
F i g . 5- 4 7 A. F lo w is o g o in st se o t' Bo th s hutol Í cocks o¡e ín the clo se d p o sítio n . ( Vle o th e ¡heodC o,)
HOSE of hose, both low and sections Numerous are used on the modern autohigh-pressure, They are generally identified by use, mobile. and pressure capacity, method of construction materials used. installed, will withstand viHose, properly bration and flexing (within limits). . The cooling, lubrication, fuel, vacuum, steer-. ing, brake, etc., systems a1l utilize some flexible meh ose in t heir des ign. I t is im por t a n t t h a t t h e chanic know what replacement types are needed and the correct
methods
hose.Noterñe 6ui/t-i¡ ::!,:;r.or
of installation.
S Y S TE MA NDHE A T E RHO S E CO OLING
STEELI{IRE
low so the hose are relatively Pressures used in both the cooling and heatlng systems is generally of a single or doubLe-plyconstruction. heavier hose is applieations, For heavy-duty
Fi g. 5-49. Typi col l l exi bte rodi otortrose c ons f¡uc l i on. fhe fo6¡rc pl y ond spi rol w i re o¡e mol ded befw een tw o l oy ers o( ¡ubber.
F UE LS Y S T E MHO S E
available. Radiator hose is available in straight (can be bent only a trifle), curved (moulded into the (designed to shape) and flexible appropriate without collapsbending withstand considerable
Fuel systems operate on low pressures so a single-ply synthetic (Neoprene, Buna N) hose is generally used. Some use is made of plastic
84
Tubing qnd Hose hose. When used on the vacuum side (between :':rel pump and tank) the hose must be heavy :nough to prevent collapse. NEVER USE HOSE THAT IS NOT SPECIFICALLY DESIGNED TO ,T,ITHSTANDGASOLINE,I See Fig. 5_b0.
'RYU NBTB HE ER TIC C OYER
SYNT HET IC RUBBERT UBE
L UB RI CA T I OHO N SE When used, oil fílter hoses can either be made up or procured ready made. The filter h o s e s s h o w n i n F i g . b - b 2 u t i l i z e a s y n th e ti c rubber hose covered with a soft wire braid for pressure strength. Fabric p1y lines are also used. The hose must be oil resistant, Fig. b_b2.
NO NRE I NF O RCE D SE HO Many of the smaller diametervacuum, wind_ shield washer, drain and overflow, etc., hoses are made of rubber with no reinforeing.
R AYONBRAID a ig , 5 - 5 0 . F u e l s y s t em /r o se co n sfr u ctio n .Ho se sid e wo lls o¡e ¡el _ o t i v e l y t h i c k fo p r e ve n t co //o p se u n d e ¡ vo cu u m . (Gores Ruó6er Co.)
H OS E E N D FITTIN GS There are numerous tJ,?es of end fittings. Fi g. 5-53, pi ctures a number of reusabl e ( can
P OWER STEERING A NDB RA K EHOS E T hes e s y s t em s c re a te p re s s u re s e x c e edi ng --0 0 pounds pe r s q u a re i n c h (p S I). T h e hose ':sed must be of multiple-ply construction. Re_ :-acement hoses are readily available. DO NOT :.:AKE UP HOSES FOR THESE SYSTEMS - USE :. E P UT A B LE F A C T OR Y R EP L AC EME NTS , l -e . 5- 51.
#
{@n
ffi^
ffi
ffm"ffi
ftqDñffigtudWffiSR lF=3¡F+s¡*'FA
a@il ffi
hC'ó@d
Fi g. 5-53. R euso6/e/roseends. t -90 deg. tube el bow . 2-Mo l e pi pe. 3^-l nve¡tedl l ore, ri si d. 4-l nverted l l orel S -45 ;.;.;;;. etbow . 6S w i vel . 7-90 deg. e/óow {l o¡e..g-37 aeg.l .t.C ., ,ísi j .-l _l O a "g..t_ bow llare, rigid. (yteo¡he¡heod Cá.)
be taken off and remounted o n n e w h o s e ) h o se fittings. Notice they include p i p e , 3 7 a n d 4 b - d e g . flare types.
FABRIC PLIES
Reusable fittings 5-55 are typical.
i. , 5 - 5 1. M u l t i p . l e . - p ly.h ig h - p r e ssuhroese . Ke e p in n in d thot pl y . k n e s s , m o t e r i o l a n d we o ve m u sf ó e co n sid e ¡ e d o s we // os the n u m b e ro l p l i e s i n d e te r m in in gth e wo r kin gp r e ssu r e .
shown i n F i g s .
/
5-54
and
GRIPPER SERRATIONS
S O CK E T
5 - 5 2 . O i l f i l r e ¡ á o se lin e s, No fe th e u se o l o n o u te r co ver o( soft woven wire to provide strenglh. ( Ed e ln o n n & Co .)
Fi g. 5-54, H i gl r-pressure¡euso6/e áose end consrrucfi on, N ore how ni ppl e fo¡ces hose i nl o gti pperse¡roti ons.
85
t
¡{ c
4. NUT F i g . 5 - 55 . L o w- p r e ssu r eh o se e n d co n st¡ u cti on. Tfi e spl i t s/eeve fo r ce s in sid e o f h o se o g o in st ni ppl e.
1. 2. 3.
HOSEEND INSTALLATION
4.
F ig . 5 -5 6 , d e ta i l A , s h o w s s i mpl e B arbtype. 1. Lubricate the hose and fitting. DO NOT USE A LUBRICANT THAT WILL ATTACK THE HOSE OR CONTAMINATE THE SYSTEM: 2. Shove hose eompletely over barbed end.
1.
2.
Hose is shoved against flat surface to seat insert fully. Nuts are pushed over insert, hose shoved over nipple and nuts tightened. Fi g. 5-56, detai l C . Air brake hose spring slid over hose. Hose pushed into socket. Nipple threaded into socket squeezing hose between nipple and socket. See Fig. 5-54. Spring snapped over socket shoulder. Fi g. 5-56, detai l D . Hose marked and skived (outer layer of rubber removed down to first layer of cord). BE CAREFUL NOT TO CUT CORD. Skived end shoved into socket.
,#w
w*
2
3
4 A
B
c
E
D
F ig .5 - 56. Generol methodol ol tochi ng vori ous type hose ends. (l nperi ol B ross Mfg' C o.)
?
3. Remove by cutting the hose. Fig . 5- 56, det ail B, illus t r at es a c o m p r e s s i o n fitting used for wire braid hose. 1. One end of the braid is necked down and the other flared. The nuts are installed. 2. The hose is installed over the nipple toadapt
Nipple and hose lubricated.
4. Nipple threaded into socket. Fig.
5-56, detail E.
1. Hose shoved into socket. (pilot Mandrel proper seating) 3. Nipple threaded 4. Mandrel seated 2
it to size, and is then removed. 3. Insert is placed over hose and under braid.
86
to expand hose and assist lubricated. in. and then removed.
1n
Tubing qnd Hose
RIGH
When assembling hose ends, always lubricate xith water, soap, oil, brake fluid, airconditioning compressor oil or some other agent that is given compatible with the system. Directions ior fittings in Fig. 5-56, are general. Always instruciollow the particular manufaeturerrs :ions. A skiving knife and mandrel set are shown :n Fig. 5-5 6,A'.
ÍFC--Eotr
@-.:rEb
]F
E
Ff
ñ
u* HÉ Éfi W U
K
ñ
A
4
ru U ,re hÉ q
F íg . 5 -5 6 A . lools
f]Fc
S ki v'i n g knile ond mondr el sef. These or e es s enfi ol for proper inslollolion ol certoin fype frose ends.
5
when instructions mentioned, call for a hose be careful not to cut the cord. A using a skived section is shown in Fig. The Skive only that portion necessary. portion should not extend out ofthe fitting.
F i g. 5- 58.
Inc or ¡ ec ! ond c or r ec t hos e i ns tol l oti ons ,
D ou 6 / e 6 e n d s
or e fo be ov oi ded.
that the radius of the bend sháuld be AT LEAST FIVE TIMES the outside diameter of the hose. F o r e x a m p l e : A h o s e w i t h a n O D o f 1 / 2 i n . sh o u l d i n . I n o t h e r w o r d s, have a bend radius of 2-ll2 i f t h e h o s e w e r e p u l l e d a r o u n d a c i r c le , th e cirele would be at least 5 in. in diameter. When making straight run connections, allow some slack to avoid stressing the hose from pressure, vibration or part shifting. hose fittings, tighten the When tightening one portion support swivel end last. Always
Avoid sharp or double bends and twisting as In de:his tends to cause premature failure. termining how sharp a hose bend may be, figure
( SKI VED) RUBBER REMOY ED LAYER
Hiil
ond tw i s ti na
HOSES MOUNTING
OUTERLAYER
) (
V
S KIVEDHO SE As skiving iitting i-57. skived
lll=
ñ :
with one wrench while tightening with another t o p r e v e n t t w i s t i n g t h e h o s e . U s e f l a r e w r e n ch e s. Fig. 5-58, illustrates s o m e t y p l c a l h o se i n stallations. Those in the left column are WRONG. The correct methods are shown inrightcolumn. Notice how single, smooth bends, without twÍsting are made, Fig. 5-58.
FABRI CP L I E S
F i g . 5 - 5 7 , P e r m o ne n(l n o ¡ r e u so b le )h o see n d . No te skivedsecti on.
87
Auto Service ond RePoir If the hose fitting has a raised rib, make sure the clamp is installed on the fitting side of the rib. This will prevent the hose from working loose, Fig. 5-59. methods of attachFig. 5-60 illustratesthree ing a hose. is experienced when attempting If difficulty to remove an old hose, split the portion of the hose over the fittings. In short runs it is helpful to split the ful1 length of the hose.
Keep hoses away from the exhaust system. If the hose run is long, use clips to secure it in plaee. On off-highway vehicles,"keep hoses and tubing well up within the frame to prevent snagging and shield from flying rocks, etc.
HOSECLAMPS such as hose installations In low-pressure the heater and radiator, the hose is merely slid over the fitting and a spring or screw-type clamp
HO S ECO NDI T I O N Any hose that shows signs ofcracking,undue softness, or swelling, should be replaced. Hoses often deteriorate inside causing portions to break loose, producing partial or evencomplete blockage. CHECK HOSES CAREFULLY AND IF AT ALL DOUBTFUL, REPLACE.I S TOR IN G H OS E S U P P LIE S Store hose in a cool spot. Avoid exposure to sunlight, fuel, lubricants and chemical compounds.
\ HOSECLAMP
Fig. 5-59.lnstoll hose clampón the(itting sideoÍ the roised¡ib'
S U MMA R Y Use a smatl amount of sealer to is installed. and to provide extraprotection ease installation against leaks. Locate the elamps so that they Tighten may be easily reached for tightening.
Copper, steel, aluminum andplastictubingis used in automotive work. Brake and steering systems MU S T use doubl e-w rappedbr azed st eel tubing. Handle tubing carefully.
securely.
F ig .5 - 6 0. H oses attoched by usi ng snop-fyP e spri ng cl omps, screw-type clomp ond borbed Íitting with no clomp'
88
Tubing ond Hose
Tubing should be cut with a tube cutter and bending should be done with either a spring or mechanical bender. Tubing ends must be square and all burrs removed. Connections are made with either flared, compression or pipe fittings. Flare fitti.ngs, 3Z and 45-degree, SAE and inverted, use a flare üat must be forrned with a flaring tool. DoubLellare all double-wrapped steel tubing. Doubleflare all high pressure applications. When installing tubing, avoid straight runs. Support long runs and related parts. Protect from heat. Assemble both ends loosely before final tightening. Compression fittings, sleeve and double compression t¡pes, are quick, easy andsuitable. lor fuel, lubrication, vacuum, etc., lines. When Cghtening, be sure to hold tubing all the way :¡r the fitting. Compression fittings on soft plastic *bing require a special insert. Both standard and long nuts are available. Pipe fittings use a tapered thread. Theyproduce a seal through metal-to-metal contact rhen tightened. Connectors, unions, elbows, tees, O-ring, Cistribution blocks, shutoff and drain cocks, are the commonly used fitting t)pes. They are available for either flared, compression or pipe connections. -{utomotive t¡pe hose uses rubber, Neoprene, Buna, and other synthetic compounds in its construction. Nonreinforced, single and multipleply'types are needed. Radiator hose is either straight, molded or flexible. FueI line hose must be resistant to Easoline and unless plastic is used, should have a reinforcing ply. Lubrication system hose nust be reinforced and oil resistant. Power steering and brake hose uses multipleFlv construction. Do not make up these hoses buy quality replacements. Vacuum wiper, over-flow, windshield washer, etc., applications often use plain, nonreiniorced hose. Hose end fittings canbe classed as permanent or reusable. Some hoses are attached with clamps. Barb type fittings, where used, provide sufficient holding power. Threaded hose fittings can be of the flare, compression or pipe t¡pe. When installing hoses, avoid double bends, twisting and sharp bends. Protect from heat, noving parts and road damage. Sllit old hoses for easy removal (barb and clamp types).
Both hose and tubing must be clean before installation. Where sealant or lubrication is used, it must be compatible with the- system involved. Support fittings with a wrench when tightening connections. Tighten swivel ends last. Use flare nut wrenches. Always testthe finished job for leaks or malfunctions. Protect stored tubing and hose from damage.
ii
li'
t¡ ir:
SUGGESTED ACTIVITIES 5
1. Cut off a piece of copper tubingusinga hacksaw. Cut another piece using a tubing cutter. Is there a difference in the appearance ? Which one made the best cut? 2. Ream and double-flare the end of a piece of brazed tubing. Follow the tool manufacturerrs instructions. 3. Try to mqke a tight 90 deg. bend in a piece of copper tubing with your hands. Did the tubing remain round ? Try it with both a spring and mechanical bender. 4. Carefully go over a car lookingfortubingand hose fittings. Make a complete list of the different ones - elbows, connectors, tees, etc. How many did you find? 5. Check the same car for different types of hose. List each hose, the system it serves, type, and method of attachment.
SIMPLE JOBS Flaring tubing is a simple job compared to reboring an engine. Measuring the diameter of a crankshaft is a breeze in relation to obtaining the proper mesh in a set of differential gears. Selecting the proper fastener - not very complicated. Picking the right tool - nothing to it. In that these, and many other jobs, are relatively simple, students often tend to overIook their significance and when studying a textbook or working in the shop, concentrate only on what they feel are the IMPORTANT jobs. The experienced mechanic, who each day performs many so-called simple jobs, witl be quick however, to inform you that despite being simple, they are very important and that many major service jobs have failed due to careless or improper handling of the simple steps. As regards the simple job, remember these FACTS: 1. They must be done. 2. They must be done CORRECTLY: 3. Somewhere along the line, you will have to LEARN HOW TO DO THEMJ
89
AutoServiceond Repoir flare and an INVERTED flare fitting? 24. Tubing bends should start at least_ of the fitting nut from the actual connection. 25. Brake line and power steering tubing shouÍd be 26. Name two t¡pes of eompression fitting. 27. Compression fittings are generally used where_pressures are encountered. 28. When using a sleeve compression fitting on soft plastic tubing, an_is necessary. 29. On a flare fitting, after bringing the nut up solidly, how much more of a turn of the w rench i s requi red? 30. On new compression fittings, how much should the wrench be turned afterthe sleeve grasps the tubing - for ll8 - | /4 in. for 5/16 i n. and for 3/B to 1 i n.? 31. After firm hand tightening, how many turns are necessary for pipe fittings ? 32. The _compression fitting WILL handle high pressure. 33. As opposed to the standard nut, the long nut provides better resistance to_. 34. Install drain cocks so that the confinedfluid rests against the_and not the_. 35. Pure rubber hose would make a fine fuel line connection. True or Fa1se? 36. Name three basic types of radiator hose. 37. Double bends will prolong the life of hose. True or False ? 38. Brake hoses are of_plyconstruction, 39. It is not necessary to secure long runs of hose. True or Fa1se ? 40. Barb type hose fittings use clamps. True or Fal se ? 41. What is meant by skiving a hose? 42. In determining how sharp a bend a hose shoul.d be subjected to, what handy rule would you use ? 43. If a hose Looks good on the outside, it will surely be good on the inside. True or False? 44. A small amount of _will make radiator hose i nstal l ati on easi er and willhelpt opr event seepage. 45. Describe three types of hose clamps. 46. Hose should be stored in a warm dry area. True or False ? When tightening hose or tube fittings, always ^n fitting body while tightening the -the nut. of the hose lást. 48. Tighten the_end 49. The word DRYSEAL refers to a special pipe thread sealer. True or False ?
Keep this in mind as you studythis and other texts. Read EVERYTHING carefully and consider EVERYTHING you read IMPORTANT. You will be glad you didl
OUIZ - ChoPter5 1, Tubing is widely used in automobiles. True or F a l s e ? 2. The two most commonly used tubing materials are-and-. 3. When removing tubing from a ró11, lay the roll flat on the bench and pull the free end upward. True or False? 4. The more tubing is worked, the softeritbec o m e s . T ru e o r F a l s e ? 5. Double-wrapped, tin-plated brazed steel tubing is suitable for brake line work. True False ? Plastic tubing cannot be used for any automotive work. True or False ? 7 . Aideal for cutting tubing. -is while doing After cuttrng, remove-and this, hold the tubing end-. 9. To make satisfactory connections, tubing must be cut_. at steel 1 0 .Always -double-wrapped tubing. n
il , ' , ri l8
t" ' | 'ir
tB iri. 1l ]!i -fri lt ' l t
[i ''
11. What are two flare angles? 12. What is the first forming step called when making a double-lap flare? 13. As long as the flare is the correct angle, it
1^
15. 16.
1?. I
lir !rl ,rl
18. 19.
:ii ii i "l
20.
i t,ll 21. 22. 23.
can be slightly Fals e ? The_should
cocked to one side. True
or
be placed on the tube be-
fore flaring. Tubing can best be bent by using either a a-bender. -or A few particles of dirt, metal, etc., as long as they are small, can be left in the tubing without harm. True or False ? Straight runs of tubing shouldbe made whenev e r p o s s i b l e . T ru e o r F a l s e ? When installing, connect the-legfirst. If you force fittings that start hard, youwill them. -thread When fittings are properlyaligned, theymay turns byhandbefore be given a w re n c h i s n e e d e d . When making long tubing runs, be certainto tubing. -the Always use tighten tubing _to fittings. W h a t i s th e b a s i c d i ffe re n c e betw eenanS A E
90
Tubing qnd Hose
50. Study the following drawing of a theoretical tube installation. All fittings are missing. Can you name the correct fitting for each c onnection ?
A list is provided. Some are needed, some are not. Write down the number of eachmissing fitting and directly opposite it write the name of the fitting you have chosen to use.
PIPE
(J"',, E
Mcle Run fee.
Femole Conneclor.
Femole Double 90 deg. Elbow.
Femole 45 deg. Elbow.
Un io n C ross.
45 deg. Street Elbow,
Femole Run fee.
Femole Broncfi Tee.
P i pe C oupl i ng.
Distri6urion Bloc/<.
Bulkheod Union.
Mole 90 deg. Elbow.
Mole 45 deg. Elbow.
Stroight Union.
Mole 8¡oncfi lee.
Mole Connecto¡.
Mole Double 90 de7. Elbow,
U ni on Tee.
tt*l
r--llr-l
'rll ll li l i l á ill il: -
\\@ \ Ai
UJ
[=l \#/ \I-L--l
A
% Nffi
W
Y)' q
F ig .5 - 6 1 . l.S.O. r yp e of l l are i s sñow n i n A . B and C depi ct vorious fiose litting mounting Ílange sáopes. (Chev¡olet)
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Auto Service ond Repoir
v i ew s ec fi ono/ Longi tudi nol overfieod camshoh 4-cylinder,
of F i ot engine.
Chapfer6
WIREAND WIRING
New wiring, properly installed, is relatively trouble free but as the car ages the wires tend to deteriorate from exposure to heat, oi1, gas, fumes, acid, vibration, etc. Vehicles damaged by collision or fire often require extensive rewiring. The auto mechanic shouldbecomefamiliar with types of wire, sizes, insulation, connections and general installation procedures.
S T RA NDI NG MA T E RI A L S oft copper i s w i del yusedforw i re stra nding. It is an excellent conductor, bends easily and solders readily. Aluminum also is employed to some extent. C opper, stai nl ess steel , car bon impregnated thread and elastomer type conductors are used for secondary wire stranding. The carbon impregnated thread and elastomer type (Duoprene G, for example) impart a control l ed resi stance (about 10,000 to 20,00 0 ohm s per foot) in the secondarycircuitto reduce radio interference. WHEN WORKING ON THE IGNITION SYSTEM, HANDLE RESISTANCE TYPE HIGH TENSION WIRES CAREFULLY. SHARP BENDING AND JERKING ARE APT TO SEPARATE THE CONDUCTOR, THUS RUINING THE WIRE. WHEN REMOVING OR INSTALLING SUCH LEADS, GRIP THE INSULATION BOOT NOT THE WIRE: Resistance t¡rye wires may be identified by such letters as IRS, TVRS, etc. Automotive wiring uses stranded (conductor made up of a number of small wires twisted together) conductor.
PRIMARY WIRE The primarywiring handlesbatteryvoltage 6, 12 a nd in som e c om m er c ialv ehic les , 24v olt s . It has sufficient insulation to prevent current loss at these voltages. All wiring circuits inthe car, with the exception of the ignition high tension circuit, use primary wire. NEVER USE PRIMARY WIRE FOR SPARK PLUG LEADS.
S EC ONDARY WIRE Secondary wire is used in the ignition system high tension circuit - coil to distributor, distributor to plugs. It has a heavy layer of insulation to afford protection against excessive (loss of electrons corona to the surrounding air) which could impart suffi.cient current into an adjacent wire to cause it to fire a plug. This action is known as cross-firing. Even with good insulation it i.s important to arrange spark plug leads so that leads to cylinders that fire consecutively are separated. Fig. 6-1, shows the relative difference in the amount of insulation on primary and secondary wires.
wlREstzE Each conductor size (do not count the thickness of the insulation) is assigned a number. The larger the number', the smaller the wire. The Ameriean or Brown and Sharpe wire gauge, i s t h e c o m m o n l y u s e d s t a n d a r d f o r w i r e si ze ; To find the gauge of a solid wire, simply measure it with a micrometer and locate this a n s w e r o r n e a r e s t o n e , o n a w i r e g a u g e ch a r t. Moving across to the wire gauge column, determine the correct wire gauge. To find the gauge óf a stranded conductor, count the number of strands. With a micrometer, measure the diameter of ONE strand. Square this answer and multiply by the number of strands. This will giveyouthecross s e cti o n a l
STRANDING
t
P RIMA RYWIRE
F i g . 6 - 1 . M o r e i n su lo tio n is r e g u ir e d o n se co n d o r ywi res.
93
Auto Service ond RePoir properties. Silieone secondarywire insulationis very heat resistant.
area of the conductor in CIRCULAR MILS. Locate this (or the nearest one) number on the chart. Directty across, under the wire gauge column, determine the gauge. Special steel gauges are also available for quickly checking wire gauge. Fig. 6-2, shows a portion of an AWG (American Wire Gauge) chart. A ME RICAN WIR E GAUGE
Wire end terminals (connecting device) are offered in a myriad of shapes and sizes. In general, primary terminals may be classified as spade, lug, flag, ro11, slide, blade, ring and bullet t¡pes. They may either be solderable or solderless. They are generallymade ofcopper often tinplated. See Fig. 6-3.
CRO55 sEC T IO N AL AR EA IN' CIRC U LAR M ILS
WIRE DIAMETER IN INCHES
2l l ó00 r ó7800 133100 I 05500 83ó90 66370 52640 41740
.4ó00 .40964 .3648 .32486 ,2893 .25763 .2 2 9 4 2 .20431 .l8 l9 4 ,16202 .12849 .1 0 1 8 9 .0 8 0 8 0 8 .0 ó 4 0 8 4 .0 5 0 8 2 .040303 .0 3 1 9 ó l .025347 .0 2 0 t .0 15 9 4 .012641 .0 10 0 2 5
0000 000 00 0 1 2 3 4 5 6 I l0 12 t4 ló I8 20 22 24 26 28 30
TERMINAL TYPES
Q? l
B A T T E RYCA B L ET E RMI NA L S cables (with factory new battery Although are generally used to reinstalled terminals) useless place a used cable with a corroded, it is occasionally desirable toreplace terminal, types A number of different only the terminal. Fig. 6-5. are available,
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262s0 0 I ó5',I I 0380 ó530 4107 2583 1624 1022 642.4 404.0 254.1 I 59.8 I 00.5
F i g . 6 - 2 . Am e ¡ ico nYlir e Go u g e Ch o ¡ ¡ - ( No t ol l si zes ore sfi ow n')
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Plastic of various kinds, is used for' automotive wire insulation. Rubber is sometimes used. Plastic is highly resistant to heat, cold, fumes, aging, etc. It strips (peels off) easily and offers excellent dietectric (non-condueting)
Fig. 6-5. Typicál battery cobles ond te¡minols. l-Solenoídfo storte¡ coble. 2-Bottery ground cable. 3'Engine ground strop' 4-Bottery fo solenoid coble. S-Closed bo¡rel terminol. 6'Open'split bor¡el l ermi nol ,7-C l osed bonel te¡mi nol ' N ore fl ot the ground coóles [ove no insulolion ond are of o woven conslrucfíon. Regulor insuloted batlery eoble is olso used lor ground cohles'
ffiffiffiMeW WWNWNNE
should be cables Terminals on battery SOLDERED ON. This will insure a good connection with no appreciable voltage drop (lowering of line voltage due toloose, dirty or corroded It will also protect aga,inst the connections). acid and fumes. The soldering battery of entry technique will be covered later in this chapter.
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T E RMI NA LB L O CK S F i g . 6 - 3 ' Co m n o n p r im o r y wir e te ¡ m in o l typ es. I-Mol e sl i de. 2Bitlet o¡ sndp-in. 3-Femole snop'on. 4-Butt connectot (must be crimped), 5-Tfi¡ee woy connector. 6-Female slide. 7-Bullet. 8F e m o l e slid e . 9 - L u g . tl- Rin g . ll- Ho o k. l 2-S pode, l 3-R ol l . l 4 - F lo g . l5 - F e n o le b u lle f co n n e cfo r . (B el den Míg. C o')
The terminal block is used to supplycurrent to several cireuits from one feeder source. The hot wire (wire connected to source of electric-
94
:'ly) is attached to one terminal. This terminal :s connected to all others by a bus bar (metal :1ate ), Fig . 6 -6.
IN S UL A T ING WA S H E R
BU5 BAR
HOLE FOR TERMINAL SCREVI
N ONC O N D U C T IVE BASE
TERM INALSCREYI
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Fi g. 6-8. Fuse ó/ock. Fuse ól ocks often contoi no numbero f fus es . S ee fuse bl ock i n Fi g.6-9.
FUSEBLOCK BUS BAR
The fuse block is similar to the junction block except that a fuse is inserted between the points. connecting This protects each circuit against electrical overloads, and groups anumber of fuses in one location, Figs. 6-8and 6-27. E A S EMA D E N ON CON DU CT IV E M A T ER IA L
WIRINGHARNESS In an automobile, various sections of wiring are made up in units withcommonwires (located in same area) either pulled through loom (soft woven insulation tube) or taped or tied together. This speeds installation, makes a neat package and provides proper securing with a greatlyred u c e d n u m b e r o f c l a m p s o r c l i p s . F i g . 6 - g sh o w s portion of typical wiring harness.
F ig. 6 - 6 , O n e t y p e o l te ¡ m in a l 6 /o c/< .No r ice h o w t/r e o n e hot w i re is ottocfred to fhe 6us bor lhus supplying cuilent to t/re other leods.
JUNCTION BLOCK Th e jun ctio n bloc k s er v es as a c om m onc o n nection point for a number of wires. It may be of the terminal screw or the plug-in type. Unlike the terminal block, the junction block merely connects one wire to a corresponding wire on the other side. There is no common bus bar, F ig.6-7 .
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COLORCODING A11 automotive wiring is color eoded (each circuit is given a specifie color or number of colors) to assist the mechanic intracing various circuits. Manufacturers publish wiring diagrams that show all wires and color or colors of each.
F i g . 6 - 7 . Ju n ctio n 6 lo c/< .( Scr e wr yp e .)
95
After aging or exposure to dirt and oil, some wires are difficult to identify by color. In this c a s e , t r a c e t h e w i r e b a c k t o w h e r e i t e n te r s th e harness. Then, cut away a small portion of the harness T h i s w i l l e xp o se a cl e a n covering. portion of the wire so the color may be readily determined.
WIRINGDIAGRAMS A wiring diagram is a drawing showing electrical units and the wires connecting them. Such a diagram is helpful when working on the
fig . 6 - 1 0 . Vlir in gd ia g r o m( o r sto r ler system. lG.M .C.)
F ¡ g , 6 - 1 0 A. Qve r o ll wir ing di ogrom for the l ¡ont hol { o{ ¡he cor. f.fol e use ol sym6ol s ond col o¡ coding, (lmericon llotors)
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wiring system. As mentioned, wiring diagrams are' available in various shop manuals and in some automotive reference type books. Use themi Fig. 6-10, shows a typicalwiringdiagram for a speeifie unit. The modern auto electrical system is becoming more complicated each break down the year. Many manufacturers diagrams, (Fig. into separate various circuits 6-10), as well as providing an overall diagram system. Fig. showing the entire electrical 6-10A shows an overall diagram for the front h a lf of t he aut o. S e e F i g s . 6 -1 0 a n d 6 -1 0 4 -
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There is a wide variation in the use of automotive electrical symbols. Some companiesuse their own drawings for sorne units and standard symbols for others. The units basic internal circuit is sometimes shown and in other diagrams, symbols are used for all units. Fig. 6-108, illustrates a number of typical symbols widely used in automotive electriial diagrams.
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Line voltage, electrical load and wire length are the three important factors in determining co rr ec t wir e ga u g e o r s i z e . Keep in mind the fact that as wire length INCREASES, resistance (with resultant voltage drop) INCREASES. Resistance causes the conductor to heat. Excessive resistance can heat it to the point where the insulation will melt and the wire burn. A s wir e s ize IN C R EA SE S, re s i s ta n c e D E CREASES. A simple rule then would be to state :hat to prevent high resistance andvoltage drop, rvire size must be increased as length is increased. It is obvious then, that with a given voltage and load, a wire 20 ft. Iong must be of a Iarger gauge than one 2 ft. long; The electrical load imposed on a wire is merely the sum of the individual loads of each unit serviced by that wire. Common automotive system voltage is now 12 volts. Some commercial vehicles use 24v. Most carrs produced a number of years ago used 6v. systems. Most wire manufacturers furnish charts, si m ilar t o t hat s h o w n i n F i g . 6 -1 1 , to assi st the mechanie in proper gauge selection. To use the chart shown, determine the total length of the wire needed. The wire lengths shown in the chart are for a single wire ground return (no
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wire needed from the unit as the frame or metal parts of the ear act as a return ground wire). If (one wiré to the circuit installing a two-wire unit and another from the unit to ground), count the length of both wires. load to Next compute the total electrical to Be certain wire witl be subjected. which the figure the load of ALL units concerned. If the use the peak load figure. fluctuate, load will The load may be figured in AMPERES, WATT(Candel.a is the international AGE or CANDELAterm
for candlepower.)
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Auto Service qnd Repq¡r When the load is determined, look on the chart under the correct voltage column for the nearest listed load. Move across the charthorizontally until under the nearest listed footage. This will give you the recommended gauge. For example, say you have a l2v. system, a computed electrical load of 20 ampereb and a wire length of 15 feet, Locking on the chart you will find the recommended gauge to be No. 14. For the same load and length butwitha 6v. system, the recommended gauge is 10. You will notice that a 12v. system uses a smaller gauge wire than a 6v. system. Using a l.arger gauge than necessary will cause no particular harm unless the wire being replaced MUST produce a specific resistance in t he c ir c u i t, F i g .-6 -1 1 .
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20 22 21 30 ,t0 50 t00 150 200
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108 120 t32 111
óo 70 80 90 100
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ló 21 30 10 50 ó0 70 80 90 100 120 140 l óo r 80 200
l8 l8 t8 t8 t8 't8
¡¡d¡cot.d obovc lh¡s linc could be 20 AwG
l8 t8 't8 l8 t8 l8 t8 t8 *t 8 l8 t8 tó t2 t0 lo
S E L E CT I NG P RO P E RT E RMI NA L S After the wire gauge is determined, select the proper size and t¡pe terminal. The terminal selected must be suitable for the unit connecting post or prongs. It must have sufficient current carrying capacity and should be heavy enough to prevent breakage through normal wire fLexing and vibration. Fig. 6-12, shows some common errors in terminal selection. Arrange terminals so they have clearance from metal parts that could ground or short them out. On critical applications or where heavy vibration is present, use a terminal such as the ring t¡pe that eompletely encircles the post. In the event it loosens, the wire will not fall off.
¡ó l8 t8 t8 l8 l8 t8 l8 l8 l8 l8 l8 t8 l8 t8 t8 t8 tó ló 'tl l2 lo 8
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l8 t8 l8 l8 l8 t8 l8 t8 t8 l8 l8 t8 l8 tó ló ló tó ló t1 t2 l0 8 8
!8 t8 t8 l8 l8 t8 t8 't8 l8 l8
l8 l8 t8 l8 t8 l8 t8 t8 l8 't6
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| 8 AWG is rcconmendcd for m.chon¡col ¡tr.ngth.
Wire gauge selecfíon cho¡t. Vlire lengtfis sñown o¡e Ío¡ o single wire ground return,
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W R O N GST YLE
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Fig. 6-12. Some commone¡rors.in terminol selection.
98
(Belden Mlg. Co.)
TE R MI N A L
. W ire o n dWirin g
TERMINA LS ATTAC H ING Terminals maybe either soldered or crimped in place. Crimping is fast and forms a good connection. Soldering, if properly done, forms an excellent connection and, in some cases' may be desired. It is possible to both solder and crimp a connection. Solder forms an electrical path and is not depended on for strength' Aluminum wire requires crimpedterminals'
size for the wire used. NEVER CRIMP A WIRE WITH THE CUTTING EDGE OF A PAIR OF PLIERS. This would crimp the barrel but would also weaken it, Fig. 6-14. S OLD E R IN G TE R MIN A LS Terminals do not have to be especiallymade for soldering but the lip-type terminal tang lends itself to soldering better than the closed or open barrel tang, Fig. 6-15r
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CRI M P I NG T E RM IN AL S will A crimping tool is shown in Fig' 6-13' it proper a form as eut and strip the wire anwell crimp.
IN SU LAf ION T AN G
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OPEN BAR R E L
C LO SEDBAR R EL
Fi g' 6'15' Termi nol tangs'
To solder the lip type, strip the wireback as shown in A, Fig. 6-16. Insert the wire as shown in B. Crimp the wire hotding lips, one after the other, tightly over the wire then carefully fold the insulation tang around the insulated portion of the wire as in C. Fig' 6'13' Crimping tool'
IN SU LAT ION T AN G S
(Cole-Hersee Co'l
M:d
The first step is to strip the insulation back for a distance equal to the lengthof the terminal barrel. The wire is then shoved inio the barrel is and while being held in, the crimping tool to sure Be be crimped' to placed over the spot use the proper crimping edge. The handles are together and the terminalbarrel firm"qrru"""d ly crimped to the wire. Follow the tool manufácturers instructions. Use the correct barrel
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Using ROSIN CORE (NOT ACID CORE) wire solder, pt""" a drop of solder on the holding tips. Iiotá the iron in contact with the drop until it flows into the lips and wire' Do not hold the iron in contact with the terminal anylongerthan necessary as this tends to melt the insulation' When soldering the open barrel t¡rpe' strip (coat as for crimping. Tin the exposed wire end barrel the in insert with a thin layer of solder), heat and while holding the exposed end upright' wire keep heating, While iron. the socket with solder against socket end. Whenthe solder melts'
CR IMP
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Fi g.6-16, S ol deri ng l i p rype termi nal '
INSERTTT IR E
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TER$INAL
F i g . 6- 1 4 . Cr in Pin g o te r m in o l'
99
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Auto Serviceond Repoir flow it into the barrel. Make certain a sufficient amount enters. Hold the iron in place for a few seconds longer to allow the solder to bond to both barrel and wire. Barrel may also be cri.mped if so desired. Crimp before soldering! See Fig.6 - 17.
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barrel until about one-quarter futl. While retain_ ing the heat with the torch, force the tinned cable down into the socket. When it slips in the futl depth, solder will flow up and over the tip of the barrel. Hold the heat, moving the flame around the terminal outside, fon a fewsecondslongerro allow the heavy cable_,íó heat up andbond firmly to the barrel. Remové heat andholdcable steady until solder sets. CooI under a cold tap. .Dry terminal and cable insulation and then apply plastic tape as shown in Fíg. 6-1g. For open barrel termi.nals, tin both cable and inside of
SOLDE R IN G IRON
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Fig.6-17. Solderingborreltype terminoltong, The closed barrel type should be heated and a small amount of solder flowed into the hole. While keeping the barrel hot, press the tinned wire into the hole. HoId the iron in place for several seeonds to insure bonding. For more complete instructions on the use of the soldering iron, see the chapter on soldering, brazing and welding. When an insulator boot is to cover the terminal tang or when attaching slide type terminals that will be snapped back into a housing, always slide the boot, housing, erc., on the wire before soldering.
Fi g.6-18, S ol deri ng o battery termi nol . I- C ut oÍl c orroded s ec _ tion. 2-Strip. 3-Tin. 4-Tin borre! and odd solder. S_lnserr co6le. 6-Tape.
SOLDERINGBATTERY TERMINALS The common practice is toreplace the entire battery cable when the terminals are no longer fit for use. However, if it becomes necessary to install a new terminal, use the following pro ce dur e.
res@N
Cut the cable back far enough to remove the corroded section. Peel the insulation (ground cables often have none) back equal to the depth of the terminal barrel. place the terminal in a vise, open barrel end up. Using an acetylene torch (low heat, flame rich in acetylene) heat the stripped cable end. Using rosin core wire solder, flowsolderfreely into the wire until all strands have been tinned. It may help to rub onalittle rosin tJrye soldering paste to assist with tinning. Place a dab of solderingpaste inthe terminal barrel. Hedt with the torch (keep flame on outside of terminal). When hot, flow solder intothe
WwffiW Fi g.. 6-19. S porkpl ug w i re fermi nol s ond boots . I, 2,7-di s t¡i butq end te¡mi nal s. 3, 4, 5, 6,8, l l -spork pl ug e nd terni nol s . 9-R i ght ongl e di stri butor end 6oot. l I-Fl exi bl e pl ug end 6oor. l 2_s ropi es {or use w i th ¡esi stonce type w i re. I3-R epl oc emen t pl ug w i re w i th . 6oofs 6onded to wi¡e.
t00
SX barrel heavily. While heating, slide together as above. Do not try to solder battery terminals mith a soldering not produce iron - it will s':¡fficient heat.
PLU G W IR E
Fi g. 6-20. C fi ooseo l e¡mi nal shope l hot w i l l al l ow the w j re to 6e al tached w i thout sharpbendi ng, The w i re i n B w i l l soon l oi l,
P LUGWIRETE RMINAL S ATTAC H ¡ N SPARK G Fig. 6-19, shows various spark plug wire :erminals. The boots shown protect against noisture and dirt than can cause flashover fspark jumping to ground along the outside of :he plug porcelain top). Ready-made sets often bond the boots to both the terminal and wire for added proteetion against flashover. When Selecting plug end terminals, choose a shape that will snap on the plug without bending :he wire sharply. The same applies to distributor te rmi nals , F ig. 6- 2 0 . Although some plug end terminals have a sharp barb that is designed to penetrate the r.nsulation and contact the wire (as well as providing holding power), it is good practice to strip the insulation enough to allow the wire to be bent around and laid against the outside of 'üe insulation, This insures a good electrical contact. See A, Fig. 6-21. Some distributor end terminals, such as that in B, Fig. 6-21, have the barbs both at the sides and end. Wire stripping :s n o t nec es s ar y if th e b a rb i s c a re fu l l y i n s e rte d i¡rto the wire end. When attaching terminals to resistance type plug wires, always use staples. The staple is pushed up into the wire, thus insuring a large contact area withthe specialcond u ctor , C, F ig. 6' 21 .
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J O I NIN G WIR EENDS In addition to the terminal, fuse and junction blocks, wires may be connected together by soldering, crimped butt connectors and slide or bullet-tJ¡pe connectors. If the wire ends are being joined permanently, soldering orbutt connectors work very weIl, Fig. 6-22. The slide and the bullet-type connectors are used where the wires must be separated at some future time. The appropriate slide or bullet terminals are crimped or soldered tothewires. They are then snapped into the connector body and the two halves plugged together, Fig. 6-23.
Fi g. 6-22, J oi ni ng w i res by sol deri ngA or usi ng o cri mp type butl connecfor8.
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INSfALLI NG W I RE Install the wire, make certain terminals and posts are clean, conneót terminals and tighten securely. Lock washers should be used on screw
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Fig. 6-24. Yliring instollation hints. A-Connecfions musf 6e CLEAN and BRIGHT. B-Use grommetsto Prolect wire possing rhrough-thick metol. C-Tope common wires fogelfier. D-Avoid moving porls when locoting wíres' E-Sup'porr with suitolle clomps. F-AIIow some slcck when wire runs to o unit thot moves. G-Connecforsmusfáepusfted (or the iob, l'Tighten termitogether tightly. H-llse 6oots on terminol tongs and select terminols Éeovy enough nil" ¡n o fo";iion AWAy FROM metol - use 6oots olso. J-Hondle resislonce plug wires by grasping tfieboots.
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used or the popular in-line lfuse canbe installed. Be sure to inform the owier as to the location of the new fuse, Fig. 6-25. NEVER TAP INTO (CONNECT) THE HEADLIGHT CIRCUIT TO POWER AN ACCESSORY. THIS COULD OVERLOAD THE HEADLIGHT CIRCIIIT BREAKER AND CAUSE TROUBLE. If it is desired to have radios, heaters, etc., inopet'ative when the ignition key is in the OFF position, the unit hot wire must be connected to the key switch.
and post connections. Stip insulatorboots, where used, over exposed terminal tang. If of the slide or bullet t¡pes, shove together tightly andeheck to see that the connection is secure. Keep all wiring away from the exhaust system, bily areas and moving parts. Secure in place with mounting clips.or clamps. Fasten in enough spots to prevent excessive vibration and chafing. Where the wire must pass through a hole in sheet metal, install a rubber grommet (see Fig. 6-241. When a wire must pass from the fender well or splash shield to the engine, leave enough slack to allow the engine to rock on the mounts without pulling the wire tight. Wtren installing spark plugleads, avoidsharp bends. If the wires pass through a metalconduit (tube), the conduit should be securely grounded. Install or remove the plug wires by grasping the insulation boots and not the wire proper. snap tightly on the Make sure the terminals plugs and that the distributor ends are all the way in the housing towers. Follow the manuin arranging the plug instructions facturers wires. If two leads are together going to cylinders that fire consecutively (one afterthe other) - especiallyas there is a danger ofcrossfiring the wires age. If a number of primary wires travel in a common path, pull them through loom (woven fiber conduit) or tape them together, Fig. 6-24.
P RI NT E DCI RCUI T S A number of cars use a printed circuit as part of the instrument cluster wiring system. The printed circuit uses a nonconducting panel upon which certain units are attached. Instead of connecting the units with wires, they are connected with thin conductor strips printed (cemented) on the panel. Such a technique permits a great deal of circuitry in a very small space.
WI RI NG CHE CK I NG Many problems throughout the car can be traced to faulty wiring. Loose or corroded frayed and bare spots, oil soaked, terminals, broken wires, and cracked andporous insulation are the most frequent causes. When troubleshooting a proJrlem, check the wires, fuses and connections carefully. Remember that wires can separate with no break in the insulation (especially resistance type secondary wire). A terminal may be tight and still be corroded. A fuse link may burn out at one end instead of in the center where it will be visible.
FUS EWHE NNE E DE D When adding accessory units such as spotlights, heaters, etc., and no provision was made for them in the original wiring, be certain to place a fuse in the circuit. Fuse as closely as possible to the electrical source. This will reduce. the possibility of a short between the fuse and souree. A small fuse block may be
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A small test light (battery operated) may be ::sed to test wires for internal breaks. The test point prods can be pushed through the insulation :i desired (not on plug wires). Hold one prod e-gainst one end of the wire and place the other
Wires and connections must occasionally be checked for resistance, voltage drop, short or near-short circuits. These checks are made with precision instruments - ohmmeter, voltmeter, etc., and w i l l be di scussedi nthe chapt er s to which these tests pertain.
S UMMA RY Primary wire (copper stranding, relatively thin insulation) is used for circuits handling battery voltage. Secondary wire (stainless steel, carbon impregnated thread and elastomer stranding wi.th very heavy insulation) is used on the ignition hightension circuit. Plastic is widely used for insulation. AII automotive wire uses a stranded (not
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solid) wire conductor. The AWG (American Wire Gauge) is determined by the cross sectional area in circular mils. The larger the AWG number, the smaller the size. A microrheter or wire gauge can be u s e d t o d e t e r m i n e 'w i r e size. Spade, lug, flag, ro11, slide, ring and bullet terminal types are used. Terminal blocks allow one feeder wire to service These can a number of other wires. be of the screw, bullet or slide tJpe. Junction blocks provide a central connecting point for a number of wires. Fuse llocks give protection against circuit overloads. A wiring harness contains a number ofwires either taped together or pulled through loom. This keeps common wires neatly arranged and facilitate s installation. Automotive electrical systems are color Use an accurate wiring coded. diagram for troubleshooting or replacing wires. Line voltage, wire length and electrical load must be taken into consi.deration when choosing wire gauge. A wire gauge chart will assist in making the right Remember selection. that undersize wires increase resistance, r e d u ce unit efficiency and can overheat and burn. On (one wire for ground) count two-wire circuits the length of both wires. A 6v. system requires heavier gauge wire than the 12v. system. Be certain that terminals are of the correct style and size. They maybe soldered or crimped
;:od against the other end. Ifthe test lamp burns, :he wire is continuous. This simple test light :s also handy for checking fuses, shorted field x:ndings and for tracing wires where there are ::c c olor c odes . F i g .6 -2 6 , i l l u s tra te s s e v eral : -re c k s .
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E. 6 - 2 6 . S o m ew i r i n g ch e cks u sin g o sim p le te st lig h t. A-P rods ¡n e n d s o Í w i ¡ e . L o mp lig h ts in d ica tin g wir e ís co n tin u ous, B e'cd held on the end ol one wire ond the other prod ¡ouched ¡o , : rio u s w i ¡ e e n d s . W [ en lo m p lig h ts p r o p e rwir c e n d is id e nri l i ed. C-C/recking o fuse. P¡dds in ploce, lomp does not light. This int cdtes o loulty luse and in this cose ffie luse will be burnl out r' tlre end insteod oÍ the usuol norrow centeÍ seclion. D-One prod '¡ucÁed to o wire end and the othe¡ prod to ground. Il lamp lights wire is shorted out.
Battery to the wire. replacement should be soldered. When crimping,
103
terminals use a suit-
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able crimping tool. If soldering, use rosin core wire solder. Always slide insulation boots, housings, etc., on the'.wire before attaching terminal. 'Use staples when installing terminals onresistanee t¡rpe secondaryleads. Handle secondary resistance wire carefully. .Wire ends may be joined by soldering, using butt connectors or by attaching bullet or slide connectors. When installing wíres, keep away from heat, oily areas and moving parts. Terminals must be clean and tight. Use clips to prevent chafing and excessive vibration. When adding accessories, fuse the circuit as close to the source as possible. Do not tap into the headlight circuit for an accessory. Clean, tight connections with propet size wire and good insulation, are imperative. When troubleshooting, always check connections and insulation. Replace cracked, spongy or frayed wir es . Many wiring checks can be made wíth a simple test light. Printed circuits find some application onthe auto.
harness and see how many kinds ofwireclips and clamps you can find. 5. Study the wiring diagram of a car electrical qystem. Trace several circuits starting at the unit and going back to the source. Note the color coding and use of symbols. TOOLS A R E IMP OR TA N T Remember - to do good work, a mechanic needs a good assortment of tools. To learn, a student needs a good assortment of words. Words are very important t'toolstt for learning. When YOU come across a new word LOOK UP THE MEANING and add it to your "TOOL CHEST."
OUIZ - ChoPter6 1. Primary wire makes excellent spark plug leads. True or False? 2. The most commonlyused insulation material i s-. 3. Resistance tJ@e spark plug wires are used to provide a hotter spark. True or FaLse ? 4. Name three materials, used for secondary wire stranding. 5. Stranding for primary wire is made of
SUGGESTED ACTIVITIES 1. Using the primary wire size selection chart in this ehapter, determine the correct size wire for the following: A. Load - 100 candela Wire length - 11 feet Voltage - 12 Wire gauge should be_. B . Loád - 50 amperes Wire length - 2O feet Voltage - 12 Wire gauge should be_. C. Load - 70 watts Wire length - 15 feet Voltage - 6 Wire gauge should be_. 2. Attach several terminals bycrimping. Solder several. 3. On a damp, dark night, start the engine in a car (especially one several years oldthathas been parked outside). Without turning on the lights, raise the hoodandseeifyoucan detect the corona effect around the plug wires. DO .NOT RUN THE CAR IN A CLOSEDGARAGEJ 4. Inspect the wiring on a late model car. What kinds of terminals are used? Studythe wiring
6. Resistor spark plug cables are easily damaged by sharp bends and jerking. True or False ? 7. All primary automotive wire uses a stranded conduetor. True or False. 8. The is the standard for wire size. 9. The larger the wire number, the larger the wire. True or False ? 10. Cross sectional area in square mils determines the wire size. True or False ? 11. Name five common primary terminaltypes. 12. Replacement battery cable terminals should be
13. One feeder wire can service several others through the use of a_block. 14. A number of wires can be connected together. in a common location by using a _b1ock. 15. The_protects a circuit from an overload. 16. A number of common wires, tapedtogether, with leads leaving at various spots.i, is referred to as a wiring_. t7. Automotive wiring is_ coded.
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18. What is a wiring diagram? 19. The three major considerations inselecting the correct wire gauge for a specific circuit are , wire -and electrical -. 20. An undersize wire will increase and will_, 2 1 . In computing wire length for a twowire circuit, both wire lengths should be counted. True or False ? 22. No. 16 wire is smaller than No. 18 wire. True or False? term for the international 23. -is candlepower. 24. 12 volt wiring is of aheaviergaugethan that for 6 volt. True or False ? 2 5 . As long as a terminal fits the stud or post, it is O.K. to use. True or Fa1se? to the wire is more terminals 26. widely used than . attaching terminals to 2 7 . Use-when resistance t¡pe secondary wire. 28. Copper or stainless steel secondary wire should have a smalL portion of theinsulation stripped and the wire bent up andaroundthe outside of the insulation. True or False ? 2 9 . If, when joining wire ends, it is desirable to
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through thin sheet metal. True or False ? 32. When plug leads pass through a metal conduit, the conduit should be_. 33. Wires should be held by in order to prevent ehafing and vibration. wires are 34. Spark plug wires can-if too close together whentheyserve cylinders that fire consecutively. 35. As long as the insulation is alright, a wire can be considered O.K. True or False? 36. A frayed wire can cause a_circuit. 37. A corroded connection will increase_ to electrical flow. 38. The electrical symbols in the left hand column are all numbered. Write down these numbers, one beneath the other. The right hand column lists the items these symbols stand for. Each item has a letter. Matchthe items to the symbols by placing the letter of the item you have chosen beside thenumber of the matching symbol. A. Resistor.
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miniolu¡ized fuse. Fig.6-27. A-Fuse btocx incorporoting o number oÍ miniolu¡ized fuses. B-"Good" Nofe tñot elemenf is sound. Cu¡renl flows l¡om one blode, lhrough element ond out tfie otfier 6lode. C-Fuse is "Bod." Elemenf is Aurned in holÍ, thus opening circvit. (Pontioc-Buick)
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PULLERS, LIFTs, JACKS, FIXTURES HOLDING PRESSES, A wide assortment of ,pressing, Iifting and p.;lling equipment is available in most garages. Proper use of this equipment will both lighten and speed up repair work. EX T RE M E CAR E MU ST B E U SE D W IT H ALL HIGH OF DEVELOPING TOOLS CAPABLE ?R,ESSURES,STRESSES AND TENSIONS. NEV=R USE EQUIPMENT WITHOUT FIRST RE:EIVING INSTRUCTIONS FROM SOME PERSON :.I,IÍILIAR WITH ITS USE: THERE ARE MANY S.iFETY RULES IN THIS CHAPTER. STUDY :ITEM CAREFULLYJ
PUMPITANDLE
When using, make sure the jack is securely placed and aligned so that as pressure is developed, it will not slip. Be careful of dropping as it is quite heavy, Fig. 7-1.
HYDRAULIC FLOORJACK A floor jack is usqd to raise a car. It can raise the entire front, back or side. It is also handy for maneuvering cars into tight quarters. The jack is placed under the front or back, the car lifted and by pulling on the jack in the direction desired, the car can be moved forward, backward, or sideways. Floor jacks are available in many sizes with lifting capacities varying from around one to twenty tons. Fig. 7-2, illustrates a typical floor jack.
HANDLE CONTROL VALVE SADDLE
F i g . 7 ' 1 . Hyd r o u lic h o n d io ck'
}IANDJACK
RAPID RISE FOOT PUMP
The hydraulic hand jack is very useful in rmany applications. It is short, compact and eapable of producing great pressure. It can be used to raisg heavy weights, to bend parts, to p'rll or push parts into alignment. Hydraulic poffer is quite often used as a power source in sme1l pr es s es .
Fi g.7-2. H ydroul i c (l oor i ock. B y operoti ng the ropi d ri s e l oot pump, the soddle ís quickly elevoted. Heavy Pressu¡e con then be developed by wo*ing rhe t\s hondle bock ond lorth' (Weove¡)\
107
Fig.7-3. poísing
co¡ with lloor iock, Moke cerfoin soddle is ProPerlY Positioned. (Honda)
You must follow the manufacturerrs specifications carefully. Fig. 7-3 shows a car being raised by plaeing the saddle under the center of the differential housing. NEVER WORK UNDER A VEHICLE SUPPORTED ONLY BY A FLOOR JACK; Once the car is raised to the desired height, place jack stands in the desired location, and lower the weight onto the stands. STANDS MUST BE PROPERLY AND SECURELY PLACED. The jack may then be removed if desired, or if not needed in some other area, it may be left in position with a very light liftingpressure exerted to keeP it Positioned.
P RO P E R P L AC EME N T IS IMP O R T AN T
JACKSTANDS
When positioning the jack saddle for lifting, make certain it is securely engaged. Select a spot that will be strong enough to support the
Jack stands are made in numerous heights and are usually adjustable. The stand in Fig. ?-4 is typical. Note the ratchet adjustment. When inserti.ng jack stands, place them in contact with some unit capable of supporting the load. Do not place them in contact with edges that may cause them to s1ip. tapered Make sure they have a secure bite. Fig' 7-5 (often called stands of jack a pair shows axle rear the place under in safety stands) housing. Note that the stand tops (saddles)
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load. Never try raising the car by jacking on the engine pan, cluteh housing, transmission' tie rods, gas tank, etc. Proper placement requires care' GET DOWN AND TAKE A GOOD LOOK, WITH AMPLE LIGHT, BEFORE RAISING. If the car is part way up, andthe jack saddle slips, serious damage can oecur. On some cars, jacking one side of one end or near the center of the frame on one side, can cause damage. Car manufacturers il!.ustrate correct lifting points intheir manuals'
Properly ploced iock sfonds províde sofe supporf' (Honda)
E NDL I F T S The end lift can be air (pneumatic) or hyoperated. Two basic designs are draulically used, one of which will reach under the car far enough to contact the rear axle housing, and the other designed to engage the bumper only' An air-operated long-reach end lift is pictured in Fig. ?-6. Notice the height to which the
108
7" FAST, LOW LEVEL AIR LIFT
F i g . 7 - 6 . L o n g r e o ch e n d li( t. (Hein-Ylerner) T h e ja ck may be raised. sta n d s a r e being .sitioned so that when the rear of the c ar i s :-,¡;ered, the front will clear the floor. The bumper lift shown in Fig. 7-7 is also : : r-ope rate d. Note t he t win s addle engagem e n t , : : r'
A handy, quick-acting air lift is illustrated in Fig. 7-8. The car is driven over the lift until the rear wheel is centered in the frame. A control box actuates the rubber air bellow which in turn causes the saddle to lift the car. This jack wheels partially is useful for washing rear covered by the body.
Fi g.7-8,
Low l evel , w ash rack /i ff. N ofe rubbe¡ bel l ow s .
SINGLE POST FRAME LIFT A single post frame lift leaves bothfrontand rear of the car completely exposed. It does howin the central ever, create some obstruction portion. F i g . 7 - 9 , s h o w s a c a r i n t h e r a i se d position on a single post frame lift. Note the lift points REMEMBER: contact on the frame. PROPER CONTACT POINTS FOR DIFFERENT INCARS VARY. FOLLOW MANUFACTURERSI STRUCTIONS.
F i g . 7 - 7 . R o isin g co r with o b u m p e re n d líft.
-:re distance between saddles mav be varied to the bumper where desired. Remember -:gage ::at bumpers, especially near the outer ends, =ay not be particularly strong. If the bumper : a¡ be used, prace the saddles at the main bumper : frame attachment points. End lifts are generally provided with strong :.fety locks so the mechanic may safely work (car ; dt MAKE Lllg without wrLttvuL stands. D ldrruD. eneath the -=trgd Lrt Jiack du^
:''-T.E THE SAFETY LOCK IS FULLY ENGAGED, '.\D THAT THE LIFT CONTACT POINTS ARE SOLID. If there is the slightest doubt, use iack -.tands for additional protection.
Fi g.7-9. S i ngl e post l ¡one l i l t. N ote coreful pl oci ng o( l i l ¡ s odd/es or brockets.
DO UB L EP O S TF RA MEL ¡F T the The double post frame lift eliminates single central post thus leaving the center portion of the car more accessible. As with the single post lift, the car must be carefully centered. In Fig. ?-10, the mechanic hascenteredthecarand is adjusting the swivel lift arms.
109
Auto Service dnd Repdir
A n a u t o i s s h o w n i n t h e r a i s e d p o si ti o n i n F i g . 7 - 1 1 . T h e e q u a l i z e r r a c k s i n s u r e th a t b o th c o l u r n n s w i l l r a i s e a n d l o w e r t o g e t he r .
DOUBLE POSTSUSPENSION LIFT
F i g . 7 - 1 0 . Ad iu stin g swive / q r m s o n d o u b le P ost l rome l i l l
T h e d o u b l e p o s t l i f t p i c t u r e d i n Fi g . 7 - 1 2 , c o n t a c t s t h e f r o n t s u s p e n s i o n a r m s, a n d e i th e r t h e r e a r a x l e h o u s i n g , o r . r e a r w h e el s. Th e fr o n t l i f t c o l u m n c a n b e m o v e d f o r w a r d o r b a ckw a r d t o a d j u s t f o r v a r i o u s w h e e l b a s e l e n g th s. Th i s type of lift presents a minimal amount of underO n s o m e m o d e l s, obstruction. a si n g l e car c o l u m n c a n b e r a i s e d t h u s a c t i n s a s a n e n d l i ft when so desired.
DRIVE-ON LIFT The drive-on 1 i f t , F i g . 7 - 1 3 , o ffe r s p l a ce m e n t s p e e d b u t d o e s p r e s e n t a r e l a ti ve l y l a r g e obstruction area.
CHOICEOF LIFTS
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REAR CONT ACT S
F l o o r j a c k s , e n d I i f t s , t r a m e l i fts, e tc., m u st a l l b e u s e d w i t h e x t r e m e c a r e . R em e m b e r th a t many cars can weigh TWO TONS or over. E a c h y e a r a n u m b e r o f m e c h a n i c s a r e ki l l e d o r injured by careless u s e o f l i f t eq u i p m e n t. In a d d i t i o n t o u s i n g s a f e o p e r a t i n g p r o c e d u r e s, i ti s imperative that lift equipment be kept in sound o p e r a t i n g c o n d i t i o n . C r a c k e d o r b e n t p a r ts, fa u l ty s a f e t y l o c k s , l e a k i n g c y l i n d e r s , e t c., m u stn o tb e tolerated, apply T h e f o l l o w i n g l i s t o f s a f e t y p r e c a u ti o n s tn LU
l i g . 7 - 1 2 . Do u b le p o st su sp e n sio n lih . T h is /i ff creotes Y er Y l i t t l e u n d e r - ca ¡o b slr u ctio n . ( D.e sse ¡ Industri es)
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earefully, OVER AND OVER, until you remember each and every one. l o ca te d a n d 1. Lift saddles must be properly in secure contact. 2 . \ \ ¡ h e n u s i n g a f l o o r j a c k , a l w a ys u se i a ck stands. 3 . O n c e s a d d l e s a r e l o c a t e d , a p p ly so m e p r e ss u r e , s t o p a n d e x a m i n e t h e m a g a i n b e fo r e liftinE the car.
110
Jocks, Pullers, Presses, HoldingFixtures
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it fro m ro lling f or war d or bac k war d) r elea s e -he ha nd b rake and plac e t he t r ans m is s io n in ne utra l. In t hat eit her t he c ar or t he l i f t must move a s t he llf t ing or lower ing oc c u r s , -his will p revent s addle s lippage. r\Jlen r:isino ihp eniira ¡¡n r¡r¡inh * . - . ^ fnr --- any sld e or o ve rhe ad obs t r uc t ions . \Iake certa in t hat t he lif t s af et y loc k i s se cu rely e ng aged bef or e get t Í ng under t h e A D JU S TIN G B OLTS
\e ve r remo ve a lif t or jac k f r om anot h e r me ch an ics se t up wit hout c hec k ing wit h h i m fi r st. If
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of th e veh icle dur ing t he job, do not m o v e it un til all p er s ons ar e "out f r om under . " -\lwa ys che ck f or equipm ent , par t s or pe r so nn el be ne ath t he c ar bef or e lower ing. Lo wer SL OWLY and wat c h t he c ar dur i n s :h e e ntire de sc ent . Fi g. 7-l 4. Typi col fronsmi ssi onfoc[. I
!¡
F i g . 7 - 1 3. Dr ive - o n li{ t.
( Vle o ve r )
TRANSMISSION JACKS jac k is es s ent ial t o t he s a f e , -\ tra nsmission =ificient removal and installation of automatic : : ans mission s. Th e s addle ut iliz es a s er ies o f = : apte rs a nd a b inder c hain f or s ec ur e at t ac h : : -ent. The sa dd le c an be r ais ed and lower edhy ::aulically and tipped in any direction through . re use of a dju stin g s c r ews . Fig. 7- I 4, s how s a ---oical jack with the t r ans m is s ion in plac e. jac k , be c er t a i n Whe n u sin g a t r ans m is s ion : : attach th e tra nsm is s ion s ec ur ely . I t is he a v y ::d if it slip s, it could c aus e s er ious iniur y .
Fi g. 7J 5. Ihe w hee/ dol l y hondl es heovy w heel ossem6/i es w i th eose.
W H EELD OL L Y PORTABLE CRANE AND CHAIN HO¡ST Shops engaging in truck repair find a wheel iolly helpful in removing wheel and installing assemblies. Note the use of a hydraulic hand ' aek o n th e d olly in Fig. 7- 15.
The norfrhle nr¿¡g and the Chain hoist. are excellent tools for engine removal. They can a l s o b e u s e d t o l i f t h e a v y p a r t s t o b e n c h t o p s,
111
:i:,"$iü:::{sw,lryr;
LI FT CHAIN
CF ANE
fig.7J6.
J
Portoblecronebeingusedto pull on engine, (GuY-Chart SYstems)
truck b eds , et c . Fig. 7- 16 depic t s a h e a v y being used to pull an crane duty portable engine. IMPORTANT SAFETY RULES T O O B S E R V E WHEN USING CRANE OR CHAIN HOIST: 1. Sta nd c lear at all t im es . 2. Lo wer t he engine as s oon as it Í s c l e a r o f
Fi g. 7-17. fhe extensi on j ack i s hol di ng the nuÍ(l e¡ thus l reei ng both honds.
the ca r . 3. Never r o11 t he c r ane wlt h t he l o a d h i g h i n fhe :ir Keen jt ius t c lear of t he f l o o r . 4 . Never leav e t he engine s us pended w h i l e w o r k in g o n it . Lower t o t he f loor o r p l a c e o n a suitable engine stand. 5. Ne ve r leav e t he c r ane or hois t w i t h t h e l o a d suspe nded. I f y ou m us t leav e, e v e n t e m p o r e ni 1r¡
I nr¡ro
RAMHEAD LOCK
CONfROL VALVES
r PRESSURE 6AUGE
6. \\¡hen moving heavy 1oads, alert your fellow mecha nie s . ? . Never giv e t he load, when s usp e n d e d b y a ch ain hois t at t ac hed t o an ov e r h e a d t r a c k , a h ard s hov e and let it c oas t al o n g . M o v e i t slowly and s t ay wit h it . c ables , c hains , bolt s, e t c . , m u s t B. Atta ch ing
TABLE WINCH PUMP }IANDLE RAM
WORKTABLE OR BED
h ave am ple s t r engt h. 9 . Whe n us ing nut s t o at t ac h lif t c a b l e s , t h e n u t mu st be f ully on. W hen us ing c a p s c r e w s , th ey m us t hav e a t hr ead engag e m e n t d e p t h o ne a nd one- ha1f t im es t he diam e t e r . More information on the use of this equipsection men t fo r engine wor k will be giv enin t h e o n e ng ine r em ov al and ins t allat ion.
TABLE PINs
AXLE BEARING
LOWERWORK TABLE fABLE PINs
JA CK EXTENS ION An extension jack is a valuable tool for exand for holding parts to erting mild pressure lea ve bo t h hands f r ee. Suc h a iack , F i g . 7 - 1 ? , is shown supporting a muffler while the mechanic o pe rate s an ex haus t pipe c ut t er .
Fi g.7-18. Typi col Íl oor model hydroul i c pres s . (F. A . N ugi er C o')
112
Jocks,Pullers,Presses,H oldingFixtures H Y D RAU LIC PR ES S Removing bearings, straightening shafts, ;ressin g b ushin gs, et e. , ar e jus t a f ew of t h e -any jobs that can be performed on a hydraulic :ress. The p ress is f ar s uper ior t o s t r ik ing :oo1s in that the pressure is smooth and con::olled, there is no metal "upsetting" shock, = :d e no rmou s p res s ur es c an be gener at ed . ::g. 7-1 8, illu stra tes a t y pic al f loor hy dr aulic ;:'ess set up to remove an axlebearing. A wheel :--;b and drum assembly is also in place for rlieel lug work. When using a hydraulic press, make sure :he table .pins are in place and that the table ¡:nch is slacke d o ff. Failur et odot his c an br ea k ::,e winch gear or cable.
CONNECTOR
m
P O R TABL E HYD RA ULIC P OWE RUNIT
Fi g.7-19, P o¡tobl e hydroul i c pow er uni t ond occesso¡res. (B l ockhow k)
There are many occasions when heavy, con: : olled pre ssure s ar e needed f or par t align*ent, body and fender work, etc. The portable i-: ; draulic p owe r set s hown in Fig. 7- 19, pr o ides a number of useful adapters that allowthe .:cl t o be used fo r m any jobs . set is being us ed, Fig. ?- 20, to -\ h yd rau lic :-se a d ama ge d roo f c or ner pos t s ec t ion.
J F ETY PRECAUT IONS hydra ulic p res s ing and pulling t ools ar e -il : : ntially d an ge rou s if im pr oper ly us ed. G en := - sa fety rule s a pplic able t o al1 t y pes ar e: . : an d free while pr es s ur e is applied. rpply p ressu re c om m ens ur at e wit h t he job . S hield b rittle p ar t s s uc h as bear ings t o pr o:ect a ga inst flyin g par t s . , F ngag e ram se cu r ely and in line wit h wor k .' -ihen , an y ch an ce of par t br eak age is pr es ent , -. vear g og gle s. . -f w ork mu st be p er f or m ed while m aint aining : ressu re, be ca ref ul t o k eep out of line wit h :he to ol. , .3e care ful o f p art s nap- bac k if t he t ool s lips .
Fi g, 7-20, P ortohl e hydroul i c pow er uni t bei ng used to ¡oi se ro of . cotner post sect¡on,
HYDRAULICAND MECHANICALPULLERS THREE TYPES OF PULLING JOBS
A good assortment of pulling tools is im:ortant. An attempt to "get by" with a few pullers ;r:1I result in a great deal of wasted time and damaged parts, lVLanyjobs are almost impbssible -'c'ithout proper pullers. Pullers can be mechanically or hydraulically :perated. Both have certain advantages.
All pulling jobs wi.ll be covered in the three basic setups: 1. Pulling an object (gear, pulley, bearing, retainer, etc.) from a shaft. 2. Pulling a shaft (axle, transmission, pinion, etc.) from
il3
an object.
3. Pulling an object (bearing outer ring, cylinder a from et c ' ) bear ings , cam s haf t sle eve, i l l u s ?2 3 and 7' 2t , 7' 22 Figs . b or e. h ou sin g trate the three basic pulling jobs.
'S H A FT B E A R TN G
R E TR A C
Fi g.7'24. H ydroul i c pul l er remov' i ng rol l er beori ngÍrom pi ni on shoÍt'
puller is shown in hydraulic A typical Fí9. 1-24. pullers mechanical Several universal-type F i g . 7 2 5 . i n p i c t u r e d are on a board and keep related Store pullers parts and adapters together. Some shops mount puller sets on "tote" boards so all indivídual parts may be carried to the job.
RE P A I RS T A NDS ( g e a r )lrom o sho(!' F i g . 7 - 2 1 . B a s í c P u llin g io b - p u llin g o n o b ie ct
(o.r.c.)
and differEngine block, head, transmission by using are greatly facilitated ential repairs a repair stand. Many types are available. When stands, attach the unit securely to using repair t h e s t a n d . C a r e l e s s n e s s h e r e c a n b e c o stl y. Fig. 7'26, shows an engine block mounted in a stand. Note the crank that allows the engine to be turned to varíous Positions. stand mounted in a similar A transmission 7 F . i g . 2 7 . i n p i c t u r e d is heads are attached to a bench Two cylinder fixture in Fig. ?-28. As with all stands, tighten holding screws
securelY.
HAND LIFTING ( o xle ) lr om on obi ect' F i g . 7 - 2 2 . B o s i c p u llin g io b - p u llin g o sh o lt
P R E S S INGA GAINST HOUSINGEND
a mechanic will want to hand Occasionally important There are several object. an lift in order to avoid injury. points to remember If the object is quite heavy, 1. Never overlift. ask for helP or use a lift. 2. Keep your back straight and lift with your l e g s . K e e p l e g s a s c l o s e t o g e t h e r a s p o ssi b l e ' 3. Unless you KNOW you can handle the weight, never hold some part with one hand while you remove the last fastener with the other' 4. Get a firm grip to prevent dropping the unit - possiblY
on Your feet.
5. Do not "show off your strength" by attempting
Fíg.7-23. Bosic
p u llin g io b - p u llin g o n o b ie cf (seol ) l ¡on o h o u sin q b o r e '
Á
114
If all a to lift heavy obiects. Remember: be you could garage needed was STRENGTH, replaced with a JACK. Be careful of sharP edges.
rg
Wr 4tffi\
ff,,g P\
#?
k
ás
yoke l or F i g . 7 - 2 5 . M e ch o n ico l p u lle r s, l- He o vy- d uty, 2-Medi um-duty. 3-S l rde hommer,4-Three-j aw ,5-S pl i t g r o s p in g b e h in d g e o r s, b e o r in g s, e lc. ó - Reo¡ w heel hub adopl er, 7-R eor w heel hub pul l er, S -S /otted cross o¡m, 9 - S f i o ¡r slid e h o m n e r ¡ o d , l0 - Re ve r sib le p ul l er l ow s. l l -S tep pl atesforpul l i ngondi nstol l i ngbushi ngs,beori ngs, se o /s, e lc, l2 - T in in g g e or ¡ow s, I3-S i ngl e-l ow . l 4-C Iutch pi l ot beori ngpul l er. ( P¡oto)
S U P P O R TARM
ENGINE
SUPPORTA R M
Fi g,7-27. Tronsmi ssi on i n repoi r stond.
(o.T.c.)
F i g . 7 - 26 . On e typ e o l e n g in er e p o ir sto n d .
tls
HEAD MOU N TIN G BRACKET
ing all types of shop equipment. Study them and even though your shop may not have all the different types, you should be ful1y informed as to what is available.
L UCK ?. DO N' TY O UB E L T E V EI T !
F i g . 7 - 2 8 . T he cylin d e r h e o d h o ld in g lixtu r e g reotl y l oci l i to¡es r e p o ir wo r k. ( Sto r n - Vu lco n )
SUMMARY
1r ,i i , r flrai. ! EG l:t ¡
Me ch an ic s s hould be f am iliar w i t h varl0us lifting, pu11ing, pressing, etc., tools to make their work easier and more efficient. The tools covered in this chapter must be used with extreme caution. Observe all recommended safety precautions. Hand jacks have many applications. jacks are very handy for raising and Floor positioning ears. Never get under a car supported by a floor jack without first placing jack stands. Be careful not to damage parts when lifting. End lifts have a fairly high reach and support the car safely. Make sure the safety lock is in position. Single and double-post lifts can be designed to engage either the frame, suspension system or the tires. All have advantages and disadvantages. Cars must be centered on the lift and the lifting brackets should be properly and securely p laced . Use care when determining tift points to avoid chassis distortion or parr damage. Transmission jacks, wheel dollies and portable cranes, facilitate the removal and installation of heavy parts. Hydraulic presses are superior to striking too1s. Use whenever possible and use withcar.e. The shop should have a wide selection of pulling equipment. Repair stands for engines, transmissions, etc., make the job faster, safer and easier. Always place unit in stand securely.
The auto shop, by its very nature, presents nurnerous hazards. Despite this, many mechanics work at the trade for a lífetime without serious injury. Others, however, are frequenily injured, some are killed. Is shop safety then, a matter of luck? Absolutely notj The major things that wiLl keep you in one piece on the job are an understanding of and respect for the dangers involved, consistently following all safety rules, and the development of a "think before you act', attitude. On each anci every task, apply these suggestions. Apply them over, and over and over until they become habits- -habits which may someday save you from serious injury or death.
OUIZ - Chopter7 1. A car srrppo"t.i on a good floor jack, well placed, is safe to work under. True or False ? 2 . J a c k c o n t a c t p o i n t s a r e n o t i m p o r t an ta sl o n g as the jack gets a good grip. True or False ? 3. End lifts, ifproperlydesigned, provide holding power sufficient to allow the mechanic to work beneath the car without iack stands. True or False ? 4 What type would better tend itself to drive line work - the single-post frame or the double-post frame lift ? E T h e d r i v e - o n l i f t i s i d e a l f o r p u l l i ng w h e e l s. True or False? Never_a lift without checking beneath the car. ¡7 Lift height can safely be varied without getting out from under the car. True or False? B . Despite the type of lift, always check the before getting under the car. _lock o A lift should be raised and lowered_. 1 0 . Transmissions are best handled with a 1t
Heavy wheel assemblies are easily handled with a_ t2. When moving an object with a portable crane, keep the Load as_as possible. 13. An engine, suspended from a crane, is safe to work on. True or False ? 14. When attaching lift chains and cables with
SU GG ES TEADCTIV ITIE S 1. Make it a point to receive instruction in the use of, and practice using, all lifting, pressing and pulling equipment in the shop. 2. Maintain a file of up-to-date catalogs cover-
116
Jocks,Pullers,Presses,HoldingFixtures
15. 16. li. 18. 19. 20.
e t c . , t h e y a r e b e s t p l a c e d o n an appropriate
cap screws, how much thread engagement is ne ce ssary? Stand_of heavy loads. Of wha t u se is an ex t ens ion jac k ? Give three reasons why a hydraulic press is superior to stríking tools. What tool is very helpful in straightening heavy body sections ? List the three basic pulling setups. When working on engines, transmissions,
2L. Give
three safety precautions concerning hand lifting. 22 List seven safety rules regarding jacks and lift s. 23. List five safety rules regarding portable cranes and chain hoists, 24. Give five safety rules to observe whenusing hydraulic pressing or pulling tools.
.i:
A porrobre -.""',?l;'";1,:;i;
u7
"
vervhondvtoot'
Auto Service ond Repoir
T ILT sC R
TE LESCOPIN G RAM
FOOT PUMP LEVER
F L EVER REL EASE
SWIV EWH L E E LMOU N T
Hig h r eoch f¡onsmíssíon i ock. Thi s j ock noy o/so be u se d to l rondl eengi nes thot ore pul l ed l ¡on under the cor,
lr 8
Chapter8
NG,BRAZING, SOLDERI WELDING CRACKDETECT¡ON AND REPAIR
This chapter is designed to províde basic :echniques, machine operations and safety rules pertai.ning to soldering, welding and brazing. Most welding and brazing is confined to the body shop. However, you will find that welding skills jobs. can be used on many different Students of auto mechanics should take at least cne basic course in the welding field. USE CAI1E WHEN WELDING, HEATING OR ::'TTING. FiRE O R EXPLO SiO N CAN O C C U R . :.:EP AWAY F RO M FUEL TANKS, BATTE R I E S .:.\D OTHER FLAM M ABLE I TEM S.
Fi g. 8-1. 7ñe sol de¡ ond metol "ski n" omal gomoteupon c ool i ng lhus Íorming o tight bond.
the chart in Fig. 8-2, and note how temperature and plastic range is affected by alloying in different proportions. A solder that has awideplastic range is required for ear body work.
s OLDER ING Soldering-can be defined as the act ofjoining :wo pieces of metal through the use of a lead and ::n alloy. There is no actual fusion (melting toEether) involved. The solder, when the base metal :s heated to the correct temperature, seems to o'terally dissolve a minute "skintt on the metal. --pon eooling, the solder and "skint'amalgamate rmix together) thus forming atightbond, Fig. 8-1. In soldering, the pieces to be joined should :--t together as closely as possible. The less solder separating the parts, the stronger the - oint.
TIN-LEAD FUSIONDIAGRAM ',2f 621
''r + -EAD+
\ r
t
o/ /eo
?a/ /3a
\a/ /7o
t76"
tu 136'
4a/ /6a
/5o
I I i
]".
.a/ /aa
70, /ra
ao /2a
so/ + / a +
\I
&
S O LDER Solder is a mixture of lead and tin plus 'ninute traces of zinc, copper, aluminum, etc. The proportion of tin to lead affects both the :oelting point (poi.nt at which solder becomes a i':11 liquid) and the plastic range (temperature span from the lowest point at which the solder becomes mushy or plastic, to the highest point ;ust before the plastic mixture liquifies). You will note from Fig. 8-2, that pure lead :nelts at 621 deg. F. and pure tin melts at 450 Ceg. F.. A mixture of about 63 percent tin to 7 percent lead will melt at 361 deg. F. Study
Fi g.8-2.
I
PLASTIC
I
399.
\
-F^a
UID
}\ t\
,35.
rrñ
Q10"-
-
{t
PLAfiTrcf
Ti n-l eod ol l oy pl osti c ronge ond mel ti ng po i nt c hort. (K este¡)
C o m r t r o n l y u s e d s o l d e r s a r e 4 0 l 6 0 ( 40 p e r c e n t t i n , 6 0 p e r c e n t l e a d ) , 5 0 / S O a n d 6 0 /4 0 . Solder is available in bars or ingots for plumbing, and body and fender work. Flux core wire solder (wire solder with a hollow center fi11ed with flux), solid wire solder, and solder ground into fine grains, and mixed with flux, are used for general soldering.
lt 9
36r'
F í g . 8 - 3 . H on d y size so ld e r ín g ir o n s. A' L ig h t duty' B -Medi um d u ty. Q,' He o vyd u ty. ( Sn o p - Onfo ol s)
SOLDERINGFLUX Soldering obviously heats the metal andin so (surface of the oxidization doing accelerates metal combining with the oxygeninthe air). This leaves a thin film of oxide on the surface that tends to reject solder. It is the job of the flux to remove this oxide, andprevent the reoccurrence d urin g th e s older lng Pr oc es s . Chtoride or acid flux is excellent for use on ra dia tors and ot her s older ing wher e a c o r r o s i v e and electrical conductive residue (f1ux remaining on the work after soldering) is not harmful. Hot water should be used for cleanup after soldering. BE SURE TO KEEP ACID FLUX OIIT OF YOUR EYES. Organic flux is somewhat like the acid type, and t he f lux r e s i d u e b e b ut is les s c or r os iv e comes flakey and soft, and can be readily reor wiping with a moved by dusting, tumbling da mp clo t h. I t s ef f ec t iv enes s is los t i f s u b j e c t e d to su sta ined high t em Per at ur es . Ro sin or r es in t y pe f lux M US T B E U S E D WORK. The residue ELECTRICAL FOR ALL nor will it conduct corrosion, will not cause be rernoved with may The residue electricity. kero se ne or t ur pent ine. for soldering A special flux is required aluminum.
SOLDERINGIRONS Th e s older ing ir on, s om et im es c a l l e d a c o p per, should be of ample size for the job. An excessive iron that is too 9ma1l will require time to heat the work and may never heat it The proper sizé iron will bring the properly. rnetal up to the correct soldering heat (around and will produce a 525-575 deg. F.) quickly good job. Plain irons or coppers (must be placed in a furnace to heat) gas flame or in an electric work, range in si.ze from around 1/2 lb. forlight up tci several pounds for heavier tasks. irons are fast and efficient. A 100Electric wa tt siz e is r ec om m ended f or light w o r k , a 2 O O watt size for medium work and a 35O-watt iron work. (Wattage will vary - these for heavier
gun suchos ?hiswo¡ksfosf' Fig.8-4. A solderíng (SnoP'On Tools) See size recommendations.) are approximate Fig. B-3. gun as a soldering wiring For electrical s h o w n i n F i g . 8 - 4 i s i d e a l . T h e ti p r e a ch e s soldering heat in a matter of a few seconds.
CL E A NI NG WO RK A 1 l t r a c e s o f p a i n t , r u s t , g r e a s e , sca l e , e tc', wheel, wire The grinding must be removed. file, steel wool, emery c1oth, cleaning brush, the solvent etc., are all useful in preparing that GOOD Remember surface for soldering. WEL L CLEAN, REQUIRES SOLDERING FITTED
SURFACES.
TINNINGTHE IRON The soldering iron tip is made of copper' and will through the solvent action of solder and prolonged heating, pit and corrode. An oxidized transfer or corroded tip will not satisfactorily heat from the iron to the work, and should be cle-aned and tinned. Use a file and dress the tip File the surfaces down to the bare copper. smooth and f1at. See Fie. B-5.
\ T IP BAD LY C O R R O D ED
Fis.8-5.
F ILED C L E A N AN D SMO O TH
F i l e ti p s ur foc es l l ot ond s mo o f f r.
Then, plug the iron in. When the tip color begins to change to brown and li'ght purple, dip the tip in and out of a can of soldering flux (rosin core) and quickly apply rosin core wiré
120
Soldering,Brozing' Welding,Crqck RePoir
solder to all surfaces. If no paste flux is availab1e, rosin core wire solder will do' However' and usually a faster the tip provides dipping better tinning job. The iron must be at operating heat to tin When the iron is at the proper temproperly. and flow melt quickly will solder perature, THE UNTIL TO SOLDER TRY freely. NEVER If 8-6' Fig' See TINNED. IRON IS PROPERLY to adheres solder of surplus a tinning, during the tip, wipe off the excess with a rough textured cotton rag.
W IR E SO LD ER
I
fr ¡ Fis. 8-8. Apply soldet . tT""'J;01
the iron whereif conrocts
the flux where it will do the most good' Flowing solder at this point will also provide a mechanical bond between iron and work that will speed up heat transfer, Fig. 8-8.
WORKMUSTBE HOT CORRECTLYTINNED
Fig.8'6. The tip mustbe properlylinned' Some shops use a block of sal ammoniac to The hot iron is rubbed on the aid in tinning. block as solder is aPPlied.
HOLDINGTHE IRON The iron must be held so that the flat surface work' This of the tip is in full contact with the Fig' B-7' heat, of will permit a maximumtransfer
A PPLYSOL DE RTO E DGEOF IRON Apply the wire where it contacts
solder at the edge of the iron the work. This will release
should be Pieces to be joined by soldering in the heat heated so the solder is melted by is this When to be soldered together. metals job good a and done, solder will flow readily is will result. If the solder melts slowly and If hot enough' not is work the pasty looking, be careful parts, the heat to using a gas flame to avoid overheating
S WE A T I NG T w o p i e c e s m a y b e j o i n e d b y t i n n i n g th e ' contact surface of each, placing them together and applying heat. When the tinning metal melts' T h i s p r oce ss the pieces are held infirmcontact. union' if a strong produces called sweating, B 9 . F i g . S e e d o n e . properlY
SOLDERINGW¡RE SPLICES Apply the tip flat against the splice' Apply core wire solder to the flat of the iron rosin where it contacts the wire. As the wire heats' t h e s o l d e r w i l l f l o w t h r o u g h t h e s p l i c e , F i g ' B- 1 0 '
DO t{OT lvlOVEWORKUNTIL COOL
TIP IN FULL CONTAC I W ITH WORK RIGHT
F i g . 8 - 7 . Ho ld th e tip llo t o g o in sr th e wo r k'
When joining two or more pieces by soldering' be careful not to disturb them until the solder has set (cooled to the solid state)' If they are moved rvhile the solder is still in a pasty state' fracture lines wil'I be set up that will produce a weak joint.
121
t u x
¡
Auto Service qnd Repq¡r
point high enough to melt the brazing material but not the work itself. Steel, for e*ample, is brought to a dull red heat. A suitable brazing rod is brought into contact with the heated joint and melted. Capillary action (attraction between a solid and a liquid) draws the brazing alloy into the joint. The work must be clean, properly fluxedand brought to the coruect temperature. Parts should be held together securely during the operation and while cooling, to avoid internal fractures.
B RA Z EWE L DI NG
F i g . 8 - 9 , "Swe o fin g " fwo p ie ce s o l m e ¡ o l together. A -Ti nni ng ports. B-Place together an¿ heot. C-Hold tightly logether until so /d e ¡ se ts.
Braze welding is quite simr'lar to brazing exeept that the joint between the parts is of a poorly fitted type. Brazing rod is actually flowed into the joint and built up until the joint has sufficient strength. See Fig. 8-11.
B RA Z I NGRO D (brazing with Brazing and silver soldering a filler rod of silver alloy) rods come in a wide variety of alloys. A regularbronzeor manganese bronze rod is fine for average garage use on steel, cast iron and malleable iron. Melting temperature is around 1,625 deg. F. with a (bonded to steel) of around tensile strength 40,000 psi.
WIRESPL IC E F ig . 8 - 1 0 . So ld e r in go wir e sp li ce.
RUL E SFORGOODS OLDE RING 1. Cle an ar ea t o be s older ed. 2. Parts should fit closely together. 3. Iron must be of sufficient size and must be hot. 4. Iron tip must be tinned. 5. Apply full surface of tip flat to work. 6. Heat metal to be joined until solder flows readily. 7. Use proper solder and flux for job at hand. B. Apply enough solder to form a secure bond but do not waste. 9. Do not move parts until solder sets. 10. Place hot iron in a stand or on a protective pad. 11. Unplug electric iron as soon as finished.
Fi g. 8-l I.
B ¡ozed ond braze w el ded j oi nts ,
B RA Z I NGF L UX Numerous fluxes are. avai.lable. Choose one compatible with the brazing rod being used. Rods are available with ftux coatings. Flux in both powder and liquid form is commonly used. The uncoated bronze rod is heated (the tip) and dipped into the flux. Enough will adhere to phovide proper fluxing for a short while. The flux helps to remove oxides, and keeps oxides from f o r m i n g d u r i n g t h e b r a z i n g p r o c e s s.
BRAZING In brazing the temperatures involved are higher than in soldering (above 800 deg. F.). Brazing consists of heating the work to a
122
Soldering,Brozing, Welding,Crqck Repoir
SOURCES OF HEAT FOR BRAZING A Bu nsen b ur ner , blowt or c h, pr opane to r c h , :xyacetylen e tor c h, c ar bon ar c , et c . , wil l a 1 l :rod uce su ffieie nt heat f or br az ing and b r a z e ',relding. torches Propane an-d oxyacetylene rre well suite d f or t he job and ar e gene r a l l y :i'ai.lable in the shop. The a ce tyle ne t or c h, Fig. B- 12, is s im i l a r :o a p rop an e tor c h. A r egulat or is at t ac h e d t o a tank of gas, the tank valve is opened and set :cr th e de sire d f low. As t his t or c h ut i l i z e s rxygen from the air, only one tank (acetylene)
FLAMECONTROL TANK CONNECTION
:s req uire d. Se v er al t ip s iz es ar e av ailable . A regular oxyacetylene outfit (uses a tank :1 oxygen and a tank of acetylene) is shown in aig. B-13 . Oxyac et y lene f lam e t em per atu r e s : rce ed 6 ,00 0 de g. F. See Fig. B- 13.
Fi g. 8-12. S o/de¡- broze ki t.
YG ENCYLI NDERG AU G E
(Morquette)
TIP PRESSURE A C E T Y L E N EG A
ETY LEN E I N D E RGAU GE
LIGHTER
TANKCO NNECT I O N
ACETY LEN E R E G U L ATOR
ADJ UST PRESSURE
M I X E RV A LVE
GOGGLES
TIP CLEANER
BRAZINGAN D W E TIP ATTACH M ENTS I T T I N GT O ATTAC H T O M I X E RHAN D L E ATTACHMENO T X Y GEN C O N T R O LV A L Y E C U T T I N GA T T A C H M E N T
C U T T I N GT I P
F ig . 8 - 1 3 . Oxyo ce tyle n ew el di ng, brozi ng ond cutti ng outl i t.
123
(Morquel te)
I Auto Service ond Repoir
BRAZINGTE CHNIOUE Select a tip size appropriate tothe work. The size chart, Fig. B-14, will give you an in_ dication of size in relation to metal thickness. Note the recommended gas pressures. tip
APPROXIMATE GAS PRE5SURES FOR OPERATINC AIRCO WELDING TORCHES Tip
000
No.
M ix er Thic k nes s M et al
00- t
00- l
t/64
t/32
1231561 t- 7 1- 7
t- 7
1-7
l./8
3/16
t- 7
TIP DISTANCEAND ANGLE IS IMPORTANT t_7
ó- 10
of
( I n. )
Oxygen Pr es s ue
( ps i)
Pr es s u¡ e
( ps i)
l/16
3/32
1./1 5/16
3/B
7 5
F ig .8 J4 ,
and clear; a trifle more heat will be sufficientTouch the filler wire to the work. When the heat is eorrect, it will melt and tin the parts. Use the tip to guide the flow of metal (tinning action follows the heat). Make sure the filler enters the joint full length and that it tins properly.
7
Iip size o n d p r e ssu r ec hor!.
The distance the torch tip is held from the work affects the rate and extent of heating. Parts with a low melting point will require holding the tip further from the area to be brazed, Fig. 8-1?. By holding the tlp at an angle, trig. B_1g, the work is kept at brazing temperaturé with minirnum danger of overheating. Note how the distance is varied to suit the work, while the angle is maintained.
A CE TYLEN E F E A THE R
K E E PT I P I N MO T I O N Keep the tip in motion to spread the heat. If the flame is kept in one spot too long, over_ heating may result. A circular motion, Fig. B - 1 9 , i s d e s i r a b l e . T h e s i z e o f t h e ci r cl e sh o u l d be decreased as the joint becomes heated. When brazing temperature is reached, the circles should be quite small. Using a zigzag motion during the application of the welding rod is also satisfaetory.
o xtDtzrN c
fiir
NEUTRAL
F i g . 8- 1 5 . Co r b u r izin g , n e u t¡ o l o n d o xid i zi ng Íl ames.
Adjust the torch to produce a neutral or stightly carburizing (excess acetylene) flame, F ig. 8- 15 . With the parts CLEAN, CLOSELY FITTED ( ideal jo i n t g a p fo r b ra z i n g i s .0 015 - .003), FLUXED and FIRMLY HELD, apply heat to the joint. Use a brushing motion of the torch tip as s hown in F i g . B-1 6 . Watch the flux. Wben it starts to turn watery OXY - ACETYLENE TORCH
B RA Z EWEL DI NGT E CHNI O UE In braze welding, a groove, fillet or slot is filled with nonferrous filler metal, having a melting point below that of the base metals, but above 800 deg. F. The filler metal is not dis_ tributed by capillary attraction. The technique used for braze welding is similar to brazing. Once the brazing rod has flowed out and the parts tinned, the heat should be carefully controlled so the braze metal can be built up to the desired thickness. The rod meta1, as it is fed, must mixwiththat added be_ fore but must not cause the buildup to flow. See Fig. B-20.
BRUSH MOTIO N OF TORCH FIL LER M ET AL AP PLIEO F R OM S EN O OF J O IN T ,
TORCH M OVEO IN TH IS D IR EC T ION .
JOINT
RUL E SF O RG O O DB RA Z I NG
F i g . 8 - 1 6 . H e o t jo in t p r io r to o p p lyin g b r a zin g m ateri al . When hot, stort opplying liller metal from one edge and use rfie brushing motion of the llome to drow materiol olong ond ínto the ¡oint. ( AT RCO)
1. Work must be clean and well fitted. 2 . U s e a t i p a n d g a s p r e s s u r e s i n k e e p i n g w i th the job.
124
Soldering, Brozing, Welding,Crqck Repoir
3. Use a neutral or slightly reducing (carburizing) flame. 4. Keep tip in motion. 5. Hold the tip at an angle to the work. 6. Heat may be controlled bychangingdistance from tip to work. 7. Braze metal should be suited to the job. 8. Use a good flux. 9. Braze metal must penetrate the joint and tin the surfaces. 10. Parts must be held in position and not disturbed until braze metal sets. 11. Avoid overheatins,
F i g . 8 - 1 7 , f l r e d i s fo n ce Ír o m tip to wo r k o ( Íe cts h e o t t¡onsl er.
G A SWE L DI NG Unlike brazing, welding is a fusion process. A portion of the metal of eaeh part is melted. The melted areas flow together and upon cooling form one solid part. Filler rod is often added during the process.
PREPARINGTHE JOINT Fig. 8-18. Hold to¡ch tip ot on ongle to the work. (Brozing.)
Thin metal, ll32 in. or less, is oftenflanged to protect against heat warpage - A, Fig. B-21. P a r t s n o t e x c e e d i n g 1 / B i n . m a y b e w e l de d b y using a square edge-butt joint - B. When -metal t h i c k n e s s r a n g e s f r o m a r o u n d 1 / 8 - 3 / B i n ., a V-joint is used - C. Parts o v e r 3 / 8 i n. a r e prepared usually with a double V-joint - D, Fig. B-21. Both the joint and the immediate area must be cleaned of rust, scale, paint, etc.
COR RE C T
\
W RONG.
Éia) \ rt
\
I
rl
IJ htt tfi t{i )fd.
F LAN G E J OIN T
B U TT
!--¿::--/::
F i g . 8 - 1 9 . K ee p tñ e to r ch tip in m o tio n .( Br o zin g .)
ilbü
O. K.- LESs HEAT
FLAM E TOO HOT AND TOO CLOSE
Fi g, 8-21. Y l el d ¡oi nt preparoti oni n vo¡i ous thi cknesses o l me¡ol .
USE NEUTRAL FLAME
B RA Z E MATERIAL B U IL DIÑGUP IN JOIN T
Use a neutral flame for gas weldi.ng. The neutral flame will permit smooth, dense welds of high strength. There will be no foaming, sparking, etc. A carburizing flame (excess acetylene) wiII cause molten metal to pick up carbon from the flame. This causes the metal to boil and upon cooling, to become brittle.
ERAZE BUILDUP FLOWINGTHRO U GH JOINT
F;s.8-20.Broze welding.
A-Corect. 8-7oo ñot. Nofe fiow 6roze m e lo l 6 o se so o s.
t25
Auto Service ond Repq¡r
(excess of oxygen) will flame An oxidizing cause the metal to foam and send off a shower of sparks. The excess oxygen combines withthe porous, steel causing it to burn. The weldwillbe weak and brittle.
ing rod can be moved from side to side, in small circles or in half-circles. THE WELD SHOULD PENETRATE THROUGH THE JOINT. Fig. 8-22 shows both the forehand, and backhand, techniques.
TIP SIZES E LE CTION
OXYACETYLENE CUTTINGTORCH
Torch tip size must be suited to the job. Fig. 8-14, gives typical tip sizes and gas pressures for different metal thicknesses.
The cutting torch finds many uses in the auto shop. In an oxyacetylene eutting torch, a preheating flame is maintained,at the tip through small orifices or openings around the center orifice. The preheating flame is held close to the work at the point where the cut is to start. When the spot has been heated to a bright eherry red or hotter, depress the oxygen jet lever. When the stream of pure oxygen strikes the heated area, it will cut (burn) through the steel. As soon as the cut starts, move the torch along the work. Move as rapidty as the cutting will allow. Keep the oxygen lever fully depressed. If the cutting action stops, release the oxygen lever and with the preheat flames (they burn continuously), preheat again. Holdthe toreh tip at right angles to the work with the preheat flames just clear of the surface, Fig. 8-23.
WELDINGTE CHNIOUE METHOD BACKHAND back into the The tip should be directed molten puddle, away fromthe direction of travel. The rod is held between the flame and weld.
PR EHEAT IN G T H E ED GE
+ PR EH EAT F LAM ES J U ST C LEAR WORK
ACKHAND
Fig. 8-22. Forehondond hoclchond weldingtecñnigues. lAiRCO) C U TTI N G S TR E A T
(metal When the base metal of parts being joined) melts and forms a puddle, the filler rod is added as the weld progresses. MELT THE ROD BY INSERTING THE END INTO THE PUDDLE. Do not hoLd the rod above the puddle and allow it to melt and drip ín. THE INNER FLAME CONE MUST NOT TOUCH EITHER THE ROD OR THE PUDDLE. Move the flame along the weld in a steady fashion, causing the base metal to reach the fusion state just ahead of the puddle. The weld-
Jr {
ill
Fig. 8-23. Hold ¡he cutting tip at right ongles to tlre work so preheot flomes just clear the work.
Note how the eutting toreh removesanarror kerf (cut) and how the molten metal (stag) is blown out from beneath the work, Fíg. 8-24.
126
Soldering,Brozing, Welding,Crock Repoir
E OUIP ME N T SETTIN G UP O XY A CE TY LE NE Keep both the acetylene and oxygencylinders supported securely. The acetylene cylinder should be in the upright position to prevent loss of acetone (acetylene cylinder is filled with
acetone soaked porous filler material). Keep cylinders away from heat and flames. Protective tank valve caps must be in place when cylinders are stored. Mark empty tanks with the letters MJ¡ tsig.;8-24AA, id.ustrptes how tankS or ,cyünders are--attached to the welding setup.
RE G UL A T O RS The oxygen regulator has a right-handthread and the acetylene a left-hand thread. This preon the wrong vents instaliing the regulators cylinders.
F i g . 8 - 2 4 , T o r c h c u ttin g o cfio n . No le u se o f g lo ve s. ( L i n co ln Ele ctr íc Co .)
OXYGEN HOSE CONNECTION
WELDING TORCH
L I N D E RC O N N EC TION (RIGHT.HAND THREAD)
CYTINDERPRESSURE GAUGE WORKING PRESSURE GAUGE
t
WORKING PRESSURE GA U G E
T
CYTINDERPRESSURE GAUGE
\
OXYGEN HOSE
I
ACETYLENE VALVE WRENCH
OXYGEN REGUTAIOR
É u ACETYLENE HOSE
= J
APPARATUS IVTENCH
rKR EE rruK S StU R E TIrrI P P
C ON TR OLH A N DLE
ACEIYTENE REGUTATOR A
3E:ú3
i i rl ói ¡_.i IX OTH R E A D )
Fi g.8-24A . Typi col oxygen regul olor. Nole high reoding cylinder gouge.
tr=-p sP^.RKLIGHTER
H OS E C ON N E C TION
I
I
z u o x o
u z U J
TWIN HOSE
F E I
Fig. 8-24AA. Oxyocetylene weldíng sefup.
(ATRCO)
The regulators reduee cylinder pressures to a controlled and useable amount. Figs-8-?44' and 8-248, illustrate typical regulators; Note the cylinder and hose fittings. The right-hand gauges read cylinder pressure, while the lefthand gauges indicate tip operatingpressure. Tip pressure is varied by adjusting the handles. Before attaching regulators to cylinders, crack (open slightly) the valve on each cylinder a small amóunt for a second to blow out dust or other foreign material. Do not crack the acetylene near any open flames or near a welding operation. Attach the regulators to their respective tanks. Tighten gently. NEVER USE
127
TYL ENE CYLINDER P RE S S U R E GAUGE
ATTACH TORCH MIXING HANDLE The torch mixing handle should be attachec t o t h e h o s e e n d . D o n o t o v e r t i g h t e n e i th e r m i xend hose connections. ing handle or regulator Wh e r e r u b b e r O - r i n g s e a l s a r e u s e d, h a n d ti g h tNote the oxygen and acetening is sufficient. ylene mixing valves, Fig. B-25.
CYLI NDE RC O N N E E T I O N ( LEFT- H A N DT H R E A D ) TIP PRESSUR E GAUGE
ADJUSTINGGAS PRESSURE
TIP PRESSURE CONTROL HANDLE
HOSECONN ECTI O N (L EFT.HANDTHREAD) Fig. 8-248. Typícol ocetyleneregulotor.Note
l eÍt- hond
thr es d
connectlons.
DO NOT HANDLE GAS OIL ON REGULATORS. ORGREASY WELDING EQ UI PM ENTW I THO I LY AND DO NOT WEAR OIL SOAKED HANDS, CLOTHING. OiI, in the presence of pure oxygen, becomes highly flammable. Back out t he pr es s ur e c ont r ol ha n d l e o n e a c h re gu lato r ( c ount er c loc k wis e) unt il fr e e .
I
ATTACH HOSE Atta ch hos es t o t he r egulat or s . T h e a c e t y l e n e ho se is nor m ally r ed and t he ox y g e n g r e e n . fittings are left-hand threads while Aeetylene
A f t e r i n s t a l l i n g t h e d e s i r e d t i p , M AKE SU R E PRESSURE CONTROL HANTHE REGULATOR ( C O U N T E R CL OC KWISE DLES ARE BACKED O F F . T H E T A N K V AL VESM Al COMPLETELY T H E N B E O P E N E D - V E R Y S L O WL Y. Op e n th e VALVE about ONE TURN. Ope: ACETYLENE the OXYGEN valve ALL THE WAY in order tc prevent leakage around the valve stem. Leave WR E N C H i n p l a c e o n th e va l ve the ACETYLENE to facilitate an emergency shutoff - if requirec at any time. mixing valve. OPE\ SHUT the ACETYLENE the OXYGEN mixing valve. Turn the OXYGE\ regulator handle in (clockwise) until the desirec w o r k i n g p r e s s u r e i s o b t a i n e d ( r e a d l o w p r e ssu r e gauge). PURGE (clear the hose of air or othe: gases) the oxygen hose line by allowing oxyge:. to flow from the hose momentarily. SHUT of: the oxygen mixing valve. OPEN the acetylene mixing valve (oxyger. valve off) and adjust acetylene regulator to des i r e d p r e s s u r e . F o l l o w i n g p u r g i n g , cl o se a ce tylene mixer valve. LINES IS VERY IMPORTANT. PURGING F A I L U R E T O D O S O C A N A L L O WA C E TYL EN E TO ENTER THE OXYGEN HOSE AND VICE-
M IXERVALVE
F ig . 8-25. Torch ni xi ng hondl e w i th o ti p ottoched. (Morquetl e)
V E R S A . TH IS OF C OU R S E , C R E ATES A CO M BUSTIBLE MIXTURE TNSIDE THE HOSE AND CAN CAUSE A FLASHBACK (FIRE BURNING INSIDE THE HOSE).
When using the oxygen fittings are right-hand. e qu ipme nt , k eep hos es away f r om h o t s p a r k s , flame, oí1, grease, etc. Avoid kinking, and coil when finished workins.
128
Soldering, Brozing, W el di ng, C rqck R epoi r
LIGHTINGTOR CH Open the acetylene mixer valve a small amount while operating a seratcher or spark lighter in front of the tip. KEEP THE TIP FACING IN A SAFE DIRECTION. HAVE YOUR WE L DI NG G OGG L E S IN POS IT IO N .. S eE Fi g. 8- 26.
minutes, hang the torch up out of the way. If it will be some time before the torch is needed, drain the lines. To drain the lines, shut offboththe acetylene and oxygen cylinder valves. Open one mixer valve at a time until the 1ow pressure gauge indicates there is no pressure left in that line. Back off the regulator adjuster handle. Close the mixer valve. Repeat on the other line.
L I G HT I NG CUT T I NGT O RCH pressure. to give required Set regulators oxygen valve. Open Close the cutting attachment the mixer oxygen valve all the way. Open the mixer valve and light the torch. Open acetylene oxygen valve and adjust preheat attachment flames to neutral. Depress oxygen jet lever and if preheat flames are altered, readjust. These are for a cutting attachment - shown directions i n F i g . B - 1 3 . G f a n o t h e r c u t t i n g t o r c h i s u se d , instructions.) follow the manufacturer's
moveso flinfoc¡oss Fig. 8-26. Sparklighter, thehondle Sgueezing o roughmelol surlocethvs producingo showerof spor/
BASICSAFETY RULES FOR OXYACETYLENE EOUIPMENT We a r p r o t e c t i v e g o g g l e s . Wear protective gloves and clothing. Keep all oil and grease away from equipment. Never use equipment with greasy hands or when wearing greasy garments. Have ample ventilation. Do not cut, we1d, or braze fuel tanks, until special precautions have been taken. n Do not work in an explosive atmosphere. 8. Always have a fire extinguisher on the job. o Open eylinder valves slowly. 10. Maintain good hoses and fittings. 11. Purge lines before lighting. '1, Never use defective regulators. 13. Inspect hose for damage following a flash1. 2. 3. 4.
r} r}D D
t / ,ll/ ,l l/ Dll/ ^ul / r/ / t/ / r/ /
,,# p¡ ñ,
,t llh
t
fil lK/ rc¡n|lY lr"tr A l///\ \
/,,;t;:'l
l'A
I:"':;':':"'¡ l/ \ l,'.i',1.,.,,;'l,l'l l/ 1,,:',,fl -/
\ -,t:" ;,',,t,1
l/l;,'A"Xl
z Y\
l/ \
I \
'*rr'.or\
t x oFEA T H E R ) \ sLrcHrLycaRBURrzrNG ( s HoRrFEATHER)
HEAVILY caRBURlzlNG
\
(LoNG AcETYLENE FEATHER)
back.
áfi;'.'*'
14. Never try to repair hose with tape. If a hose l eaks, di scard i t. 15. S tand to one si de of regul atorsw henopening cylinder valves. 16. Open acetylene cylinder valve no more than ONE turn. 1?. N ever use acetyl ene at pressuresexce eding 15 psi . 18. When adjusting either oxygen or acetylene pressures, make certain the other mixer . valve is closed. This willpreventflashbacks. 19. Hold torch in a safe direction whenlighting.
Fig. 8-27. Adlusting to o neutrol flome. Note ocefylene "Íeather'"
SHUTTING OFF TORCH Close the acetylene mixer va1ve. The oxygen ¡ill blow óut the flame at once. Then, shut off -Jre oxygen 'mixer valve. When using this tech*'que of shutting off the flame, make certain -Jre acetylene valve is not leaking. If you will be welding again within a few
129
Auto Service ond RePoir
20. Know what you are cutting or welding. Some coatings produce deadly gases when heáted' THERE ARE MANY MORE SPECIFIC SAFETY RULES. PROCURE A BOOKLET ON SAFE PRACTICES FROM ONE OF THE COMPANIES HANDLING GAS WELDING EQUIPMENT. HAVE AN EXPERIENCED OPERATOR ASSIST YOU UNTIL YOU HAVE MASTERED SETTING UP, A N D U S IN G T H E EQÜ I P ME N T LI G HT I NG ,t, SAFELY.
AR CWELDING
with the str.aight (negative) symbol (-). For a reversed polarity hookup, plug the rod holder cable into the crossed (positive) symbot (+). Polarity is not a factor in AC welding as the current is constantly reversing itself (60 times per second), Fi g. 8-30.
WE L DI NGS E T UP Study Fig. 8-31. This setup shows the welding machine, rod holder, ground clamp andconnecting cables.
By utitizing the intense heat (6,000 - 10,000 deg. F.) generated by an electric arc between the end of the welding rod and the work, both rod quickly reach the base metal and filler fusion state. As the work puddles, the rod end melts and flows into the molten base metal. The so-called arc force actually causes the molten globules of rod metal to travel through the arc to the puddle. This allows the arc welder to be used for overhead welding. See Fig. 8-28. T Y P E O F MA C H IN E Basically an arc welding machine may be an AC (alternating current) or DC (direct current) machine. Combination AC - DC machines are also available. The AC or AC - DC machine is generally a that alters the incoming power transformer (utility line voltage) to a lowvolt220-440 volts age, high amperage current for welding. Atypical AC - DC machine is pictured in Fig. 8-29' The DC machine is usually motor (electric or gas engine) driven. Both types have certain advantages and disadvantages. Machines are rated by maximum output in amperes. Thehigher the output, the heavier wetding the machíne will perform.
M O LT EN R O D
Fig. 8-28. lJsing the elecfric orc lor welding. Note molten globule tuoveling lrom ¡od to Puddle.
stLt€oN RECTIFIERS FAN COOLING
D, C. ELECTRODE ANDGROUND OUTLETS
D. C. REACTOR col L
TRANSFORMER
P O LA RI T Y
INSULATED GROUND fAPS FORHEAT SELECTION
A. C. HEAT RANGETAPS
D. C. HEAT RANGETAPS
Two common terms used in DC arc welding are STRAIGHT POLARITY and REVERSE POLARITY. Reverse polarity means the currentis traveling from the work, up through the arc to the rod and rod holder. Straight polarity means that the. current travels from the rod holder (often called a stinger) through the rod, across the arc, to the work. For a straight polarity hookup, merely plug (unless a polarity switchis used) the rod holder cable into the hole marked
PROfECTIVE
Fi g. 8-29. C ombi no¡i onA C -D C orc w el di ng m oc hi ne' (Morquette)
r30
R ODSIZE Welding rods (electrodes) usually t2 - L4 in. length, are available in many sizes (diameters) starting at 1/16 in. For general auto shop use, a n as s or t m ent in s i z e s 1 l t6 ,3 l 3 2 ,L l 8 ,5 l 3 2 a nd 3 /16 in. will or d i n a ri l y b e a d e q u a te .
D A R K GLA 55
H ELM ET \I
1-,
I,' ,. I
I
TO (+)
S T RA IGH T P OL A R IT Y
LE A TH E R JA C KE T
I I
t
TO (+)
FR9M ( _)
Fie. 8-30. Cu¡renl
WORK
trovel with straight and with reye¡sed
Fi g. 8-32. P rofecti ve equi pmenti s o musf,
polority,
PROTECTIVEEQUIPMENT EL ECT RODEHOL DE R
-- rl-=-
EL ECT RODE
\
IIIIELDIII{GMACHINE
Always wear a welding helmet to protect your face and eyes. A helmet has a dark glass window that will allow the operator to watch the blinding arc without eye strain or damage. L e a t h e r o r a s b e s t o s g l o v e s s h o u l d b e u se d to protect your hands from radiation and from spatter (flying bits of molten metal) burns. Clothing must be heavy and of ahardfinished cotton (no wool or synthetics) to shed sparks and spatter without igniting. Overhead andhorizontal welding can cause a rain of hot spatter to fall on your arms and shoulders. In these c a s e s , a l e a t h e r j a c k e t s h o u l d b e w o r n . S ee Fi g . 8 ¡ . 3 2 . P o c k e t s m u s t n o t b e o p e n t o r e c e i ve r e d hot drops. Shoes must have leather tops and should be high enough to prevent the entry of Do not rilear a ring as it is possible, sparks. with heavy welding currents, to inadvertently ground the ring between the work and the rod. This can heat the ring to a high temperature very quickly.
I
P O W ER GROUNDCL AM P PLUG
--_.-,_ STEEL
TABLE TOP
ELECT R OD E HOLDE R CA
F i g . 8 -3 1 . T yp ico l a r c we ld in g se tu p , ( L in co ln Ele c¡ r ic Co .)
R ODTYPE Welding rods are usually coated to provide a gaseous shield around the arc. Thisshieldhelps :emove impurities and prevents oxidization. A special self-starting, rod is ofself-spacing fered. The coating is kept in contact with the Tork thus maintaining distance the corráct irom rod to.work. Rods are available for welding mild steel, carbon steel, cast iron, cast iron to steel, alu*inurrl, etc. Select a rod suited to the welding both in diameter and rod material. "ob
CAUTION,I Your eyes can suffer severe burn damage from rays produced during arc welding. NEVER WATCH THE An,C (PVEM FOR A SECOND) WITHOUT THE USE OF'A HELMET OR FACE MASK. Never strike an arc when another person
f3t
I I
AutoServiceond RePoir .i l
" w x r e "Ro Do u r r o
|
;
F ig .8 ' 3 3 '
T H | S POS I TI O N
-
Str ikin g a n o r c'
prois standing nearby unless he is wearing in that sneaky are tective gojgfes. Eye burns exthe follow immediately the pain does not posure.
UP TO WE LD SETT¡ NG Attach the ground clamp securely to a spot After on the work that is free ofpaint, rust, etc' set rod' of t¡pe and size correcl the selecting rnachine Turnthe recommended. as the machine on (make sure rod holder 'is not contacting holder work), insert a rod in the rodholder' The an provide to jaws must grip the uncoated end 3trike and on Llectrical path. Turn the machine an ar c .
PU D D LE
(rod)' Fig, 8-34. Welding with o whipping motion o( ¡he elect¡ode
5 - 15 deg' with the top of the rod tilted work 8-34' Fig. travel, of toward the direction Whipping should be done by flexing the wrist' of a series produces motion The whipping It will weld' the of top the along ridges circular for a while, to maintain correct arc be difficult, will enable you to practice Length. Continued machine develop skill. Always use recommended settings. a weaving motion will be reOccasionally help to bridge wider gaps and will quired. This metal over a wider surfaee' weld *i11 d.posit 8-34,4.. Fig.
S T RI K I NG A N A R C
START
work Strike the end of the rod against the arc the When with a short, scratehing motion. recommended forms, Pull the rod awaY the distance, Fig. B- 3 3 .
srARr-D
WELDING (melts)' move When the base metal puddles may be held the rod forward slowly. Some rods motion' steady while others require a whipping molten the of move the rod out When whipping, (solidify freeze to puddle ,rtttii ttt. puddle starts dutl sheen) - it trtrr" from a shiny wet look toa intothe back way part it move then immediately the hold again' fluid is puddle the puddle. When it out whip then second a split for place rod ln top' again. Repeat this process. Viewedfromthe straight a the whipping process can form either depending on the need' line or . C "tt"pu, Whipping is handy in c ontrolling burn-through wide gaps' in thin metal, or when working with to the angles right at The rod should be held
srARr-N /r-g¡¡¿gTto¡
oF WELD
Fig. 8-34tA. WeovingPottetns Íor orc welding' (Mo¡guefre)
S tudy are type
show n. and
*áfai"g effects.
132
Fi g.
8-35,
A I1 w el ds
si ze
in
w hi ch
w ere
el ectrodes.
a seri es
made Machi ne
w i th
of w el ds the
s etti ngs
s ame and
speeds were varied to demonstrate the
Soldering,Brozing, Welding,Crqck Repoir
,\. B. C. D. E. F. G.
Chip the slag (brittle eoating left on the weld from the rod coating material) from the bead job and use a wire brush tocompletethecleanup before making the next pass (bead). Some thick p a r t s r e q u i r e a n u m b e r o f p a s s e s . I f t h e sl a g i s not removed the joint may be full of slag inclus i o n s {p a r t i c l e s ) a n d b l o w h o l e s ( a i r p o cke ts) . WHEN CHIPPING OR WIRE BRUSHING, WEAR PROTECTIVE GOGGLES UNLESS YOUR HELMET I S D E S I G N E D T O T l P U P T H E D AR K G L A S S A N D P E R M I T Y O U T O L O O K T H R OU GH THE CLEAR GLASS. GETTING A P I E C E OF SLAG IN YOUR EYE CAN BE EXCEEDINGLY SERIOUS.
A good, smooth weld. Note the even whip marks and lack of spatter. Machine settings too low. The wetd is narrow with little penetration. It is piled high. Machine too high. Note excessive settings width, blowholes and heavy spatter. Se tting s O.K . but ar c t oo s hor t . Settings O. K. but arc too 1ong. Settin g O. K. , ar c O . K. but s peed t oo sl o w . Arc O. K., set t ings O . K. but s peed t oo f a s t .
BASICSAFETY RULES FOR ARC WELDING 1 . N e v e r l o o k a t t h e a r c u n l e s s w e ar i n g a suitable helmet or face shield. 2. Do not permit bystanders, unless they are wearing protective gear. 3 . We a r g o g g l e s w h e n c h i p p i n g o r w i r e b r u sh ing. 4 . We a r p r o t e c t i v e c l o t h i n g a n d g l o v e s . 5. Make certain the welding machine is properlrr
c¡n"-AoA
6. Never ..t^* ^
weld
while
standins
in water
or
on
^- ^,,- á
7. Never t r ¡ g. 8 -3 5 . fh e e ffe cts ol vor ious m ochine seffings, or c Iengths o n d w e l d i n g sp e e ds. Rod r ype ond size r em oined constont. ( Lincoln E/ectr ic Co.)
B. 9. 10.
The sound of the arc is helpful in determining -¡h en it is th e c or r ec t lengt h and of t he p r o p e r :-eat, A good arc has a steady "bacon frying 1n :ie pan" sound. A short arc will make popping ---o ise s a nd will t end t o c aus e t he r od t o s ti c k t o :re work. Excessive arc length will cause a :--gh, humming noise with a lot of spatter. The =r'c also tends to go out.
11.
c a r e l e s s l y s t r i k e a n a r c o n a ca r g a s tank, or on eompressed gas cylinders. D o n o t s t r i k e a r c o n a u t o m o b i l e b r a k e l i n e sgas lines, etc. Have adequate ventilation. Be careful when weldingmetalwithcoatings such as zinc, cadmium, beryllium, e tc, Th e fumes may be deadly. Disconneet the welding m a c h i n e b e fo r e attempting any repairs.
H O R I ZO N TA L
ED G E W ELD
MANYTYPESOF W E LDS Weld po sitio n and wor k s et - up c an be q u i t e '.-aried. This will requíre ski1l inflat, horizontal, ' "-ertie al an d o v er head welding. See Fig. B - 3 6 .
WORKSHOULDBE CLEAN Despite the fact that a good welder ean run = b ea d.th rou gh r us t , pai. nt , m ois t ur e, et c . , a l l neld are as sho uld be dr y and c lean. The w e l d arll go faster, look better and will. be stronger.
B U TT WE LD
D OUB LEB U TT WE LD
Fi g. 8-36. D i l h¡ent w e/ds ond w el di ng posi l i ons .
t33
Auto Service qnd Repoir
G ENER ALCA UTIONS 1. Do not adjust machine settings or attempt to change polarity while the machine is under load (wetding). To do so will damage the switch contacts. 2. Keep the ground clampandtoolholderapart. Never start the machine until certain the rod holder is not touching the work. 3. Keep cables tight in the sockets, clamp and rod holder. This will prevent excessive resistance and overheating. 4. Protect paint, glass, upholstering, etc., from hot spatter. 5. Keep cables coiled when not in use. 6. Do not attach ground clamp to bumpers or other chrome parts. Any looseness will cause arcing that will pit the chrome.
AL WAYSCHE CKFORP A RTCRA CK I NG
hi ,t ': t,
r.i' '
l:,
Many parts of the automobile, suchasengine blocks, pistons, crankshaftsr g€4rs, axles, wheel spindles, etc., can crack during service. During overhauls, parts shouldbe thoroughly cleaned and visually inspected for signs of cracking. Pay particular attention to suchareas as cylinder head valve ports, cylinder walls, bloc k wat e r j a c k e ts , P i s to n s , e tc . Critical parts such as wheel spindles, steering gears, axles, etc. should be checked with special detection equiPment. Cracks or fractures may be groupedinthree types: Cracks plainly visible to the eye, cracks so fine as to be invisible without deteetion equípment and internal cracks that do not reach the surface.
ME THODS CRAC KDE TE CTION
the feet of the magnet becomes heavily magnetized. A crack will interrupt or break this magnetic field enough to cause the iron powder to collect along the crack. The magnet should be moved into different positions as the process works best when the crack is at right angles to the magnetic field. Fig. 8-3?, illustrates the use of a powerful permanent magnet. Note the crack (in eolor) that has been exposed by iron powder collecting along the entire length. The poles of the magnet are at right angles to the crack.
F I E L DWI T HF L I J O RES C E N T MA G NE T I C MA G NE ITC P A RTI CL E S F E RRO This method also requires that a strong magnetic field be set up in the part. A special soLution that contains fluorescent ferromagnetic particles is then sprayed on the area to be tested. Fig. 8-38 shows a crankshaft being checked for cracks. Note the ring magnet and black light lamp. As with iron powder, the ferromagnetic particles are attracted to and held along the crack line. When exposed toblack light (invisible ultraviolet rays) the particles packed along the craek line will glow white while the remainder of the part will remain blue-black. Black light (ultraviolet rays) is not harmful to skinoreyes. The erankshaft in Fig. 8-39, has two cracks along the journal edges. Note that the cracks are cleprly visible under black light. NOTE: Magnetic crack finding will work ONLY ON MATERIALS THAT MAY BE MAGNETIZED. Nonferrous metals such as copper, aluminum, bronze, etc., cannot be magnetized. If in doubt, apply a magnet to the questionable metal. If the magnet sticks to the metal, it can be checked magnetically.
There are a number of techniques used to check for the presence of cracking ineluding X ray, magnetic, fl'uorescent, dye p,enetrants and (The X ray of these techniques. combinations expensive equipment and is technique requires not often used ín other than large speeialty
FLIJOR E S C EN T P E N E TR A N T This method involves the use of a special fluorescent penetrant 0iquid that readily enters even the finest cracks). The area to be checked is first cleaned with a patented cleaner. See Fi g. 8-40. Then the fluorescent penetrant is sprayed over the area, Fi g. 8-41. A small amount of cleaner is sprayed on the gear and the excess penetrant wiped off with a cl ean cl oth, Fi g. 8-42. The part is then sprayed with a developing
sho ps.)
FIE LDW ITH IRONP OWDE R M AG N ETIC A powerful' magnet (can be a permanent or an electromagnet) is placed across an area suspeeted of eontaining a craek. A fine ironpowder is then dusted over the area. The metal under
134
F i g.8- 40.
I R O NP O W D E RP OWERF UL CRACK DUSTER P E RM ANENT MAGNET F ig . 8 - 3 7 . C r o c k i n cylin d e r ñ e o d is e xp o se d th r o u g h the use ol a powerlul mognet ond iron powder. (Storm-yulcon¡
C l eani ng
s ec ti on of l ar ge geor i l i ot penelron!, lluo¡escent
to oppl i c o t i o n
ol
l Fi g. 8-41. A ppl yi ng l l uorescent penetrcnt. (Mo9no(l ux)
l
l
F i g . 8 - 3 8 . Ch e ckin g cr o n ksh o { tlo r u o cks. Fi g. 8-42, R emovi ngexcess penetront.
Fi g. 8-43. A ppl yi ng deve/opersol ufi on.
Fíg-8-39.Crocksin cronkshoftore ploinly visihle underblock light. (Mosnollux)
solution. The developer will draw the penetrant :o the surface of the cracks, if any, Fig. B-43. The gear is ex4mined under a lamp that e:nits black light. If any cracks are present, the developed penetrant will glow quite visibly, F rg . B-44 .
Fi g.8-44. E xami ni ng the port under bl ock Ii ght. N ote tl ¡e c ¡oc k .
. ii
iij ,t
135
fr
i' /'::,
Auto Service ond Repoir
DYE PE NE TRA NT Th is t ec hnique ut iliz es a s pec i a l p e n e t r a n t that when exposed to a developer, will show as a bright red stain line against a whitish background, The part is cleaned, penetrant applied, penet r ant surp lus r em ov ed and developer sprayed on. Note the red stain lines indicating crae ks bet ween t he gear t eet h, Fig . B - 4 5 . NOT E: The penet r ant m et hods w i I I w o r k o n both ferrous and nonferrous materials.
Fi g.8-47. C rock repoi red by pi nni ng. E och pi n s houl d s l i ghtl y overl op l he precedi ng pi n. B roken /i ne i ndic otes c roc k Ii ne.
U s e s p e c Í a l , t h r e a d e d , t a p e r p i n s d e si g n e i for crack repair. Start by drilling and tapping a hole (drill tap must be right for the pins to be u s e d ) t h a t c e n t e r s o n t h e c r a c k l i ne , j u stb e yo n c the end of the erack. Thread a pin (pin may be c o a t e d w i t h s p e c i a l h e a t p r o o f s e a l a n t i fd e si r e d , into the hoLe. When tight, noteh the pin, abou: 1 / 8 i n . a b o v e t h e c a s t i n g , u s i n g a .sh a r p ch i se a n d t w i s t o f f t h e e x c e s s . I n s o m e ca se s a h a cksaw may be used to cut the pin. Drill and tap for the next pin sothe hole jus: cuts through the threads of the first pin. Install p l u g a n d t w i s t o f f e x c e s s . R e p e a t th i s p r o ce ss until the fu11 length of the crack is pinned. EACIi PiN MUST CUT PART WAY INTO THE PRECEDING PIN. See Fig. B-4?. If steel pins are used, they should be lightl¡ peened. Grind pins nearly flush with work and finisl: with a clean, sharp mi11 file. If the area canno: be filed, grind flush. Wh e n a c r a c k p a s s e s o v e r a n e d g e ( su ch a s across the head and down into the combustior_ chamber) insert pins in the order shown ir Fig. B-48.
'i j {
¡(crs ,j .¡* € ,a-::i!
'lé
.s
. i"$
,+ .{ F i g . 8 -45.
Dya penetr on! exposed these cr oc k s i n thi s Q eor ,
CRACK REPAIR Cra c k s in t he c y linder head or b l o c k e a n o f t e n be repaire d by e ithe r br azing, we lding or pinning. Some tim es s older c an be us ed on w a t e r j a c k e t cracks. The us e of t hr eaded pins is qui t e p o p u l a r b e cau se no heat is r equir ed ( noc hanc e o f w a r p a g e ) . IF THE PI NS ARE TO BE EFFECT I V E , THEY MUST REACH SLIGHTLY PAST THE ENDS OF THE CRACK. I f t hey do not r eac h t h e e n d s , t h e craek will likely continue to lengthen. Further cracking can generally be halted by drilling a ho le at t he end of t he c r ac k . See F i g . 8 - 4 6 .
SUMMARY
F i g . 8 - 4 6 . No te c¡ o ck- 1 .Ho le s h o ve ó e e n d r illed ot the very ends-2. T l r i s p r e v e n fs lu r th e ¡ cr o ckin g . Ho le d r ille d in l ¡om the ends-3, o llo ws c¡ o ckin g to co n lin u e -4.
136
S o l d e r i s a m i x t u r e o f l e a d a n dti n i n va r yi n g amounts. Joints to be soldered must fit well, as solder in itself, has but little strength. Wire solder with flux-filled c e n t e r c o r e , i s d e si r a b l e . Flux, (organic, acid and rosin) helps remove oxides and also prevents the formationofoxides while soldering. Be sure to use solder witl: ROSIN core ONLY on ELECTRICAL work. K e e p t h e s o l d e r i n g i r o n c l e a n an d w e l l ti n n e d . Use an iron large enough for the job. The joint to be soldered must be clean anC dry. Lay the flat tip of the iron against the work and apply wire solder where the iron and work contact. Solder must run and tin freely. Do not move work while it i.s cooling. Brazing takes place above a temperature of
Soldering,Brozing, Welding,Crqck Repoir
Foll.ow all safety precautions in setting up equipment, lighting torch and in welding. Arc welding is fast and applies a minimum amount of heat to the work. Although the arc temperature i s h i g h , t h e w e l d i n g p r o c e s s i s so rapid that the work remains relatively coo1. This helps control warpage. Select appropriate rod size and t1pe. Adjust machine to correct polarity and curTip the top of the rod in the rent settings. ( 5 - 1 5 d e g . ) . A w h i p pi n g direction of travel motion will help control the heat, direction and penetration of the weld. The bead should be smooth, even, with good penetration and should be free of slag andblowholes. Remove slag from a bead before welding another pass over the original bead. Follow all safety rules in setting up and operating. Cracks can be detected by using a magnetic technique involving iron powder or fluorescent
300 deg. F. The work must be clean. Flux work, a¡d heat until brazing rod will melt when in eontact with the parts. action will Capillary Craw the brazing material into the joints. Donot ryverheat. Braze welding requires tinning the work with braze material and then building up to fill joint :rregularities, and to provide strength. Bronze brazing rod may be used on cast :ron, malleable iron and steel. Either a propane or an oxyacetylene torch :ray be used.
niz.B/tÁ
liquid, or, by using either dye or fluorescent penetrants. Cracks in engine blocks and heads can often be repaired by pinning. Use tapered, threaded pins. Pins should overlap slightly and must run full length of the crack.
MANY SKILLS ARE REOUIRED Fig.8-48. lnserlpins in the o¡de¡shown.Pin 6 will lock pin 5 in placein cosepin 7 doesnot properlyoverlap.
The top-leve1 mechanic, capable of handling must the many phases of automotive repair, skills have a number of talents. Numerousbasic not all. of which are commonly are required, associated with auto work. Being a successful mechanic involves much inspection, part more than mere disassembly, replacement and reassembly. Quite often parts must be rebuilt, altered, adapted, welded, etc. To cope successfully with allthese demands upon his skills, the mechanie must have some knowledge of machine shop, welding andbrazing, sheet metal work, electricity, etc. When you, in your work as a mechanic, meet you do not a situation that calls for skills possess, DEVELOP THEM. Night sehool, exbooks, tension courses, on the job training, manuals, trade journals and magazines, allprofor you to learn. vide opportunities Remember that each year sees changes in design, the introduction ofnew units, new service techniques, service equipment and materials. Be sure to develop a regular program of reading and study, so you are always UP-TO-DATE. It will pay big dividends.
Choose a torch tip appropriate for the work. as recommended by the Set the gas pressures f lam e Us e a neut r al torch ma nu factur er . (approximately one-to-one mixture of acetylene flame (oneand oxygen) to slightly carburizing give excess of to mixture is varied to-one acetylene). Hold the tip at an angle to the work. Vary the distance from tip to work as needed. Keep tip in motion to avoid localized overheating. (melting and fusion Gas welding involves mixing) of the metals to be joined. The work should be clean and dry. Thick metals shouldbe beveled. Select a torch tip of the size recomSet gas pressures mended by the manufacturer. flame. to a neutral for selected tip. Adjust keep the inner flame from When welding, rod or puddle. Bring the touching either filler work to the molten state and, if required, add filler rod. The weld must penetrate the work and should be solid añd free of slag and blowholes. Cutting is fast cutting torch.
and easy
with
oxyacetylene
;¡i
ii ii
iir ili
ii
lll
iii: ti rli ilI ii
137
ir iii ln
li
ri
Auto Service qnd RePq¡r
OUIZ - ChcPter 8 1. Soldering involves fusion. True or False? soldering. 2. Joints should be wellfittedbefore Tru e or F a1s e? 3. So lde r is a m ix t ur e of - and- . used solder alloys are 40/60, 4. Commonly
^-^ 5. Flux is used in soldering to:a. Clean the metal. b. Prevent overheating of metal. c. Cement Parts together' d. Prevent rusting. 6. Three kinds of flux are:
7. B. 9.
10.
1 s ]F
il
11. 12. 13.
should be used on all electrical -flux work. The tip of the iron should be well-. When applying solder, touch the wire: a. To toP of iron. b. To work away from iron. c. To iron where it contacts work. d. To side of iron. Brazing involves temperatures above: a. 1800 F . b. 450 F. c . 800 F. d. 3000 F . Brazing and braze welding are one and the .same. True or False ? F lux is r e q u i re d fo rb ra z i n g . T ru e o rFal se? When using an oxyacetylene torch for brazslightly ing, the flame should be-to
14. The torch tip shouLd be held at right angles to give better penetration whenbrazing. True or False ? 15. For brazíng, tip size and gas pressures are True or False ? not too imPortant. the parent metal be that requires 16. Brazing True or False? point. fusion to the brought be--. should welding for The flame 1?. 18. The inner flame cone-touch the weld puddle or rod tiP. 19. Add filler metal to the weld bY: a. Touching rod to Puddle. b. Holding rod above puddle and allowing it to driP in. c. Laying a length of rod flat on the joint. drops of rod all and depositing d. Melting along the joint before puddling the base
pr o20. The cutti ng torch uses a j et of-to duce the cutting action. 21. Hold the cutting torch at a sharp angle to the work. True or False? 22. Acetylene tanks should be used in aposition. 23. The oxygen regulator has a thread. 24. Open tank valves a n d- _ 25. Always wear-,-' when welding, brazing or cutting. 26. Before opening tank valves, regulator handles should be: a. Removed. b. Backed out until free. c. Tightened securelY. d. Baeked half waY out. 2 ? . O i l a n d g r e a s e s h o u l d b e k e p t a w a y fr o m g a s welding equiPment. True or False ? 28. Before lighting the torch,-bothlines. 29. The aeetylene tank should be opened: a. All the waY. b. Four turns. c. One turn. d. 1/16 turn. 30. Some coatings will give off poisonous fumes when heated. True or False? 3 1 . N e v e r u s e a c e t y l e n e p r e s s u r e s i n e xce ss o f
psi . 32. Arc welders can be either-or or a combination of both. 33. Arc welding imparts less heat to the work (overall) than gas welding. True or False? five welding electrode sizes suitable List 34. for garage use. 35. Welding rods are usually coated. True or False ? 36. Watching the arc without protective equipment can cause serious eye damage. True or False ? be in keePing 3?. Rod-and-must with the job. 38. The hotterthe arc, thebetter. True or False? 39. Deseribe the sound of a proper arc. 40. Never weld, braze or solder fuel tanks until special precautions have been taken. True or False? 41. Describe four methods of craik detection. 42. Cracks can often be repaired without heat
metal.
t38
Chapfer9
EQUIPMENT CLEANING AND TECHNIQUES on the car or off, can be a Cleaning parts, slow, tedious job unless the proper equipment Onmany jobs, is available and is usedcorrectly. the cleaning portion, using the best equipment, can account for nearly one -half the time involved. To use even more time because of poor equipment and techniques will run the repaircharges up to the point where the sbop will be hard pressed to offer competitive repair price schedules. Time is like money - it must not be wasted.
BE THOROUGH On an in-car engine clean, or an under-body ttholidays" (missed spots) clean j ob, leaving a few but mechanieally will displease the customer, On the other hand, ¡nill not prove disastrous. eareless cleaning of parts during engine, transm ission, re ar e nd , et c . , t ear downs , m ay r uin :he job, and cause expensive combacks andpoor customer
The only safe course is to be absolutely Remove ALL in your cleaning. meticulous from the part and protect foreign materials against contamination during subsequent storage and handling.
TYPES NUMEROUS '
The equipment and techniques vary with the size and type of job involved. You are obviously clean one not going to fire up a steamcleanerto universal joint when solvent, brush and airhose will handle the task quickly. On the other hand, to attempt to clean the outside of an engine with a brush and solvent, prior to disassembly, would be equatly foolish. You must tailor the equipment and solution to the job at hand. This chapter will deal with the widely used techniques. Study them carefully so you will be able to choose wisely.
relations.
WI T HWI RE CL E A NI NG B RUS HA NDS CRA P E R chambers, piston heads. Valves, combustion and grooves, etc., are subject to accurnulations of hard carbon. If they are not soakedin powerful cleaners, they must be cleanedwith scrapers and power brushes. The heavy deposits can be knocked off with scraping tools and a power wire wheel, or, a rotary brush may be used for final drill-driven
Fig.9-1.
Removing com6uslion chamber deposifs with o rolory wi¡e wheel. (Albettson & Co.)
cleaning. Clean dry. After thorough carbon removal, the part should be washed in solvent and blown dry. NEVER USE A POWER BRUSH ON SOFT ARTICLES SUCH AS PISTONS, CARBURE TORS, Fig. 9 - 1 s h o ws ETC. INSERTS, BEARING car:bon deposits in a cylinder head combustion chamber béing removed with a rotarywirebrush drill. chucked in an air-operated
139
AutoServiceond RePoir
GET AD VIC E A number of companies offer various types of cleaning equipment and solutions designed to perform tasks such as car body washing, in-car Lngine cleaning, carburetor cleaning, block are cláning, hard carbon removal, etc' There and high-pressure hot solutions, cold solutions, many So etc' agitators, low-pressure sprays, are available that it can cause confusion toanya one not an expert in the field. When choosing is it equipment' piece of or solution cleaning wise to consult other shops or mechanics for their reactions and also to discuss the problem with sales representatives from reliable companies offering products in this field'
CA NB E DA NGE ROUS S OL UTIONS (poisonMany cleaning solutions are TOXIC Be eyes)' (wiil skin, burn ous) and CAUSTIC follow and using you are certain you know WHAT recommended handling prothe manufacturerst ce du res. cleaning safety rules concerning General are: solutions area' 1. Use in a welL-ventilated 2. Never use gasoline for cleaning' 3. We.ar goggles or face shield when working with the Powerful tYPes. 4. Keep away from sparks and open flame' 5. Do not smoke around solutions' Keep 6. Ke ep solu t ions c ov er edwhennot inus e' in la be led c ont ainer s .
ín solvenf' Fig. 9-3. Ploceportsin bosketond submerge flash high with relatively ?. Use solutions will vapors (temperature which at points ignite when brought into contact with an open flame). unless specifically solutions heat B. Never recommended. 9. Avoid dampening clothing with solvent' 10. Always READ and FOLLOWmanufacturers' instructions. 11. When brushing parts in sol'vent, use a nylon or brass bristle brush to avoid sparks' 12. A large tank of solvent should have a lid that is held open by a fusible link &olding device that will melt and drop the lid in the event of fire). 13. Wash hands and arms thoroughly when cleaning job is comPlete. 14. Avoid prolonged skin exposure to aII types of solvents.
Sof€ry Covcr
PARTS WASHER
Porls Cleoning Bru¡h Rocl¡
Coñl'ol Switó
Groyñillt Pumping Un¡l I/25 HP-Abrosiv. Proo.
PLbl G.ip Sook Tonk
Fl$h Nozzlé
Fis. 9 -2 . T yp ica l co ld so lu tio n p o r ls wo sher' ( Gr cYm ills)
Although small parts can be cleaned incans' buckets, etc., a far faster and more efficient job can be accomplished by using a regular cold solution Parts washer. The better parts washers hold considerable solvent, have soaking trays, solvent agitation from the and a filter to remove impurities solvent for rinsing. Fig. 9-2, illustrates atypical parts washer. They are available in many different si zes. To use the parts washer, the heaviest deposits ean be quickly removed with a scraper' On large units such as engines, steam clean before disassemblY. The parts are placed in the basket and submerged in the solution. Parts with hollow areas
140
:t ' rl
should have the hollows facing up so that an air trap will not prevent.soLution entry, Fig. 9-3. The solution is then agitated (shaken) by air pressure or the solution passing, under pressure, through nozzles. The washer shown in Fig. 9-4, has a separate compartment that is air agitated while the main tank i.s used for soaking, brushing and rinsing.
Fi g.9-6, Gi vi ng porl s o l i nol ¡i nse i n l i l te¡ed sol venf. S ol v ent musr be C LE A N I
Fol l ow i ng
F ig. 9 - 4 . P o ¡ t s w o s h e r wilh b o th o ir o g itu r e d o n d so o kin g fonks. ( KIe e r - F lo )
ri nsi ng,
l et
parts
draín
and then
blow If there is a possibility dry. of rust formation, oil or grease the part. Keep parts covered until ready to use. Some garages utilize portable parts washers that may be wheeled to the job, Fig. 9-?.
' ' HO TT A NK ' 'CL E A NI NG Large building,
garages or shops specializing in reusually have a "hot tank" for heavy
Fig. 9-5. Mechonic rinsingsomeportswhileotherswosh. During the agitation cycle, some washers have a separate basket that will hold a few of the parts for brushing or rinsing while the remainder are still. washing. Fig. 9-5, shows a mechanic brushing and rinsing a few parts while others are soaking. After thorough cleaning, the parts should be given a final rinse. The machine shown in Fig. 9-6, has both a soft rinse and hard spray rinse. The mechanic is giving the parts a final rinse. The solution from both nozzles is filtered.
Fi g,9-7. H ondy portobl eports w osher. (K IeenFIo)
141
Auto Service ond RePoir a water pump forces water, In operation, amount of cleaning solution, with a metered through a pipe formed into a number of coils. th r o u g h A heat source (oiL orgas)passesheatup generating steam pressure. the coils quiekly From the coils the superheated water is passed into a flexible steam hose that is attached to a steam gun. The gun has a heatproof handle anC
some transmission blocks, Engine cleaning. quic k ly and t h o r o u g h ar e cases, rad iat or s , et c . , hot tank. in the ly cleaned The hot tank usually uses a strong alkaline compound mixed with water to form a solution. r uns bet ween 180 and 2 1 0 d e g . F . Temp era tur e The tank may have an agitatortospeedcleaning. Most parts are clean in thi.rty minutes or less, strength, on tank design, solution depending and Part load. temperature, The alkaline solution is CAUSTIC and when cleaning aluminum parts, the solution must be inhibited (weakened) to prevent surface erosion. When the parts are removed from the tank, washed, preferably they should be thoroughly to flush out oil Be careful hot water. with ga llerie s, wat er jac k et s , et c . Par t s o r s u r f a c e s
adjustable nozzle. Some units feed the cleaning solutionintothe gun instead of the water supply. Fig. 9-9, shows a typical portable steam cleaner.
subjeet to rusting should be oiled. WHEN USING CAREFUL BE EX TREM ELY I'HOT TANK. ' ' O BSERVE AL L S A F E T Y THE HAVE SOMEONE SKILLED IN PRECAUTIONS. ITS USE, G I VE YO U I NSTRUCTI O NS B E F O R E USING.
F*
lowered Fig. 9- 8, s hows anenginebloc k bein g into a hot tank. Note the hydraulic crane attached to the tank.
STEAMCLE A NING is excellent for many The steam cleaner engine, transUnder-car, types of cleaning. etc., cleaning are a1l handled quickly mission, and thoroughly.
Fi g. 9-9, P ortobl e sl eom cl eone¡. S teomIose ond gun nol s how n (H omes¡eodY ol ve)
N ES G E NE RA LO P E RA T ¡ORUL F O RS T E A MCL E A NE RS on the of cleaners There are a number inmarket and as always, the manufacturersr specific regarding followed structions should be There are steps and maintenance proeedures. steps tha: of operational a number however, are common to alrnost all steam cleaners, anc these will be discussed.
STARTINGTHE CLEANER The steam cleaner, if operated inside, mus: The machine shouli have adequate ventilation. be properly grounded e1ectrically. Turn on the water source. The water pump should then be switched on. In a short time yo';
F i g . 9 - 8 . En g in e b lo ck b e in g lo we r e d in to o "hot tonk." ( Sto ¡ n ' Yu lco n )
will
142
notiee
a stream
of water
fLowing from
the
Fis.9-l l. Steomcleonins ":.:r":;;:t.
r¡onsmission priorto dis-
hold the gun nozzle from one tofour inches from t h e s u r f a c e . I f t h e n o z z l e i s t o o f a r f r o m th e w o r k , c l e a n i n g i s s l o w e d d o w n c o n s i d é r a b l y. T h e s t e a m s h o u l d b e " w e t " ( a m p l e h o t w a te r along with steam) as dry steam will not clean or flush surfaces wellAvoid oversteaming t h e t i e r o d , s u s p e n si o n knuckles and other under-car b e a r i n g ar e a s. Excessive steaming will melt the lubricant as well as damage the seals. Do not drive dirt a n d g r e a s e f r o m t h e b r a k e b a c k i n g p l a t e s i n to the brake drum. Take it easy on brake lines and flex hose. Remember t h a t s t e a m c a u s e s c o n d e n s a ti o n . Do not operate in a poorly-ventilated area as part and tool rusting wiil occur. Fig. 9_10, shows an operator steam cleanÍng the underside of a car.
Fig.9-10. Usingsfeomcleoneron under-body cleaning. (ClaytonMonuhcturing Co.) gun. This indicates that the heating coils are ::lled with water and that the burner can be :snited without burning the coils. Ignite the burner. When the gun begins to ?:rrit steam, adjust the fuel valve to bring the ¡ressu re to th e des í r ed lim í t . If the machine utilizes an integral solution :.nk , che ck to see if enough s olut ion is pr es e n t . l"Iix the solution by opening the sti¡ring valve :cr ab ou t 3 0 se co nds . I f no s t ir r ing pr ov is io n i s :resent, place the gun nozzle into the solution :-:rd agitate it with steam pressure. If solution rs desired, open the solution valve.
S HUT T I NG DO WNS T E A MCL E A NE R When finished with the cleaner, first shut off the solution control valve. AlLow the cleaner to operate a short time and then shut off the fuel valve. Keep the water pump running until there is no sign of steam vaporcomingfrom th e gun. The pump maythenbe shut down. By following this procedure, all solution is removedfrom the water in the coils. The coils will be cooled down before the water flow has stopped thus pre venting possible burning and scaling. Arrange the steam hose so that it is out of the way and will not be kinked or run over. If the surrounding temperature will drop below freezing, the machine should be drained. Fig. 9- 11, illustrates h o w t h e a u t o m a t i c t r a n s m i s si o n is steam cleaned prior to disassembly.
USINGSTEAM CLEANER Cover fenders and windshi.el.d area when ioi.ng an engine or under-hood job. Remember :hat the cleaning solution can spot paint. When i:rished, flush all painted surfaces with clean ;ater. Cover carburetor, generator or alter:ator, and distributor. Avoid prolonged steam_:g of wiring. Keep away from air conditioning -:nes. Avoid close up or prolonged steaming of :.11e lectrica l un it s . Depending on the nozzle design, type of dirt : c be re moved a nd s hape of objec t belngc leaned ,
S A F E T YRUL E SF O RS T E A MCL E A NI NG 1. Do not operate without proper burner ventilation.
143
Auto Service ond Repo¡r
As with steam cleaning, whendoing anunderhood cleani.ng job, cover fenders and windshield a h i gh - p r e ssu r e areas. Fig. 9-12, illustrates spr:ay Note different machine. the cleaning patterns available.
Stea mer m us t hav e a good elec t r ic a l g r o u n d . Ke ep pr es s ur e wit hin s pec if ied lim i t s . A We ar a f ac e s hield t o k eep s pla t t e r s f r o m the eyes . ñ Ke ep o t her per s onnel away f r o m t h e i m and when swinging the gun mediate vicinity of any unexp e c t e d b y be c ar ef ul a rou nd , stan de r s , 6. If the machine does not ignite readily, shut off the fuel valve and have a qualified repaírman check the burner fuel and ignition system. I Re ad t he m ac hine ins t r uet ion boo k c a r e f u l l y a nd ge t "c hec k ed out " by an e x p e r i e n c e d
2
S P RA YCL E A NI N G L O W. P RE S S URE involving the use This is another technique mixing gun. As air passes of an air-operated through the gun, it draws in a meter:ed amount of cleaning solution and sprays it with force on the object being cleaned. After waiting for deposits to soften, the object can be either washed down with a hose or the cleaning gun suction hose can be dropped in a container of water, cleaning solvent, etc., depending on the need. generally are solutions Special cleaning added to water, kerosene or cleaning solventfor the initial cleaning spray. NEVER USE GASOLINE OR ANY LOW FLASH POINT SOLVENT. THUS THE SOLVENT ATOMIZES SPRAYING SEE EXPLOSIVE. IT HIGHLY RENDERING Fig.9-13.
op era tor . B. If the m ac hine m us t be light ed by h a n d , k e e p face and body away from burner opening.
SPRAYCL EANING HIGH.PRESSURE Effective cleaning can be aecomplished through the use of cold tap water, under highpressure, into whieh a cleaning solution is injec t ed. P r e s s u re a t th e n o z z l e ru n s uptoaround 500 psi (pounds per square inch). By adjusting the gun, a soft mist, containing a. detergent solution, is sprayed over the objeet to be cleaned until thoroughly saturated. Following a short waiting period to allow the deposits
SOLV.ENT ltoSE
AtRllosE CONNEC
Fi g.9-13. Low -pressure sprdy gun, H ose i s pl oc ed i n c onl oi ner of sol venf. (l mpe¡i ol B ross)
CA B L E RE MO V EB A T T E RYG RO UND Whenever doing under-hood cleaning, it is a good idea to remove the battery ground cable. This prevents possible short circuits that could be caused by grounding a hot wire or terminal with the cleaning gun.
' );'^11i--rSPRAY ANDSO LUTI O N W ATER I NLETHO SE
CO L DS O A K . CL E A NI NG
sproycleoner' Fig. 9-l 2, High-pressure (L & A Producrs)
For soak-cleaning, the part or parts are placed in a basket and lowered into the cleaning solution. Following a period of fromtentothirty minutes, the parts are removed and rinsed in solvent or water. They are then blown dry with an air gun.
to soften, a fine, hard, fan-shaped stream of plain water is used to lift off the dirt. For hard the spray can be adjusted to to clean corners, narrow stream. a high velocity,
t4
CleoningEquipment,Techniques
S olutio ns of va rious k inds f or s pec if ic appli :at ions such as carb ur et or , pis t on, et c . , c lean .ng, ar e a va ilab le. M os t of t he s olut ions ar e ex : remely ca ustic. KEEP AW AY FRO M SKIN iN D EYES] T he so lutio ns g ener ally c om e in a s pec ia l ¡aiI or d rum th at inc iudes a par t s bas k et . Th e solution i.s far enough from the top so that a : ormal loa d of p arts will not dis plac e enough to :ause sp illag e. A spec ial s ealing s olut ion f loat s 3n t op to pre ve nt ev apor at ion and ex c es s iv e :dor. Whe n p lacing par t s in t he c ont ainer , m ak e ' ert nin th ev :rp n nr nnlet elv qr hm er oed and ar e :el.ow the spe cia l s eal s olut ion. Fig. 9- 14, : epicts a typical six gallon pail of s oak - c leaning -. o1ution . Notice th e par t s bas k et . F i g.9- 15.
that are prolonged or produce much dust, wear a breathing mask also. Never sand blast around a repair area as the abrasive will contaminate parts - with disastrous results. Fig. 9-16 shows sand blasting a we1d.
PARTSBASKET
QAKIff
Yopor c l eoni ng unít. U s e onl y r ec om m ended s al v e n t . ( AC R A El ec tr i c )
PAI L CO NTAI NI NG CLEANI NGSO LUTI O N
$rg-¡-q"t
A B R A S IY E C ON TA INE R
,i
= ig, 9-14 , S o o k - c l e o n i n gkft. T h is p o r ticu lo r so /u iio n is e sp e ci ol ly d e s i g n e d l o r g u m , va r n ish o n d h o r d co r b o nr e m o vo l. ( Oo k¡ ¡ e )
VAPORCLEANING T he cle an er illus t r at ed in Fig. 9- 15, c lean s :art s b yh ea ting a Per c hlor et hy lene s olut ión. Th e : esultan t vap ors re m ov e depos it s on t he par ts suspend ed in th e m et al bas k et . The s olut ion i s ::onflammab le, Fig . 9- 15.
l;**, ro,,
SANDBLAST CLEANING Fi g.9-16. S ondbl osti nga w el d to remove s/og.
With the exception of spark plugs, automotive :arts are rarely sand blasted. The body shop and welding shop has occasional use for a sand 'ilaster, for quickly removing paint, rust, weld'no
snnle
(A .L.C . C o .)
SUMMARY Automotive repair and maintenance work require considerable u s e o f c l e a n i n g t e c h n i q u e s, equipment and solutions. The mechanic wlll do faster and better work if he is able to selectthebestcleaning p r o c e d u re for the job at hand. As with all work, cleaning must be THOROUGH.
e fn
A sp ecial bla st g un, oper at ing under air pr es sure of a rou nd 5 0 to 200 ps i, dr aws in a m et er ed (alumi.num oxide, amount of abrasive material silica san d, meta l s hot , et c . ) and pr opels i t against the object with great force. Always wear a face shield and in situations
t45
I
Aüo Service ond RePeir
occasionally Hand brushes and scrapers are of removal for are fine useful. Power brushes hard carbon from some Parts' are that many cleaning solutions Remember with handled be must and both toxic and caustic care. is excellentfor A cold solution parts washer carbon' Parts hard with coated not many parts solution' brushed' are soaked in an agitated rinsed and blown drY' are hard to For larger ob3ects or parts that alkaline strong a a hot tank containing clean, will not parts Aluminum sotlrtíor,, is desirable. solutions' tank hot stand full strength is a fast and efficient The steam cleaner good for removing is especially and cleaning tool Under-hood and deposits' grease and heavy dirt accomplished' ,rrrd""-body cleaning is easily cleaning handles dirt High-pressrrt" "ptty Large areas may be and grease very well. cleaned quicklY. on spray cleaning is effective Low-pressure somewhatslowerthan generally many jobs. It is or using the high-pressure steaming either washer' 'Ldelyused solutions are wl Cold soak-cleaning and hard carbon. removal' for gum, varnish, transmisand automatic carburetors PistJns, A cleaner' a such in cleaned sions are usually pail or the with furnished parts basket can be drum of solution. and has some advantages cleaning Vapor parts' well on certain works particularly is useful for paint' rust cleaning blast Sand Do not operate a sand and weld scale removal' blaster near a rePair area' Observe Cleaning solutions canbe dangerous' all safetY rules.
SU GG ES TEADCTIV ITIE S in the use of' and use' the Get instructions in your pieces of cleaning equipment various garages many as visit shop. If you are a student' and observe the cleaning techniques io""itl" "" ask the shop foreman or service ,r""d. Al*tys Do not to visit' manager first for permission avoid and to"ch equipment get in"the way, do "ot thank leaving' Upon unnece ssary conversation' well as the manager' as concerned mechanics the
LOOK''5HARP'' There is no Obviously mechanics get dirty' At the end of need however, of staying- dirty'
of ihe each working day, a thorough cleansing hand hands with one of the many industrial relative to hands cleaners will restore your cleanliness. -etc') tt".r. your uniforms (coat' coveralls' shave daily haircut' neat A cleaned rlgularly. andfreshuni formw i l l keepyoul ooki ng' ' shar p. '' public must be concerned about its A garage -Tn" and floors ¡rritaing, equipment,_ ',imag?." appearpersJnrret must all present a favorable ance. Do Your Part.
OUIZ - ChoPter9 1l5ot L12 1. C l eani ng often accounts for 1/10 ' time' of the total rePair doesnot 2. A shop with a steam cleaner really equipment' cleaning of type other need any True or False ? cleaned with 3. Piston ring grooves are best False? or True the Power wire wheel' should be that 4. List ten safety precautions solutions' cleaning observed when using of the de5. Cleaning means: 1' Getting most single bit every Getting 2' posits removed. correct of foreign material removed' Circle answer. effective for 6. A cold solution parts washer is False? or hard carbon removal' True an airtlght ?. When submerging a part with place the always compartment or hollow' will solution the that so hollow enrer. for cleaning B. The "hot tank" is excellent False? or True bloeks. engine cleaning is 9. The solution used for hot tank False? or both toxic and caustic' True done in a cLosed 10. Steam cleaning should be area. True or False? beforelighting 11. Always start the water pump True or cleaner' steam a the burner on ? False shut offthe water 12. To stop the steam cleaner' fromthe gun' comes pump and when nowater False? or True the burner' about one to four "trrt-ott 13. Keep the steam nozzle False? inches from the work' True or the ------areas 14. Cover the-and hood' before steaming under the observe when using 15. List six safetylules to the steam cleaner' spray cleaning will doagood 16. High-pt""""t"
146
TI
I
Cleoning Equipment, Techniques
job of removing dirt and grease. True or False ? 1n Gasoline, or any flammable, low flash point solvent, if used for cleaning, canverylikely cause a serious fire or explosion. True or False ? L8. It is a good idea to removethe
I I
cleaning under thc hood, to pre-when vent accidental short circuits. 19. Carburetors are best cleaned in a strong alkaline solution such as that used in some cold soak-cleaning pails. True or False? 20. Engine parts may be cleaned satisfactorily with the sand blaster. True or False ?
fl
plynoulh lour speed ove¡d¡ive f¡onsmissíon. ln flris f¡onsmission, no plonetary geors ore used to pro' du." on overdrive eÍÍect. Fourth geot, as with the offier fáree speeds, utilizes convenlionol geors. .67,3rd-l .00and4¡h-.73to|. @ e o r r o tio s fo r th e vo r io u s g e o r sorei Is¡.3.09toI,2nd-l
147
Auto Service ond RePoir
Engine employing a double overheod comsñolf setup. Note lremispfiericol combuslion chomber, (Fiot)
Chapter10
FRICTION BEARINGS DEFINITION B e arin gs can b e c las s if ied as FRI CTI O N o r .:.\TIFRICTION. The friction bearing contact irea SLIDES (sliding friction) against the bear(that portion of a shaft designed to :rg journal The antifriction accept the bearing) surface. (rolling friction) utilizes ball or roller :earing :iements that ROLL against the contact area :hus reducing fuut not eliminating) friction. Both types are used in the automobile. l,Iajor use of the friction bearing is confined to :he engine while the antifriction bearing is used :l such a rea s a s the t r ans m is s ion, dr iv e line s , : : iferentia l, etc., Fig. 10- 1.
p o u r e d i n t o t h e b e a r i n g a r e a . I t w a s t h e n c ar e fully bored to a specified size, Shims (thin strips o f s t e e l o r b r a s s ) w e r e o f t e n p l a c e d b e t w e e n th e two halves so that as the bearing became worn, t h e y c o u l d b e r e m o v e d t h u s r e d u c i n g t h e c l ea r a n c e . F i g . 1 0 - 2 , s h o w s a t y p i c a l c a s t b a b b i tte d c o n n e c t i n g r o d b i g e n d b e a r i n g . N o t e t h a t th e i s b o n d e d ( a c t u a 1 1 y a d h e r e s) bearíng material to th^erod. See Figs. 10-2, and 10-2-A. ' As engine horsepower and rpm was inc r e a s e d , t h e c a s t b a b b i t t e d r o d f a i l e d t o p r o v id e
':¿r. o ta, <. ,. {J
F RICTION
$.'
<-
-t- 3 zd
E=
Fig. 10 - 1 . T h e l r i c t i o n b e o r in g u se s o slid in g co n to c! wh ile the o n t i { r i c t i o n b e a r in g u tilize s o r o llin g co n fo ct.
Fi g. I0-2. C osr bo66i rted connecti ngrod.
L A Y E R SH E L D T O G E T H E R B Y A . T H I NC O A T OF SOLDER ALONG
ENGINEFRICTIONBEARINGS The camshaft, crankshaft and connecting rods all u se friction -typ e bear ings . Ant if r ic t ionbear ing application in these areas is largelyconfined h igh s peed engines us ed f or boa t s , t o s mall, chain saws, e tc.
C ASTORSPU NBA B B ITTE DB E A RINGS rnost automobile engines For many years The babbitt used the cast babbitted bearing. (tin, antimony, copper) metal was melted and
INATIONS.
Fis.
l 0- 2A.
T y pi c ol
s hi m poc k s l or fhe c onnec l i ng ( C /ev i te Ser v i c e)
beor i ngs .
149
r od ond mo í n
rrFFr
-'-\
BAEElrr
ST EEL
ST EEL
S
I ¡lutltxulr I llur'rxulr
C O PPE RA L L O Y
frffi(ffir \\N\\)
proper strength and wear c-haracteristics. Rebabbitting was expensive and adjustment by the use of shims was time consuming and unless done most carefully, often produced poor fits. Today, babbitt bearings have been largely replaced by PRECISION INSERT bearings.
BABBIT I
/ -€
B A R R TE R ?LATE
B A B B I TT
Fig, 10-5.Someinserfbeoringlining com6inotions.
P RE CI S I O N IN S ER T BE AR IN GS
flash plated over the entire bearing (sides, back, etc.). The flash tin prevents rusting and oxidization of the steel back and parting surfaces (edges where the bearing halves come together). Other bearing lining combinati.ons are shown in Fig. 10-5.
The precision insert bearing is light, strong, possesses excelLent bearing characteristics, is available in a wide iange ofsizes, andis quickly replaced. It does however, demand care in handling and installation. These bearings are made in both one and two-piece t¡pes. Most insert bearings utilize a steel (low earbon) back upon which one or more layers of other materials such as lead-tin babbitt, copper alloy and aluminum alioy, are bonded. A lead-copper alloy can be affixed to the steel back by a process known as sintering. The lead and copper are melted togetherandthrough a process of atomization, this mixture is reduced to very tiny (.002 ' .005) particles. This powder is then spread on the steel and by heating, and rolling under pressure it is compressed into a relatively solid layer that adheres to the steel, F ig. 10- 3.
THRUSTFLANGE Whenever an insert bearing must control thrust (pressure parallel to the shaft centerline) forces, a thrust flange is incorporated on one or both sides of the bearing. The thrust faces are Iined with bearing material such as used on the bearing proper. Some thrust flanges are not part of the bearings, but are inserted as separate R i ecel Fi g. l 0-6. IN S E R T MU S T FIT H OU S IN G P R OP E RLY In order to provide adequate support and proper heat transfer, as well as accurate alignment, it is essential that the insert contact the housing or cap properly. Inserts are manufactured to produce proper fit by incorporating bearing spread and crush in the design. B E A R IN G S P R E A D The insert diameter aiross the partingedges is slightly (.005 - .030) larger than the bore. This makes it necessary to force or snap the insert into the bore by applying thumb pressure to the parting edges. DO NOT FORCE THE INSERT INTO PLACE BY PRESSING ON THE CENTER. THIS COULD WARP THE INSERT. Spread also helps hold the bearing in place during assembly operations. Ol der Ford V -B engi nes (1932 - 1948) useda "floatingtt insert lined with bearing material on both sides. These inserts utilized a negative spread to prevent insert parting edges from hooking against rod bore parting edges. Fig. 10-7, il.lustrates positive bearing spread.Fig. 1O-?A, shows the early Ford "floating" insert setup.
Fig. l0-3. Five loyer(counting steel6ocft)insertbearing. In Fig. 10-3, the steel back is covered with copper all.oy lining. A barrier plate (to prevenr the tin in the overplate from enteringthecopper alloy) about .000075 thick is plated over the copper alloy. A thin overplate (about .001) of tin-lead alloy is applied to the barrier plate. A final coating, extremely thin, of pure tin is
t50
Friction Beorings
B E A RI NG CRUS H The insert is is snapped into protrude a slight edge. In effect, larger than a full
also designed so that after it p l a c e , t h e p a r t i n g e d g e s w il l amount above the bore parting each insert half is slightly half circle, Fig. 10-8.
PAR T IN GED GES
Fig. l0-6. Cronkshoft moin beoring with th¡usl llonges. (Clevi¡e Service) Fi g. l 0-8. B eori ng C R U S H . N ofe fhot 6ofh i nsert porti ng edges (exoggeroted for emphosis) protrude slightly oóove tfie cop.
When the bearing is bolted together, the crush area touches first. As tightening prog r e s s e s , t h e c r u s h a r e a i s f o r c e d b e n e a t h t he bore parting edges thus creating a tight insert to bore through radial pressure, contact Fig.10-9. NEVER FILE BEARING CAPS OR CRUSH. TO DO SO MAY RUIN THE BEARING. Füg. l0-7. Posi¡ive beoring spreod. Nofe fñol diamete¡ A oc¡oss porling surfoce is o trille lorger thon bore diomere¡ B.
INSERTMUST NOT TURN With the exception of the floating insert mentioned, inserts are provided with locating lugs or dowels to prevent the insert from turning. WHEN INSTALLING INSERTS, BE CERTAIN THE LUGS ARE PROPERLY ALIGNED WITH THE SLOTS IN THE HOUSING. DOWELS MU S T E N TE R TH E IR H OLE S . S ee Fi s. 10-9 A.
I NS E RTA NDHO US I NG B O REMUS T B E S MO O T H A NDCL E A N The housing bore and insert back and parting surfaces, must be free of nicks, burrs or foreign material. If the insert is prevented from making perfect contact, pressure spots, misalignment and overheating will result. ALWAYS CAREFULLY CHECK THE HOUSING BORE AND INSERT BACK TO MAKE CERTAIN THEY ARE SMOOTH AND CLEAN. DONOTOIL THESE SURFACES.
,Ó F,g" I0-7A. This eorly Ford Y-8 connecting rod beoring u ¡ i lized o negolive bearing spreod.
t5l
Auto Service qnd Repqir
HOUSING BOREHALVESMUSTBE ALIGNED sert still
Even though bore and insert are clean, inspread and crush correct, the bearing will be ruined if the upper and lower (in the
WAYS MARK THE UPPER AND LOWER HALVES (BEFORE REMOVAL) PREFERABLY WITII NUMBERS SO THAT YOU MAY REPLACE THE C A P IN ITS OR IGIN A L pOS ITIO N. See Fi g.10-10.
CRUSHHEIGHT EACH HALF BEARING
PRESSURE i
I
I
Fig' l0-9. llhen ¡od ond cop ore drawn together as in B, the beoring crusfi, os sáown in A, produces rodiol pressure lorcing,izsed tightly against the bore.
LOCATINGLUG
The inserts should always be saved for study. If they appear usable, mark them on the back with a fine scribe. If plans include replacement, you may mark them on the bearing surface. W R E N C H S ID E P R E S S U R E C A N A LS O
DE S T RO CA Y P A L I G NME NT
Thick wrenches can create'enough pressure against the cap to shift it out of alignment¡' Use correct size socket and tighten by alternating from one bolt or nut to the other. WHEN CAp IS JUST SNUG, TAPLIGHTLYWITIIAPLASTIC HAMMER TO ASSIST CAP ALIGNMENT. USING A TORQI]E WRENCH, TORQUE THE FASTENE R S TO TH E R E C OMME N D E D VALUE, Fi g. 10-11.
Fig. l0-9A, Locoting lugs ond dowels fteep rñe insert lrom turniig.
HOUSING BORESMUSTBE ROUND
case of split bearings) bore halves are not properly aligned., It is possible to reverse some bearing caps 0ower halves). This will shift the upper and lower bores out ofalignment. WHEN DISASSEMBLING BEARING CAPS, AL-
The heavy stresses within the engine can cause the housing bores to elongate. When the insert is installed in such a bore, it will conform to the bore elongation thus providing an
152
COR RE C T
CAP REVERSED
I C ON N EC T IN GR O D
BEAR IN GIN S E R T
Fig. 10-10. Reversing beoring cops will shiÍr upperond lower bore fiolves ouf ol alignment.
EXC E55tVE C LEAR AN C E
Fi g. I0-12. E l ongotedrcd beori ng 6ore. N ote l fi e excessi v e c l eoronce ol l l re top ond bol tom w hi l e zero cl eo¡onceexi sl s ol the s i des . The i nsert l i Íe w oul d 6e sfi ort.
BO W EDC R AN KC ASE
SHIFT ED CAP
INT ERFERENCE Fig . t 0 - t l .
T h i c k w o ll so cke f h o s e xe r fe dsid e p r e ssu r etfius sfi i fting cap to one side.
Fi g. t0-13. A óow ed cronkcose w i l l shi {¡ the moi n beori n g 6ores out o( olignnen+:with thei¡ l¡ue cenle¡ line.
bution or spreader grooves are often incorpoor grooved, are drilled rated. Not all inserts Fig. 10- 14. If one of the insert halves is drilled and the other is not, be certain to place the drilled half its bore so it may accomplish in the drilled
in one egg-shaped bearing surface. Clearance will be excessive while clearance in direction the other will be nonexistent causing extreme and wear. Such bores must be reeondifriction t ione d, Fig.
1 0-1 2.
ALL BO R ESM US TB E A LIGNE D The block, through the effects of heating and cooling, can become distorted. This will throw the camshaft and crankshaft bearing bores'out the force will in turn, This, of alignment. out of alignment thus and crankshaft eamshaft and uneven loading heavy bearing creating st r e ssing , Fig.1 0- 13.
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D O NO TM IX BE A RINGHA LV E S Insert halves come in pairs. It is important that they are not mixed.
ANDHOLES OIL GROOVES The insert is often drilled to permit oil to enter freely; in other cases to allow oilpassage to other areas. Annular, thumbnail and distri-
Fi g. l 0-14. Typi col i nserl beori ng oi l grooves. Thís portíc ul or moi n beori ng uses seporote thrust Íl onges' (C l evi te S e¡vi ce)
ls3
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,i
Auto Service ond Repoir
purpose. Neglecting to do this can cause immediate bearing failure. full When installing round inserts, such as the camshaft bearings, make sure the oil holes are aligned, Fig. 10-15. Fortunately, many split bearings are manufactured with both halves drilled to prevent improper asse mbly.
WHEN INSTALLING INSERT BEARINGS, ALWAYS FOLLOW THE ENGINE MANUFACTURES RECOMMENDED BEARING CLEARANCES. The chart in Fig. 10-16, shows AVERAGE MINIMUM CLEARANCES for engine bearings of different sizes and types. The chart is intended to indicate average clearances only, and should not be used when engine manufacturersl recommendations are available.
CHE CK I NG B E A RI NG CL E A RA NCE
INSERT O I L H OL E D O W NO. I L B L OCKED F ig. l 0 - 1 5 . A l i g n i n s e r t o il with o i/ p o sso g e . A- ln se r t o il hol e lros 6 e e n p l a c e d d o w n l h u s cu ttin g o ll o il su p p ly. 8 - ln se r f oi l hol e o l i g n e d w i l ñ p o s s og e wo y, Pr o p e r lu b r ico tio n will r e su l¡.
BEAR ING OIL CLE A RA NCE The precision must have insert bearing enough clearance to allow oil to penetrate and form film. The clearance must a lubrieating be sufficient to provide proper flow through the bearing to aid in cooling and passage to other critical areas receiving their lubrieation via a partieular bearing. On the other hand, too much clearance will allow an oil fLow that can lower oil pressure, eause excessive "throw off" (oil running from bearings at and being thrown off the crankshaft high veloeity) that in turn will flood the cylinder walls beyond the capacity of the piston rings to Excessive will control. clearance also allow parts movement between sufficient enough to pound the bearing to pieces. literally
Approximate clearance of engine bearings can be determined by attaching an engine "pt"(air pressure operated oil tank) and lubricator" observing the amount of oil dripping from the This is often done after the pan is bearings. removed, but before disconnecting any bearings to give the mechanic idea of an approximate The prelubricator bearing is used condition. again after engine assembly primarilyto charge the lubrieation system with oil but will at the same time, provide a final visualcheck onbearing clearances. - -,-/ One of the most widely used methods of obis the taining precise clearance measurements (trade name plastic use of a special wire Plastigage). A section is placed either on the journal or on the i.nsert, the bearing is tightened, then removed. The plastic willbe flattened and !y using a paper gauge supplied with the wire, the width of the wire can be accurately related to clearance in thousandths of an inch, Fig.10-17.
PAPER GAU G E
RtcotttilDEo0[. Gtttnil{cts
s8
CA AP&CP AI (Copper (0verplated umtnu (H¡ghlead bear¡ng) Alloy) SHAFf-SIZT or tin base) Alloy)
.0010
.mm
.0010
2 t%¡-3 V z
0015
0025
0015
0030
3e/rs-4h
0020
.0030
0020
0037
2
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F LAT T EN ED PLAST IG AG E
.0025 Fig. l0-17. Clrecfti;g beoring cleoronce with Pldstigage. Beoring ños .003 cleo¡once.
mininum diamelral clearances. For NOTI:Chartaboveindicates permiss¡ble maximum clearance, add.001"
Complete instruction on the use of the prelubricator and Plastigage will be given ín the chapter on engine overhaul.
F i g . l 0 - 1 6 . Typ ico l o ve Ío g e m in im u m cle o r onces for engine óeorings. (Federol-Mogul)
154
Friction Beorings
I
I
F ig . l0 - 1 8 . T yp ico l c amshoÍti nserl beori ngs. (C l evi te S ervi ce)
U ND ERSIZE BEA RINGS In order to compensate for wear, inserts are available in a serles of undersizes. If the journal wear is slight, the recommended clearance can often be obtained through the use of inserts .001 or.0 02 u nd er s iz e. The s haf t m us t bec a r e ful1y measured and the largest diameter compared to the original size in order to determine t he co rrect u nd er s iz e. Wh en jo urn al wear is s ev er e or whenjour n a l s are scored or egg shaped, inserts are available in.01 0, .02 0, .03 0, et c . , under s iz e. The s h a f t i s ground to one of these undersizes thus bringing the bearing condition and clearance up to acceptable standards. (greatly underOccasionally semifinished size) inserts a r e bor ed out t o a s pec if ied s i z e .
c i r c l e w i t h e i t h e r a b u t t o r b u t t a n d c l i n c h j o i n t. The bearing material is usually b a b b i tt, Fig.10-18.
BUSHINGS Bushings are full round bearings, usually made of solid bearing bronze (mixture of copp e r , l e a d , t i n , z i n c , e t c . ) . T h e y c a n a l so b e made by the sintering process. Although some a p p l i c a t i o n s u s e s t e e l b a c k p r e c i s i o n b u s hi n g s; i n g e n e r a l p r a c t i c e , t h e b u s h i n g i s p r e s s e d i n to p l a c e a n d e i t h e r b o r e d , r e a m e d o r h o n e d t o si ze . Bushings are usually of smaller diameter than bearings and are used for slower speed applications, Fig.10-19.
quite The camshaft bearing is constructed like the connecting rod and crankshaft inserts except being of one piece design. The camshaft bearing must be pressed into p1 a ce . In a dd ition t o t he s t andar d s iz es , t heya r e to permit line in large undersi2es available boring (attaching a cutter to a long, rigid steel bar and passing it through the bearings one after the other thus boring them in line with each is affixed to steel is rolled into a full
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other) after installaticin. The bearing material strio stock and the stock
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Fi g.10-19. Typi col A ushi ngs' These ore the stee/ boc k ed preci si on fY P e.
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Auto Serviceqnd Repqir ROU ND
'N"H A
the maximum depth is g0 micro inches, the measuring device would indieate a finish of 30 micro inches.
SfRAIGHT
AB
r \ \ ll/ / ¿
HA NDL I NG B E A RI NG S
' HM AAB E G GS H A P E
T APERED
SCORE D
Fig. I0-l 9A. Beoring lournols musl be round, straight, ond smooth.
Precision insert bearings are just what the name implies - they are PRECISION units and should be handled with utmost care. Do not mix halves, protect from dirt and physical damage. Keep fingers from bearing surface as finger marks can cause fine surface corrosion.. When installing, never force or pound into place. Make certain bore and insert'is spotless. Locating lugs (sometimes called tangs) should be in place. After installing, coatbearing surface with CLEAN engine oil. Never file an insert. Always check for proper clearance.
B E A RI NGF A I L URE A bearing of the correct size and t¡npe, properly fitted to an accurate housing bore and operating against a smooth, round shaft, will under normal operating conditions, last in excess of 50,000 road mi l es. There are however, many things or comtrination of things, that will cause premature failure. It is important that the mechanic understand the most signifieant ones as well as being familiar with the visual effects these have onthe bearing insert. In this way, by close study of the damaged bearing, the cause witl often be apparent. In any case, whenever an engine is torn down, bearings should always be cleaned and carefully inspected.
BEARINGJOURNALS The section of a shaft that contactsthebearing surface is termed a JOURNAL. It must be RO UND, S M O OT H a n d S T R A IG H T. N i cks, scratches, etc., will ruin the bearing inaterial, F ig. 10- 19. A . It is recommended that a surface finish of 16 micro inches or smoother be attained. The micro inch (one-millionth 0.000001 of an inch) is used as a measurement of surface finish. To measure a surface finish in micro inches, tests are made to determine the depths of allgrooves or scratches. The RMS (root-mean-square) or AA (arithmetical average) is used to find the AVERAGE depth. For practical purposes, this amounts to about one-third of the maximum depth. In Fig. 10-20, you will note that the red line indicates one-third the maximum depth. If
D A N GE R S IGN A LS Bearing failure is generally preceded by a lowering of oil pressure due toincreasedclearance. The engine oil consumption will rise from excessive oi1 throw off and finally as the clearanee increases, the bearings will starttoknock.
DI RT ,T HE NUMB E RO NECA US E O F B E A RI NGF A I L URE Field and laboratory studies, over a period of many years, have been summed up relative to the causes of bearing failure and the pereentage of failures attributed to each cause. From the results of these studies, Fig. 10-21, you will note that DIRT is by far the most frequent cause of failure.
Fig, l0-20. Determining surloce linish rn MICRO ,NCHES.
l5 ó
Friction Beorings DIR T
of parts. Keep clean parts covered until ready for installation. Work in a CLEAN area, protected from windborne dust. When not working on a part, even for a few minutes, throw a cover over it. Keep hands and tools (especially sockets) free of dirt when assembling parts. Avoid the use of the air gun, sandblaster or steam cleaner near open engines or other units.
The word dirt, as used to describe foreign particle damage to moving parts, includes sand, cast iron and steel chips, pieces of bronze, grinding stone grit, etc. NORMAL engine wear will produce fi.ne parti.cles worn fromthe various parts. Normally these are removed via the oil filtration system. They DO contribute to engine wear but at present will not be emphasized. A B NO RM A L e n g i n e w e a r w i l l produce LARGE bits of dirt that will greaily accelerate the wear process.
DIRT FROMEXTERNALSOURCES Once the engine is assembled and plaeed in serviee, dirt can still enter. Some of the most eommon sources are through the air cleaner, breather system, fuel system, cooling system, dip stick and lubrication system. The vacuum lines can also be offenders. Cover carburetors when the eleaner is removed. Keep air cleaners elean and properly serviced. CIean and properly service crankcase br:eather systems. Maintain a good filter in the fuel system. Check for coolant leaks into the (ethylene glycol antifreeze cylinders forms a gummy residue in the bearings and rings and will cause serious problems). Never lay a dip stick on a dirty surface. Wipe both stick and area around stick entry hole before returning. When changing oil filters, wipe contact area thoroughly. Oil filler cans and spouts should be cleaned and stored to prevent contamination. When removing drain plugs, clean them thoroughly before replacing. Keep ''bulk oil tanks clean. Wipe the surface of oil cans before puncturing. Check filler tube for dirt before adding oil. Why such a fuss about dirt? Once again: DIRT IS THE MECHANICS WORST ENEMY. GET IT OUT OF THE UNIT AND USE EVERY PRECAUTION TO KEEP IT OUT. Study the bearings s h o w n i n F i g . L 0 - 2 2 . E a c h o ne w a s damaged by dirt.
DIR T FRO MRE CONDITTONING Valve grinding, cylinder boring and honing, shaft grinding, etc., deposit metal andcorundum (abrasive particles). These MUST be removed by thorough cleaning. (See chapter on cleaning processes.) There is always the possibility of machined particles being present innew engines also.
DIR TFRO MCLE A NING A sloppy job of cleaning oftenloosenscarbon and other deposits but fails to completely remove them. Once the engine is assembled and put into operation, the washing and cleaning action of the oil will cause these deposits to reaeh the bearings. REMEMBER: DO NOT EXPECT OIL FILTERS, EVEN THE FULL-FLOW TYPE, TO COMPLETELY PROTECT THE BEARINGS. THEY CAN CLOG, THUS FORCING THE BYPASS OPEN AND CHANNEL LARGE CHUNKS OF DIRT DIRECTLY INTO THE BEARINGS. Final rinsing in dirty solvents often contaminates parts.
DIRT FROMPOORWORKAND STORAGE CONDITIONS The engine may be contaminated by working under dusty conditions or by careless handling
B E A RI NGL UB RI CA T I OF NA I L URE Low oi l pressure caused by w orn bear ings, faulty pump, clogged pi.ckup screen or an insufficient supply of oi1 will cause rapid failure. Dry starts (engine overhauled and started without charging the oil system with oil under pressure thus allowing the bearings to operate until pump forces oil throughout the system) can eause initial damage that will cut down the life expectaney of the bearings. Loss of oil through damage to the pan,
C AUSES OF BEARING FAILURE D i rt.... .,.....42.90% fn su ffi ci enlLubr icotion .,.,15.30% Mi so sse mbfy .....13.40% Mi so l i g n nent .....9.80% Ove rl o o ding. ,.... 8,7O% Co rro si o n .......4.507" 5.40% In d e te rminqfe ond Other Couses. ..., F i g . 10- 21. Couses of beor ing Íailu¡e ond the percenloge of occurence.
t57
l0-22. D i r t r v i n s b e o r i ng s - F AST I A' Dir t e n b e d d e d plate d b e o r i n g , B - D í r t in p r e g n o te d b a b b ¡ tt b e o r in g .
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F íg, 10- 248. N i c k ed qnd dented c op bor e w i l l tr ons l er m or k s l o the 6oc k oÍ the íns er t fhus c ous i ng l oc ol i z ed hi gh pr es s ur e or eos .
OIL HOLE
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W: =' t .
1 0 - 2 3 . A l u mi n vm
- rk pn
nrrmn
b e o ri ngs r uined lr om ( F e der ol- M ogul )
o r I i n e . le a kín g
Iock oÍ Iubr icotion.
sa ske t.
b - - _ _ - ',
o- - r
OIL PA5SA:lrlilri I M P R ESSIC) \i i l I N S E RTB¡ I,
f a ilu r e
: . re p l a c e plug af t er d ra i n i n g , w i l l c a u s e s u d d e n : a rl u re , F ig. 10- 23. B EARING F A I LURE F R OM IMPR O P E R A S S E M BL Y \s alr eady m en ti o n e d , d i rt o n th e i n s e rt .:ck, i ns uf f ic ient c l e a ra n c e , re v e rs i n g c a p s, ¡i a ci n g a lower inse rt i n th e u p p e r p o s i ti o n , io* ,e d c r ank c as e, s p ru n g s h a ft o r ro d s , e tc ., ',r-1 1ca us e bear ing f a i l u re . F l g s . 1 0 -2 4 A , B , C , l, E, F, G , illus t r at e th e re s u l ts .
Fi g. 10-24C . The upper i nsert, w i th oi l hol e, w os i nstol /ed i n fhe boftom posi ti on, The l ow er i nsert (see oíl possogew oyi mpressi o n on back) 6l ocked the l l ow ol oi l to the beoríng.
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rt
F i g.
F í g. 1 0 - 2 4 A . B e a r i n gdo m o g elr o m to p e r e dh o u sin g b o r e .
1s8
l 0- 24D ,
A ni s ol i gned c onnec ti ng r od pl oc ed one s i de of thi s íns e¡ l under P¡ es s ur e. N ofe l oi l ur e o¡ eq.
q 'rq
ilrd
Fi q. l 0-25A . E xcessi ve i dl i ng w i l l produce beari ngs /i ke r/r¡s
= :. 10-24E , A b o w e d c ¡ o n k c oser u in e d ¡ h is se t o f m o in 6 e o ¡ in q s.
Fi g. l 0-258. R i di ng (hol di ng {oot on the cl utch ol l the ti me) the c/ufcl r p/oces the moi n beori ng thrust l l onge underprol ongedl oodi ng. N ofe rui ned th¡ust surfoce. (C l evi te S e¡vi ce)
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i 0-24F. A r o u g ho n d s c o r e djo u r n o l co u se dth is b e o r in gto fu il.
DI RTB E H IN DC A P RUI NE D T H ISA R E A
F ¡ g. 10- 25C .
Anti - l r eez e l eok i ng i nto the pon w i l l c ontom i note N or e r he gum m y depos i ts on tÁes e i ns er fs . D epos i fs c on bui l d up ond el i m i nate oi / c /eor onc e - w i th di s os tr ous r es u/ts . ( F eder ol - M ogul ) beor i ngs .
: :
iA -24G . A p o r r i c l e o l d i r t b e twe e nth e in se r t o n d 6 o r e co u se d o f iig ñ p r e s s u r e o r e o t h a t d o m o g e dth is b e o r in g .
:PERATIONAL FAULTS (pulling hard at low engine rpm), Lugging ( f ir ing : : t ressive sp ark a dvanc e t oo s oon) , r::cnation or spark knock (too rapid burning of , . 1 charge cau se d b y a s ec ondar y f lam e f r ont ) ,
(fuel eharge firing before ptug fires preignition - usually from overheated plug, glowing carbon or overheated thin valve rnargin), prolonged slow idling, and excessive rpm will aII place (and other parts) under a heavy the bearings Ioad. This can easily lead to premature failure. Wh e n b e a r i n g c o n d i t i o n i n d i c a t e s s u c h p r o b l e m s , a couple of friendly tips (make certain they are friendly) to the owner would be in order. Fios1o-254, B, C.
159
Auto Service qnd R epq¡r
Bearing failures are most often caused by dirt. Low oil pressure, excessive oil consumption and knocking, are danger signals that indicate excessive bearing wear. Dirt enters the engi.ne from normal. wear, reconditioning, cleaning, poor work and storage conditions, through the fue1, cooling, lubrication, vacuum and ventilation systems. Inadequate lubrication, improper assembly, and improper driving habits also cause bearing failure s..
ADDITIONALINFORMATION determinÍng bearing clearance, Checking prestart lubrication, bearing size requirements, etc., will be and torquing, bearing installation in detail in the chapter on engine discussed overhaul. Steel and rubber suspension system to in the chapters be covered will bushings which they pertain.
SUMMARY
SUGGESTED ACTIVITIES
bearing operates with sliding The friction to acceptable Friction is reduced friction. limits by a film of oil. Most modern bearings are of the precision insert type. They can be of the full round or type. They utilize steel backs that split-halves can be faced with lead-tin babbitt, copper alloys alloy. The bearing ¡haterial is often or aluminum Some bearings have several by sintering. affixed is End thrust materials. of different layers on one thrustflanges controlled by incorporating
using in a bearing, 1. Check the clearance Plastigage. . and failures a number of bq4|ing 2. Examine see if you can determine the cause or combinatíon of causes. both main and rod 3. Mike a used crankshaft, journals. specificaUsing manufacturerrs the amount of wear. Would tions, determine the shaft accept a standard undersize ? Check the journals for nicks and scoring. 4. Make a collection of bushings, full-roundand and see if you split. Study their construction the type of beari.ng material. can determine
or more bearings. The insert must have intimate (close) contact with the housing bore. Bearing spread, crush and cleanliness assure a proper fit. Ne ve r f ile bear ing ins er t s or c a p s . Locating lugs should be in the proper slots. Bearing back and'bore ,must be clean and free of nicks op foreign material. Never reverse or mix bearing caps. Tighten properly using a torque wrench. Check bores
il
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WHOTSLAUGHING? Your favorite suit has just been returned from the cLeanersin time for "thet' dange.Upon removing the garment cover, you discover abig grease stain on the lapel. Are you happy? engagement. On Or, you have an important the way, to look your best, you stop for a quick haircut. The barber drips hair oildownthefront of your shirt. Are you happy? as the about as "happy" You are probably and customer who picks up his cár atthegarage grease on the seat, smudges on the discovers steering wheel and chipped paint on the fenders. He may be slow in leaving fte will probably thousand well chosen words to háve several he leaves), deliver to the scrvice managerbefore and you can rést assured he will be a lot longer
for alignment. Oil grooves and holes are vithl. They must inserts. properly when instálling be located Bearing clearance is critical. An average clearance would be around .002. Follow n¡anufacturerrs recommendations. { must be fitted Worn or reground journals Common undersizes bearings. with undersize are : .00 1, . 002, . 003, . 010, . 020, .0 3 0 a n d . 0 4 0 . Se mifinished ins er t s m ay be bor e d t o a s p e c i fied size. Be ar ing c lear anc e tic wire (Plastigage).
is bes t c hee k e d w i t h p l a s -
Camshaft bearings are of the full-roundtype, usually babbitt lined. or bronze-faced Bushings are usuallybronze steel, and are bored, reai¡ed or honed to size. Journals must be round, straight and smooth. used The micro inch is a unit of measurement in describing surface finish. A microinchfinish of 16 or better is required for journals. Handle bearings carefully.
coming back. Remember: Regardless of age or condition, always treat your customerrs car with real respect. Use fender and seat covers. Never rest tools on the top, hood, etc. Do not place your feet on the bumpers nor lean against the body. Watch door panels when entering or leaving. When finished,. wipe the steering wheel and check
ló 0
I
Friction Beorings upper halves and to use the lower halfinthe " bore. True or False ? 14. All bearing inserts must have oil grooves. True or False ? w o u ld 'b e bearing clearanee 15. An average around-.
carefully for finger prints. These precautions, i n good s hops , a re a m a tte r o f s ta n d a rd p ro c edur es .
OU¡Z - ChoPterl0
16. When journals are worn or reground,inserts are required. 17. Describe a bushing. 18. Bearing journals must be
bearing. 1. Define the term friction 2. The castbabbitt bearing is-widelyused today. True or False ? usuallYhas 3. The precisiona-b ack. 4. Name three popular bearing materials. flanges are used to control end 5.
and smooth finish is the newest type of bearing True or False ? material. prints Finger on insert bearing surfaces 20. can and-do cause_. 2t. Snap inserts into place by shoving on the
19. A micro
play in the shaft. 6. Define beafing spread. i:::'*' assures a tight contact ?. Bearing between the insert and housing. the insert from B. Locating-prevent
with your_. ,2 23.
turning. A few nicks in the insert housing bore are not harmful. True or False ? 1 0 . Reversing or mixing bearing caps will cause the bores to become misaligned. True or False ? 11 A bearing cap can be shifted out of alignment by using athick wrench. True or False ? distorting the t2. Blocks often-thus main bearing 1 3. It is always permissible to mix bearing o
24. 25. 26. 27.
List three danger signals thatcouldindicate imminent bearing failure. Oil filters will always screen outallforeign particles. True or False? List four What ean cause poor lubrication? reasons. List four assembly mistakes that will ruin the bearings. (driving) faults that List three operational will cause bearing dainage. from external ways dirt, Describe five sources, can enter an engine after it has been placed in service. :r
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H€AVY PATf€RN ON ñAC¡3 ANO ñOLLERS CAUSE' AY FI'$EABRAS¡VES. CL€AN AL! PAFTS AND HOUS'NGS.CH€CT g€AL$ ANO R€PLACEg€ARINCS iF ROU6H OA NO$Y.
SUEFACE O€PR€SSIOI{$OftI ñACE A|\|Ó NOLLEFS SAUSÉD AY HAi' PASTiTL€S OF FOg€ICi¡ iñAT€R IJIL. CL€AN ALL FAfiTS AIi¡D I{OU9II{G', CHICK SSALS anto RÉaLA6e gsaRl¡¡es lF RcusH oR nrolsY.
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IIH€IÉ TDGF P¡T¡ING FLAK¡ÑG üÉ SURFACEMÉTAL NÉSUI"I¡NG FAOM rATl*{JE. {JSUALLYA! CÑT EO€É 8F RACE AND ñ{}LLE*S.
FIAXING OF SURSACEM€TAL R€SULfING FROM fATIGUÉ. USUALLY A1 BOÍH EDGESOF 8AC€ AND ROLLERS.
SURFAC: iNOEN}ATIüNS IN NAC€IYAY CII!,SE BY NOLL€RS EIÍHER UND€R IMFAEf LOADINC OR VISR¡.'ION WHILE TH€ BEARINE IS NOf ROfA}ING.
ñ€PLACI B€ARI¡}E '' CLÉ.q¡}ALL RELATSD FARTS
REPLACEST.A*ING '' CLEAN ALL RÉLATEOPAFTS'
FEPLACTAEANING IF ROUGF OA NOISY.
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,ti$sAusN*1É¡¡T ¿:IÉFLAC€B€AF!NG AND TiA'{S S$RE RACÉS AR€ Í*üFisLY igATe0. RFPLACI S}14É¡ IF A€AR!}¡G OPqRAIINC SURÍACE G¡IMA*'I}.
""" **#i.?",tr1"*s5l+üX: :,?i?** CHECX REPTACÉ6EARING.CLEAN RILAf ED PAqTS' slais Áro csrcx FOF PRopER r ll AND LUBRI cAlroN, R€FLACE S}IAFf IF OAMA6ED.
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162
5MÉARS
stáEARlNe oi MFIAL DUE fo sLlpP^GE. SLIPPAGE CAN AÉ CAUSED gY POOR FITS. L{JBRICATION, OVERHÉATING.OVTRLOAOSOR HANNLIN6 OAM. AG€. RTPLACEBEARINGS,CLEAN RELATEO PARIS AND .}IECK FOR PRO¡ER F¡T AND LüARTEATIOII' REPLAC€ SIAFT IF DAMAG€D.
( C hev r ol et)
Chapter11
ANTIFRICTION BEARINGS CONSTRUCTION
each other. In the case of separable (can b e taken apart) bearings, the cage prevents the loss of the elements.
The antifriction type bearing utilizes rolling (ba1ls or rollers) elements to reduce friction :hrough rolling contact. In most applications, :he rollers or balls are placed between inner
The balls or rollers as well as the inner and outer rings, are hardened and ground to assure proper contact and clearance. Needle bearings (long, thin rollers) oftenuse only an outer shell. In some needle roller applications, the bore and shaft are hardened then ground and pLaced in direct contact with the rollers.
T HRE EB A S I CT Y P E S Bearings are commonly divided into three types: BALL, ROLLER, and NEEDLE. Each t¡pe has certain applications it serves best. The ball bearing produces the least amount of friction but for a given size, does nothave quite the load carrying ability of the roller. Al1 three type.s are used in automotive construction. Figs. 1 1 - 1 , 1 1 - 1 A a n d 1 1 - 1 8 i l l u s t r a t e t h e t h r e e t J p e s. Learn the names of the parts.
! T I I 3 l
L O A DI NG DE S I G N {f,Bearings are designed to handle RADIAL, THRUST, or a combination of both radial and thrust loads. Radial designs handle loads at right angles to the axis of the bearing. Thrust designs handle loads parallel to the axis while combination designs handle loads from any direction. Fig. 11-2, shows the loading designs.
V A RI A T I O NS
F i' g. 11 - 1 . T y p i c o l b o l l b e o r in g co n str u ctio n . No te h o w th e coge keeps 6olls even/y spoced. fNíce)
There are many variations of thethreebasic t¡pes. Each different design attempts f.o meet a specific demand. The installation may call-for light or heavy loads, high or low speeds, radial, thrust or a combination loading. By understanding the proble.mÉ involved and the type of
s¡d outer rings. The rolling elements are separated by a cage or separator generally r¡ade of steel by stamping. The cage prevents túe elements from bunching and sliding against
tó3
Auto Service ond RePoir
C - C ombi noti on Fi'rodíal g. 11-2. Loodíngdesi gns. A -R odi ol ' B 'Thrust' oÍ l ood' ondffi rusl . A rrow s i n col or i ndi cote di rec'ion e l¡J F UI
-l *'ointsO.D .C OR N E R
u
F
= ul= 6 u 6 F 3
R OLLER
l¡t E
o
fnr,**,,o
o
1r
'\L- BOR E
CORNER
LO AD
OU TSDI E D IA ME TE R
ER5
o F
u o SE PA R A TO R
l!
o
z
li_
u¡
I
b e a r ing utíl i zes the F í o . l l ' l A . R o lle r 6 e o r in g ' T h ís p o r tícu lo r (S K FJ t o p e r e dr o l le r d e síg n ' T h e o u te ¡ r in g is se p o r ate
I-
RETAI LIP
ro.t
I
F
lo¡ rodiollood onlv F i s ' 1t-3. Stroightroller beoríng'Designed (AFBMA) SPHER IC AL R O LLER
LENG TH- {
OU TS ID E
ROLLE
th e rol l ers operol e F i o , l l - 1 8 . Ne e d fe 6 e o r in g' ln th is b e o r ín g ond ' " r t t i , r t r ' r í " . r i "t t¡ "ll .o n í ín d i' "t' co n lo ci wilh o ho¡dened M fr s ' A ssn' A FB MA ) Be o r ín g ( An liF ¡ íclio n o r o u n ds h o l t su r fo ce '
Fis'
164
l 1- 4,
Spher íc ol r ol l er beor i ng' N ofe " 6o¡ ¡ el "
(SKF)
s h o p e o ( ro l l e rs
i --l
li ll
ll
Antifriction Beorings
bearing be st suite d, t he m ec hanic will be gr ea t Iy aide d in a ll b ea ring wor k . Some of the more common variations are the st raight ro ller, sph er ic al r oller , t aper ed r oller , deep groove ba11, angular contact ba11, multiple row , se lf-alig nin g, et c .
OUTERRINGOR
i
a11ows the roller to follow the taperedraceways w i t h n o b i n d o r s k i d d l n g . C o m m o n p r a c t i c e i s to secure the rollers to the cone with asteel cage. The cone raceway is indented thus forming a lip that keeps the rollers centered. The cup is then separable, Figs. 11-14, and 11-5.
INN E R R IN G OR
CUP RACEWA Y
ROLLERS
'il\
CAGEORSEPARATOR
Fig,
l 1 -5 .
fo per ed
r oller beor ing por ls. Once ossem bl ed,
thi s por ti c ul or beor i ng w íl l but the r oller s, cog e ond i nner r íng w i l l be one uni t.
hov e o s epor obl e
STRAIGHTROLLER
DE E PG RO O V E BALL
T he straig ht r oller is des igned t o hand l e aeavy RADIAL loa ds . I n m os t des igns it w i l l : : andle little or n o t hr us t , Fig. 11- 3.
The HEAVY Neither Fig. 1 1-
SPHERICALROLLER T h e ro llers in t his bear ing ar e of c ur v ed o r shape. It will handle HEAVY radial --:herical lcads an d MODERATE t hr us t 1oads . I t is s el f = lignin g (to a de gre e) , Fig. 11- 4.
outer r i ng
deep groove ball bearing will handle radial and MODERATE thrust loads. the inner or orrler rino.iq " o p a r a b l e, 6.
ANGULARCONTACT BALL T h i s b a l l b e a r i n g w i l l h a n d l e b o t h H E A VY thrust and radial loads. The balls are contained within a cage, and both inner and outer rings are separable, Fig. 11-7.
TAP.EREDROLLER
MULTIPLE ROWBEARING
T h e tap ere d roll er is t he m os t widely us edof .he ro lle r b ea ring s as it will c ar r y bot hHEAVY :hrust and radial loads. The apex of the angles icrmed by b oth the r oller s and r ac eway s , i f : xt ende d, wou ld me et on a c om m on ax is . Th i s
Bearings can employ two or more rows of bal1s or rollers so that heavier l o a d s , b o th r:di¡l erd ihrnsf onn lre c:rried T h e v c a n a l so be designed to provide for thrust loads inBOTH directions, Fig. 11-8.
165
VY RADIALLOAD
MODER AT E TO LIGHT THRUST LOAD
THRUSTDIRECTION will note that several of the bearings ONE direction on1-y' shown will sustain thrust in would force the Thrust in the opposite direction bearings' more apart. By using two or rings in either thrust facing in opposite directions, 1 1 9 ' F i g ' direciion can be handled, You
T H R U s T F O R C ES BEAR IN GT OG ET H ER
DEEP GROOVES OR RACEI{AYS
T H R U STF O R C ES BEAR IN GAPAR T
Nole the use of s eol s on F i g . 1 1 ' 6 - D e e P g r o o ve boll beor íng, 6ofá sídes. BEAR IN GSF AC IN G IN O PPO s IT E D IR EC T ION S.T H R U STC ON T R OLLED I
THRUST LOAD
ER RING
di ¡ec l i on l h¡ust i n Fi q, 1l -9. B y usi ng l w o beari ngs' .ei the.r .on¡otted. A r¡ow s i ndi col e l hrusf di rectíon'
-to,o*tnr* --t'/Rlno
CASE
b e a r in g ' T h is typ e i s often used F i q . 1 1 - 7 . A n g u lo r co n to ct b o ll o s co r lr o n t wh e e l b e o r in g s'
LUBRICA
PASSAGE
OUTER RING OR C U P
INN ER RIN G OR CON E
thrus! beori ng' Fi g. l 1'9A . Typi col l opered rol l er OR A R AT OR
T HRUS TB E A RI NG shown in Fig' The bearing forces THRUST signed to handle
fH RU S T D IRE C T ION
1 1 - 9A' only'
is
de-
SELF.AL IGNINGBEARINGS is apossibiliWhen, during operation, there of perdesirability' a ty, or in some instances, a misalignment' shaft or either housing áittirrg
RADIALLOAD b e o r in g ' T he oul er ri ng i s F i g ' 1 l - 8 . D ou b le r o w, to p e r e d r o lle r se p o r o te ' ( Ti mken) o r e r in g s in n e r o n e p i e ce , th e
166
1
N O SEALS
self-aligning bearing is used. This bearing will '11ow a degree of tilt without distortingthebear:ng elements. Both internal and external selfaligning bearings are shown in Fig. 11-10.
OUTER RING
F i g. l IJ l .
IN T ERN A L
Beor i ng s eo/ c ons l r uc l i on
EXTERNAL
F ig. lI - 1 0 . l n t e , r n a o l n d exle r n o l se lÍ- o lig n in g b e o r in g s.No fe how * e s Áo f i i s l ¡ e e t o t i p . T h e e xfe ¡ n o l d e sig n will h a n d le h e ovi er Joods os the boll hos o wider contoct oreo with the outer rinq.
t s E ARIN G IDEN T IFICA TION All bearings are marked with part number, lsually on the face of the rings, for ease of re¡l.acement. If necessary, replacement bearing size can be checked by careful measuring.
BEARINGSEALS Bearings can be open on both sides or sealed on one or both. Sealing on one side is often used :o help confi.ne lubricant and topreventthe entry cf dirt. When both sides are sealed, the bearing :s lubricated during assembly and no lubricant can be ad de d in the f ield, Fig. 11- 11.
R E M O VIN G BEARINGS
Fig. lI-12. RemovingdiÍlerentiolpinion shalt beoringwith hydroulic puller. (O.T.C.) There are some instances, as you will see later, that require force on either the free ring or rolling elements. However, WHENEVER POSSIEXERT BLE, THE FORCE ON THE TIGHT RING ONLY. Fig. 11-13, shows both the right and wrong way of applying pulling force. Note that in A, puller plate rests on the free the supporting
Prior to pullingbearings, clean the surround:ng area to prevent contamination. Bearings are generally best removed with srechanical or hydraulic pushing or pullingtools, w hich e xe rt f or c e , a h eav y and STEADY F ig. 1 1- 12 . In the absence of such pullers, or in cases 'where their use is impossible or undesired, a suitable hammer in combination with soft steel drifts, will handle sleeves and cup drivers, many jobs. a bearing by Any attempt to pull or install exerting force on the freg (not tight) ring is apt The ring itself ro chip the bal1s or rollers. eould crack and fly apart inadangerousfashion.
PRESB SED Fi g. l l -13. P ul l i ng setups. A -V l rongos force i s oppl i ed th rov gh lree oule¡ ring ond rolling elements. 8-Correct. Force is ffirough ti ght ri ng onl y.
167
Auto Service qnd Repqir
outer ring. In B, the plate supports the inner ring only, thus avoiding damage to the outer ring and rolling elements.
WHENINNE RRINGCA NNOTB E GRA S P E D Occasionally is the bearing inner ring pressed against a shoulder that is as wide or wider than the ring. In the case of the tapered roller bearing, a special segmented (made in parts) adapter ring ean be used. It applies the pulling force to the ends of the rollers whl1e forcing them against the cone. This allows the wit hout b ea ring t o be r em ov ed damage, Fig . 11 - 1 4.
Another type of puller especially adaptedfor axle shaft bearing work, is pictured in Fig" 11-144. A split sleeve, with pulling rings, i*q used. The axle shaft passes up throughasectior: of tubing. The puller sleeve grasps bothbearing and tubing. The top section of the tubing is fastened to a heavy plate onthe bed of the press. As pressure is applied to the shaft end, it is forced through the tube thus pulling the bearing. Note that the entire bearing is shrouded or shieLded thus protecting the operator from flying parts if the bearing should explode. This puller will remove both tapered roller and ball bearings, Fig. 11-14A.
WHEN BEARINGCANNOTBE GRASPED PRESSRAM
PULLERSEG M E N T S ADAPTORR I N G
1,1
PRES SB E D
ir li
There are instances in which a retaining plate, dust shield, etc., is so close to, or surrounding, the bearing that it is impossible to g r a s p i t . I n t h e s e c a s e s , i t i s n e c e s s a ryto grind away a portion of the inner ring (protect the shaft with a metal sleeve), cut out the cage ani remove the elements. The outer ring can then be removed thus exposing the inner ring for grasping. Unhardened retaining rings are sometimes used to hold bearings in place. They are best removed by notching with a sharp chisel. This will loosen them enough to be easily removed, Fie. 11-15.
l; F i g . 1 l - 1 4 . P u llin g b e a r in g b y o p p lyin g p r e ssu r e through rol l ers. The nognilied porlion at lhe lowe¡ rigfit sñows how lhe end o( the r o l l e r i s g r o sp e d b y th e p u lle r se g m e n ts. ( Ti nken)
I
R ET AIN IN GR IN G
S PL IT S L EE YE ST EEL B L O C K
ring by notchingwith o Fiq. ll-15. Removíngbeoring.rctoi.ning
F i g . l l - 1 4 A . Re m o vin g o xle sh o { t b e o r in g with speci ol pul l er.
Inner bearing rings can also be removed by grinding partial or by cutting part way through torch. WRAP TIIE with an acetylene cutting
168
SHAFT, ON BOTH SIDES OF THE BEARING, WITH WET CLOTHS TO PREVENT HEATING. CUT ONLY PART WAY THROUGH. The ring is then squeezed tightly in a vise and struck smartly with a hammer where indicated by the a rr ows in F ig. 1 1 -1 5 A . T h i s w i l l c ra c k th e ri ng and allow it to be pulled. WEAR SAFETY GOGGLES \A/HEN STRIKING BEARING PARTS. Always pull bearings whenever possible. AVOID GR,INDING AND ESPECIALLY USE OF THE CUTTING TORCH, IINLESS ABSOLUTELY NECESSARY.
F¡g. II-16. Troy l ul l ol beori ngs bei ng pl oced i n keros ene.
ING. WEAF, SAFETY GOGGLES. KEEP OTHER PERSONNEL AWAY FROM WORK AREA. C LE A N IN G B E A R IN GS
F ig. I l - 1 5 A . B e o r i n g in n e r r in g p o r tio lly cu l o n d tfie n sgueezed in o vise. Srrike with a hommer where indicoted by orrows.
When the bearing is removed, wipe off all surpl us grease or oi l . S oak i n kerosene or cleaning solvent. A regular cleaning tank with tray and solvent hose, is ideal. If none is availabl e a cl ean bucket w i l l suffi ee, Fi g. 11-16.
K EEPBEAR ING P A RTSTOGE THE R CAUTION: When a separable bearing is removed, keep the parts together. Under no circumstances should bearing elements be mixed.
G EN ERALR U LE SFORB E A RINGRE MOV A L 1 2
, A
Exert force, where possible, onthe tight ring. Use pullers of the correct size and shape. Mount puller to exert force in a line parallel to the b ea ring ax is . Use unhardened, mild steel drifts and sleeves. Never strike the outer or free ring. Use care to avoid damage to the shaft or housing. If ne ce ssary t o ham m er a s haf t , us e abr a s s , Iead or plastic hammer. Keep all parts of one bearing together.
WATCH OUT: PULLING BEARINGS, BOTH WITH PRESSURE OR STRIKING TOOLS, CAN BE A DANGEROUS OPERATION. BEARINGS UNDER SUCH PRESSURE CAN SHATTER AND SEND PIECES FLYING OUTWARD WITH LETHAL FORCE" WHENEVER POSSIBLE, SHIELD TITE BEAR-
NEVER USE GASOLINE OR OTHER VOLATILE FLUIDS FOR CLEANING AS THEY ARE ROUGH ON HANDS AND WILL'IG}TITE READILY. DO NOT USE CARBON TETRACHLORIDE AS IT PRODUCES POISONOUS FUMES. W hi l e some beari ngs are soaki ng,brusheach in turn with a nylon bristle brush and blow out the worst of the grease. Continue soaking and brushing until bearing looks clean. Blow the bearing out again. If any sign of grease is visible, soak, brush and blow out once more. DO NOT SPIN: NEVER SPIN A BEARING WITH AIR PRESSURE. NOT ONLY WILL IT DAMAGE THE BEARINGS, IT CAN ALSO BE DANGEROUS. WHEN THE OUTER RING OF A SEPARABLE BEARING IS REMOVED, THE ROLLING ELE. MENTS ARE HELD TO THE CENTER RING WITH THE CAGE. IF TIIE CAGE ANDROLLERS ARE SPUN, THE TREMENDOUS CENTRIFUGAL FORCE GENERATED CAN CAUSE ONE OR MORE ELEMENTS TO FLY OUTWARD WITH VIOLENT FORCE.
169
r\ ,r,:;,rl
*;Í3:r, BEARING
B EARI NG cle on ,dr y oí r , blow beor ingdr y ' Do not o l l o w F ig. - ll-17 , Usin g t o s Pin' ( Tim k en) b eo r í ng \ \-h en ce rtain t he bear ing is CLEAN, r in s e of CLtrAN kerosene and blow :l a container ir\ ' , Fig. 1 1- 17 .
DEFECTS
to discussing checking procedures, it Prior yourself with some of the familiarize to wise is that will be defects bearing common most cause for rejection. Fig. tl-32. As is the case with friction bearings, DIRT one enemy of ball and roller is the number pitting and It will cause scratching, bearings. include defects common Other wear. rapid rings, cracked overheating, spalling, brinetling, c o r r o de d a n d s e a l s d a m a g e d c a g e s , broken areas.
USECLEAN, DRY AIR
SPAL L ING
s y s t em s ar e equip p e d Nlost a ir comp r es s or Service them -,','ith filter trap. and moisture int o a wh i t e air of s t r eam a cf t en . Directing pr es ent ' is oiI or dir t lf clot h will sho w
overloading and norrnal particles, Foreign a n e x t e n d e d p e r i o d c a n l e a d to over wear s p a l l i n g . S p a l l i n g s t a r t s w h e n t i n y a r e a s f r a c t ur e and flake off. These sma11 flakes are carried around in the bearing causing more flaking' Advanced flaklng or spalling will prodr'rce large
D O N OTWASHS E A LE DB E A RINGS Wh en a be arin g is f ac t or y pac k ed and c o m pletely sea led on bot h s ides , it m us t no t b e t' ashed . Wip e off t he out s ide r v it h a c lean' d r y clot h. Wa sh ing will dilut e t he lubr ic ant and l e a d to early fa ilure .
craters,
Fig.
11-18.
CLEAN WORK AREA IS A MUST ar e c leaned and dr i e d ' On ce th e b ea r ings take the m to a CLEAN wor k ar ea. I t is a g o o d idea to reserve a s ec t ion wher e t his as s em b l y area will b e fre e of dus t y air , gr inding m a pic t u r e s chine s, ste am cleaning, et c . Fig' 11- 1?' this near as y our s Keep sec t ion. wo rk an id ea l as p ossib le. See Fig. 11- 174'
F i g . 1 1 - 1 8 .B o d l y s p o l I e di n n e rr i n g ' (AFBMA)
BRINELLING i s t h e t e r m u s e d t o d e s c r i be a Brinelling b o th series of dents or grooves worn in one or and r a c e w a y t h e a c r o s s r u n g r o o v e s T h e rings. On ce i n t e r v a l s ' r e g u l a r a t s p a c e d u s u a l l y are starts (often from inadequate lubribrinelling i r o n o x i d e p o w d er i s cation) a fine reddish a r o u nd ' i t As the powder is carried formed. 1 1 1 B A ' shows a F i g . increases the wear rate. s h e l l . badly brinelled outer
OVERHEATING down the physical will break Overheatlng failure' oroperties of the bearing and cause rapid
F í g . 1 l -1 7 A. ld e a l b e o r in g wor r ( oleo. ( SKF )
170
Antifriction Beorings
CRACKEDRINGS One or both rings may be cracked. Improper removal or assembly techniques and wrongbore o r s h a f t s l z e a r e c o m m o n c a u s e s , F i g . 1 1 -2 0 .
BR IN E L L
B RO K E NO R DE NT E DCA G E I m p r o p e r r e m o v a l a n d a s s e m b l y p r o c e du r e s w i l l o f t e n r e s u l t i n a d e n t e d o r b r o k e n ca g e . P i e c e s o f d i r t a n d m e t a l c h i p s w i l l a l s o ca u se cage breakage, Fig. II-21.
Fig. ll-1 8A. B¡ inelledneedlebeor inqs hell_ im pr oper lubr ic at ion, p o o r -ack o f lu bricatio n, = djustmen t, e tc., ar e t he pr inc ipal c aus es . T h e :earin g ring s an d r olling elem ent s whic h h a v e :een o ve rhe ate d, will hav e a blue or br owni s h :iue disco lora tion , Fie. 11- 1g. F i g.
l l _21. gr o/
DENTED SHIELDS A s w i t h a b r o k e n c a g e , c a r e l e s s a s s e mb l y o f t e n p r o d u c e s d e n t e d s h i e l d s . T h i s c o u l d a l so damage the eage as well as cause binding and lubricant loss, Fig. IL-22.
F i g . l l -1 9 .
Ove rheoted beor ing - note disco/o¡ or ion.
Fig. ll-20.
Fi g. l l -22. B odl y dented6eori ng shi el d or seol (N ew D eporture)
Cr o cke d in n e ¡ r tn o .
171
Auto Serviceond RePoir
coRRosloN (often from the air The entry of moisture lubr i c a n t , s t o r a g e c ont am inat ed ho se ), wr ong or c an p r o d u c e c o r et c . , v apor s , n ea r c or r os iv e remaining A bear in g bear ing. in t he rosion static (not being rotated) for an extended time, o ften c or r odes , Fig. t t - 23.
"ji
Fi g. 1l -23A . R ol l er donoge. A 'C or¡osi on' B -E l ec tríc ol pi tti ng C -P oor l ubri coti on ond di rt' (S l (F)
¡
¡S NORMAL SOME LOOSENESS
C OR R OD E D AREAS F ig . 1 I - 2 j. Co r r o d e db e o r ing'
A n e w b e a r i n g o f t e n f e e l s r a th e r l o o se sc d o n o t a s s u m e l o o s e n e s s a s a si g n o f w e a r ' When either raceways or rolling elements are w o r n e n o u g h t o p r o d u c e l o o s e ne ss, i t w i l l b e evident by examining the surfaces. One or more of the conditions mentioned above willbe visible'
BEARINGINSPECTION n o n s e p a r a b l e b e a r i n g s, Wh e n i n s p e c t i n g hand through the center' one of place the fingers r o t a t e t h e o u te r r i n g w i tl a n d F i g . 1 l 2 4 , ring,
DIR TW E A R If the dirt is very fine, it will have a lapping (removal of surface metal through fine abrasive action) effect that will leave the rolling elements and raceways with a dull, matte (nonrefleeting) produce will particles dirt Larger finish. scra tc hes
and Pit s .
ELECTRICAL PITTING or generator bearings are motor Electric pitted by the passage of current sometimes (from an internal short or from static electricThe minute arcing ity) through the bearing. Fig. 11-234, pit s . t iny num er ous p rod uc es pitting, dirt, the effect of electrical illustrates corrosion
and poor lubrication
F¡g.11-24. H ol di ng beori ng {or i ns pec tíon'
on rollers.
17?
Antifriction Beorings
-he other, The bearing should revolve smoothly ¡;-th no catching (stopping momentarily) or : cughness. If e ithe r c ondit ion is pr es ent , r ins e blow dry again. If the symptoms still per-rd = :st, disca rd th e be ar ing. Als o c hec k f or s igns :i overheating and wear on the outer surfaces :l both rings. A bearing that has been loose in ::re bore, or on the shaft, will have highly - clished are as sh ow ing. For separable bearings, carefullyinspect the ::ceways a nd rollin g elem ent s . They s hould b e ::solutely smooth and free ofheat discoloration. -:-spect EACH ball or roller, as quite often only :1e or two may be damaged. When satisfied as ,o condition, place the elements together. While Jrreing them together, rotate the bearing. The -r?eration should be smooth. When revolving bearings, do so a number of rmes, as a single damaged ball or roller may :ct "catchrr the first few times around. When :hecking thrust bearíngs, place one side on a .clid surface. Press down on the other with the :-ee1 of your hand and while maintaining pres..:re, rota te. KEEP HANDS CLEAN, DRY AND '''{Y FROM RAC EW AYS AND RO LLI NG a- E MENTS. Se e Fis . t t - 24,
Fi g. I I -25. B eori ngscl eoned,oíl ed ond pl oced i n protecfi ve contdi ne¡.
future rotate
date.
When
toi nsure
coati ng
proper
beari ngs
penetrati on
for
storage,
and coverage,
Fi g.11-26.
P A CK I NG WI T HG RE A S E Wh e n a b e a r i n g c a l 1 s f o r g r e a s e ( s p e c i f i c recommendations for each type will be given in the section to which they pertain), use abearing
D ON OTSAVEONEP A RT If any part, outer or inner ring or rolling :-ements are da mag ed, dis c ar d t he ENTI RE iearing. Ne ve r re pla c e a par t of a bear ing. Before discarding, write down the part :-:lmber. It is a good idea to wire the parts to:ether and keep for comparison with the re:Lacemen t be arin g. M ar k as DEFECTI VE.
B EAR ING L UBR ICA TION If the bearing will be placed into service at :nce, it may be packed with the proper grease rr it may be oiled, depending upon the need. Cover with a clean cloth until ready to install. -l it will be stored for a few days, coat with oil :nd place in a clean box or container. At any :ate, IMMEDIATELY FOLLOWING INSPECTION, COAT WITH THE DESIRED LUBRICANT TO PREVENT THE FORMATION OF RUST >ee Fig. Ll-25. If the bearing will be stored for an extended reriod, coat with light grease, wrap in oilproof _¡aper and place in a clean box. Be sure to :dentify the bearings to prevent opening a number of them when looking for a specific one at some
F i g.
l l - 26.
Beor i ngs gr eos ed ond w r opped l or ex tended s tor oge.
packer. If no packer is available, place a "gob" of grease (hands clean and dry) on the palm of one hand. With the other press the edge of the b e a r i n g i n t o t h e g r e a s e ( n e a r t h e e d g e ) . R e p e at this until grease flows out the top. Move around to different sections until the bearing is fully packed. Separable rings should be coated also. See Fig. LL-27.
P RO T E CTL UB RI CA NT S All grease and oil in the shop should be kept in clean containers and kepttightlyeovered when not in use. When opening, wipe dirt off li.d and avoid dusty areas. An open can of grease near a grinder, cutting torch, etc., is anopeninvitation to disaster.
173
CONTACTAREA B EARING
WH E E LH U B TA P E R E D
I LUBRICA N T FORCED II¡:f! BEARING
F i g . I t ' 2 7 . A b e o r in g r Po cke r fu st o n d e Ílicient' r is
CHEC KSEA LS
Fi g. 11-28. R emovi ng burrs hom oxl e shol t beori ng oreo w i l h o l i ne ¡ooth fi l e-
T O E A S EA S S E MB LY US EL UB RI CA NT The use of a thin film of oil or micronized graphite (finely powdered) will ease installation, prevent corrosion around ring contact area, and d a te , at some future removal facilitate Fig. 1 1-2 9.
If any oil or grease seals are related to the job a t h an d, ins pec t and if nec es s ar y r ep l a c e a t be inthís time . In s om e ins t anc es s eals m us t sta lled a fter t he bear ings .
BEAR INGINS TA LLA TION calls for care and inBearing installation good telligent use of tools. Many an otherwise job h as b ee n r uined by c ar eles s ins t allat i o n '
M AKECER T A INY OUHA V E B E A RING TH E C ORRE CT (but not exact) in Bearings are often similar installation' attempting Before size. and type make ce rtain y ou ar e ins t alling t he c or r e c t o n e ' wit h new r epla c e m e n t c ar ef ul Be e sp eciall y b ea ring s. Chec k num ber s and m eas ur em e n t s '
CLEAN BORESAND SHAFTS an d s h a f t s hous ing bor es Cle an b ear ing etc', with burrs, nicks, any Remove thoroughly. spot)' flat a file not (be do careful, file a fine Following filing, polish with very fine emery or is crocus cloth. On a shaft where the inner ring aroundthe (creeping movement designed to walk If shaft) inspect carefully. Polish if necessary' are areas shaft press-fit or the counterbores wo rn fro m ring s lippage, do not c ent er p u n c h o r kn url (cro sshat c h pat t er npr es s ed int ot h e m e t a l ) will in atte mpt to inc r eas e s iz e. Suc hpr oc edu r e s o nly re su lt in f ailur e as t he bear ing, und e r l o a d ' will quickly flatten these raised areas' The area (spraying molten should be built up by metallízing to the correct ground metal onto shaft) and then s plin e s ' e t c " t hr eads , in dir t size. Wa tch f or Fie . 11 -28 .
Fi g. tl '29. l Jse l ubri con¡l o l oci l i ¡ote ossem 6l y '
HE A TA NDCO L DHE L P S large assembly jobs, primarily In difficult or in ice dry in ring bearings, placing the outer help and diameter the reduce a deep freeze will (NEVER heated be can rings Inner installation. F.) in clean oil. Use a 275 DEG. ABOVE bearings with atorch' heat Never thermometer. See Fig.
11-294.
POSITIONPROPERLYAND START SOUARELY correct installation posiAfter determlning or fail to put (do backwards press on not tion must go on that etc., rings, snap any retainers, first, in place), start the bearing or ring with the fingers. Attach puller or set up inpress and IT lorce bearing into place. MAKE CERTAIN FULL THE TO AND GOES ON SQUARELY whenApp1y pressure DISTANCE REQUIRED. puIlin As ring' tight the to ever possible, only ing, observe safetY Precautions.
174
-5' Antifriction Beorings
S HA F TA NDHO US I NG B O RE S MUS TB E T RUE
SIMPLE TOOLSWILL OFTEN SUFFICE If regular pressing tools are not available, simple driving tools will handle many jobs in a satisfactory manner. Make sure they are clean. Strike the tight ring on1y. Use soft steel tools. Brass tools tend to mushroom and chip thus cont amina ting the bear ings .
A s p r u n g s h a f t o r b e n t h o u s i n g w i l l c a u s e t he bearing to operate in a distorted position, thus greatly shortening its life. For those jobs in which the bearing failed in a short time, despite proper installation, lubrication and adjustment, always check shaft and housing for any warpage or other misalignment.
BEARINGADJUSTMENT Some bearings require adjustment after inProper depends on the adjustment stallation. application. Some require a specific amount of f r e e p l a y a n d o t h e r s r e q u i r e p r e l o a d i n g ( p l a ci n g so that when a under pressure the bearing driving force is applied to the parts, they will As the various not spring out of alignment). a r e d e s c r i b e d t h r o u g h th e service operations will book, general adjustment recommendations be given.
Fig. l1 - 2 9 A . H e a l i n g o b e o r in g in o il. Ho o k ke e p s b e o r in g l rom touching boltom of confoiner.
GENERAL RULES FOR BEARING INSTALLATION 1 . C l e a n a l l c o n t a c t s u r f a c e s a n d r e m o v e b u rr s, nicks, etc. 2 Install parts that precede bearing. Lubricate for easy installation. I f h e a t i s r e q u i r e d , d o n o t e x c e e d 2 T 5 d e g . tr . Start bearing squarely. Align tools so that bearing will be forced h
nn
qnrraralr¡
7. For driving tools, use soft steel. B. When possible, applying pressure avoid through balls or rollers. 9 . I f a v i s e i s n e e d e d , u s e p r o t e c t i v e j a w c o v er s. tools must have smooth, square 10. Driving cut ends. 11. Do not mar shaft or bore surfaces. 12. Use safety precautions. 13. Press on the full distance required. Fig. 11-30, illustrates a f e w d o r s a n d d o n r ts b e a r i n g a s s e m b l y . regarding
SUMMARY Bearings c a n b e d i v i d e d i n t o t h r e e b a si c R O L L E R , a n d N E E D L E . Th e types; the BALL, bearing usually consists of an ball and roller inner and outer ring with the rolling elements p l a c e d b e t w e e n t h e m a n d p o s i t i o n e d w i t h a ca g e The needle bearing can use an or separator.
R, iS.ll - 3 0 .
B e o r i n g i n sto llo tio n Iin r s. A- Do n o l str ike o eori ng * it h o h a m m e r .B - D o n o l u se wid e p u n cñ e so n b e o r in g s. C- Doappl y ürc e l o t i g h t r i n g ( l ) a n d h o ve cle o ¡ o n ce ( 2 ) h r sh o f¡ . D-U se ariv er w i t h s m o o l h ,s g u o r e cu f e n d s th o ¡ sr r ike tig h t r in g , E- C l eon 'eorí n g r i n g r e c e s s ( 5 ) a nd lo r ce r in g to fu ll d e p lh . F - Blo ck p loced ffi open pipe driver ollows driving force to be centralized. Use p r o t e c t i v e v ise jo w co ve ¡ s ( 6 ) . ( AF BM A)
t75
Auto Service ond RePoir
placed in direct contact outer shell, or can be and shaft' hardened and ground bore *irt either c ar r y " t o ar e des igned Bea ring s loads' combination or thrrist, radial and tapered roller' "ttJghi spherical The straight, contact ball' and the deep groove bal1, angular are the common of both types' "áit-.rii"I"g variations. are marked with part number' Bearings or both are often sealed on one Bearings sides' onboth sealed sides. Uerr-er wash bearings striking or puller mechanical Hydraulic, bearings' All must tools can be used to remove and hydraulic be used with care' If available' mechanical pullers are recommended' ring possible'bythe PuIl bearings, whenever for available are Speeial tools that is tight. balls the pressureby-exerting p"irt"e lhr?ue: not mar Avoid the use of heat' Do toir""". it removed' is Whenbearing bore or shaft surfaces' parts together' if separable, keep a1l Blow dry' rinse kerosene' in Clean bearings dry again' Do not in fresh kerosene and blow be clean and dry' spin the bearing. Air should If bearing' inspect in a clean area' Working once' at grease with satisfac-tory, oil or pack Rejected to install' Keep covered until ready with comparison size for bearings may be kept but MARK them as REJECTS' replaclments cor'S"t"t"ted, spalled' brinelled' pitted, plus bearings' roded, cracked, and overheated shields dented or with damaged cages it."" Never replace onepartof MUST be REJECfBD. a - bearing. not in use' lubricants covered when f.ep"atl with lubing is handy for packer A bearing gre ase. or oil seals' Clean Replace defective grease any and install burrs bore and shaft, remove bearing' parts that must Precede .
L ub rica t ebear ings eat ar ea' pos it ionbea r i n g press' or drive and start Uyttana' PulI' correctly square at all fulIy into pi"ce kt"ping bearing or bore' Installation times. Do.not aamage shaft In difficult clean' be sploltessty must tools (carefully heat of both assembly jobs, thá use installation' ease controllád) and cold will bearing' If necessary, carefully adjust
SU GG ES TEADCTIV ITIE S l.secure an um ber of dam agedballandr olle r one and Clean and inspect each bearingsto find Try identify the cause of rejection' defect' typlcat one good example of each
properly' inspect Remove a bearing' clean the bearing Install grease' and pack with recommendations' followíng all exact as closely as possible' the 3. í"t""*irr", bearings of ba1l, roller and needle ;;;;"t in ALL a specific car' Count them 1., t""A rear line' drive areas, clutch, transmission' and motors pumps' end, wheels, steering, other accessori es.
,
HONESTY! feel (with Unfortunately, many car owners service garages' justification in some cases) that really not are etc" station repair centers,ttpadt' time' mechanics honest, that they often perform and installed' charge for parts not that were (or claim to have performed) repairs unnecessary. things dohappen There is no doubt that these of COMPLETE occasionally. The importance th" mech-anic and HONESTY on the p"tt of Customer cannot be tveremphasized' ;;;;e", rnake or can they that relations are vital in an EXACT give ALWAYS break a business' ONLY REQUIRED record of labor, perform some essential re(if encounter you repairs with covlred in an estimate' consult p"i" charge "., before proceeding). -1"u it "lr"to-er " ACTUALLY INSTALLED' parts for OUI,V good business If this basic foundation of folscrupulously is (trrJ gooa living) practice of trust and respect the lowed, you wiII earn no is that there your customers. Remember than a SATISFIED effective more advertisement customer.
OUIZ - ChoPterll bearings are used and in automotive construction' designs' 2. Name three bearing load bearings' 3. List three t¡ryes of roller will handle bearing ball 4. The deep groove False? or True HEAVY thrust loads. by the selfis offered advantage 5. What aligning bearing? a bearing sealed onboth sides' A Naver pullers or mechanical are hydraulic Z. Wty for tools to striking superior generally bearing work? foree to the free ring' B. Always apply pulling True or False ? it is persome circumstances' 9. Under I
176
Antifriction Beorings
10. 11. 12. 1 3.
14. 15. 16. 17.
missible to apply pulling pressure through the rolling elements. True or False ? Bearings, under pulling pressure, canliterally explode. True or False? When heat must be applied toabearingring, it should not exceed_deg. F. Name two safety devices used when pulling bearings. I f a bear ing i s s ta rte d i n a ttc o c k e d " posi tion, it will line up under pressure. True or F als e ? AU pulling tools (striking type) should be of soft steel. True or False ? In that bearings are hardened, a little fine dirt will not hurt them. True or False ? I t is per m iss i b l e to mi x b e a ri n g p a rts i ft hey are in good shape. True or False ? B ear ings a re b e s t c l e a n e d i n or
to
List 10 general rules regarding bearing installation and removal. 30. Write down the numbers of the bearings illustrated in Fig.11-31. O p p o s i t e e a ch number, write the letter of the correct name. Some of the following names are wrong: A. Single row, deep groove ball. B. SeIf-aligning thrust. C. Single row, tapered roller. D. Angular contact ball. E. SeIf-aligning ball. F. Self-aligning roller G. Spherical roller. H. Double row, deep groove ball. I . Ball thrust. J. Straight roller. K. Needle.
18. When blowing dry, never_a bearing. 19. If you could only use one word to describe a proper bearing work area, that one word would be 20. List six common bearing defects. 21. A bearing showing some looseness should always be rejected. True or False ? 22. AI bearings before inspecting. True or F als e ? 23. It is important, on a separable beari.ng, to inspect EVERY batl or roller. True or FaIse ? 24. When bearings wilt be storedfor sometime, they should be coated with_. 25. Always keep bearings_until ready t o us e. 26. Immediately following inspection, bearings should be--. 2?. Keep fingers away from_elements ¡n ¡l
28. Before
instalting
and wear.
and -for
a bearing,
inspect
both
nicks, burrs, Fi g. l l -31, N ome táese beori ngs. (S r(F)
177
Auto Service ond Repqir
* -+ff i S T E PWT A R
W EAR
wtéK%
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INDTilTATIONS
FRfTTlf.lC
¡¡ll5AllGNneENT
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T R A C K T ÚI N N T R R A {T
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ffi; *8thCtt,l.¡{;
TAIIGU€ SPAIIING
TTCHIN6 F ig . ll - 3 2 , So me commonrol l er beori ng defecfs. B eori ngs show i ng th e se sí9ns musf 6e di scorded. (C odi l l oc)
178
SMTAR;
ll ri
i;: l"
Chapter12
REMOVAL ENGINE R EM O VA LP ROCE DURE GEN ER AL in engine reThere are many variations body clearance, and Frame =roval procedures. removing of possibility :ccessory equipment, :ransmission attached to engine, etc., must be shop for each job. Manufacturersr :onsidered speeific ¡anuals will be helpful in determining =teps for specific engines. of engines are pulled upThe vast majority Different rard out of the engine compart'ment. when the engine must be is required ¡rocedure : e moved fro m b elo w, Fig. 12- 1. al1or¡¡ the removal of the Some installations to the engine while others :ransmission attached :equire it to be separated and the engine pulLed Fig. l2-I.
by itself.
Mecfionic removing engine lrom beneofh cor' Nofe fhe hydrou Ii c exfension iocft . (WeoverJ
SUPPORTTRANSMISSION SC R IBEAR OU N D T H ESE ED GES
If the engine alone is to be pulled, be certain :: provide proper support for the transmission. .he drive plate (provides drive from the crankshaJt to the torque converter) will not support a is not properly laad and if the transmission Serious damage can be done. An s:pported. cross =djustable stand or a special frame support maY be used. -ember
IKIAKEROOM pads. If the Cover fenders with protective rood hinge attaching point is adjustable, scribe a¡ound the hinge with a sharp pointed tool. The lines will speed up hood alignment when 'cribe replacing , Fig. 1 2-1 A. lift off hood and hinge fasteners, Remove area. Place PROTECTED in a upright -ore f=.steners back so they will not be lost. Drain the cooling system and remove hose core. Handle radiator core cares:d radiator 51ly and protect during storage. Remove the battery and battery
cables.
Fi g. l 2-1 A . S cri bi ng oroundthe edges of the hood hi nge ottochi ng p/ole will moke hood alignment easy during reossem6ly' (Chevrol et)
W¡RI NG , A L L A T T A CHE D DI S CO NNE CT ANDCONTROLS TUBING,HOSES and lead, starter coil primary Disconnect wires, oil pressure and temperature generator wires, engine ground strap and any indicator
179
AutoServiceond RePoir other accessory wires. As the wires are removed, they should be marked with masking tape for correct installation, Fig. t2-2' Disconnect gas tanktofuelpump line, vacuum lines, oil pressure gauge line (if used) and any other line attached to the engine. Remove the air cleaner and cover carburetor with a plastic bag. linkage and transDisconnect carburetor (throttle valve) rod where used' mission T.V. pipe at exhaustmanifold' Diseonnect exhaust transmis s ion c onand linkage Di sc onnect clutch be pulled with will (if transmission trol rods engine). Disconnect speedometer cable to transmission connection. Drairi engine and transmission. Remove oil filter. On automatictransmi.ssion, remove fluid cooler lines' Tape lines to prevent entry of dírt. Disconneet propeller shaft and wire out of the waY. Where used, remove transmission parking brake controls. Remove any exhaust pipe, fuel or brake line support brackets attached to engine or transmission. Remove the starter and alternator if necesto sary. Power steering pump may be moved be must one side on some models, on others it removed. Check to make certain all necessary items have been removed.
A VOIDPAR TDA MA GE \Áft-renpulling tubing, hose, etc', back out of the way, be careful not to kink or damage them in any way. Cover the ends of hose and tubing with tape to prevent the entry of dirt'
R EPLAC EFAS TE NE RS It is good practice, once a wire, controlrod' etc,, has been removed, to put the fasteners baek into place. This will speed up reassembly placing of fasteners' and avoid improper
A TTAC HLIFT INGDE V ICE Attach the puLler cable, strap or bar to a suitable spot. Eyebolts may be used or head cap screws may be removed, placed throughthe prrit"" brackets and reinstalled' Some engines have specific attachment points' Consult manual' Regardless of the attachment point' make certain that the eyebolt, cap screw, bolt, etc"
Fig. l2-2, Morking wires wítñ tope will locilitote installotion'
H OISTH O O K EYE BO LT .
bolt Fig. l2-3. The puller losfener nusl hove omple threaé' Eye dístonce into fñe hole ond will very likely in'A thteods o ".ry "hort os in B' ,:ip out unde, pullíng pressu,e. By using o longer eye bolt omPle threod is ossu¡ed'
is
threaded
into
the
hole
for
a distance
of at
least one and one-half times its diameter' This See w i l l assure proper hol di ng strength' Fi g. 12-3.
P UL L E RB RA CK E TMUS TB E SNUGAGAINSTENGINE Occasionally the head or heads have been removed from the block. Never use the head cap screws or studs toattachthe pullerbrackets unless they are shimmed to force the strap against the block. Failure to do this will place . h"".ty side pull onthefastenerthatcould cause it to fail. This same principle applies to any fastener that is too long, Fig. t2-4' When attaching puller brackets, select fasteners of sufficient strength, threadedintoareas that will withstand the pressure of lifting'
B A L A NCEP O I NT S E L E CTP RO P E R Attach the puller so that the weight of the will be engine, or engine and transmission, dothis to FaiLure balanced at the angle desired. parts and spring could that will cause tipping Fig. 12-5' difficult, make removal
180
Engine Rernovql
PUL L P O I NT M UST N OT SL IP Make certain that the pull point (point of attachment on the puller) cannot slip under pres_ sure. Fig. 12-6, shows what can happen when a chain hook is placed on a plain cable pulling strap. The puller s t r ap i n F i g . 1 2 -? , a l l o w s th e p u l l point to be moved along the length of the cable, but under pressure the hoist bracket will bind against the cable thus preventing slippage, Fi g . l 2- 7.
{ PU LLER ST R AP
POSITI O N LI F T After the pulling device is firmly attached, move the lift into a position that will raise the engine without causing any undesirable side or fore and aft pressures. Insert the lift hook into the puller and place a light lifting strain on the engine. Remove the engine mount bolts.
Fi g. l 2-5. E ngi ne can be l ¡f¡ed i n o l evel posi fi on by orrongi ng pul l poi nt os i n A . tn B , ti l ti ng ongl e i s ai tered by novi ng pul l poi nl tow ords {ront ol engi ne. A ny numberoÍ ongl es ore poss;6/e.
/
H OT STH oO K SLID IN GU P C ABLE
'
Fig, l2-4. In A, puller ó¡ockers (t) ond (2) hove slid up the cop screws. Wáenñoist exerts force on the puller coble, puller b¡ocket (3.) will lo¡ce cop screw sidewoys cousing i¡ ¡o break or 6end os slrown in B. ln C,6rocket ís held against block by o sñorf sectíon pipe of to prcvent cop screw damoge,D illust¡o¡is o typicol puller 6o¡. Note odjusfmenf Áoles.
Fi g. 12-6. E ngi ne w os bei ng l i l red by pl oci ng hoi st hook orou nd o.pl oi n cobl e pul l er strop. The reor ol the engi ne ti pped dow n ond tfie ñoisf /roo/
t8t
AutoServiceond RePoir SAFETY RULES FOR PULLING HO lST BRACKET
ATTACHING BRACKETS
balance 1. Attach lift strap or bar at correct point. thread Z. Lift strap fasteners must have ample with and strap brackets should be in contact screw cap engine - not on the end of a long or stud. at all 3. Wateh hands and keep clear of engine time s. 4. Lower as soon as engine is removed' 5. Do not use a rope as an engine sling' Bolt it 6. Do not depend on a knot in a chain' together. wide ?. If a chain is used as a strap, use heavy' to fastener the washers under the head of through pulling from prevent the fastener head the link. B. Make sure the pulling point cannot slip'
Th.e lr.ois-t6 ¡ o c k e t F¡o. 12-7. Coble tvpe engine pulling slrop' '"ii""l-,r, will bind under lifting pressure hut od¡"ro6le i, ,.,r, -""""''ri ( Sn o p - Onfo o ls) o r " v e nl p ' u ll p o in l ch o n g e '
LIFT ENGINE for the engíne while checking Start raising liftingangle' the proper clearance. Be careful of balance angle' wrong the assumes engine the If either the change lower back into position and of the location the or pull point on the puller puller brackets. i.t forward As the engine begins to rise' Pull (when transtransmission the free of until As lifting promission will be left in place)' plate (autobe careful that the drive g"""""", does not hang up' áatic transmission) with engine' the transmission If removing steep relatively a unit will often have to assume order in 12-8' Fig' in angle, such as that shown to clear. continues, give the engine an As the pulling This will motion' rocking gentle occasional stops that it is free. If the engine ascertain another' at moving at one point and continues Continue check for an obstruction' stop Ád hands the with wnite guiaing the engine ""i"tübY altering lift Position and clear the car' Raise to a height sufficient to until just lower immediately Remove engine aná Move to the cleaning area of the floor. clear (if transmission Remove clean. and steam repair in a suitable attached) and place engine stand.
S UMMA RY pulted with Determine if transmission willbe remove engine. Cover fenders, scribe hinge s and hood. If Drain water, remove hose and radiator. desired, drain engine and transmission. and conDisconnect aI1 wiring, tubing, hose to necessarY, if and engine attached to trols transmission.
LIFTTN G B A R
\)
\|
{i
lr
'
\/
\ ,i:
E N D E RC O V E R S P R OTE C TIVFE ' Fi't'o.l'-2'8,-
t82
hoi sf' N ote s teep P ul l i ng an engíne w ítfi a chai n cl eoronc e' provi de to n"t"""oty oí9l t t¡i r¡nn
EngineRernovol A
to properly puller strap securely Attach balance assembly. PulI engine slowly, checking to make certain all parts are free. When high enough to clear, remove and lower. Steam clean and place in a repair stand. Be very careful. t ime s.
Keep clear
5.
of engine at a1l 6. n
OUIZ - Chopter12 1
2 a
(-). Engines must always be pulledwith: attached. a. Transmission removed. b. Transmission c. Varies - sometimes attached, sometimes
8.
removed. hood hinges beIf adjustabl€, -oround fore removal. always-fastenWhenever practical, ers after part is removed.
Tronsverse
cross-sectiono/
9. 10.
view ol an overheod comshah,
wire ends after removal to facilitate reassembLy. Engine angle duringlifting shouldbe (-). a. Level. b. Back tipped down. c. Front tipped down. d. Depends on job at hand. As soon as the engine will clear the car, and will help to deA gentle_motion termine if engine is clear during pulling. shouldbe attached Lift strap or barbrackets to: (_). a. Head bolts. b. Intake manifol.d. c. Exhaust manifold. d. Depends on situation. When pulling tubing free of e n g i n e , b e ca r e ful to avoid List seven safety rules for engine pulling.
6-cylinder,
t93
Íuel
injected gos engine.
(Mercedes'Benz)
Auto Service ond Repoir
Curowoy
view
of a
six
cylinder
engine in which ( Pl y m outh)
s l onted fo one s i de.
184
the 6/oc/< is
Chapfer13
CYLINDER HEAD,VALVEAND VALVETRAINSERVICE CYLINDER HEAD REMOVAL
&-ooJUsrNG
Never remove a cylinder head until the engine has cooled. Removal while hot will very Iik ely ea use the head t o war p upon c ooling . Remove intake and exhaust manifolds (when req uire d), spa rk plugs , wir es , r oc k er ar m c o v er a nd an y a cces s or y unit s at t ac hed t o t he h e a d .
W - BALL
NUr SwtvEL
ROCKERARM
REMOVINGROCKERARM ASSEMBLY PUSH Remo ve the r oc k er ar m as s em bly by s t a r t ing at o ne en d, and loos ening eac h s uppor t br a c k e t bolt, one after the other, a couple of turns. Repeat u ntil th e as s em bly is f r ee. I f eac h br a c k e t bolt is comp lete ly r em ov ed bef or e m ov ingto t h e next, the last br ac k et c ould be dam aged b y t h e valve spring pressure pushing the free portion of th e sh aft up war d, Fig. 13- 1.
SUPPORTBRACKET CAP SCREWS
Fig. l3-2. Loosenodfusfingnul enoughto ollow rockerormto swive/sidewoyst6usc/eoringpushrod. (G.M.C.)
In cases where rocker arm shaft support brackets are an integral part of the head, the h e a d m a y b e p u l l e d b e f o r e s t i d i n g t h e ro cke r shaft out of the brackets.
REMOVEPUSHRODS
F i g . l 3 -1 ,
L o o se n
¡o cke¡ otm suppott br ocket cop scr ew s , o l te ¡ the othe¡ , a little ot o tine. ( Plynouth)
R e m o v e a n d p l a c e e a c h p u s h r o d i n a m a r ke d holder so it can be replacedinthe o r i g i n a l p o si tion. A holder such as shown in Fig. 13-3, will suffice.
one
LOOSENCYLINDER HEAD FASTENERS
On engines using ball stud type rocker arms, loose n e ach b all nut unt il t he r oc k er ar m c a n b e swive led sideway s t o c lear t he pus h r o d , F ig .13 -2.
U s i n g t h e r e c o m m e n d e d t i g h t e n i n g s e q ue n ce , r e v e r s e t h e o r d e r a n d c r a c k ( j u s t b r e a k l o o se ) e a c h h e a d c a p s c r e w . O n c e a I I h a v e b e e n l o o sened, they may be removed. If lengthvaries or if
18s
Auto Service ond RePoir
KEEP VALVES IN ORDER MA R K SF OR LEFT A ND RIGHT BANKs
As they are removed, place valves in a rack s o t h e y m a y b e r e p l a c e d i n t h e i r o r i g i n a l g u i d e s. U s e a r a c k s i m i l a r t o t h a t s h o w n i n F ig . 1 3 - 3 .
V A L V E ST E L L A S T O RY
'Y::2222
IÑ DIC A T E S F RON T OF EÑGINE
F i g ,1 3 -3 ,
P l oce push r ods in o m qr ked holder -
in pr oper or der '
passa cap scre w is dr illed or m ac hinedf or o i l Fig. 1 3 4 . loc at ion, t he c or r ec t ag e, no te If th e c y linder head is s t uc k , us e pr y b a r s o r a le ad h amrn er . Be c ar ef ul not t odam age t h e h e a d .
I n s p e c t e a c h v a l v e f o r s i g n s o f b u r n i n g , p i tti n r Burned or pittec deposits. and heavy carbon s t i c k i n g i n g u i d e svalves can be causedbyvalves w e a k sp r i n g s, tappet clearance, insufficient c l o g g e d c o o l a n t p a s s a g e , w a r p e d va l ve ste m , i m p r o p e r i g n i t i o n o r v a l v e t i m i n g , e t c .,Fi g . 1 3 - 8 . H e a v y c a r b o n d e p o s i t s , e s p e c i a l l y u n d e r th e head of the intake valve, indicates worn valve g u i d e s , d a m a g e d s e a 1 s , w o r n r o c k e r a r m b u sh clogged oil drairings allowing overlubrication,
i I
.1,
Fi g. l 3-5. R emovín9cyl índer heod' N ote Ii Í¡ broc k ets . (G.M.C .)
I
i
I
rl
C Y L I N D E RH E A D ASSEMBLY
Fíg. 13-4. "Crock" cylinderheodcop screwsloose' Removein the reverseo¡deroÍ tíghtening. (Plymouth)
SPL IT KEEP
r1
Avoid ja m m ing any t aper ed objec t be t w e e n h e a d and block mating surfaces as the slightest nick or de nt m ay c aus e s er ious dam age' W h e n h e a d i s loo se , rem ov e, YFig. 13- 5.
R E P A I RS T A N D
PLACE CYLINDER HEAD IN HOLDINGFIXTURE l-o llow ing r em ov al, plac e t he c y l i n d e r h e a d in a suitable repair stand. Compress the valve sprin gs, r em ov e t he s plit k eeper s , s p r i n g a n d sp ring ret ainer as s em bly , Fig. 13- 6 .
Fi g. l 3-6. R emovi ng spl íl v ol v e k eep e rs . (C hrysl er)
18ó
Fig , l3-8 , A b ur nedv olv eindic olespr oblem s . (A/be¡tson'Sioux) holes in he ad , rocke r ar r n s haf t oil holes f ac in g -i-: rvron g d irection , et c . , Fig. 13- 9. Dis ca rd all b ad ly bur ned, c r ac k ed or war pe d ' . ' alves. Th e g rind ing nec es s ar y t o c leant hem up ' , i.11le ave in su fficie nt v alv e m ar gln, Fig. 13- 94 .
S P LITKEEPERGROOVE
F i q,
l 3- 10.
U s i ng o w i r e w heel , m ounted on o gr índer m ol or , t o ( Bl oc k ond D ec k er ) c l eon c o¡ bon {r om o v ol v e.
To
nrowide
f ¡ s t i n i t i a l s e a t i n o . i t i s o f te n p r a c t i c e t o g r i n d t h e 3 0 d e g . v a lve recommended to 29 deg. and the 45 to44 deg. This provides an interference fit that produces a hairlinecontact between the valve face and the top of the valve seat. Some manufacturers f e e l t h a t d u e t o v a lve design and material, the valve when heated, will then form a perfect fit, Fig. 13-11.
l3- 9 , H e o v y c o r b o n de p o sifs u n d e r volve Ir eods indicote ex c e s s o i l c o n s u m p tío nth r o u g h volve guides. ( Cle víte )
VALVE T OU C H ESs EAT H ERE
:,1 ,;É r¡f i
l, 'ft
MARG I N
FACESTI LL PI TT E D F i g.13- Il . l nte¡ {er enc e ongl e. }.{ote the ON E deg. di Íl er e n c e i n ongl es and how v al v e l ac e c ontoc fs T OP edge of s eof. O n e m onul oc tu¡ er r ec om m ends o T YIO deg. di l l e¡ enc e on one s pec i f i c engi ne.
3 i g . 1 3-9 A , T h e o mo u n l ol gr lnding r equir ed to cleon up o volve i n ' r i s c o n d i ti o n w i l l re mo ve the m or qin ond r ender the volve usele s s .
V A L V EG RI NDE R is shown valve grinder A typical 13-12. Study the names of the parts.
CLEAN VALVES THOROUGHLY U sin g a p owe r wir e wheel, br us h all t r ac es o f larbon from va lve head and s t em . Following wi r e : rushin g, in s olv ent andblow dr y , rin se irg. 1 3 - 10 .
in Fig.
DRESSSTONES A valve grinder will only perform a job in direct relation to the condition of the stones. (tTued up) TO THEY MUST BE DRESSED THE CORRECT ANGLE AND KEPT IN THAT d r e s s ed , A good stone, properly CONDITION. will do better and faster work. Put the diamond tipped dressing tool into position, tighten securely, start machine and
GRINDVALVES Determine the correct valve face angle. On some e ng ine s, bo th int ak e and ex haus t angles a r e :he sa me, on oth ers , t hey ar e dif f er ent . Com m o n a.ngles are 3 0 an d 45 deg.
187
l
Auto Serviceond Repoir
CHUCK
cltucK SWIVE L NUT
CHUCK AN6LE ALIGNME}I
WHE EL CARRIAGE ANGLE CHUCKSWIVEL NUT SADDLE LOCKING TRAYELLEVER
F íg . 13- 12. A typicol
volve gr inding mac hi ne.
toward the diamond. advance stone SLOWLY Wh en th e diam ond jus t t ouc hes , t u r n o n t h e coolant and move the diamond back and forth across the stone until the stone is smooth, clean and true. Several VERY FINE cuts may be req uire d. M ov e t he diam ond s 1ow1y , Fi g . 1 3 - 1 3 .
l 3- 14.
F i g.
Setfi ng v ol v e c huc k to the des i re d o n g l e '
P L A CEV A L V EI N CHUCK Place the valve in the chuck. Various grippin; r e cd e v i c e s a r e u s e d s o f o l 1 o w m a n u f a c tu r e r r s Make sure the valve is in th= ommendations.
) '{}A I
DIAMONDTIP
Fi s .
l 3- 15.
l n A, the v ol v e pr otr udes l oo {ar out o l l h e c h u c k o r: c hotter . In B, the v ol v e depl h i s co rre c l .
will
Fig.
l 3 -1 3 ,
Dr essíng
the gr inding
wheel with a di om ond dr es s er .
SETC H UCKA NGLE Loosen chuck swivel nut and swing chuck to the proper angle. Adjust the chuck alignlng edge to the selected angle marking very carefully. angle setting, Lock nut and recheck swivel Fig. 1 3- 1 4.
Fi g. l 3-16. A di usti ng vol ve stem depth i n ¡he c huc k .
r88
Cylinder Heod,Volve, Vqlve Trqin Service
chuck far enough so an excessive amount does not protrude and cause chatter (valve vibrating durin g g rind ing ), Fig. 13- 15. Fi.g. 1 3-1 6, s hows a v alv e being plac edi n t h e chuck. Close chuck tightly.
A VALVE F AC E
ffi;l'ffi-, z> t
CHECKFORRUNOUT
PARALLE L
Turn on the chuck and watch the valve as it rotates. If a noticeable amount of runout (wobble) is pre se nt, sto p t he c huc k , loos enandr epos iti o n the valve. If excessive runout is stil1 present, a warped stem is indicated. If warped to the point that grinding will leave insuffi.cientmargin, discar d th e valve, F ig. 13- 1?.
+
zi1
I
N OT PAR A L L E L
Fi g. l 3-18. l l ¡he chuck i s sel ot the properongl e, the vol v e Íac e ond sl one w i l l be porol l el os i n A ,
ST ON E MARGIN
WARPEDSTEM
Y\ I
M ARG IN
I
t_¡
F i g . I3 -1 7 .
NO M ARGIN
E xce ssi ve volve "wobble" - A, will couse fh e v ol v e morgin to 6e removed on one edge, B.
G R INDVAL VEFA CE Move the chuck saddle until the valve is in front of (not touching) the stone. Turn on the machine, engage chuck drive to spin valve, turn on the coolant and advance the wheel toward the valve. The valve face and stone shouldbeparal1 el if y ou hav e s e l e c te d th e p ro p e r a n gl e, Fi g. 13- 18. If parallel, slowly aovance the stone (make sure valve is turning) until it just starts to cut. Move the valve face back and forth across the stone. NEVER RUN THE VALVE OFF TIIE ST O NE , F ig. 13 -1 9 . If your machine has a micrometer feed, set it to zero at the point where the stone just starts :o cut. Advance the stone against the valve around .001 to .002 at a time. Watch the valve face and as soon as all dark spots disappear, center the valve face ón the stone, allow the
Fig. I3-19. llhengrinding,movelhe vo/ve6ockond lorth keeping the volve foce in Íull confoctwilfi fñe sfone.
stone to run a few seconds without advancing it, then carefullyback the stone awayfrom the valve. Disengage the chuck drive and rotate the valve by hand while examining closely for any remaining pits, burns, etc. The valve face should be bright, smooth and free of ALL defects. The margin should be ample Í132 in. or more). If the valve is not cleaned up, repeat the process. When finished, inspect the micrometer feed dial and mark down the amount of material removed from the valve. Return the valve to the holder. Using the same procedure, grindthe remaining valves. Do not forget to ehange angles if intake and exhaust are different. WHEN FIRST USING A VALVE GRINDER, PROCEED MANY BEGINNERS INSLOWLY. THE FEED ADVERTENTLY TURN STONE WHEEL THE WRONG WAY OR TOO FAST AND JAM IT AGAINST THE VALVE. IF THE CUT IS TOO HEAVY, DO NOT PANIC AND SUDDENLY C R A N K T H E WI Í E E L - Y O U M A Y T U R N I T T HE OFF AND WRONG WAY. SHUT THE MACHINE WHEN STOPPED MOVE STONE AWAY.
189
Auto Serv¡ceond Repq¡r
in Fig. 13- 20, is gr indi n g a The op era tor Notice how the stone feed wheel is face. valve grasped. Even though it has a crank knob, once the stone is close to the valve, holdit as shown. smoother and rnore This method will permit accu rate a dju stm ent s .
SADDL E CHUCK
Fi g. l 3-21. Trui ng the vol ve sfem end. (V on N orman)
ST
If move
F i g . l 3 -2 0 . Gr in d in g th e vo lve ( o ce . ( Al6 e ¡ tso n - Sio u x,)
the
machi ne
enough
to
has
no mi crometer
produce
a
smooth
feed , square
reend,
Fig.13-21. When using a plain V-block, in which the valve must be hand held, make certain the block is close to the wheel to prevent the valve stem from and pulling the valve between catching block and wheel. Position the valve stem in the block, hold down firmly and advance stem against wheel, Fig.13-22.
GRINDVALVE STEM END Th e valve stem end s houldalway s bet r ued u p and smoothed by grinding. If you have marked down the amount removed from each valve face, it is recommended that you remove a comparable amount from the stem. This will help in mainHowever, tappet taining original clearance. (up to about never remove an excessive amount is not t oodee p on har dening as th e surfac e .010 ) If ground below the hardening, some valves. rapid wear will result. Dress the s ide of t he wheel us ed f or s t e m grinding. Chuck the valve in the V-blockholder, and run it in until it just touches the stone. If so f eed dial t o z e r o . equ ipp ed , set the m ic r om et er Back off the valve, start the wheel, turn on the coolant and advance the stem against the wheel. Continue advancing with light cuts until the that you have remicrometer dial indicates moved the same amount as was taken from the face. As with valve face grinding, direct a good of coolant on the portion of the valve stream being ground.
V BLOC K H OLD ER
F-- t Fi g. 13-22. K eep V -6l ock cl ose to the gri ndi ng w heel os i n A . The setup i n B i s dongerous'
t90
Cylinder Heod,Volve, Vqlve Troin Service
C H AM FERVALV ES TE ME ND If much of the chamfer on the valve stem : nd has be en rem ov ed t hr ough wear and r e _ iacing, th e ch amfe r m ay be r enewedby gr inding. ?Iace the valve in the V-b1ock, set the holder at i5 de g. a nd a dju st s t op t o gr ind about a ll32 i n . : hamfe r, Figs. 1 B- 23 and 13- 23A. R E MA IN INGC HAMFER ORIGINAL CHAMFER
r /32 tN.
NEWCHA^{ F
_l_/
b u r n i n g . V a l v e s t e m w e a r m u s t n o t b e e x c e s si ve a n d t h e s t e m s h o u l d b e f r e e o f n i c k s , s c r a t c h e s, e t c . , . t h a t c o u l d c a u s e e v e n t u a l b r e a k a g e o r s t i c k_ ing. Keeper grooves must be undamaged. Valve stem end must be smooth, squared and lightty chamfered. CAUTION: SOME VALVES USE A SPECIAL COATING SUCH AS NICKELCHROME, ETC., O N T H E F A C E A R E A AN D ONLY A LIMITED AMOUNT C A N B E REMOVEDI Check manufacturerrs s p e c i f i c a t i o ns. Fig. 13-24 illustrates t w o v a l v e s : o n e i s a c_ ceptable, the other is not.
Tffiffiil' flliit
taRG|N GooD z.-/
l i]lfl
|rr]HIU
B
fÍ'lT--------Ítn
l l l l i l ,l l l l i l
illlillru B
I 3 - 2 3 , V o l v e s t e m e n d in A h o s ch o m ( e rwo ¡ n ol(. The some B , o { t e ¡ r e n e win g th e ch o m le r ,
n
sEAL GROOVE
KEEPERGROOVE
ExcEss EXCESSIYE
lK"'^' Ll
KEEPEI KEEPER
G R O OVE
ffi*-..-SlilXi
DAMAGED
,* oor n/
R.oor,
*o"*
Fi g. l 3-24. Y ol ve A i s occeprobl e. V ol ve B i s nor.
WASHAND STORE Following the final inspection, each valve must be thor oughly washe d (check keeper grooves carefully) and blown dry. place in a clean rack and cover until readv to use.
CL E A NCY L I NDE RHE A D
F i g . I 3-2 3 A .
If the cylinder head coolant passages are badIy clogged, give the head an initial cleaning in a "hot tank." Remove all carbon from the combustion chambers and valve ports. Wire brushes i n a h a n d d r i l l w i l l d o n i c e l y . C l e a n t h e h e a d to b l o c k s u r f a c e w i t h a s c r a p e r . B e c a r e f u l n o t to put scratches in the surface, Fig. 13-25. Run a spring-type valve guide cleaner up and down through each guide to remove the carbon, Fig.13-26.
Gri n d i n g o new chom le¡ on the valve stem end.
EACH VALVE MUST PASSINSPECTION I nspe ct ea ch val v e f ac e. I t m us t be s m ooth and f ree of a1 l pits, gc r at c hes , bur ns , et c . Ther e rrust be ample margin remaining to prevent
t9l
ports and guides. Push a clotl:, chambers, through all the valve solvent, with moistened NO foreign materiaguides to make certain remains. This is very important because if some check wi'is left in the guide, the stemclearance not be accurate and when the seat grinding pilc: is inserted, it will be tipped and throwthe valv: seat out of ali.gnment.
F i g , l 3 - 2 5 . R e m o vin g co r b o nlr o m cylin d e r h e o d .co mbusti onchombe r s o n d Po r ts. ( Blo ck o n d De cke r )
CHE CKV A L V ES T E MT O G UI DECL E A RA NCE When deciding whether or not to use the o1i about toc valve guides, you are not'coneerned (unless new oversize stemValves 1itt1e clearance are being installed). ExceÉsive clearance wiloften be present. ihis will promote oil consumFtion, poor seating and possible valve breakage, Fis.13-28.
F I l
..1
VALVE G U ID E
,#
: ., ;i
HEAD
corbonlrom lhe volveguides' Fig' l3'26, Removing Follow the valve guide cleaner with a valve guide bristle brush to remove all loosened carb on , Fig . 13- 27. Blow all dust and carbon from the combustion
V A LV EG UI D E B RI S T LEB RU S H
H A N DD R IL L LAR GE G AP
ST R I K E SH E R E
Fig. t3-28. Excessivevolveguideweo¡will cousefrouóle' fo r T w o m e t h o d s a r e c o m m o n l y u s e d t o ch e ck gauge hole A small excessive stem clearance. (some valve seat grinder pitots can be usedtool fitted to the largest valve guide is carefully diameter (do not measure exhaust guide counterbores), removed and measured with an outside The valve stem is then miked at a micrometer. wear area, and the difference corresponding computed, Fig. 13-29. method is to drop the valve into Another position with the head just free of the seat. It can be heLd in this position by a special insert
F i g . 1 3 - 2 7. Re m o vin g lo o se n e d co r b o nÍr o m o vol ve guíde' ( Bla ck o n d De cke r /
192
Cylinder Heod,Volve, Volve Troin Service
to determine the travel in thousandths. Re member that the reading will not be the actual c l e a r a n c e b e c a u s e t h e m e a s u r i n g p o i n t i s a b o ve the guide. The tipping effect will magnify the Follow reading. the manufaeturerrs r e co m mendations for maximum allowable sh a ke , Fig.13-31.
E X CE S S I VCL E E A RA NCE Engine design, type of oi1 sea1, amount of I u b r i c a t i o n , e t c . , a l 1 d e t e r m l n e a c c e p t a b l e cl e a r ance. Follow manufacturerrs s p e c i f i c a ti o n s. Generally, w h e n t h e a c t u a l c l e a r a n c e e xce e d s .005 to.006, it is considered excessive. R e m e m b e r t h a t b o t h t h e g u i d e a n d s t em w e a r less in the center. Even though a stem-to-guide clearance at the center is correct, t h e cl e a r a n c e a t t h e e n d s m a y b e e x c e s s i v e a n d ca u se tipping, Fig.13-32.
Fig. l3-29. Usingo smollholegaugeto meosurevolve guideinside diomerer._ er{;ct Circl:) -f r- l ,' -or by slipping a piebe of rubber tubing of the co rrect len gth ov er t he v alv e s t em , Fig. 1 3 - 3 0 . A dial indicator is then clamped to the head. The indicator stem is placed against the valve margin. Without raising the valve, move it back and forth against the stem. Watch the indicator
tll VALVE ST EM
G U ID E
C EN T ER C LEAR ANC EO . K ,
EN D C LEAR AN C E EXC ESSIVE
(((,
Fis. l 3 -3 0 .
P o si ti o n ing volve pr ior to checking stem lo gui de c l eor ( Chr ysler ) o n ce wi lh o diol indicoto¡ .
F i g.
l 3- 32,
be w i ¡ hi n
i:-'\\)
Sten to gui de c /eor onc e neor the end ol ¡ he g u i d e mu s t N ote l hat c or ¡ ec ! c l ear onc e i n l he guid e c e n l e r w íl l not pr ev enl ti ppi ng.
/i m i fs .
When an excessive stern to guide clearance is present, the valve guides (if removable) may be replaced. When the guides are integral (part o f t h e h e a d ) , t h e y m a y b e r e a m e d t o o ve r si ze , and new valves with oversize stems installed, Fig.13-33.
RE P L A CI NG V A L V EG U¡DE S
F is. l 3 - 3 1 . C h e ckin g vo lve
The guides may either be driven or pressed out. The punch should have a pilot section extendi.ng into the guide. The pilot should be a few thousandths smaller than the guide hole to pre-
stem sho/
lo g u id e cleor once.
193
Auto Service qnd Repq¡r
redue to guide hole diameter vent binding, duction when using the punch for installation. The main body of the punch shouldbe a trifle guide smaller than the guide so it willfollowthe through the hole. Contact edge should be smooth and square with punch centerline.
P ORT
HEAD
VALVE SEAT
Fi g.13-34A , Gui de deprh, i n thi s engi ne, i s m eos ured l rom the valve spring seof su¡foce. (Chevrolet)
Place the punch in the guide, and whileholding the punch in firm contact (guides are brittle and may crack if punch is loosely held), drive the guide from the hole, Figs. 13-35 and 13-354. T N T E GRAL/ GÚIDE '
\
\
R EPLAC EABLE GU ID E VALVE G U I D E P U N C H
volve guides' Fig. l3-33. lntegralond replaceoble l*:i lj
'4 li'
Before driving out the guides, make anote of the distance from the surface of the head io the face of the guide as well as the shape of the end that extends into the combustion chamber. Identi-
!
tf
,li r1 l: li ll iii I ' ll
EX HAUST
CO UNTERBO RE
I :ti
Fig. l3-35. One lo¡m oÍ volve guide punch,
I NS T A L L I NG G UI DE S The guide holes must be SPOTLESSLY or freezer is handy, CLEAN. If a refrigerator thé guides may be placed in the freeze box long enough to thoroughly chill them. The resultant reduction in diameter will aid in their installation. Give the guide and hole a thin coat of hypoid lubricant, (Lubriplate, etc.). Insert the proper end in the correct guide hole, and drive to the specified depth. DO NOT DRIVE PAST THE REQUIRED DEPTH. A stop on the tool may be used or a punch mark, Fig. 13-36, may be used to provide a means of measuring from a given surface.
Fig. 13-34, Guide depth in tlrís cose is r¡eosu¡ed lrom lhe surfoce on the volve seof side. Note tñe shope ol the ends Íocing (AMC Jeep) ffie seofs.
fy exhaust from intake shapes. By doing this, it will be possible to get the correct guide for each hole, proper end up, and driven intothe correct dept h, F i g s . 1 3 -3 4 a n d 1 3 -3 4 4 .
t94
CYlinder Heqd,Volve, Vqlve Trqin Service
E:AMING GUIDESAFTER INSTALLATION Some guides are factory reamed and f ollowing I f t he guid e s -. : . llatio n, req uir e no r eam ing' use a special valve guide :- *;: be reamed, -; : r: r er o f the exaet s iz e. St ar t t he r eam er c a r e '---',- and turn it clockwise both while entering
to and leaving the guide. Ream dry' Be careful Allow reamer' the on avoid any side pressure the pilot portion to guide it through' A properly s t e m to r e a m e d g u i d e w i l l p r o v i d e a r o u n d '0 0 2 s p e cs) ' ( s e e m a n u f a c t u r e r r s guide clearance Fis.13-3?.
Volve Guide Remover :nd Replocer-KF
volve gv i de' I 3 - 3 5 A . U s i n g o m e ch a n ico l Pu lle r to r emove o ( AM C Je e P)
Fi g. l 3-37. R eomíng the val ve gui de'
,$
\'!$ '
rerlox txsenr
SEAL OUTER COVER
PR
PUNCH MARK ON TOOL ALIGNED WITH STRAIGHTED G E PLACED ACROSSFACE OF CYLINDER HEAD
Fi g. t3'38. Tefl on vol ve gui de oi l seol '
G UI DE S WO RNI NT E G RA L head' it When the guide is cast as part ofthe wear' ofthe is necessary to determine the extent oversuitable a If excessive, a new valve with is then guide worn The size stem is selected. oversizes Stem stem' reamed to fit the valve
dele¡mine when guide F i g . 1 3 - 3 6 . l J s í n g o p u n ch m o r k o n lo o l lo ( Kelsey- HoYes ) depth' proper the lo driven hos 6een
t9s
fr tl
Auto Serviceond Repdir PREPARINGVALVE GUIDE FOR OIL SEAL S o m e g u i d e s a r e d e s i g n e d t o a c c e pt sp e ci a l o i l s e a l s ; o t h e r s a r e n o t . F i g . 1 3 - 3 8 , sh o w s o n e is altype of guide seal. The guide illustrated ready machined to fit the Teflon seal. Bcth integral and removable guides may be a p r e p a r e d f o r t h i s s e a l . F i g . 1 3 - 3 9 , i l l u str a te s machining an integral guide in special cutter preparation for seal installation. To install this particular seal, the valve stem end is covered with a protective plastic cap. The seal i.s then pressed over the end and down the stem, Fi"g. 13-40. The seal is forced over the machined section of the guide as far as possible with the fingers. T o c o m p l e t e t h e s e a t i n g , a s p e c i a l t o o l i s u se d the seal and force it fully down, to grasp Fig. 13-41.
¡,
T UI DE S B O T H¡NT A K EA ND E X HA US G N MBER A DMI TO I L T O CO MB US T I OCHA
t1
Atthough oil is somewhat more likelytopass through the intake guide due to the strong vacuum in the cylinders during the intake stroke, the exhaust valve is also subjected to a mild vacuu m c a u s e d b y t h e e x h a u s t g a s e s r u s h i n g o ve r th e head of the guide. As the overhead valve design dominates the fie1d, oil control through the guides is critical. Great quantities of oil are pumped to the rocker arms and a considerable amount finds itswayto the valve stem end. The combined forces of gravity, inertia and vacuum, attempt to draw the oil downthroughthe
k li
Fig.
l 3 -3 9 .
Mochining a volve guide for seo/ inslol l oti on. ( Per Íect Cír cle)
ge ne rally a r e av ailable in . 003, . 015 a n d . 0 3 0 . As with re mov able guides , us e aSHARP r e a m e r of the CORRE CT s iz e. Following r eam in g , w a s h guides and blow dry.
guides, Fig.13-41A.. In addition to the special guide seal shown, and neoprene protective shields or "umbrellas" rings are often used on the valve stem end to prevent oil from flowing down the stem to the guide. Valve guides are often cut to an angle to prevent oil from puddling on the top. When installing the valve assembly,be careful to avoid daimage to any seals used. Occasionally only the intake valves are protected with guide seals, tapered guide heads and stem end
,l
i
i
I
shields. Make sure they are correctlyinstalled, Fig.13-42.
V A L V ES E A T S CHE CK I NG
F i g . t3 -4 0 ,
P re ssíng seol ove¡ pr ofeclíve
Inspect eaeh valve seatfor signs ofexcessive burning or cracking. If the seat is of the insert
cop on volv e s tem end'
196
Cytinder Heod,Volve, Volve Trqin Service type (special steel ring pressed into head) and looseness, burning or cracking is present, it must be removed and replaced with a new ring. If the seat is of the integral t¡pen and is cracked or badly burned, it must be cut out and an insert installed.
V A L V ES E A TI NS E RT RE MO V I NG A special chisel or mechanicalpullermaybe used to pull the seat. When removing, be careful not to damage the seat recess, Fig. 13-43.
F i g . 1 3 - 4 1 . Se a r in gth e va lve g u id e se o l' i'i :
i.-1 t4t
i
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o lL \
/\o tL ./\./
R emovi ngvol ve seol i nserfs' F¡s.13-43.
A 'speci of chís el ' B ' Me-
choni col P ul l er' ----4.
-
,- - - 1 | --?-
- '- i i
INSTALLINGVALVE SEAT INSERT
EXHAUSTSTROKE
INT A K E S TROKE
Make certain you have the correct size indiamsert. Outside diameter, depth and inside rebeing insert eter should match that of the placed, Fig.
13-44.
p oss oi l ' F i g . l 3 - 4 1 A . B o th in to ke o n d e xh o u stg u id e s will
D E P TH
+
i:lf fl--'.o.----*l o,D . l
A
T APERED
PUDDLE
through the, F i g . 1 3 - 4 2 . D e v í c e s u se d fo Pr e ve n lo íl.co n su m ¡ tio n guídes. A-Guide seol. B-Neoprene seo-l ond-shield' C'Topered gui.dein D ollows oil to pud' itia. rop. Note how rlr. "gror" cut dle ond run through the guide'
T-_! lt
R epl oc em ent
s eof íns er t m us l be of l he c or¡e c f s i z e '
inserts were cast iron' cast If the original can be used. If a hard type iron replacements steel such as (special resistant heat insert type' Stellite) is removed, replaee with a similar of nicks The recess must be clean and free pilot in the and dents. Place a special driver onthedriver' head valve guide. Install a driving than the smaller Head should be just a little ipsert OD. the Lay the insert, beveled edge down, over assist and OD the reduce will Freezing recess. Slide driver over pilot and start ininstallation. As the insert nears sert with several firmblows.
197
Auto Service qnd RePq¡r the bottom, reduce the strength of the hammer blows. By listening to the sound of hammering, you can tell when the insert is fully seated. DO NOT CONTINUE POUNDING AFTER FULLY S E A T E D. F i g . 1 3 -4 5 , s h o w s a c ro s s secti onof a typical insert driver set up for work.
I I
a small chamfer on the upper OD into which the head metal is forced. For peening, a pilot is placed in the valve guide, and a special peening toolbodyis dropped over the pilot. The peen is adjusted so it contacts the head metal along the edge of the in¡ert. the By turning and at the same time hammering wiII be upset bulged). peening tool, the metal to swage Other toots apply a rolling pressure the metal into the chamfer, Fig. 13-46.
I
I
Fi g. I3-4ó. l !si ng o speci ol fool l o "peen" ¡he mel ol o¡ound the inserf edge. Note fiow the metal is forced ogoinsf ilre inserf.
Fig, l3-45. lnstollingvslve seol insertwith o specio/pilot ond driver combination.
S EA T F O RI NS E RT CUT T I NGRE CE S S
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The insert OD will be one ortwothousandths than the recess. This will produce an larger (tight) fit to assist in securing the interference insert as well as producing good heat tranSfer from insert to head or block. If the inserts have been chilled in Drylce or remove them one at a time and in the freezer, they will warm up If all are removed install.
Where no insert was used and the integral .seat is damaged beyond repair by grinding, a recess may be cut and an insert seat installed. In cases where an insert is used but is loose, a recess may be cut for an insert of slightly larger OD.
before installation. Soft gray cast iron inserts have the same of expansion as the head metal (when coefficient fitted will not have to if properly and iron) cast be peened (upsetting the head metal around the insert OD to hold it in place). Many mechanics peen ALL types of inserts to provide an extra measure
of safetY.
PEENINGINSERT The head metal around the OD of the insert or swaged may be either peened (hammered) (upset by a rolling or rubbing action). All hard inserts, and all inserts set in an aluminumhead must be peened or swaged. The insert will have
Fig, 13-47. lnstalling volve seof inserf recess cutter on o pilot' lA 16ertson-Sioux,l
198
SELEC TPILO TANDCUTTE R (guide should Select a pilot that fits the guide be in good shape) as recommended by the tool Choose a cutter of the correct manufacturer. size a nd in sta 11 , Fig. 13- 4?.
INSTALL PILOT, ALIGN AND SECURETOOL The pilot assembly is fitted to the guide and pilot ' A 1 1 the bo dy o f th e to ol is dr oppedov er t he 1oose. be alignment screws must The anchor bolt slot is placed over a coninvenient head bolt hole and the anchor bolt motion shaking slight toolbodya the stalled. Give (a11 screws loose) to allow it to align with the pi1ot. Lock the anchor bolt securely' Lockthe other When screws in the o rder s hown in Fí g' 13- 48' with revolve all are secured, the cutter should I oos en pr es ent , is I f binding iinge r p ressu re.
l fi e w or k ' F i g' 13- 48. $ec ur i nq the r ec es s c utl e¡ l ool l o
ís to screws, readjust and retighten. The object secure mechanism drive have the tool body and without binding the pllot and cutter assembly, Fis.13-48.
F ig . 1 3 - 4 9 . Ad ivsti ng cul ti ng depth for recess cul l er'
*
$ C U TTE RS LE E V E
F E E D S C R E WL O C K
S T O PC O L L A R
STOPBLOCK J U ST C U T T ER T OU C H INWGOR K
Auto Service ond Repoir
ADJUST CUTTINGDE P TH
VALVE SEAT
With the cutter just touching the work, place the insert ring on the stop block. Run the stop collar down until it touches the ring. Lock the feed screw to the cutter sleeve and remove the ring. The cutter will then cut to the exact depth of t he r ing, F i g . 1 3 -4 9 .
The valve seat must be cut at correct angle, be smooth, clean and free of cracks, nicks, pits, etc. It must bethe correctwidth, andengage face of valve near central portion. Common seat angles are 45 and 30 deg. Where an interference fit is desired, the interference angle may be ground on either the seat or the valve. Follow manufacturerts specs. Seat widthvaries (see manufacturerts specs.) but wilL average around 1/16 in. for both intake pound and exhaust. A seat that istoonarrowwill out of shape more easily. It will also fail to dissipate enough heat from the valve face. A seat that is too wide will tend to collect carbon, thus eventually preventing a good seal with resultant val ve overheati ng and burni ng, Fi g . 13- 51.
CUT RECESS Make certain all alignment screws are tight. Use either a ratchet handle, or a power drive mechanism to rotate the cutter. With the cutter just clearing the work, start turning. Feed the cutter into the workbyturning the knur:led stop collar. Do not force the cutter. Give several turns, and thenrunthe cutterlightly down. Repeat this process until stop col1ar engages the stop block. At this point, give the tool a few additionál turns to produce a smooth seat for the insert. Run the cutter outof the recess and remove tool. Fig. 13-50, shows the mechanic moüng the cutter into the work by turning the stop collar.
= j{3, i t) C O R R EC T .SEATST R IKES C EN T ER OF VALVE F AC E
frxr::'
WW%7W T OO N AR R O W
T OO W ID E
T OO LOW
TOO HIGH
Fig, I3-51. Co¡reclond inco¡recfvolve seofs.Nofe ffie inle¡Íerenceonglesin B ond C.
of stock When refacing a seat, the removal specifiwill widen the seat beyond original cations. It must be narrowed by removing metal from the upper portion, Fig. 13-514. In cases where the valve port walls narrow, or are uneven, metal will have to be removed from the bottom also. If the walls are smooth and of constant diameter, only a veryLIGHTcut with a 60 - ?0 deg. stone should be taken. If inserts are used, the bottom cut is notnecessary, Fig.13-52. The light bottom cut will produce a seat that is the same width at all spots.
F i g , 1 3 - 5 0 . Cu ttin g th e in se ¡ f ¡ e ce ss.
200
Cylinder Heod, Volve, Vqlve Trqin Service
REFACIN G VA LV ES E A T
ST ON E SLEEVE
After alt valve guide and insert work is complete, the valve seats are readytobe refaced. The seat must be free of carbon, oil, dirt, etc., as the grinding stone will quickly load (pores of stone fill up with carbon, dirt, etc.) thus ruining :he cutting action. _ | .t f_ --l t:,r-{
ST O N E ST O N E C LEAR S
trt fffi!!*ffi'lt rroRN sEAr !ll49l9 T OO W|DE I
ST ON E ST R IKES
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SLEEVE PILO T
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S TO N E TO O NA R R O W
Wdru)W F ; g .,1 3 -5 1 A . No rro w i ng the volve seat width oÍter r eh c i ng. A J U d e g . sfo n e ís o ccosiono//y used lo nor r ow 45 deg. seor s , onc e i n o while, o llat stone is r equir ed.
Fi g. I3-53. S tone musr 6e of co¡¡ect w i drñ. A -S rone O,K . g-foo wide. C-foo wide. ltill produceo horizonto/ step of bofiom ofseot. D-Too no¡row. ,o0". ol step at the rop ol rñe seor. ":::.rr"
"5 DE G, f i ^ R ROW|NGCU T
:- ;-.-, . S E LE C T P R OP E R S TON E
BASICSEAT TOO WIDEON THIS SIDE
S E AT
S ÍOOT H, C ONS T A NT D IA T 4 E T E R WA L L
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Seat stones are available in various widths. Coarse textured roughing stones are usedforthe initial or roughing cut on steel seats. The fine textured finishing stone is used for the last cutting on steel seats. The east iron block or head requires only the use of the finishing stone. For grinding Stellite and other hard seat inserrs, a special stone is available. The stone must be a little wider than the finished seat in order to prevent counterboring. It must not be so wide as to strike other parts of the combustion chamber. Fig. 13-b3, illustrates how various widths affect the job.
WALL CURVESIN CA U ST N G SEAT TO WTDENON ON E SID E BASICSEAT WID T H K. ON ALL 5ID E5
óO OEG. BOÍTOM NARROWING CUT
DRESSING STONE ROU GHWA L L
SMoOTH EDGE
H EA' Y ó O DEG. CUT WRONG
After selecting a stone ofthe correct size and texture, screw the stone snugly on the stone
ROUGH WALL
L IGHT ó 0 o EG. CUTRIGHT
5LE EVE
Fig.. 13-52. Nonowing tfie volve seor. A-15 deg. cut lrom top ¡sftes o good seol when port wolls o¡e smoorh lnd of consron, Jicmeter. B-Rougñ woll leoves o rcgged lower edge on seot. C_ -lower Havy. bottom cut pro¿uces smootlr seot ejge but widens srot diometer, D-Curved port wolls produceon un.i.n seot width, E-Eotfom cut produces on even width, F-yery light botron cut saootlrs seot edge without opprc:b,t:cr"o"" i, seot diometer. -L--tl
*
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.1
5 DEG.
The valve guides b'é bpoit'eésry cleanto -ubt allow the pilot to properly align with the guide hole.
Fig. 13-54. Some stones can hove on ongle dressed on óotñ ends. A.Stone with 45 deg. ongle down. B-Some sfone, reversed, wifá l5 deg. ongle down.
l ,l
201
1 il ,a
1
Auto Service ond RePoir
US ET WOO R MO RES L E E V E 5
h oL de r or s leev e. I f one is av ailab l e , s e l e c t a angle. This will save stone with the correct prolong the life of the will and time in dressing so that an c ons t r uc t e d ar e s t ones M any sto ne . angle may be ground on both ends, Fig' 13-54' Pla ce s t one s leev e on t he dr e s s i n g s t a n d pilot. Adjust the stand diamond holder to the
seat angle stone on one Mount the correct s l e e v e a n d t h e 1 5 d e g . a n d 7 0 d e g . sto n e s o n two other sleeves, This will a11ow you to grind and narrow the seat without removing and changing stones. Once the pilot is inserted, finish the seat operation before moving to the complete
angle. Loc k all adjus t m ent s ' core ct stone' Engage away from diamond Back Run the stone' spin and sleeve drive motor stone' the of face full the diamond tip across Ta ke light c ut s unt il t he angle is c o r r e c t a n d t h e fu 1l sto ne J ac e is c lean and t r ue, F i g ' 1 3 - 5 5 "
next one.
D RIYEM OT OR
ST ONE SLE
D IA MONHDA SFA LLE NOU TI IDE ST OP s t¡i k e s l eei Fi g. I3-56, D o not rui n the di onond' A 'H eovy c ul w i l l thot buíon di o^ond. B 'Foi l ure to dress l ul t w i dth l eov es o l edge the beneoth rh e s teel C -When di amond. beneoth con srri ke steel di onond i s undercut,the di onond ti p w íl l Íol l out'
HOLD E RA N GLE DIAM OND LOC KS C R E W T OOL DIAM OND 5 L EEYE P IL OT
PIL OT HEIGH T L OCKSCR E W
sl ond' F i-g . 1 3 -5 5 . Dr e ssin g fh e slo n e u sín g o typícol dressi ng ( Alb e ¡ fso n - Sio u x)
B Y UNDE RCUT T I NG DO N OTRUINDIA MOND Use ear e when dr es s ing t o s e e t h a t t h e f i r s t must cut is not too heavy. The ful1 stone angle diamond' also b e dr es s ed t o pr ev ent injur y t oth e t he ef f e c t s o f b o t h a n Fig. 13- 56, illus t r at es heavy cut and failure to dress the full initial wid th.
INSTALL STONESLEEVE PILOT There are basically two types of stonepilots tlpe that is in use. One is the ADJUSTABLE The slipped, into the guide and then expanded' is that CONSTRUCTION other ís of TAPERED and guide the between secured through friction a ta pe r ed s ec t ion. of the type used, make sure that Regardless Wipe off the pilot with a clean' is clean. guide the rag and insert the pilot. The pilot üghify-oiled mu st be RI G I D. See Fig. 13- 57.
Fi g. l 3-57' l nstal l i ng on odi u s tobl e pi l ot'
20?
CylinderHeod,Volve,Vqlve Trqin Service G R INDIN SE G AT Using a clean, dressed stone, place the sleeve on the pilot. The stone should contact the seat, F ig.1 3-5 8.
and pol i sh up the seat. R E ME MB E R : THE FINISHED SEAT WILL BE ONLY AS ACCURATE A S TH E S TON E , Fi g. 13-59.
*ñr,
CONT ACTS SEAT PROPERL Y
Fi g. l 3-59. Gri ndi ng the vol ve seof. N ofe how operotors upports w ei ght o( dri ve moto¡ w i rh l eÍt hond.
I NARROWING SEAT Using a 60 - 70 deg. stone, grind until the 60 - 70 deg. angle touches the basic 30 - 45 deg. seat surface all the way around. This 60 - ?0 deg. stone cuts very quiekly. Do not applydownpressure and cut for only about two seconds before checking, Fig. 13-60.
F i g. l 3 -5 8 ,
S fo n e o nd s/eeve in ploce on pilot, Note cor r ec t s eol ( Black ond Decker ) co ntocf.
Insert drive motor head into end of sleeve. Tilt motor up, down and sideways to feel for a nonbinding, central position. While supporting weight of motor, engage switch. AIIow stone to grind for a few seconds, then stop and remove motor, raise sleeve and examine seat. Repeat until seat is smooth, clean and free of burns, REMOVE ONLY ENOUGH pits, etc. CAUTION: S TOCK TO CL EAN SEATJ I F I NTEG RAL S E A T CAN EXCESSIVE GRINDING IS HARDENED, CUT THROUGH THE HARDENED AREA. ChCCK manufacturerrs specifications. dress stone several times On hard inserts, for each seat. NEVER CONTINUE GRINDING WHEN STONE SURFACE NEEDS DRESSING, stone, stop when the If using a roughing seat is cleaned up. Switch to a finishing stone
Fi g. 13-60. Toki ng o LIGH T cut on ffi e bofl om of tfi e seot w i th o 60-70 dea. stone.
With the 15 - 30 deg. stone, (see mgnufacturerrs spees.) remove stock until the seat is dow n to the speci fi ed w i dth, Fi g. 13-61. A small measuring tool such as shown in Fi g. 13-62, w i l l assi st i n a careful me asur ement of seat width. Use a light and be aecurate. A triek often used for seat grinding is to mark the seat (after grinding the basic angle)
203
j
i I
{¡ I
r--_ Auto Service ond RePoir
V A L V ES E A T T E S T I NG
F¡ s ' l 3 -6 1 .
Nonowíng lhe seof fo specified w ídth by r em ov i ng m etol lr on the top with o l5 deg. stone.
(true To test a valve seat for concentricity roundness) place a special valve seat dial indicator on the pilot. Adjust the indicator bar so that it contacts the center of the valve seat. The dial needle should travel about a half turn when the bar length is correct. Set the dial to 0. Hold the upper dial section and slowlyturnthebottom completely section around so the bar travels will indicate needle The dial seat. around the be should The seat entire present. runout any within.002. I f r u n o u t e x c e e d s . 0 0 2 , c h e c k t he se tu p ca r e ful1y bar tip should be in the center of the seat) and try again. If runout still prevails, regrind the seat, Fig.
rX lE6.
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-¡
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.:
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13-64.
I
INDICATOR NEEDLE SETAT O
"ia G
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.INDICATOR
&\ Fig. l3- 62. A hondys eotwidf hm eos u r i nlgo o / ' (Storre¡) with a series of soft pencil marks across the r.vidth. When removing stock from above and below the seat, the pencil marks will clearly sho w wh at is lef t of t he bas ic angle , F i g . 1 3 - 6 3 .
INDICATOR
PENCIL M ARKS
REMAININGPORTIO N OF PENCIL MARKS
F i g. I 3- 64.
C hec k íngv ol v e
s eof c onc entr i c i ty
w i t h o d i o l i n d i c o t o ¡'
VALVE LAPPING '15D E G'
There are two schools of thought regarding lapping the valve into the seat withlappingcompound (fine abrasive powder). Some feel that it
F i g . l 3 - 6 3. lJsin g p e n cíl m o r ks lo h e lp d e te rmi new i dth o( bosi c 3 0 o ¡ 4 5 d e g . se o t.
2U
Cylinder Heod,Volve, Vqlve Trqin Service produces a more accurate seal between valve and seat while others contend that it is of no value. Many authorities agree that when modern valve grinding equipment, in good condition, is properly used, that lapping is NOT necessary. Lapping when an interference fit is desired, can actually damage the seal.
ROCKER A R MB A L L S T U D P U L L IN G S L EEVE
F I NALC H ECKFORCONCE NTRICITY O F BO THSEATA NDV A LV EFA CE Rub a very thin film of prussian blue on the -;alve face. Place the valve in position. While pressing (in the center) against the seat, rotate :he valve about one-fourth turn to the right and :hen back to the point of beginning. Remove the -;alve and examine the seat. It should be marked -¡ith blue around its entire circumference. The -
Fig. l3-66. Pulling a rocke¡ orm stud.
rc.M.C.) Iarger oversize is needed, ream the hole in two s t e p s - u s e t h e s m a l l e r o v e r s i z e r e a m e r fi r st, then finish with one of the desired si ze , Fig. 13-67.
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P E N CIL MA R K S
PORTIONOF PENCIL M ARKS W IPEDOFF
F ig. 1 3 - 6 5 , P e n c i l m o ¡ks o n vo lve lo ce will d e te ¡ m in evo lve foce lo seot dccurocy. A-Morks opplied. B-Po¡¡ion al mo¡ks wiped oll b y p l a c i n g v o l v e i n se o f o n d g ivin g it o n e - q u o d e rtu tn.
Fig. l3-67. Reomingfhe ¡ocke¡o¡m stud hole. Thread the replacement stud in the driver. Coat the plain end with hypoid lubricant or Lubriplate. Place over the hole and drive down until driver body touches stud boss. This willbe the correct depth. Remove driver to o l , Fig.13-68.
R E PLAC ING R OCK E R A RMS TUD If the cylinder head uses individual rocker arm ball studs, check them for signs of damage or looseness. If a replacement is necessarydue to breakage, a standard size replacement will suffiee. If the stud is loose, the hole will have to be reamed for one of several available oversizes. To remove the stud (if brokenoff atthe boss, drill and remove with a studextractor)placethe pulling sleeve over the stud. Run the nut down against the sleeve. Continue turning to pull the stud, Fig. 13 -66 . If an oversize stud is required, reamthe hole with a special reamer of the correct size. If the
CL E A NI NG V A L V ES P RI NG S Valve springs should be soaked in solvent, brushed and thoroughly rinsed. Never clean springs that are painted, in strong cleaners as the paint will be removed. The paint and other coatings prevent rust. Wire power wheels will also remove this protective coating and spring life will be shortened.
205
1 i
I
I
STUDDRIVER DRIVEUN T IL STUDDRIVER STUD ENGAGES BOSS
difference between top and bottom) you can assume that the spring is square' Place on the opposite end and check it for squareness' Fi g. 13-68B
sTt D BOSS
IN S P E C T S P R IN G FOR E TC FIIN G
O R O T HE RDA MA G E
ploce' Fig. l3-68. Driving rocker o¡m stud into
Check the spring for any signs of rusting' etc' corrosive etching and for scratches' nicks'
TE NS ION C H ECKSPRING
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After extended service, valve springstendto lose tension. Since correct tension is important valve action, each spring must be to proper retested to make certain it meets minimum specificaprovide Manufaeturers quirements. pounds' tions listing the amount of pressure, in compressed when that a given spring should exert
C H E C K D A MP E R S P R IN GS A N D C LIP S
to a speeific length. an appr opr iate m e a s The sp ringis plac edin to the specified compressed device, uring determined' pounds in pressure the and length, Fig. 1 3-6 8A . .
P OOR S P R IN 6
(used inside the Inspect damper springs and regular spring to reduce spring vibration) worn are that damper clips if used. Discard any or fail to meet sPecs.
Reject springs that fail to meet specified compressed pressure, free length, squareness' or that shows signs of rusting, etc' (valve A weak spring will cause valve float camshaft the closing so slowly that the lobe on seated)' starts to open it againbeforeithasfully causing guides the in Valves may start sti.cking andbroken burning missing, heavy tappet noise, valves. Remember that using poor valve springs can be expensive. New springs are inexpensive and will certainly raise the level of reliability and
SC ALE
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Fis. l3-684. Testing volve spr ing tension' Spr ing ís 6ose,Whenl e ver is pulled down, poinler pod compr es s es pounds . to specifiedd i stonce on tñe scole. Tension, in
on
s pttng i s l hen
r eod on ¡ he d¡ ol.
C H ECKVALV ES P RINGFRE E L EN GTHANDS OUA RE NE S S
To insure the close fit necessary between for head and block. the head should be checked in any six around warpage, Some warpage. '003 Distortion inches or.006 overall, is permissible' grinding by be conected point should this beyond See surface' the a small amount from or milling to amount permissible manufacturerr s specs for be removed. Removal of metal from the headorblockwill cha'mber (in reduce the size of the combustion the compression engines) thus raising most length effective the change also will It ratio. On an overfrom the lifters to the rocker arrns' chain length engine, the timing head camshaft
Slide a Place the spring on a flat surface'' not tip filo spring the to up square combination measure blade' the on scale the Using spring). is not under ttre t"ee length (length when spring p ressu re). I t s hould m eet s Pec s ' spring Carefully sight between the edge ofthe to parallel be should and the blade. The spring and turn partial a the blade. Give the spring indicate that the If both sightings check again. -is (not more than 1/ 16 in' parallel spring
be altered. Special head gaskets, thicker than standard' and workare available to maintain compression removed been has stock when ing dimensions block. or from head
will
206
Cylinder Heod,Volve, Vqlve Trqin Service
VALV E SPRI N G COMBINATION
MAXIMUMMEASUREA4ENT Fig. l3-70. Checking volve stemheight. (Dodse)
F i g . l 3 - 6 8 8 . C h eckin g sp r in g lr e e le n g th o n d sg u o r e ness. ( Plym o u th )
to this change, malfunctions can result. If the height of the stem is excessive, the valve must be removed and the stem end ground down the p r o p e r a m o u n t . C h e c k a l l v a l v e s , F i g . 1 3 - 7 0. While holding the valve in place, install stem t o g u i d e o i l s e a l , i f u s e d . I f r e q u i r e d , p l a c e ste e l washer around guide and in contact with head. Place spring or springs, closed coil end (one
STRAIGHTEDGE
odi, ; Do@ .
fD .@ E.ffi .ffi .
F i s . l 3 - 6 9 . C h e ckin e cyli
su r flce ( o .r - wo rpose. :e r fe ld
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Fig . 13 -69 , s hows t he us e of a s t r aighte d g e for checking cylinder head surface aceuracy. The st r aig hte dg e is plac ed ac r os s t heheadas s h o w n . Sight along the edge to detect any warpage. If any, slide a feeler gauge between straightedge and head to determine the amount. Head surface rnust also be free of nicks, scratches, gasket : eme nt, e tc.
end of the spring may have the coils spaced c l o s e r t o g e t h e r - t h i s i s c a l l e d t h e c l o s e d co i l end) toward the head, over the stem and in contact with the head, Fig. 13-71. I f d u a l c o i l s , o r a d a m p e r s p r i n g , a r e u se d , s p a c e c o i l e n d s p e r m a n u f a c t u r e r r s i n s t r u cti o n s (usually about 180 deg. apart). Install shield or umbrella and retainer over the spring. Using a spring compressor, co m p r e s s t h e s p r í n g j u s t f a r e n o u g h t o e x p o se th e S l i p t h e s e a l i n to th e stem oil seal groove.
RETAINER SPRING VALVE CUPSEAL
INSTALLING VALVES,SEALS AND SPRINGASSEMBLIES With the cylinder head in a suitable fixture, firead must be spotlessly clean) oil the valve guides. Select the proper valve, oil the stemand insert into the guide. On engines that do not have provisions for adju stin g ro cker ar m t o pus h r od c lear anc e , t h e height of the valve stem from the head should be checked. In that removal of metalfromthe valve iace and seat will allow the stem to protrude further, the rocker arm will be tipped down on the push rod side, thus forcing the hydraulic lifter plunger near the bottom of its travel. If orovisions are not built into the lifter to adjust
Fi g. l 3-71. Gui de seo/ (cup seol ) i nstol l ed, spri ng ond retai net bei ng pl oced i n posi fi on. (C hrysl er)
207
q {
Auto Service ond Repoir
groove. Make sure it is properly positioned and is no t t wis t ed. I ns er t t he s plit k ee p e r s o r l o c k s an d s1ow1y r eleas e t he s pr ing. A s t h e s p r i n g rise s, guide t he r et ainer s oit is c e n t e r e d a r o u n d th e kee per s . W hen f u1ly r eleas ed, c h e c k k e e p e r s to mak e c er t ain t hey ar e f ully e n g a g e d . i F KEEPER S ARE NO T LO CKED I NT O P O S I T I O N , THEY CAN SLI P AND FLY O UT WI T H D A N GEROUS FO RCE. KEEP YO UR F A C E T O O N E SIDE, Fig. L3- 72.
are differences between intake and exhaust springs and retainers. Be careful to assemble t h e m i n t h e p r o p e r l o c a t i o n s . F i g . 1 3 - ? 3 , sh o w s a tlpical valve stem assemblv. Note the stem SCAI.
T E S TS T E MS E A L When a stem seal i.s employed, it may be tested by placing a small suction cup over the retainer. Squeeze the bulb while holding the cup against the sssembly. When the bulb is released, it should stay compressed thus indicating an airtight seal. Such a test tool is shown in Fig.13-?4.
F¡s.13- 74.
Yal v e s fem s eo/ l es f f o o l . (Chev¡olet)
CHE CK I NG INSTALLEDHEIGHT O F V A L V ESPRING
F i g . I 3 - 72 , Co m p r e ssin gvo lve sp r in go n d in s tol l i ng sp/i t keepers. ( Ch e vr o le ¡ )
Each
va lve
from
wh ich
guide
or
it
va lve
sh o u ld wa s is
be
in sta lle d
r e m o ve d n e w.
On
in
u n less so m e
the
ei ther
engi nes
port the there
As with the valve stem end, removal of stock from valve faee and seat will allow the keeper grooves to protrude higher above the head. This will increase the installed length of the spring, thus reducing spring tension. Using specs, measure the installed height of each spring, Fig. 13-75. I f t h e h e i g h t i s e x c e s s i v e , i t m u st b e co r rected by removing the spring, .and placing a s p e c i a l s t e e l w a s h e r o r i n s e r t b e t w ee n th e sp r i n g and the head. These washers are available in different thicknesses. Donot install washers that are too thick, as the spring pressure ean be increased to the point of causing rapid lifter and c a m s h a f t w e a r . F i g . 1 3 - 7 6 , i l l u s t r a te s o n e typ e o f w a s h e r u s e d t o c o m p e n s a t e fo r e xce ssi ve stem length.
INSTALL¡NGCYLINDER HEAD When the ball joint rocker arms are used, the rockers may be attached loosely to the rocker studs and left in this position while the head is installed. Generally the roeker shaft and arm assembly is installed after the head is in position and has been torqued.
F ig . l3 - 7 3 . T yp ico l vo lve sp r in g ossembl y.
208
\.-
Cylinder Heod,Volve, Volve Trqin Service
by cutting off the head and fi.ling screwdriver slots in the top. Taper the cut end so it will enter the head easily. Screw them into the block, one near each end. Place the cylinder head gasket on the block, right side up, front end to front of engine, and c h e c k t o a s c e r t a i n t h a t a l l p a s s a g e s a r e e x p o se d , and that the gasket fits properly. Lay the gasket, upper surface down, on a clean surface. Coat the gasket with a thin coat of suitable gasket cement. Place the cemented side against the block, and carefully coatthetop l e t c em e n t side. Use a THIN coat onlyanddonot run into passageways or cylinders. Some gaskets come with a special coating that provides a seal as soon as the engine is warmed up the first time. Cement is not required on this specs. type of gasket. See manufacturerrs Place the head into position and lower over g u i d e p i n s . F i g s . 1 3 - 7 ? a n d 1 3 - ? 8 , i l l u s t r a t e th e usé of guide pins to align cylinder head, gasket Fig. l3-75. Checkingvolve springinstolledheight.
and block
surfaces.
The block must be within acceptable dis'::::on the surface absolutely measurements, :,:an an d fre e of nic k s , dent s , et c . Allhead b o l t -: les sho uld b e c lean. If the block does not have built-in guide pins, :--:.ke them out of old cvlinder head cap screws
Fi g. l 3-77. Low eri ng cyl i nder heod i n¡o posi l i on. N ofe pe rmonenf shon gui de pi ns. (G.M.C .)
=
i. l 3 - 7 6 . C o r r e c l i ng .e xce ssívevo lve sp r in g in sto lle d hei ght by r: , : i n g o w o s ñ e ¡ 6 e f w e e n h e o d o n d sp r in g e n d . E' Am o u n t ol metol ' mo v e d b y g r i n d i n g vo lve o n d se o t. H- Wo sh e r tfr ickn ess comporoble to E. (Dodge)
Fi g. l 3-78. l nstol l i ng heod usi ng l emP orotyl ong gvi de pi ns .
209
Coat the head cap screw threads (after wire with a suitable thread compound. The brushing) sealing compound should have the necessary when cap screws.thread properties, especially into a hole that enters the water.jacket. Insert the cap screws in their proper locations, (watch for different lengths). If one of the eap screws is designed to pass oil from the block through the head to the rocker assembly, be certain it is placed in the correct spot. Run all bolts down until they just engage the head. Remove guide pins and install bolts in these holes.
Fig. l3-81. Grindingrocke¡ orm end. Removeno morestoc/
TOROUEHEADBOLTS the wrench and following Using a torque sequence, bring all bolts up to recommended one third torque. Go over them againbringingto two thirds torque. They should then be brought to full torque. A fourth time over will make sure none have been missed. Remember that proper torque is a MUST. Excessive or uneventightening will distort cylinders, valve guides andvalve se ats, Fig . 13- 79.
GRINDROCKERARM The rocker arm valve stem end should be ground to a smooth even curve. Using a valve mount the rocker arrn so the end is grinder, parallel to the stone. Adjust the swivel attachment in such a way that the rocker arm end curve will be maintained. Dress the wheel. With one hand operating the swivel arm, andthe other arm against the stone, wet holding the rocker grind until the surface is clean andtrue. Remove no more stock than necessary, Fig. 13-81. Check the push rod end of the rocker. On the there wiLl be a swivel nonadjustable versions, pocket in the end. It must be smooth and free from galling. When an adjusting screw is provided, check the ball,
Fig.
13-82.
R OC KERAR M T O VALVE ST EM PAD R O C KERAR M T O SH AF T BEAR IN G
PU SHR O D SO C KET
PU SHR OD BALL EN D
Fig. I3-79. Tor.-qu.h"od cop screws in proper seguence.
R O C KERPU SHR OD BALL
ROCKERARM AND SHAFT SERVICE
PU SHR OD SOC KETEN D
Clean each rocker arm shaft. Pay speeial attention to the hollow center. Examine for signs of wear and scoring. Replace if necessary. Check the condition of the rocker-arm-toshaft bearing surface. Ifbushings are used, wear can b e co r r ec t ed by r ebus hing andho n i n g t o s i z e .
Fi g. 13-82. C heck rocker o¡m sockef ond 6ol l . Tfi es e mus t be srnootñ ond f¡ee of excessive w e or.
210
I NS P E CT P U S H R OD S Push rods should be straight and both ends must be smooth. If the push rod is designed to carry oil through the hollow section, be certain to clean the inside and blow dry. IND IC AT OR
Fi g. l 3-85. R esurfoci ng vol ve l i l ¡er end. (Yon No¡mon)
Fig. l3-83. Checkingpushrod sfroighrness with V-blockson¿ o diol indicotor. Rod straightness can be checked with Vblocks and a dial indicator. Maximum allowable runout will vary. See specs. See Fig. 13-83.
M EC H ANICALIFTE L RSOR TA P P ET S Clean lifter. Inspeet push rod socket for signs of wear or galling. The lifter-to-camshaft surface should be smooth and free of cam wear, grooving, chipping and galling, Lifters showing heavy camshaft wear or worn sockets, shouldbe replaced. If the wear is minor, the tappet may be resurfaced on the valve grinding machine. L ifter we ar pat t er ns ar e s hown in Fig. 1 3 - 8 4 . Tappet adjusting screws, such as shown in F, Fig . 13 -84, m ay als o be r es ur f ac edpr o v i d i n g the valve stem has not worn below the hardened portion. o. K.
ZA
@ t€-1L--/ \-,J
\^r/
GALLED
?-'
Zg,' @ f.---=-'1 \-_-,
\-^,
.I
,b M \J
Fig. I 3-84. Lilter weor potterns. A,B,C,E, - Consha(t end ol lil¡er. D-Push rod end ol I il¡er. F -T oppetodi ust ing screw (L-H eod engi ne).
GRINDINGMECHANICALLIFTERS Dress the wheel surface. Secure the lifter in the V-block holder. While applying a stream of coolant to the lifter end, advance the lifter a g a i n s t t h e s t o n e . C u t s s h o u l d n o t e xce e d .0 0 2 . Move the lifter back and forth over the stone surface. Do not remove any more stock than absolutely necessary. At the end of the last cut, continue to move the lifter back and forth until the cutting action stops. This witl produce a smooth finish. If both ends of the lifter are adaptable to grinding, reverse and repeat the process, Fig. 13-85. When lifter wear is pronounced, or galling and chipping are present, check the cam lobe'b carefully as they may also be damaged. O v e r s i z e l i f t e r s m a y b e u s e d t o c o r re ct l i fte r to bore clearance. Wh e n c l e a r a n c e e xce e d s . 0 0 5 - . 0 0 6 , r e p l a c e m e n t i s n e c e s s a r y . Th e b o r e s should be reamed to the exact oversize needed.
SERVICINGHYDRAULICLIFTERS The portion of the lifter body that protrudes below the guide bore is often coated with gum and varnish. This make s removal diffi.cult unle ss a special tool is used to grasp the lifter. The tool is engaged and the lifter pulled upwardwith a twisting motion, Fig. 13-86.
KEEP LIFTERS IN ORDER Each lifter s h o u l d b e p l a c e d i n a m a r ke d holder so it may be returned to the guide bore from which it was removed. Ablock of wood with two rows of holes, each row representing one bank of lifters, will do.
211
a n d a s s u c h , m u s t b e k e p t t o g e t h e r . F i g . 1 3 - 8 7 .A, The check valve lifter. shows a disassembled spring and valve are stil1 in place on retainer, the plunger. place the is disassembled, As each lifter parts in individual, MARKED traYs.
LIFTE R B OD Y Fi g . 1 3 - 8 6 . l J s í n g o sp e cio l p u lle r to r e m o ve o h yd r o ul i c l i her'
(c,M.c.)
PLU N G ER SPR IN G
LIFTER DISASSEMBLING
C H EC K VALVE C AG E OR R E TA I N E R , H OU SIN GC H EC K VALVE AND S P R I N G
Place the lifter body, right side up, on a clean board. Using a push rod, depress the plunger a nd s nap out t he re ta i n i n g ri n g , F i g . 1 3 -8 7.
TAPPETPLUNGER
PushRod
F is.
CLEAN¡NGLIFTERS A special eleaning station, such as shown in F i g . 1 3 - 8 8 , i s d e s i r a b l e . N o t e t h e c o m p a r t me n te d tray in which lifter parts are kept together. The a special cleaning tray on the left contains solvent designed to dissolve gum, varnish, etc. The central tray eontains clean kerosene for F i g . 1 3 - 8 7 . Re m o vin g lih e r p lu n g e r r e to in in gr ing. ( Ch e ú r o le t)
on the plunger and guide Release pressure out of lifter body. If the plunger sticks, and it often will, it may be removed with a tool designed for this purpose. One such tool operates body in the tool and then by placing the lifter plunger end down, against a tooL, the striking block of wood.
K EEPPAR TSOF LIFTE RSTOGE THE R close parts are made to extremely Lifter (.0001) is selectively plunger and the tolerances (several until one fits tried plungers fitted AND PLUNGER THE body. the to perfectly) BODY ARE NOT INTERCHANGEABLE LiFTER
Fi g. l 3-88. A good sefup Íor cl eoni ng hydtoul i c votrv el i l ters '
212
Cylinder Heqd,Vqlve, Vqlve Troin Service
:-nsing. The small tray contains cleankerosene rinse. A clean work area is also i:r a FINAL ::ovided, Fig .13 -BB. lifters Due to the close working tolerances' assemand CLEANED :-:rst be THOROUGHLY The SLIGHT:led in a SPOTLESS CONDITION' :S T TRACE of g rit , dus t , lint , et c ' , will c au s e i=::1ty operation. are dismantled, rinse each -\fter alL lifters USE of parts in clean kerosene' DO NOT first This IN THE TRAYS' -oup fnnOSENE :rr¡ sludge' ::::se is merelyto remove most of the oil' cleaning special ::c,, so the useful life of the -.¡h'ent will
be prolonged.
5OAK IN SOLVENT the initial rinse, plaee the tray Following intothe cleaning solvent' Lay :n::h compartments the and lifter bodies on their sides so :l:ngers one about for soak to Allow =olváni will enter. :::ur. Exact soaking time will depend onthetype used, and condition -i solvent used, how often OF CLEANING OUT HANDS KEEP :i lifters. :,')1-UTION AND AVOID SPLASHING' ITISWISE :f USE RUBBER GLOVES WHILE CLEANING --:T ERS. the \\rhen the soak cycle is completed' elevate empty to side to side ::ay. After tipping from suspend the tray over the of solvent, :arts solvent hasdrippedoff' excess :¡lution until the
RINSEIN KEROSENE place tray in the drained' When thoroughly Agitate the tray kerosene' rinse ;"n of initial Remove lowering' and lifting times by =ut"."l the remove wiLl rinse This drain. =::d allow to oftheloosened :1.eaning solvent and a great deal ieposits. surfaces with a clean' lintWipe all lifter all actiontoremove l:ee cioth. Use afirmwiping be should brush bristle gum. A soft :emaining plunger and lifter the of ':sed for the inside have been cle-aned' place ': odie s. When all lifters container of kerosene' center the :he tray in to drain' Blow all allow and remove -lgltate, ;arts drY.
INSPECTLIFTER PARTS Use a magnifying glass to in(PLUNGER): nicks' check valve' seat for spect plunger body plunger seratches and wear. Inspect outer eitherthe on ior signs of galling. Any scratches
be felt with check seat or plunger body that can Ignore the rejection' for are cause the fingernail exp^lunger the where occur may slight edge that the of surface working inner the ter'r"as Ueyond quite sharp' is edge if this However, body. lifter the plunger must be considered defective' (LIFTER BODY): Check the lifterbodyinner be smooth and and outer surfaces. They must lobe surface free of scoring. The lifter-to-eam g a l l i n g ' c h i p p in g o f must also be smooth andfree ( l i f te r r o u n d w e a r p a t t ern A and excessive wear. (lifter pattern wear square a or was rotating) is smooth not rotating) as long as the pattern is accePtable' wear, free of and body that of the lifter The outer portion show usually will contacts the lifter guide bore side load cam by a distinct wear pattérn caused can pronounced' or scored thrust. It too, unless be considered accePtable' (PUSH RoD SEAT): If the push rod seat is scored or badlY worn, rePlace' OR VALVE DISC): Examine (CHECK BALL glass' Any the cheek ball with the magnifying it render will etc', dents, scratches, nicks, usele s s. (BALL
will The ball retainer RETAINER): check the it contacts where show a bright spot A pounded area or any ball. This is normal. rejection' for cause be cracks will (SPRINGS): Inspect both plunger and check or other valve springs for signs of distortion damage. RePlace if necessarY' RING): Diseard any (p,t-UNCnn RETAINER out of shape' bent retainer rings that are
REPLACINGPARTS the Some garages replace, when required' check push rod seat, retainer ring, ball retainer' baII or disc and the sPrings' Other garages, when any part shows damage' school of This assembly' the entire discard (and is a good it practice employs the argument comsmall is lifters new one) that the cost of some from comeback possible a pared to that of ;i faihrfe' lifter premature whenthere There are also garages that will' not even is considerable mileage on the engine' autoare They clean and inspect the tifters' Disones' new of discarded in favor matically reasqeminspection' plus assembly and cleaning If the cost of bLy and testing take some time' price of new the from deducted this labor is faetor' reliability increased the plus lifters, there is much to be said for replacement'
213
I
,II i I 'i;
i' i
s;, II l
I 1 I i
l1 I I
l
Auto Service ond RePoir
ONEA T A T I ME A NDA S S E MB LE IN SPECT have been After all the parts of one lifter replaced, they and where required, inspected should be rinsed in the central tray ofkerosene'
small blown dry and thenthoroughlyrinsedinthe pan of kerosene. Each part, as it is assembled, must be put through this sequenss. One entire lifter should be inspected and assembled before going on to the next.
LIFTER ASSEMBLY push rod held vertically, With the plunger seat in place, check valve seat up, place the check ball or check disc on the seat. Set the spring over the valve. Place the check valve over the spring and snap down valve retainer into plunger recess. The plunger spring is then placed over the ball retainer and the lifter body
Pr¡shRod Oil Gallery Lüter Body Camshaft Valve Spring Plunger Spriag Yalve Ball I I Plunger I Push Rod Se¿t 10 Reiainer Ring 1 2 3 4 5 6
ir,
vol ve' F i g . 1 3 - 89 . Hyd r o u líc lilte r u tilizin g o b o ll check
lowered down over the Plunger. Turn the lifter body right side up, dépress the push rod seat and install the retainer ring' Wrap assembly in cLean, slickpaper andproceed to the next lifter. ALL LIFTER PARTS SHOI"ILD BE ASSEMBLED WET WITHRINSE KEROSENE. DO NOT WIPE OR BLOW DRY. F i g s . 1 3 - 8 9 a n d 1 3 - 9 0 , i l l u s t r a t e tw o typ i ca l One uses a round assemblies. lifter hydraulic flat check disc. Note a other the check ball, respective
Position
of all Parts.
PUSH ROD
t I i'
PUSHROD FORCES AGAINSI
ll li
I
StIGHf LEAKAGE PASÍ PIUNGER VALVE D ISC
VAI- VEDISC
cr-osED
i
lI i
t
¡
vol ve' F ¡-g . l3 - 9 0. H ydrovl i c l i l tet uti l i zi ng o di sc check (Li ncol n)
214
CylinderHeod,Volve,Vqlve Trqin Service Cf I EC K¡ N G L EAKD OW N RA TE Each lifter must possess the correct leak:c',vn rate characteristic. Leakdown rate is the of time it takes for a specified weight to -:rgth (lifter the plunger filled with test fluid) -ove j:om the top of its travel, a measured distance, ::in'ard the bottom. If a t est to ol similar t o t hat in Fig. 13- 91, is test the leakdown rate as follows: '-;ailable, ::ise the weight arm and ram. Place the lifter ::: the special sleeve inside the test cup. The ::p must have sufficient CLEAN test fluid to :ompletely eover the lifter. Lower the ram against the push rod seat. weight the arm down on the ram and de-
guide bore. Rub a small amount of Lubriplate or rear axle lubricant onboththe camlobe and push rod ends of the lifter. Install the lifter in the hole from which it was removed. When lifters have been installed without filling with oil, the engine rpm upon starting, should not exceed a fast idle until all lifters are pumped up (fil1ed with oil).
IN D TC A TOR
Fi g. l 3-91. Testi ng l eokdow n rote. (Chevrolet)
I¡i. j * !', 1.
l ,: I ,i j,
i',, lr ]'.
Another is shown in Fig. leakdown tester - : g .13-91. and \ 3 -92. T o u se , the pu sh r od s eat is r em ov ed üe lifter is submerged in elean kerosene. De¡ress the eheck valve with a elean, soft rod. Itris When will allow the bottom area to fill. push filled, install rod remove and eompletely seat. The test pliers are engaged as shown and --he handles squeezed. The plunger should slowis rapid, disly move downward. If travel Make assemble, clean, eheck and reassemble. filled with kerosure the lifter is eompletely sene prior to testing, Fig. 13-92.
i: i
ir
I
I
Ii ,, ll
Fi g. l 3-92. Tesfi ng l eokdow n ¡ote w i th speci ol test p/i ers. ' (D odse)
ROCKERARM AND SHAFT ASSEMBLY AND INSTALLATION
LIFTER INSTALLATION Lifters may be filled with 10W engine oil by
The rocker arms, spacers, springs, etc.,
removing the push rod seat and draining out the kerosene. Fill the plunger body with CLEAN oil. "Tiggle the check valve open to allow oil to fill :he lower eompartment. When this is full, fill :he plunger body and replace push rod seat. Lubricate the outside of the lifterbodyandlifter
following should be cleaning and inspection, lubricated and assembled on the shaft. Be very Iocareful to install the arms in the correct cations and facing in the right direction. They placed in relation to the must also be correctly
215
Auto Service ond Repoir
fron t o f th e s haf t . Fig. 13 - I 3, s hows t h e i n stalla tion of r oc k er ar m s on a s haf t t h a t s l i d e s ínto stru ts that ar e an int egr al par t of t h e h e a d .
I nja+,,¡aA L ur
differcnt j-
sfwle Fjx
r o c k e r a r m a sse m b l y i s Note the flat onthe front
6f
12-95.
Y'v
end of the rocker
shaft.
ROCKERSHAFT FIA T ON R OC K TRS H A FT
ARM
W;*o'o'* -* u * sPqcER-/
, a -,*%Éa
R É TA IN TR :*
30rT
II
* ./,
.\
,* RO C KE R S HA FTS TRUT qr m s. Noie
¡ ho¡ ¡ his s hoft s l i des ( Chr ysler ) th ro u g h integr al b¡ ockets or sf¡ uis.
F i g , l 3 -9 3 ,
l n stollíng
r ocke¡
Fi g, I 3-95, A nothe¡ styl e rockerormossem6/y.N ote us e of s poc ers betw eenrockets,
ROCKERARM SHAFT POSITIONING The a ssem bled r oc k er ar m s and s p r i n g s a r e sh own in Fi g. 13- 94. Not e t he dif f er en t a n g l e s o n th e inta k e and ex haus t r oc k er s . The s h a f t i s h eld in po sitlon by t he loc k plug.
I n t h a t t h e h o l l o w r o c k e r s h a f t c a r r ie s a su p nlv nf njl tn thc rnnkers i f r s i m n o r f n n f th a t th e support bracket
A RM INTAK ERO CK E R
designed totransfer
EXHAUSTROCKER ARM
ROCK E R SHA F TL O CKP L UG *,
A DJUS TING S CRE W
INTAKEPASSAGES .
EXHAUST CROSSOVER PASSAGE INTAKEPASSAGES Fig.
l3 - 94.
R oc k er or m os s em bl y c om p/efed.
216
o il fr o m th e
fr
Cylinder Heod,Volve, Volve Troin Service
The individual rocker oil passages are generally positioned so they face toward the head. This provides positive lubrication for the heavily s t r e s s e d l o w e r r o c k e r b e a r i n g a r ea , a n d a l so permits l e s s o i l f l o w d u e t o t h e r e du ce d cl e a r ance between the rocker and the bottom of the s h a f t . I f t h e o i l p a s s a g e s w e r e t u r n e d up w a r d , an
head to the shaft, be properly located. cylinder Fig . 13 -96, s hows t wo m et hods of c a r r y i n g o i l via support brackets. To assure that the oil supply opening in the bracket, make shaft indexes- with the correct end, (flat or notch) faces sure that the marked the specified end of the engine. The notch or flat
c AP SC R EW S
CAP SC R EW
R OC KERAR M SH AF T
ROCKER ARM SHAFT
R OC KERAR M SH AF T BR AC KET
R O C KER AR M SH AF T BR AC KET
CYLINDERHEAD
F ig . 1 3 - 9 6 . T wo m e th odso( suppl yi ng oi l to the rocker shoÍt vío fhe supporf brockets.
must also be positioned, (up, down, to the side) Fig. 13- 9?, illu s t r a t e s the as recorn m ended. marked ends and the various positions forthese pa.rticular assemblies.
F i g . l3 - 9 7 . Ro cke r o r m sh o lt p o silio n in g morks.
e x c e s s i v e a m o u n t o f o i l w o u l d b e p a sse d . Th i s would overlubricate the valves with resultant h e a v y o i L c o n s u m p t i o n . F i g . 1 3 - 9 8 , i l lu str a te s th e u s u a l p o s i t í o n i n g o f t h e s e o i l p a s s a g es. N o te th a t l e s s c l e a r a n c e e x i s t s b e t w e e n t h e bo tto m o f th e shaft and the rocker arm. The individual ball stud rocker arms are lubricated by a metered flow of oi1 delivered through hollow push rods. Shaft mounted rocker arms are drilled in various ways to facilitate the flow of oil to both s t e m a n d p u s h r o d e n d s . Fi g . 1 3 - 9 9 , valve shows one method.
ROCKERARM SHAFT ROCKERARMSHAFT BR AC KET LUBR IC AT ION otL
ROCKER ARM
MAXIMUM CLEAR AN C E
M INIM U M CLEAR AN C E OIL PASSAGE ALVE ASSEM BLY
PUSHROD
Fís. l 3-99.
F i g . l 3 - 9 8 , Ro cke ¡ o r m o il p o sso g e s in th e sh ol t generol l y l oce toword ¡he heod.
217
R ocker orm dri l l ed {or o i l . (B ui ck)
INS TA LLA T I O N ARMA S S E MB LY RO C KER On some engines, the push rodsareinstalled before the rocker assembly. On others the rocker assembly is installed, the push rods placed in the lifters and thevalve springcompressed, thus tipping the rocker high enough to plaee the push rod under the rocker ball end. T he engine i n F i g . 1 3 -1 0 0 , h a s th e p ushrods installed. Note the special installing rod that
Fig. 13-101. Torquing ¡ocke¡ arm shoft brocftet cop screws' (Stu¡revont)
If an oil overflow line is incorporated in the assembly, make sure it is installed rocker properIY. ossembly Fíg,13-100'Pvsh rods held in posifionlo¡ .rocke¡arm installotionwit[ specíol instolling rods' (Plynourh) so holds the push rod lrOO"" ends in alignment they installed' is assembly rocker the that when will all line uP. or some other A small amount of Lubriplate should be applied to each end suitable lubricant, of the push rod before installing'
SHAFTBRACKETS TIGHTENROCKER S LOWLY EVENL YAND
V A L V EL A S HO RCL E A R A N C E A DJ US T I NG (HY DRA UL ILCI F T E RS ) Hydraulic lifters are used primarily to eLiminate the need for lash or clearance between the end of the valve stem and the rocker arm' When the parts heat up and elongate, the lifter will leak down. Any shortening will cause the lifter to pump up. In this way, zero clearance is constantly maintained. Unfite conventional lifters that necessitate periodic valve clearance adiustments, once set' l i fter requi res no f ur t her i tru hydraul i c adjustment. Some engines have no provision for adjustment on the rocker arms. VaLve stem length above the head, head gasket thickness, push rod and rocker wear, etc., all become critical onan installation of this type. However, pushrods are available in different lengths, to compensate for small ehanges needed. The object in adjusting hydraulie lifters isto place the lifter plunger somewhere near the center of its stroke. This will allow changes as needed, inboth directions. Ifthe plunger is forced If to the bottom, it will act as a solíd lifter' allowed to remain at the top, it cannot compensate for wear and temperature contractions'
up Lubrieate bracket cap screws and run the after finger tight, Give each bracket bolt, one If the oth"er, a couple of turns. Proceed slowly' shaft andthe oil, hydraulic lifiers are filled with bent head' againstthe assembty is drawn rapidly stems valve warped oush rodq; bulged lifters, sp*urrg rockers can result. By drawing the "rra assembly áown slowly, the lifters willhavetime to leak down without undue strain on the various parts. The rocker adjusting screws, where used' should be backed off before tightening the assembly. This applies to conventional lifter setups the too. When the brackets are snugged against F i g . 1 3 -1 0 1 ' p e r s p e c s , head, t or que a s
218
=l
PU SHR O D
L I FTERM USTBE ONCA M L O BEBASECIRCLE Rotate the engine until the cam lobe nose jaees directly away from the lifter. The lifter -nrll then rest on the base circle. There are several ways of determiningwhen :he lobe is in this position. On some engines, such as the overhead eamshaft type, the lobe is -isible. If the engine is inthe car and the ignition :s properly timed, the engine can be slowly ::lrned over until the plug lead to the cylinder :oncerned, fires. At this instant, bothvalves are :losed and the lobes are in the proper position jor Iash setting. By slowly eranking the engine until a particular valve is fully opened and then giving the aRANKSHAFT exactly (mark one full turn jamper with chalk) the cam lobe will be turned rne-half revolution thus placing the lobe nose ryposite the lifter. When a piston is brought to TDC (top dead :enter) on the compression stroke (both valves :iosed) the lobes are in the correct position for :iat cylinder. -{no the r techn ique inv olv es div iding t h e l=.mper, with chalk marks, into three 120 deg. sections (six cylinder), or four g0 deg. sections -;-8). One of the marks is on the timing notch, :-:-d the others are related in degrees, to this *"rk. By cranking the engine, in various se_ ::ences, until the marks index with the timing it is possible to set certain valves and ;cinter, :l:¡s reduce the amount of eranking required,
LIF T ER C AM BASE C IRC L E
C AM SH AF T
C AM F LAN K
-
C AM N O SE
F i g.
l 3- 102.
7o s er v ol v e /os [
or c l eor onc e, on t/re cqm 6os e c i r c /e.
the l i l te¡ m us t re s t
AD J U ST IN GN U T
R O C KERAR M
I I
I 'l
tr+ii rl
R O C KERST U D
PLU N GERST OP R IN G
-:g. 13 -10 2.
LIF T ER BO D Y
TI FTERPL UNGE RMUS TB E AT T OPOF TR AV E L
PLU N G ER EALL C AG E
The rocker arm adjustment should be l:osened so the lifter plunger travels to the top ¡j its stroke. At this point, the push rod can be ':g g l ed" s ideway s a n d u p a n d d o w n , F i g . 1 3 -1 03. Grasp the push rod concerned withthethumb :nd forefingers. While genily shaking it siderrays, slowly tighten the rocker arm adjustment. -r-s the rocker arm push rod end moves down¡ard, the amount of shake will be reduced. Stop :: the instant all play or shake is gone. At this ;oint the lifter is resting onthe cambase circle, :b.e plunger is at the top of its travel, and no lash is present between valve stem and rocker :r rocker and push rod. Following manufacturerts specs, give the
PLU N GERSPR IN G
C AM BASE C IR C LE C AA.T SH AF T
Fi g. I3-103. H ydraul i c Ii l ter pl unger ogoi nsf fhe stop ri ng, roc k er o¡m bocked ofi un¡il push rod sáoke is evident.
rocker arm adjustment an additional number of turns (1-1/Z typi cal ). Thi s w i l l forcethepl unger down to the midpoint of its stroke ortravel. Re-
219
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F i g .1 3 J0 4 ,
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rk
i\
ROD
4
Re mo vi ng pusá r od shoke pr ior to linol (h vdr aulic lílter s) . ( G.M .C.l
od i us l m enl
b y fe e l e r as determined clearanee, correct b e t w e e n va l ve gauges or a dial indicator, exists stem and rocker arm. or a A feeler gauge of the exact thickness stepped GO - NO GO blade (GO = .001 below s p e c s ) ( N O G O = . 0 0 1 a b o v e s p e c s ) s h o u l d p a ss and valve stem (hold push rod between rocker end down) with a slight drag, Fig. 13-105. Fig. 13 - 106, illustrates valve clearance being c h e c k e d w i t h a d i a l i n d i c a t o r . T h i s d e v i c e g i ve s highly accurate settings.
peat this p roces s on all r oc k er s . Fig. 13 - 1 0 4 , sh ows a me ch anic s hak ing t he pus h r od a s h e downwar d t o t he po i n t a l l dr a ws the rock er W her e adjus t m ent is n o t p r o cle ara nce is go ne. and c hec k pus h r o d t o lif t er vid ed , comp res s s pec s . I ns t all l o n g e r agains t cle ara nc e ro cker or sho rter
p ush r od if nec es s ar Y.
ADJUSTINGVALVE LASH (MECHANICALLIFTERS} A ce rtain a m ount of las h or c lear anc e b e twe en th e valve s t em and t he r oc k er ar m i s a are employed. lifters MUST when mechanical The exact amount will vary from engine to engine dep en din g o n the us e, des ign and c ons t r u c t i o n . Always use the amount specified by the manufacturer, for the engine at hand. t appet c lear anc e will c aus e n o i s y Exce ssive operation, late valve opening and early closing, lowe red va lve lif t , ex c es s iv e wear and p o s s i b l e valve breakage. Insufflcient clearance will cause early opening, higher lift, late closing andvalve burning. As with the hydraulic lifter, the mechanical The must re s t on t he c am bas e c ir c le . lifter the t h a t s o adjus t ed arm i s c ar ef ully r o cker F i g ,1 3 -1 0 5 .
Checking
volve cleor once wilh o feele r gauge'
c.) tc.M.
Fi g.13-106. U si ng o speci of di ol i ndícotorsetup i o ch ec k toppet c/eoronce. The adi ustmentscrew s fi ove o Iock nut' (P ond G C o.)
COLD AND HOT CLEARANCESETTINGS (MECHANICALLIFTERS} an initial or When an engine is reassembled, i s n e ce sv a l v e c l e a r a n c e t h e o f s e t t i n g COLD setting the sary. For a flnal HOT clearance e n g i n e m u s t b e u p t o n o r m a l o p e r a t i n g te m p e r Th i s a t u r e ( o i l a s w e l l a s w a t e r t e m p e r a t u r e ). mínutes of warrnup about thirty will require operation. IS IM CLEARANCE VALVE ACCURATE is hot and the engine Make certain PORTANT. e x a c t . a r e s e t t i n g s that clearance
ROCKERARM ADJUSTINGSCREWS S o m e r o c k e r a r m a d j u s t i n g s c r e w s a r e se l flocking. A specified amount of torque rnust be a p p l i e d t o m o v e t h e m , I f t h e 'r b r e a k a w a y " to r q u e
Cylinder Heod,Volve, Volve Troin Service -_= below accepted limits, change the screw F.g. 105) or the nut (Fig. 104) as the case :nay be. If a lock nut adjusting screw is used, loosen . :he nut, adjust the screw, and while hotding the screw, firmly tighten the nut. After tightening, r ec hec k v alv e c l e a ra n c e , F i g . 1 3 _ 1 0 ? .
Reface a1l valves. Reject any that will not clean up and those with insufficilnt margin. An interference angle may be used. Dress stones, Smooth and chamfer stem end. Stem musr not be worn beyond limits. Check valve stem to guide clearance. If ex_ cessive, replace guides or ream for an oversize sJem. When replacing guides, be certain to get the proper guide, right side up, in the correct hole. Drive in to the specifieJ distance. Some guides require reaming after installation. To prevent excessive oil consumption, seals are often used on the guides, and on ihe stem of both intake and exhaust valves. Cracked or burned seats can be repaired by installing a valve seat insert. Grind válve seat, at eorrect angle, until cleaned up. Narrow seat to specified width by using a 15 _ 30 deg. stone on the top and in some cases, a 60 _ ?0 deg. stone on the bottom. Test seatforconcentricity. Keep stones properly dressed. Remove no more metal than necessary.
F i , g . l 3 - 1 0 7 . A d j u s t vo lve c/e o ¡ o n ce . No r e u se o Í lo c k nuts on a d j u s f m e n fs c Í e w s . fá e scr e wd r ive r e n g o g e st[e o Jfu sr ment screw w h i l e ¡ h e w r e n ch g r o sp s ¡ h e lá ci n u ¡ . lÁ".r ""1
CHANGINGVALVE SPRINGHEAD ON ENGINE Bring the piston to TDC on the compression stroke (both valves closed). Remove the spark :1ug and insert an air hose adapter. Admit full ='r pressure to the cylinder. A_fter moving the :ocker arm out of the way, the spring may be :ompressed and the keepers removed. A new or a valve guide sea1, may be installed. _a1"g I{EEP AIR PRESSURE TO TIIi CYLINDER ;-]\-TIL THE VALVE SPRING IS REPLACED -L\D TIIE KEEPERS INSTALLED, Fig. 18_108. S UM M A RY Never remove a cylinder head when hot. Re_ =:ove rocker arm assembly brackets evenly, a couple of turns on one, the same on the others. Loosen head bolts a titile at a time in the reverse order of the tightening sequence. Keep lifters, push rods, valves and rocker arms in order so that they may be replaced in :fie same location. Head, valves, guides, etc., mustbethorough_ -l.¡- cleaned. Do not scratch aluminum head surface s.
Fi g. l 3-108.. R ernovi ngvol ve spri ng cssembl y w i th the heod on engi ne. N ote use oÍ oi r hose odopfer i n the spork pl ug hol e,
(G.M.c.)
Replace broken, loose or damaged r o cke r arm studs. If loose, ream and install a n o ve r _ size stud. C h e c k v a l v e 's p r i n g s f o r s q u a r e n e s s , t e n si o n , rust or nicks. Replace any that show the SLIGHTEST defect. Using an accurate straightedge, c h e c k cyl i n _ der head for warpage. Lubricate and install valves. C h e c k ste m height above head. Install .springs, closed coil end against head. Check installed spring height. Add insert under spring against head, iinee¿ed. Check stem seal with suction cup. Block surface must be clean a n d a c cu r a te .
221
G--
Auto Service ond RePoir
with a THIN coat of Coat gasket, Ilen-reguired, end forcement. Place right side up, correct ward, on bloek. Using guide pins, lowerheadinto position. Head bolts and holes in block must be clean and coated with thread compound. Torque head. arm ends that contact valve. Grind rocker shaft. Inspect ball or cup Check fit on rocker end. Push rods must be clean, straight and smooth on the ends. True up mechanical lifters on a valve grinder. clean, inspect and reassemble Disassemble, the parts When assembling, lifters. hydraulic Lubricate andinstall. Lubricate must be CLEAN. and install rocker arms on shaft. Make certain and that rocker end forward shaft has correct oil holes face towards the head (usual). Tighten shaft brackets slowly and evenly. This will allow to leak down. Rocker arm lifters the hydraulic screws should be adjustment valve clearance backed off. Use atorque wrenchforfinaltightening. The ends ofthe lifters, pushrods, and rocker arms should be lightly coated with lubricant' When an adjustment isprovided, centerlifter adjust valve lifters, With mechanical plunger. In both cases, arm clearance. stem to rocker must be on cam base circle. When engine lifter head should be retorqued warm, is thoroughly and the valve clearance reset. Aecurate angles, clearances andfits, coupled with absolute cleanliness, are absolutely essential to a top notch valve service job. athorCHECK LIST: If you have performed ough job, you will be able to answer each of the following questions with a definite YES. VALVE: 1. Is the valve face clean, smooth and correctly angled? 2 . Is the m ar gin 7132 í n. or lar ge r ? 3. Is the stem smooth and free of excessive wear, nicks, etc. ? Is the stem endground square and slightly chamfered? 5. Are the keeper grooves cleanandingood shape ? 6. Is all earbon,
gum, etc-, removed?
SEAT: 1. Is the seat smooth, clean and correctly angled ? 2. Is the seat width as specified by manufacturer ? 3. Does the seat contact the eenter of the valve face ? with the guide ? 4. Is the seat concentric
5.. Is seat runout within .002? th e h e a d ? 6. If an insertisused,isittightin ?. Is the seat width constant all the way around ? HEAD: after cooling 1. Was the head removed down?
Is the head immaculately clean, inside and out? a Is any di.stortion within limits ? 4. Is the head to block surface free of scratches, dents, etc. ? 5. Is the head free of cracks? If any were found, were they rePaired? Is the head gasket correctly installed? 7. If cement was used, was a THIN coat applied ? B. Is the head proPerlY torqued? GUIDES: 1. Is guide wear within limits? 2. If guide was replaced, was it correctly installe d ? 3. If guide was reamed, does it have the correct cl earance? 4. If guide seals were used, are theyproperl y i nstal l ed? ROCKER ARMS: 1. Is the end contacting the valve stem smooth and accuratelY ground? oil holes are used, aretheyopen? Where -2. 3. Is the rocker shaft or ball stud bearing surface smooth and within wear limits ? 4. Is the push rod ball or socketendsmooth and free of wear? 5. Is the rocker correctlyinstalled and does it contact the valve ProPerlY? 6. ls the rocker clean? ROCKER SHAFT AND BALL STUDS: 1. Is the rocker shaft clean - inside and out? 2. Are the rocker armbearing areas smooth and within limits ? 3. Is the correct end of the shaft forward? 4. Do the rocker arm oil holes face in the eorrect direction? Are the shaft brackets in the correctloeation, torqued and free of cracks ? o. Is ample oil reaching the assemblY? 7. If an overflow pipe is used, is it correctly located? B . Are the ball studs tight in the head? q Are the ball stud adjusting nut threads in good shape ? the ball stud nuts within breakaway Are 10. specs ? t
h
222
Cylinder Heod,Volve, Vqlve Trqin Service
rocker arm valve 11. Are the self-locking clearance adjusting screws within breakawa y spe c s ? PUSH RODS: 1 Are the rods straight? 2 Are rod ends smooth and free of exces-
a
sive wear ? If the rods camy oil, is the hollow section thoroughly clean? 4 Is the correct end uP? Are bo th ends in pr oper c ont ac t ? o . Are the rods, if no elearance adjustment is provided, the correct length? LIF TERS: been trued 1. Have the mechanical lifters
b. Loosening each bracket, in turn, a 1ittle until all are loose. c. Loosening the front end first. d. Leaving one bracket tight until all others have been loosened. Remove cylinder head bolts in the reverse order of the tíghtening sequence. True or False ? I t i s n e c e s s a r y t o k e e p a l l p a r t s i n or d e r because: (Circle best answer) a. They may be lost. b. They can be kept in a smaller area. c. It is important they be returned to their original positions. d. It is just a good habit. with: stones are dressed Valve grinding (Circle best answer)
a
on the grinder? Are ends and side smooth and free of wear, galling, etc. ? bore clearance to lifter 3. Is the lifter co rrect ? immaculately lifters 4. Are the hydraulic clean and in good condition? 5. Have the hydr:aulie lífters been checked for leakdown? VALVE LASH OR CLEARANCE: are used, is the lifters 1. If mechanical valve stem to rocker arm clearance as specified ? 2. Was the clearance rechecked afterthorough engine warmup and head retorquing ? 3 . Was the lif t er on t hebas ec ir c lewhent h e clea ran ce was s et ? 4. Are all adjustment screws and locknuts tight ? are used, were they lifters 5. If hydraulic set so that the plungers are near the center of their travel? G E NERAL : 1. When possible, were all parts replaced in the locations from which they were 2.
a. A fi1e. b. Another stone. c. A diamond. d. A hardened steel rod. to keep wheels dressed o. It is most important because: (Circle best answer) a, They cut faster. b. They will produce accurate angles. c. They wear longer. d. They look better. 7. When the valve is groundatasllghtlydifferent angle (about one degree) than the seat, is produced. an--fit 8. When grinding the valve face: (Circle best answer) a. Keep the valve in the center of the stone. b. Move the valve back and forth - staying on the stone. - off both c. Move the valve back and forth sides of the stone. d. Keep the valve on the right hand side of the stone. 9. To control stem height above the head, it is end. necessary to grind the 10. Explain how valve stem to guide clearance
removed? 2. Were all parts thoroughly cleaned? 3. Were allparts properlylubricatedbefore assembly.
is checked. valve stem to guide clearby it may be corrected an or by-for -guides stem. * -valve 12. Seals are often used on both the-ahd the valve_, 13. Exeessive exhaust valve to guide clearance oil consumption. will cause considerable False ? True or t4. A cracked valve seat can often be repaired
11. Where excessive ance
OUIZ - ChoPter13 Cylinder heads should be HOT, COLDbefore removing. Circle one. arm assembly by: (Circle Remove rocker best answer) a. Loosening each bracket allthe waybefore going to the next one.
is
present,
by installing
223
an---
Auto Service ond Repoir
15. Common
valve
26. To facilitate accurate head, gasket andblock alignment, used _shouldbe when installíng the head. 27. The rocker arm end that contacts the valve should be ground smooth and FLAT. True or Fal se? 2R Hydraulic lifter parts are all very accurately made and are thus all interchangeable. True or Fal se? 29. Following cleaning and reassembly, hydraulic lifters should be tested for_. 30. All valves, lifters, push rods, rockers, etc., should always be installed in the same spot from which removed. True or False ? 31. The rocker arm brackets, once the push rods are installed, should be drawn down to the head as rapidly as possible. True or False ? 32. Rocker shaft rocker arm oil holes usually face: (Circle best answer) a. Away from the head. b. Toward the head. c. Sideways. 33. Hydraulic Iifter plungers should be about in the center of their travel when properly installed and adjusted. True or False? 34. When adjusting valve clearance, the lifter should be on the nose of the cam. True or False ? 35. Excessive valve clearance will: (Circle best answer) a. Increase horsepower. b. Cause early valve opening. c. Prolong the life of the valve. d. Cause late valve opening and alowerlift. 36. Valve clearance ean be checked with a or a_
seat angles are-and
-d eg r ees . 16. A valve seat that is too wide will: (Circle be st ans wer ) a. Pack with carbon, start to leak andburn. b. Run too co1d. c. Break the valve stem. d. Be hard to open. 1?. The valve seat should engage the valve face near the 18. To narrow a valve seat, metal moved from the top witha
shouldbe re-
or degree stone. 19. Once the valve seat stone is dressed, approximately twelve seats may be ground before dressing again. True or False? t(r The pilot for the seat stone sleeve shouldfit the guide . 2t. The valve seat must be concentric with the guide ho1e. True or False ? 2 2 Seat runout should be kept within: (Circle
I
Ir
1., :,,,
best answer) a. . 0 0 2 . b. . 00 6 . c..020. d. . 0 0 0 3 . 23. Vatve springs should be tested for a nd - . 24. Excessive valve spring installed height can cause: (Circle best answer) a. Heavy spring tension. b. Valve float. c. SIow valve timing. d. Seal damage. . /5. Gasket cement must ALWAYS be applied to the head gasket. True or False?
TE LE S C OP IN G VALVE GA U GE
GUIDE
3/8-tNCH mml
Fi s. l 3-110. Fig. l3-109. l!sing o dial indicotor to cf,eck volve lift m e o su r e m e n l. lAm e ¡ ico n M o tors)
224
F
C l recki ng vol ve gui de i nsi de d i ameter w i th o tel escoping gouge. lAme¡icon lloto¡s)
