1972 Chevrolet 40-60 series Truck Supplement service manual

40-60 SERIES TRUCK SUPPLEMENT

SERVICE MANUAL

1972 CHASSIS SERVICE MANUAL SUPPLEMENT

NAME

SECTION

0 3

LUBRICATION FRONT SUSPENSION

c o v e r in g

4

REAR SUSPENSION

SERIES 40-60 CHEVROLET TRUCKS

5

BRAKES

FO R EW O R D

This manual is a supplement to the 1971 Series 40-60 Truck Service Manual. It includes procedures for main­ tenance and adjustments, minor service operations, and removal and installation for components of Chevrolet Series 40 through 60 Trucks. Procedures involving disassembly and assembly of major components for these vehicles are contained in the 1972 Chevrolet Passenger Car and Series 10-30 Truck Overhaul Manual or the 1972 Series 40-60 Truck Overhaul Manual Supplement.

This manual should be kept in a handy place for ready reference. If properly used, it will enable the technician to better serve the owners of Chevrolet built vehicles.

All information, illustrations and specifications con­ tained in this literature are based on the latest product information available at the time of publication approval.

The right is reserved to make changes at any time without notice.

CHEVROLET MOTOR DIVISION General Motors Corporation DETROIT, M ICHIGAN ©

SECTION INDEX

1 9 7 2 General M otors C o rp o ra tio n

6A

GASOLINE ENGINES

6D

ENGINE MOUNTINGS

6K 6M

ENGINE COOLING SYSTEM

6T

AIR COMPRESSOR AND GOVERNOR

6Y

ENGINE ELECTRICAL

ENGINE FUEL SYSTEM

7

TRANSMISSIONS AND CLUTCHES

9

STEERING SYSTEM

&TIRES

10

WHEELS

11

SHEET METAL

12

CHASSIS ELECTRICAL AND INSTRUMENTS ALPHABETICAL INDEX

P r i n t e d in U . S . A .

Sec. 0 Page 1

SECTION 0

Jluhnicatio-n A ll inform ation contained in S erv ice Manual S T -331-71 under LUBRICATION (SEC. 0, Page 1 through 12) w ill apply to v e h ic le s cov­ e red by th is publication. The follow ing inform ation w ill a lso apply:

TRANSMISSION CAPACITY CHART Manual T ran sm issio n SM465 NP435 NP540 NP542 CL282 CL285 CL325 CL327 SP5652 SP5752 SP5756

U.S. 8 7 9 10 12 12 14 14 13 15 15

IMP.

Autom atic T ra n sm issio n MT40 MT41 AT475 AT540

18* 18* 10* 22*

15 15

6% 5% U 8%

10 10 11% 11% 10% m 12%

8l4

18%

* F ilte r Change Only.

A uxiliary T ra n sm issio n SP6041 SP7041

8 11

6% 9%

ENGINE OIL (SYMBOL “ E” ON CHARTS)

*

ENGINE OIL It is recom m ended that new engines should have the fir s t o il change at 3,000 m ile s, thereafter at 3 months or 4,000 m ile in terv a ls. T his drain in terval may be in crea sed or d ecrea sed depending upon the se v e r ity of se r v ic e and exp erien ce with sp e c ific o ils or the recom m endations and used oil a n a ly sis a s furnished by the su pp lier. Such a p ro ­ cedure would be helpful in estab lishing the m ost p ra ctica l o il change period for the p articular s e r v ic e . R efer to S erv ice Manual S T -3 3 1 -7 1 .

Contaminated engine o il can cau se a m alfunc­ tion of valve lifte r s or the PCV valv e. A sticking v alve lifte r can cause leakage of unburned g a se s through the valve. A plugged or stickin g PCV valve w ill affect carburetor m ixture and w ill prevent p roper crank case ventilation.

ENGINE OIL FILTER O il filte r should be replaced at the fir s t oil change and each oil change th ereafter to filte r sm a ll p a rtic les which could affect valve lifte r s or PCV valve action.

RECOMMENDATIONS The oil industry m arkets various types of en­ gine o il under certain se r v ic e designations and sp ecifica tio n num bers.

The se le c tio n of a relia b le supplier, with c lo se attention to h is oil and filte r elem ent change r e c ­ om m endations can provide sa tisfa cto ry lubrication and longer life for engine.

G asoline and D ie se l Engines U se only high quality o ils which are intended for S erv ice D esignations "MS” and "DM” (SE/CC New A .P .I. D esignation) s e e NOTE. The follow ing additive lim itation s, w hich r e ­ quire em phasis, have been p laced on the r e c o m ­ mended M IL-L-2104B (now su p ersed ed by M IL -L 46152) and Supplement 1 oils: 1. Sufficient zinc dithiophosphate to produce a m inim um of 0.07 and a m aximum of 0.10 per cent by w eight.

2. Sulfated ash (ASTM D -874) of 1.00 p er cent m axim um by w eight, except lubricants that contain only barium d eterg en t-d isp ersa n ts w here 1.50 per cent by weight is allow ed.

NOTE: Supplement 1 engine o ils (based upon now ob soleted M IL-L-2104A) have been su p ersed ed

by M IL -L -2104B engine o ils . H owever, Supplement 1 engine o ils MS-DM (SE/CC New A .P .I. D e s ig ­ nation), with a history of sa tisfa cto ry perform ance a r e availab le, and may be u sed .

The u se of proper engine o ils and o il change in terv a ls are your b est assu ra n ce of continued r e ­ liab ility and perform ance from your engine.

IMPORTANT: N on-detergent and other low er quality engine o ils are sp e c ific a lly not r e c o m ­ mended.

POWER STEERING FLUID (SYMBOL "S32” ) GM Approved H ydraulic P ow er Steering Fluid is available through w h olesale w arehouses and truck

Sec. 0 Page 2

LUBRICATION c e n te r s. Check fluid le v e l every 6,000 m ile s or 4 m onths, w hichever o ccu rs fir s t. F ill pump r e s e r ­ voir to proper le v e l. If GM Pow er Steerin g Fluid is not available, DEXRON® Autom atic T ra n sm ission F luid (Symbol S I 9) may be used.

CAUTIO N: DO NOT use G M Power Steering Fluid in automatic transm issions.

AU TO M ATIC TRANSM ISSIO N FLUID (SYMBOL “SI 9 ” O N CHARTS)

ENGINE A N D ACCESSO RY LUBRICATION The follow ing additional inform ation applies to Lubrication Chart (fig. 4) on page 7 of S T -331-71 S er v ic e Manual.

CARBURETOR AIR CLEANER ELEMENT

A ir clean er should be inspected and se r v ic e d at in tervals sp ecified in E m issio n Control System (R efer to S erv ice Manual S T -3 3 1 -7 1 ) booklet, or m ore often under s e v e r e dust conditions, O il le v e l in the autom atic tr a n sm issio n m ust a lso , whenever dirt is v isib le in elem ent or o il. be checked at each engine o il change. Under norm al driving conditions the tr a n sm issio n fluid should be POWER STEERING RESERVOIR changed every 24,000 m ile s. Under unusual condi­ tion s such as o ff-road (construction) or constant Fluid le v e l should be checked every 6,000 stop and go driving (pickup and delivery) fluid m ile s and filled with S32 P ow er Steering Fluid, or should be changed at 1 2 ,0 0 0 -m ile in te r v a ls. It is if not available with S19 Autom atic T ra n sm ission im portant that tr a n sm issio n fluid le v e l be m ain­ Fluid. tained at the full m ark and NOT OVERFILLED.

Sec. 3 P age 3

SECTION 3 S u d s K t& n d A X U l

SECTION 3A fy n x w

U

A

U

<

f* u n e +

tt

A ll inform ation and alignm ent in stru ction s in S erv ice Manual S T -331-71 "FRONT END ALIGNMENT” (SEC. 3A) are applicable to m odels co v ered by th is supplem ent.

SECTION 3B

A xle.

A ll front axle inform ation in S erv ice Manual S T -331-71 "FRONT AXLE” (SEC. 3B) is applicable to m odels covered by this supplem ent.

A ll front axle inform ation for the F -120 axle is a lso applicable to the F -110 ax le. Illu stra tion s and sp e cific a tio n s have been updated.

1 Steering Knuckle Spindle 2 Kingpin Bushing (Upper) 3 Kingpin 4 Cap Screw 5 Kingpin Bearing Cap (Upper) 6 Gasket 7 Lube Fitting 8 Shim

9 Axle Center 10 Stop Bolt and Lock Nut 11 Draw Key 12 Thrust Bearing 13 Tie Rod End A ssy.

14 Kingpin Bearing Cap (Lower) 15 Gasket 16 Kingpin Bushing (Lower) t-8793

Fig u re 1—Steering K n uckle (F070 A x le )

1 Steering Knuckle Spindle 2 Steering Knuckle Bushing 3 Kingpin Bushing (Upper) 4 Kingpin 5 Dust Cap 6 Kingpin Nut 7 C otter Pin 8 Gasket

9 10 11 12 13 14 15 16 17

Lube Fitting W ashers or Shim s A xle C enter Stop B olt and Lock Nut Thrust B earing T ie Rod A ssem b ly Plug R etainer Ejqpansion Plug Kingpin B ushing (Lower) t-8794

Figure 2 —Steering K n uckle (F090 A x le )

S ec . 3 P ag e 4___________

T ro nt axle

1 Steering Knuckle Spindle 2 Steering Knuckle Bushing 3 Kingpin Bushing (Upper) 4 Kingpin 5 Cap Screw 6 Dust Cap 7 Kingpin Nut 8 Cotter Pin

9 10 11 12 13 14 15 16 17 18

Gasket L u b e Fitting Spacers or Shims Axle Center Stop Bolt & Lock Nut Thrust Bearing Tie Rod End A ssy.

Plug Retainer Expansion Plug Kingpin Bushing (Lower)

T-8795

Figure 3 — Steering Knuckle (FI 10 an d F I 20 Axles)

AXLE SPECIFICATIONS F050-F055

F070

F090

F110—FI 20

6.3594”

7.8906”

8.750”

8.750”

1.1090”— 1.1094” 1.1090”— 1.1094”

1.2492”— 1.2496” 1.2492”— 1.2496”

1.1855”— 1.1865” 1.14330”— 1.14340”

1.1855”— 1.1865” 1.4330”— 1.4340”

—

—

1.9063”

1.9063”

— —

— —

1.4330”— 1.4340” 1.1870”— 1.1880”

1.4330”— 1.4340” 1.1870”— 1.1880”

1.3438” 1.3438” 1.1094”— 1.1124”

1.875” 1.875” 1.2496”— 1.2526”

1.709”— 1.729” 1.990”— 2.010” *1.4365”— 1.4375”

1.760” 2.150” 1.434”— 1.437”

STEERING KNUCKLE TO AXLE CENTER CLEARANCE

0.005”

0.005”

.004”— .012”

.004”— .012”

SPACING WASHERS AVAILABLE

—

—

SPACING SHIMS AVAILABLE..

0.005”

0.005”

0.005” 0.010”

_

King Pin Nut ...........

_

_

250 Ft. Lbs. then Advance to Next Cotter Pin Hole.

250 Ft. Lbs. then Advance to Next Cotter Pin Hole.

King Pin Bearing Cap, Cap Screw . ...............

4 - 5 Ft. Lbs.

5 - 6 Ft. Lbs.

3 - 5 Ft. Lbs.

3 - 5 Ft. Lbs.

AXLE MODEL KING PIN Length .................

Diameter At Top ...............

At Bottom ...........

KING PIN BUSHING Length .................

Diameter Outer . ...............

In n e r.................

STEERING KNUCKLE BUSHING* Length .................

Upper ................

Lower ................

I.D. When Installed ....

.114”— .116” White .114”— .116” White .121”— .123” Yellow .121”— .123” Yellow .128”— .130” Blue .128”— .130” Blue

TORQUE SPECIFICATIONS

* Ream after Installation

SECTION 3C fy n &

n t S fJ S U w a A .

A ll inform ation on Front Springs contained in S erv ice Manual S T -3 3 1 -7 1 “ FRONT SPRINGS" (SEC. 3C) is applicable to m odels co v ered by this supplem ent. The follow ing “ Torque S p ecification s” chart has been updated.

TORQUE SPECIFICATIONS

Spring U -B olt ( N u t ) ................................................. . .

C -M -S M odels (F t.-L b s.)

T Models (F t.-L b s.)

105 - 130

190 - 210

Spring U -B olt ( N u t ) ................................................. . . *175 - 250

-

Spring Hanger to F ram e B olt (N u t ) ..................

60-85

35 - 45

Spring Bumper to Fram e Bolt (Nut)

...............

14-22

35 - 45

Spring Bum per to Fram e Bolt (Nut)

...............

2 -3

-

190 - 210

150 - 200

**

Spring Front Eye B olt ( N u t ) .............................. . .

20 - 25

Spring R ear Rebound Pin R etainer (Bolt) . . .

Spring R ear Rebound Bolt ( N u t ) ........................

75-95

-

Shock A bsorber B racket to Fram e B olt (Nut) . .

40-50

65 - 95

Shock A bsorber Upper and Lower Eye B olt (Nut)

65 - 95

40 - 50

130 - 190

-

Shock A bsorber Stud to Fram e ( N u t ) ................ * 9,000 and 11,000 lb. A xles Only. ** 366 and 427 V8 Gas E ngines.

SECTION 3D c J lu b i

a n d QeasUnGA.

A ll inform ation in Service Manual S T -331-71 “ FRONT HUBS AND BEARINGS” (SEC. 3D) is applicable to m od els covered by this supple­ m ent. The follow ing rev isio n w ill a lso apply:

CLEANING, INSPECTION, AND REPAIR REPAIR Brake Drum R eplacem ent 1.

Demountable Type. The demountable type drum may be se p a r ­ ated from the hub and rem oved from the veh icle without disturbing the hub. The drum is held to the hub by the w heel studs and nuts as shown in figure 4.

Sec. 3 P a ge 6

FRONT HUBS A N D BEARING S

1 2 3 4 5 6

7 8

9 10 11 12 13 14 15 16 17 18

Side Ring Lock Ring Wheel W heel Stud Nut W heel Stud B rake Drum Hub Cap Screw & W asher B earing Cone and R oller A ssy . (Outer) B earing R etainer Adjusting Nut W asher Adjusting Nut Hub Cap Cotter Pin Backing P late Inner O il Seal B earing Cone and R o ller A ssy . (Inner) Spindle

T-91 15

Figure 4 — Front H u b and Bearing with D em ountable W heel an d Drum

S ec. 4 P ag e 7

SECTION 4 ( le a / i S u A s n e t t & io s t A ll inform ation contained in S erv ice Manual S T -331-71 is ap­ p lica b le to m odels covered in th is supplem ent. The follow ing inform a­ tion w ill a lso apply:

SECTION 4A (lean. AxleA. a n d G ottisioh IMPORTANT When parking v eh icle equipped with a tw o- or th re e-sp e ed axle, the axle should be shifted into LOW range with engine running. Engage clutch and tra n sm issio n to be su re axle has com pleted sh ift into LOW range. Apply parking brake, p lace tra n sm issio n in neutral and shut off engine. When leaving the veh icle parked or unattended the p reviou s in ­ stru ctio n s m ust be followed:

VACUUM SHIFT SYSTEM MAINTENANCE AIR CLEANER A ir clea n er rem o v es dirt p a r tic le s from at­ m osphere which p a s s e s into the control valve and other u n its. A ir clean er should be rem oved and cleaned at regular in terv a ls.

SERVICING AIR CLEANERS (R efer to F igu re 1) The a ir clea n er u sed on Conventional and S50 M odels is the m etal cup type which u se s a hog's hair type elem en t. T his cup is a friction fit on the a ir intake pipe and can be rem oved by pulling straight off. It can be cleaned by rinsing in a su it­ able solvent and reu sed . R efer to LUBRICATION (SEC. 0) in th is supplem ent for se r v ic e in terv a ls.

If clean er has becom e so laden with an accum ula­ tion of dirt, that sa tisfa cto ry cleaning cannot be done, rep lace with a new clean er.

HAIR TYPE ELEMENT PLASTIC H O U S IN G

SYNTHETIC ELEMENT

The air clea n er used on a ll T ilt-C ab Models is a p la stic en cased, synthetic elem ent type filte r , and cleaning is NOT recom m ended. When cleaner b eco m es so laden with dirt, that tapping it against so m e so lid su rfa ce (such as a work bench) w ill not rem ove foreign m atter, then a new cleaner should be in sta lled .

IMPORTANT: DO NOT OPERATE VEHICLE WITH AIR CLEANER DISCONNECTED OR RE­ MOVED.

)

T-9142

F ig u re 1—A ir C lea n ers

Sec. 4 P a ge 8

SECTION 4B

(lea l BpAitUfi an d Suifiesutiott HEN DRICKSO N T AN D EM REAR SUSPENSION R efer to S erv ice Manual S T -331-71 "REAR SPRINGS AND SUS­ PENSION” (SEC. 4B), p ages 4B -7 and 4B -8 for fig u r es 9, 11 and 12.

EQ U ALIZIN G BEA M REM O VA L A N D REPAIR The follow ing p roced u res cover rem oval and installation of eith er equalizing beam without r e ­ moving any other units of the su spension sy stem .

When rem oving an axle a ssem b ly , accom p lish only ste p s required to lo o sen axle at each end of beam .

EQUALIZING BEAM REMOVAL (F ig. 9) 1. R a ise and support fram e to rem ove weight from beam s.

2. At axle b rack ets, rem ove nuts (5), w ash ers (7), and bolt (1). P ry adapters (2) from bushings and b rack ets.

3. With blocking under beam c r o s s tube (fig.

1) to support weight of beam s, rem ove saddle caps attached with four nuts and flat w a sh ers.

4. Low er the c r o s s tube and b eam s, then slid e beam s from tube ends.

EQUALIZING BEAM INSPECTION 1. Inspect beam end bushings and beam center bushing for evidence of damage or deterioration of the rubber. If any damage is evident, rep lace bush­ in gs as d irected under "Equalizing B eam Bushing Replacem ent" la ter in this sectio n .

2. Inspect c r o s s tube and thrust w ash ers and rep la ce if bent or worn.

1 2 3 4 5

Beam Center Bushing Spring Saddle Spring A ssem bly Spring Saddle Top Pad Top Pad to Spring Saddle B olts 6 Lock Nut

7 8 9 10 11 12 13

EQUALIZING BEAM BUSHING REPLACEMENT P r e s s old bushing out, using a suitable driver or p r e s s to exert fo rce on bushing outer sle e v e .

P r e s s new bushing into p la ce, exerting fo rce on bushing outer s le e v e until outer sle e v e extends an equal distance through beam at both sid e s.

EQUALIZING BEAM INSTALLATION (R efer to Fig. 9) 1. P osition beam s, with c r o ss tube and thrust w ash ers in p lace at spring sad d les and axle brackets.

NOTE: At axle end of beam , in sta ll adapters (2, fig. 9) at each sid e of bracket and into bushing.

IMPORTANT; The cu t-off (flat) sid e of each adapter must be located in a vertica l position as shown in figure 11.

2. Install bolt and w asher through adapter and axle bracket at each end of equalizing beam (fig. 11).

NOTE: Install bolt and w asher from inner sid e with nut located toward w h eels (fig. 11). Tighten nuts or bolts to torque liste d in "Specifications" at end of this sectio n . Figure 12 shows section through mounting.

3. Install spring saddle caps to attach beam cen ter bushing to spring saddle. Install saddle cap stud nuts or cap sc r e w s and tighten to torque liste d in "Specifications" at end of this section .

Setscrew Equalizing Beam C ross Tube Spring Saddle Cap Stud Thrust Washer Bushing

Figure 1— Section Through Spring Saddle an d Beam

Sec. 5 P age 9

SECTION 5 lin & k e A , A ll inform ation in this sectio n in S erv ice Manual S T -331-71 a lso applies to v e h ic le s covered by this supplem ent, except as sp e c ific a lly stated in the follow ing procedures:

SECTION 5A < M

-t^ d n < u c U c

BRAKE SYSTEM MAINTENANCE

'la h e i.

Two vacuum gauges are used oft som e v e ­ h ic le s . Two gauges are standard equipment on all

sch ool buses (d u al-sp lit-b rak e system ) and optional on a ll other v eh icles equipped with dual (split) brake sy ste m s. T hese gauges are mounted on a sp e c ia l bracket below the center of the dash panel.

One gauge is connected to one vacuum sy ste m of the dual brake sy stem and the other gauge is connected to the other vacuum sy ste m . Vacuum gauge readings may differ during operation of the v e h ic le . However, if the readings differ by ten in ch es of m ercury or m ore for an extended p eriod of v eh icle operation the vacuum sy ste m s should be checked im m ediately to determ ine c a u se s. If the vacuum gauge is su sp ected of being faulty, check gauge according to instructions in S erv ice Manual S T -3 3 1 -7 1 , page 5A -22. O therw ise, check vacuum sy stem com ponents for leak s or m alfunctions.

Figure 1—B ra k e Fluid Sticker

Figure 2—M aster C y lin d e r C o v e r

CHECKING FLUID LEVEL A stic k e r (fig. 1) reading "CHECK BRAKE FLUID LEVEL EVERY 30 DAYS OR 3000 MILES” is affixed to the cover of each brake m aster c y l­ ind er. F igure 2 illu str a te s a typical cover with the stic k e r applied.

Fluid le v e l should be maintained to within V2" of top of m aster cylinder r e se r v o ir .

VACUUM GAUGE

)

B

■

Se c . 5 P a ge 10

SECTION 5B A i/ i B 'la k e i BREATHER A N D FILTER ASSEMBLIES F igu res 1 and 2 illu stra te three different breather and filte r a sse m b lie s. F igure 1 (left view) show s the origin al type b reather. R eplacem ent is co vered in S erv ice Manual S T -331-71, page 5D -89.

To rem ove the interm ediate type filte r (fig. 1, right view ) or the la te st type (fig. 2), rem ove two s c r e w s and lift co v er and filte r off housing. To in sta ll, se t filte r in p la ce on housing and attach cov er. F ilte r s can be cleaned and reu sed but breath er cannot. If rem oved, breath er m ust be rep laced with new p a rts.

AIR LINE TORQUE R efer to page 5B -53 of S erv ice Manual ST331-71 and change the follow ing torque values: 3 /8 -in c h from 30-50 to 50-75 }£-inch from 90-115 to 120-150 5 /8 -in c h from 100-125 to 150-200 A lso change the statem ent "retorque to higher than minimum value" to read: "Retorque to higher value."

Figure 2— Filter Installed

i

Sec. 6A P age 11

SECTION 6A Q a d -a lln e . C n c u n e A , The inform ation pertinent to truck m odels covered by th is Supple­ ment is the sam e as given in S erv ice Manual S T -331-71 (pages 6A-1 thru 6A -34) with the follow ing excep tion s an d /or additions:

ENGINE MAINTENANCE Inspection, adjustm ent or replacem ent of e m is­ sion control related com ponents m ust be perform ed on a tim e or m ileage b a sis as indicated. Good judgment is required in replacem ent of parts in th ose c a s e s w here the accum ulated m ileage is substantially low er during the sp ecified tim e period.

SERVICING AIR CLEANER A ir c lea n ers should be inspected and ser v ice d every 12,000 m iles or m ore often under se v e r e dust conditions; a lso , w henever dirt is v isib le in elem ent or o il. R efer to "AIR CLEANERS” (SEC. 6M) of th is supplem ent or S T -331-71 S ervice Manual.

IMPORTANT: V ehicle operation under condi­ tion s such a s heavy dust, continuous short trip s, stop and go driving, e tc ., is not con sidered norm al u se and th erefo re m ore frequent m aintenance w ill be required. Such additional m aintenance req u ire­ m ents are included below w here applicable.

T h erm ostatically C ontrolled A ir C leaner The air clean er should be inspected to make certain that a ll h o ses and ducts are intact and co r ­ rectly in sta lled . Operational function should be checked by inspecting position of valve in air intake.

With engine stopped, valve should be open. At underhood tem perature below 100°F ., with engine running, valve should be p artially or fully closed .

A s engine underhood tem perature r is e s , the valve should open.

CHECKING DRIVE BELTS Fan belt tension on v eh icles equipped with V -b elts should be adjusted to 120 - 130 pounds on new b elts using B T -3 3 -7 3 F B elt T ension Gauge.

U sed drive V -b elts should be adjusted to 80 - 90 pounds. Gauge should be placed at center of the g rea test span.

IMPORTANT: A fter a belt has been in oper­ ation one hour or approxim ately 50 m ile s, it is consid ered u sed . B elt d ressin g can be used to ex ­ tend belt life . When V -b elts are worn they should be rep laced , as e x c e s s iv e tightening w ill not p re­ vent slippage and can cause damage to b earings.

SPARK PLUGS R eplace spark plugs at 12,000 m ile in ter v a ls.

U se of leaded fu els re su lts in lead d ep osits on spark plugs and can cause m isfirin g at m ilea g e s le s s than 12,000 m ile s. Where m isfirin g o ccu rs prior to 12,000 m ile s, spark plugs in good condition can often be cleaned, tested and r ein sta lled in an engine with acceptable r e su lts.

ENGINE COMPRESSION Minimum com p ression recorded in any one cylinder should not be le s s than 70% of highest cylin d er. For exam ple, if the highest p r e ssu r e in any one cylinder is 150 lb s ., the low est allow able p r e ssu r e for any other cylinder would be 105 lb s.

(150 x 70% = 105).

This test should be perform ed to provide r e a ­ sonable assu ran ce that engine condition is su ffic ­ iently efficient to prevent leakage of unburned g a s e s . If a problem e x is ts , have co r re ctio n s m ade.

DISTRIBUTOR POINTS, CAM LUBRICATOR D istributor points should be inspected p rio r to perform ance of tune-up adjustm ents. Burned or pitted points must be replaced. P oints in good con­ dition may be reu sed after readjustm ent and the installation of a new cam lubricator. New points and cam lubricator should be in stalled at le a st every 24,000 m ile s.

DISTRIBUTOR CAP The interior and ex terior of the distributor cap should be carefully inspected and cleaned to prevent m isfirin g and deterioration.

SPARK PLUG WIRES Inspect spark plug w ir es for evidence of ch eck ­ ing or cracking of exterior insulation and a tight fit in the distributor cap and at the spark p lu gs.

E xterior of w ir es should be cleaned, any evidence of corrosion on ends rem oved and w ire rep laced if deteriorated .

TIMING, POINTS (DWELL), IDLE SPEED T hese adjustm ents must be p erform ed a cc u r ­ ately, following the sp ecifica tio n s shown on the label under the hood. A djustm ents must be made with te st equipment known to be accurate.

S e c . 6A Page 12

G A SO LIN E ENGINES

FLYWHEEL H O U SIN G ADAPTER

12 months or 12,000 m iles (whichever o ccu rs first) when the v eh icle is used under the follow ing conditionsi • D riving in dusty conditions.

• E xtensive idling.

• Short trip operation at freezin g tem p er­ atures (engine not thoroughly w arm ed up).

POSITIVE CRANKCASE VENTILATION SYSTEM - HOSES AND CONNECTIONS The PCV sy ste m should be checked for s a t is ­ factory operation at 12-month or 1 2 ,000-m ile in­ terv a ls using a te ste r such as the AC T ester C T -3.

UNDERPAN

EXTENSION CO VER T-9141

Figure 1— Flywheel H o u sin g and Adaptor Plate (350 and 366 V8 Engine)

P roper functioning of the carburetor is p ar­ ticu la rly e sse n tia l to control of e m issio n s. C orrect m ixtures for e m issio n com pliance and idle quality have been preset. P lastic idle mixture lim iters have been installed on the idle mixture screw s to pre­ clude unauthorized adjustment. These idle lim iters are not to be removed unless made necessary by som e major carburetor repair or replacement which affects the idle screw adjustment.

POSITIVE CRANKCASE VENTILATION VALVE R eplace the PCV valve at 24 months or 24,000 m ile in tervals (whichever occu rs fir st). PCV valve h o se, when rem oved for valve replacem ent, should be blown out with an air hose to make certain that it is clean. The PCV valve should be replaced at

POSITIVE CRANKCASE VENTILATION BREATHER OR FLAME ARRESTER The breather or flam e a r r e ste r should be r e ­ moved and cleaned at 12,000 m ile in terv a ls. Im ­ m e rse in cleaning solvent to rem ove all deposits and allow to drain before rein stallin g.

MECHANICAL VALVE LIFTERS Intake and exhaust valves on V6 engines should be adjusted at 12,000 m ile in tervals.

MANIFOLD HEAT VALVE In-L ine engines and som e V6 and V8 engines are equipped with a m anifold heat valve which should be checked for free operation. A binding valve may be freed up with G eneral M otors m anifold heat valve lubricant or equivalent. (NEVER USE ANY OTHER TYPE LUBRICANT.)

FLYWHEEL H O U SIN G ADAPTER PLATE Figure 1 shows the flyw heel housing adapter plate used with 13-inch clutch on 350 and 366 V8 engines.

Inspect engine front and rear mountings as part of regular engine m aintenance program . Be su re a ll bracket attaching bolts are kept tight.

R efer to ENGINE MOUNTINGS (SEC. 6D) for engine mounting inform ation.

S e c . 6A P ag e 13

GASOLINE ENGINES TUNE-UP CHART (IN-LINE ENGINE) Except as otherwise indicated, the following specifications apply to both engine models.

ENGINE TYPE AND NUMBER OF CYLINDERS .............................. In-Line, 6 -Cyl.

...................................................... .............15-3-6-2-4

COMPRESSION RATIO 250 Engine ................................................................................ 8.5:1 292 E n g in e ................................................................................ 8.0:1

IGNITION T IM IN G .............................. Refer to Ign. System Specs. (Sec. 6 Y)

CYLINDER COMPRESSION (PSI) At Cranking S p e e d ........................................................................ 130 Max. Variation Between C y lin d e rs...................................................... 20 SPARK PLUG MAKE AND NUMBER 250 Engine .......................................................................... A.C.-R46T 292 Engine .......................................................................... A.C.-R44T Spark Plug Gap ( A ll) .................................................................. 0.035" Plug Tightening Torque (F t.-Lb s.).............................................

13-17 IGNITION DISTRIBUTOR Dwell Angle (D e g re e s).................................................................. 31-34 Point Gap (N e w )........................................................................ 0.019” Point Gap (U se d )...................................................................... 0.016” Contact Lever Spring Tension (O z .)................................................ 19-23

VALVE L A S H .................................................................................. Zero NOTE: Valve lifters are hydraulic type. Refer to “ Cylinder Head Bolt Torque and Rocker Arm Adjustment” in this section for instructions.

ENGINE GOVERNOR SETTING . . . .Refer to Governor Charts at end of Gasoline Engine Fuel Systems (Sec. 6 M) in this manual.

ENGINE IDLE S P E E D ................ Refer to appropriate chart in "Gasoline Engine Fuel System s” (Sec. 6 M) in this manual.

FUEL PUMP PRESSURE ( P S I) ............................................................... 4-5 CYLINDER HEAD BOLT TORQUE (FT.-LBS.) ........................................ 90-100

TORQUE WRENCH SPECIFICATIONS (IN-LINE ENGINES) Torque wrench specifications listed below apply to clean dry threads except as otherwise indicated.

ITEM

FT.-LBS.

ITEM

FT.-LBS.

Push Rod Cover B o lt s ...................................................................... 6-8

Main Bearing Cap B o lt s ................................................................. 60-70

Cylinder Head B o lt s ..................................................................... 90-100

Oil Pump B o lts ................................................................................9-10

Manifold Clamps (O u te r)................................................................ 15-20

Oil Filter (Throw-Away T y p e )................................. (Filter Gasket Oiled 20-25)

Manifold Clamps (Except O u te r)...................................................... 25-30

Oil Filter Stud (If U se d )................................................................... 45-50

Exhaust-to-lntake Manifold B o lt s ..................................................... 25-30

Crankshaft Damper B o lt ................................................................. 40-60

Thermostat Housing B o lt s .............................................................. 25-30

Flywheel Bolts

Water Outlet Housing B o lt s ........................................................... 15-20

250 E n g in e s............................................................................. 55-70

Water Pump B o lt s ........................................................................ 13-17 Engine Front Cover B o lt s .................................................................. 5-7

292 Engines .................................................................. 1 0 5 4 1 5 Flywheel Housing B o lt s ................................................................... 25-30

Spark Plugs— 5 /8 ” Wrench Size— Tapered Seat P lu g ...................

O ilPan Bolts End B o lt s .................................................................................. 8-12 ^ xc.......................................................................... ®-8 Oil Pan Drain Plug B o lt s ........................................................... 1 /2 15-20 7 /8 20-25

13-17

Connecting Rod Bolt Nuts 250 E n g in e s ............................................................................. 30-35 292 E n g in e s............................................................................. 35-45

S e c . 6A Page 14

G ASO LINE ENGINES TUNE-UP (V6 ENGINE)

CHART

TYPE AND NUMBER OF CYLINDERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60°, V-6

FIRING ORDER

COMPRESSION RATIO

IGNITION T IM IN G

1-6-5-4-3-2 Refer to Ign. System Specs. (Sec. 6Y)

351C Engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7:1

VALVE LASH

CYLINDER COMPRESSION (PSD At Cranking S p e e d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 Max. Variation Between Cyl. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Intake Exhaust ENGINE GOVERNOR SETTING (No Load RPM)** If Used

0.012” 0.018

SPARK PLUGS* M a k e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AC

351C

3900

Type and Gap 3 5 1 C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CR 43 N, 0.035” Tightening Torque (Ft.-Lbs.). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 IGNITION DISTRIBUTOR

IDLE S P E E D . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Refer to appropriate chart in "Gasoline Engine Fuel Systems" (Sec. 6M) in this manual.

FUEL PUMP PRESSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6V2 CYLINDER HEAD BOLT TORQUE (FT.-LBS.)............................... 60-65

Dwell Angle (Degrees). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31-34 Point Gap (New) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.019” Point Gap (U sed ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.016” Contact Lever Spring Tension (O z.)................................. 19-23

*|n extremely cold regions use plugs with higher heat range. **With engine broken in. Full load setting is approximately 300 RPM less than No Load RPM, and will vary from engine to engine.

TORQUE WRENCH SPECIFICATIONS (V6 ENGINE) Torque wrench specifications listed below apply to clean dry threads except as otherwise indicated.

ITEM

FT.-LBS.

ITEM

FT.-LBS.

Rocker Arm Adjusting Screw

.7-17

Oil Pump Cover Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-15

Rocker Arm Shaft Bracket Bolts

20-25

Oil Pump to Block Bolt .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-35

Rocker Arm Shaft Cover Bolts

3-5

Oil Filter By-Pass Valve Plug (When U se d ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35-40

Valve Lifter Cover Bolts .....

4-5

Fuel Pump Eccentric B o l t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55-65*

Distributor Clamp B o l t .......

12-17

Oil Filter Housing to Cylinder Block Bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-36

Cylinder Head Bolts ..........

60-65*

Oil Filter Center Stud (When U se d ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45-50

Intake Manifold Bolts . . . . .. . .

25-30

Oil Filter Assy (Filter Gasket Oiled). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-25

Exhaust Manifold B o lt s ........

15-20

Spark Plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-34

Water Outlet Manifold B o lts ....

20-25

Flywheel Housing B o lts. .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . .. 50-60

Thermostat Housing Bolts ....

20-25

Flywheel to Crankshaft B o l t s .. .. . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . .. 100-110

Front Cover Bolts ...........

22-27

Hub-to-Crankshaft Bolt (Without Cone) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . 180-200

Connecting Rod N u t s ........

55-65*

Main Bearing Cap Bolts Main Bearing Cap Bolts (Except W R e a r). . . . . . . . . . . . . . . . . . . . . . 130-140* Rear [Vi" Bolts) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90-100*

Damper or Hub-to-Crankshaft Bolt (With C o n e ). .. . . .. . .. . .. . . .. . .. . .. 240-260 Oil Pan B o lts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-15 Oil Pan Drain Plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-30 *Oiled with S.A.E. No. 10 Engine Oil. (See Text)

Sec. 6A P age 15

GASOLINE ENGINES TUNE-UP CHART (V8 ENGINE) Except as otherwise indicated, the following specifications apply to all V -8 engines.

Point Opening New .................................................................................. 0.019”

ENGINE M O D ELS........ - ........................................................ 3 5 0,366, 427 NUMBER OF CYLINDERS AND ENG. T Y P E .................................. 8 Cyl., V Type

Contact Lever Spring Tension (O z .)............................................... 19-23 p|R|NG 0RD[R 1-84-3-6-5-7-2

COMPRESSION RATIO ........................................................................ 8:1 CYLINDER COMPRESSION (PSD At Cranking S p e e d ........................................................................ 150 Max. Variation Between Cylinders ............................................. 20 SPARK 427 350 366

PLUG MAKE S NUMBER ..................................................................................... AC-R42T ..................................................................................... AC-R44T ..................................................................................... AC-R43T

£

plug lis t e n in g Torque (Ft.-Lbs . ) . . . . . . . . . . . ^13-17

Dwell Angle (Degrees) .............................................................. 28-32

........................... Refer to Ign. System Specs. (Sec. 6 Y) VALVE LASH ................................................................................. ero Note: Valve Lifters are hydraulic type. Refer to “ Cylinder Head Bolt 'X io n s

« - PUMP PRESSURE (PSD ........................................................ 7 W CYLINDER HEAD BOLT TORQUE (FT.-LBS.) 350 Eng.................................................................................... 60-70 366 & 427 ............................................................................... 75-85

FT.-LBS.

SPECIFICATIONS

ITEM

FT.-LBS.

Rocker Arm Cover B o lt.................................................................... 3-5

Camshaft Sp ro cket

Rocker Arm Stud (366 and 427 Only) ............................................ 45-55

Connecting Rod Caps

Distribute, Clamp Boit..............................................................................20-25

W * ' H e a d Bolt c„ , „ 350 ....................................................................................... 60-70 366 and 427 En g in e s............................................................... 75-85 Crankshaft Damper B o lt............................................................... 80-90 Manifold Bolts (In le t)................................................................... 25-35 Manifold Bolts (Exhaust) 350 Engine ................................................................ 18-22 366 & 427 E n gin e ................................................................... 20-30 Flywheel Housing and Adapter Bolt (When U sed ).............................. 25-35

f0'

ENGINE IDLE SPEED .................................. Refer to appropriate chart in “Gasoline Engine Fuel System s” (Sec. 6 M) in this manual.

TORQUE WRENCH (V8 ENGINE) ITEM

Rocker A™ AdiuStment" ™ thiS

;;

.

15-20

;;;;;;;;;;;;;;;;;;;

Main Bearing Caps (350 Engine) D ..

7 n on tolfe g ! ^ & 4 Only). .V .V .'.'.'.'.V .. . . . V .'.V . .V .V . '. ! ! ! ! ! ! ! :60-70 ^ ^ Caps ^ s 4?/ Eng|„ es) |nner ^ ^ uter B o lts Oil Pump B o lts Qjl pan

100-110 100110 60-70

3 5 0 Engines 1 /4 ” B o lts 6-7 5 /1 6 ” B o lts .............. .’ ............................................................ 12-15 366 and 427 Engines (1 /4 ” B o lts)................................................. 4-5

Flywheel Bolts 350 E n g in e ............................................................................. 55-65 366 & 427 E n gin e s.................................................................. 60-70

Oil Filter (Filter Gasket O iled )......................................................... 20-25

Spark Plug 5 /8 ” Wrench Size— Tapered S e a t...........................

13-17

oil Pan Drain P lu g ....................................................................... 15-20

Water Pu m p ............................................................................... 25-35

Flywheel Housing Underpan........................................................ 6-7 1/2

S e c . 6D P age 16

SECTION 6D C

'tu jin e

M

a u + U i+ u jA .

A ll inform ation in ENGINE MOUNTINGS (SEC. 6D) of S ervice Manual S T -331-71, p ages 6D-1 through 6D -3 applies to v e h ic le s cov­ ered by this supplem ent with the follow ing exceptions or additions:

ENGINE CU SHIO N BOLT A N D NUT TORQUE Size

B olt to Alum.

Torque (F t.L bs.)

B olt to Casting or Nut Torque (F t.-L b s.)

Nut Torque (F t.-L b s.)

3 / 8 ” 16-24

12 - 16

25 - 30

15 - 20

7/16"

20 - 25

40 - 50

25 - 30

1/2" 13-20

30 - 35

55 - 65

40 - 50

9/16"

40 - 50

60 - 70

50 - 60

14-20

12-18

5/8"

11-18

50 - 60

130 - 140

70 - 80

3/4"

10-16

90 - 110

180 - 200

110 - 130

T-9146

M O U N T IN G BOLTS, BRACKET BOLTS, A N D NUT TORQUES GM 280-M BOLT BOLT OR NUT SIZE

F T .-L B S .

e

BOLT HEAD IDENTIFICATION

GM 300-M BOLT

FT .-L B S.

F T .-L B S. 10-15

NUT TORQUE

BOLT HEAD IDENTIFICATION

5-8

1/4"

- 20-28

8-10

5/16"

-

18-24

20-25

25-30

8 - 12

3/8"

-

16-24

25-30

35-45

15-20

7/16" -

14-20

40-50

70-80

25-30

1/2"

-

13-16

55-65

85-105

40-50

9/16" -

12-18

60-70

90-110

50-60

5/8"

-

11-18

130-140

170-180

70-80

3 /4"

-

10-16

180-200

300-320

110-130

7 /8 "

-

9-14

240-270

400-430

210-230

8-14

325-380

700-730

320-350

1" * 40 - 50 ** 55 - 65 *** 60 - 70

Torque for aluminum casting.

T-9148

ENGINE FRONT M O U N T WITH AT475 T RANSM ISSIO N (ALL ENGINES)

to rem ove brackets, mounts, sp a cer, b olts, nuts, and w ash ers.

F igure 1 show s left sid e front mount used on In -lin e 6-cylin d er Gas Engine and is typical for V6 and V8 Gas E ngines. R efer to page 2 for figure 1.

NOTE: It w ill be n e ce ssa r y to bend lock tab before rem oving the cushion mount bolt (fig. 1) and after bolt torque. See next page for figure 1.

R eplacem ent 1. L oosen attaching b olts. R aise engine enough

2.

R ev erse the procedure to in stall making sure to torque bolts or nuts as shown on preceding charts.

Sec. 6D P age 17

ENGINE MOUNTINGS W A SH ER •BOLT NUT

W ASHER LOCK

‘> " V

FR O N T M O U N T IN G BOLT

W ASHER \V

Figure 1—En g in e Front M ount w ith A T 4 7 5 Transm ission (Typical)

N UT

SECTION 6K S 't K f i n e

G o a U r u j, S y d t e m

Inform ation pertinent to truck m odels covered by th is supplem ent is the sam e as explained in S erv ice Manual S T -331-71 ENGINE COOL­ ING SYSTEM (SEC. 6K), pages 6K-1 through 6K -9, except as indicated by the follow ing inform ation which is eith er new or supplem ental in nature.

R eferen ce should be made to RADIATOR AND SURGE TANK (SEC. 13) in th is supplem ent for inform ation regarding radiator mount­ ing, radiator core and surge tank and cooling sy ste m fille r cap.

C O O LIN G SYSTEM GENERAL MAINTENANCE TEST COO LANT LEVEL Engine coolant should be checked for proper le v e l regularly (daily if n e c e ssa r y , depending on sev er ity of se r v ic e ) and every six months for c o r ­ rosio n and fr e e z e protection to at le a st -20 F ., or to the low est tem perature expected during the period of veh icle operation. Each two y e a r s or 24,000 m ile s, w hichever fir st o ccu rs, cooling sy ste m m ust be drained, flushed, and refilled with a new coolant solution.

RADIATOR CORE EXTERIOR For proper cooling efficien cy, the ex terior of the radiator core and A/C condenser, if so equip­ ped, m ust be kept clean. Light brushing and r e ­ v e r se air flow is usually a sa tisfa cto ry cleaning method. In sects can usually be rem oved with a garden hose using light w ater p r e ssu r e .

C O O LIN G SYSTEM PRESSURE CHECK S everal types of cooling sy ste m p r e ssu r e checking d evices are available lo ca lly and manu­ fa ctu rer's in stru ctions should be follow ed for p roper u se. A typical te ste r is illu strated in figure 1 and proced ures are given below for testin g the p r e ssu r e cap and cooling sy ste m .

1. T esting Radiator Cap

a. With radiator fille r cap rem oved, wet the cap gasket with w ater and wash off any sedim ent from sealin g su rface, then in stall cap on te ste r . b. Pump up p r e ssu r e by operating pump plung­ er handle. When the p r e ssu r e stam ped on cap is reached, ob serve te ste r dial and note the rate of d ec re a se in p r e ssu r e . c. The indicator hand on gauge dial should r e ­ main within the corresponding p r e ssu r e segm ent of sc a le for approxim ately 10 secon d s. If p r essu re cap does not m eet this req u irem en t,it should be replaced with new cap.

2. T esting Cooling System a.

Tighten all radiator andheater hose clam ps.

A lso , check other connections for leaks at air com ­ p r e sso r coolant lin e s, etc.

G A U G E HO SE A N D .T A P PUMP A N D G A U G E ASSEMBLY

FILLER NECK1 SON RADIATOR

O VERFLOW HOSE

CAUTION: The radiator cap should not be removed while the engine is at normal operating temperature. If it is necessary to remove the cap while the engine is hot, first relieve the pressure in the system by turning the radiator cap counterclockwise to first stop, using cau­ tion not to scald hands. Push down on cap and turn counterclockwise to remove cap.

Figure 1— Use of C o olin g System Tester (Typical)

Sec. 6K Page 19

ENGINE COOLING SYSTEM b. F ill cooling sy ste m to le v e l of fille r cap se a t. c. Attach te s te r to fille r neck follow ing the in stru ction s supplied with te ste r . d. Build p r e ssu r e up to 20 p si (m axim um ). e. The cooling sy ste m should hold the 20 p si p r e ssu r e for approxim ately two m inutes. If p r e s ­ su re drops appreciably in le s s than two m inutes, a leak in sy stem is indicated.

COOLING SYSTEM PROBLEM ANALYSIS 1. R em ove fille r cap or te ste r from fille r neck so there w ill be no p r e ssu r e in sy stem , then attach sy ste m te ste r at fille r neck (fig. 1).

2. Start engine and run until norm al operating tem perature is reached (approx. 175 F .).

3. O bserve gauge on te s te r . If no p r e ssu r e in sy ste m is in d icated ,u se te ste r pump to p r e ssu r iz e the sy ste m . If sy ste m w ill not hold p r e ssu r e , in­ sp ect h o se s, fittin g s, and g a sk ets. A lso, look for w ater draining from hole in w ater pump body b e­ tw een the pump s e a l and the bearing.

4. If no leak s a re evident, it is p o ssib le that coolant is leaking internally into cran k case, oil co o le r , or com bustion cham bers.

5. To determ ine if there is coolant leakage into o il coo ler or cran kcase, look for w ater drop­ le ts on engine o il dipstick. A lso , look for engine o il in cooling sy ste m which would indicate that d efective o il coo ler or g ask ets e x ist.

ENGINE COOLANT RECOMMENDATIONS R ecom m endations are for a high quality in­ hibited Ethylene G lycol B a se Coolant m eeting GM S pecifications 1899M and to provide the freezin g and co rro sio n protection (at le a st 0 F .).

Additional inhibitors are not required on initial f ill if a m inim um an tifreeze concentration of 30% by volum e is u sed. Solutions of le s s than 30% con­ centration do not provide su fficien t corrosion p ro­ tection . C oncentrations over 67% ad versely affect f r e e z e protection and heat tra n sfer r a tes. S everal brands of perm anent an tifreeze are available with s e a le r ad ditives. The sp e c ific type of s e a le r s vary with the m anufacturer. A ntifreeze with s e a le r ad­ d itiv es is not recom m ended due to plugging prob­ le m s throughout various a rea s of the cooling sy stem .

NOTE: R efer to ’’Cooling System C apacities C hart” at the end of th is sectio n for sy ste m ca ­ p a c itie s.

COOLING SYSTEM CORROSION PREVENTION NOTE: Addition of supplem ental additives and other available m aterials which have not been s p e c ­ ific a lly approved by GM are not norm ally required.

U se of th ese m aterials w ill resu lt in unwarranted operating expense.

Every two y e a r s, the cooling sy ste m should be se r v ic e d as follows: 1. Drain coolant, when hot, through the rad­ iator drain valve.

2. C lo se valve and add su fficien t plain w ater to fill sy ste m .

3. Run engine until norm al operating tem p er­ ature is reached.

4. Drain and r e fill the sy stem a s d escrib ed in Steps 1, 2, and 3 a su fficien t number of tim es until the drained liquid is c o lo r le ss.

5. A llow sy stem to drain com pletely and then c lo s e radiator drain valve tightly.

6. Add the n e c essa r y amount of high quality inhibited glycol base coolant m eeting GM Sp eci­ fication 1899-M to provide the required freezin g and corrosion protection (at le a st to 0 °F .).

7. Run engine until norm al operating tem p er­ ature is reached.

8. Check and adjust le v e l of coolant after s y s ­ tem has cooled su fficien tly to rem ove radiator cap.

C A U TIO N : When an engine Is at norm ­ al operating temperature or above, the internal pressure built up in the cooling system will blow out scalding fluid and vapors if the radiator cap is suddenly re ­ moved.

To prevent loss of coolant and to avoid the danger of being burned, the cool­ ant level should be checked, or coolant added only when the engine is cool.

To remove the cap when engine is cool, slowly rotate cap counterclockw ise to the stop on fille r neck (DO NOT P R E S S DOWN W H ILE R O TA TIN G ), wait until any residual pressure is relieved - as indicat­ ed by a hissing sound, then press down on the cap while continuing to rotate counter­ clockw ise.

Radiator pressure caps should be checked by a qualified m echanic period­ ically for proper operation and replaced as required with the applicable A C type.

P re ssu re cap testing procedure is co v e red previously In this section.______________ R eg ard less of whether freezin g tem p eratu res a re or are not expected, cooling sy ste m p rotection should be maintained at le a st to 0 ° F ., to provide adequate co rrosion protection. When coolant addi-

S e c . 6K P age 20

ENG INE C O O L IN G SYSTEM tio n s are required b ecau se of coolant lo s s or to provide additional protection against freezin g at tem peratu res low er th an -2 0 F .,( - 3 2 F.inC anada), a su fficien t amount of an Ethylene G lycol B ase Coolant m eeting GM Specification 1899-M should be used.

NOTE: A lcohol or methanol base coolants or plain water are not recom m ended.

IMPORTANT: DO NOT run engine when gauge or te ll-ta le indicates "hot" engine. A lso DO NOT u se glycol ether (methoxypropanol) base coolant in GMC D ie se l engines, as damage to head gasket could resu lt.

V-BELT TENSION Fan belt tension on veh icles equipped with V -b elts should be adjusted to 120-130 pounds on new b elts using B T -3 3 -7 3 F B elt Tension Gauge.

U sed drive V -b elts should be adjusted to 80-90 pounds. Gauge should be placed at center of the g rea test span.

IMPORTANT: A fter a belt has been in op er­ ation one hour or approxim ately 50 m iles, it is con sid ered used. B elt d ressin g can be used to ex ­ tend belt life . When V -b elts are worn they should be replaced as e x c e ssiv e tightening w ill not p r e ­ vent slippage and can cause damage to bearings.

SPECIFICATIONS The cooling sy ste m ca p acities liste d below apply to v eh icles with standard equipment only. B ecau se of som e optional equipment which may be used, air conditioning, la rg er engine, water filte r , in creased cooling, e tc ., the capacity of cooling sy stem w ill vary. For the purpose of obtaining an accurate cooling sy ste m capacity before adding anti­ fr e e z e to an optional equipped v eh icle, it is recom m ended that the co o l­ ing sy ste m be fir st replenished until v isib le in fille r opening and then drained into a graduated container of which the contents can be m easured.

STANDARD C O O LIN G SYSTEM CAPACITIES (OTS) INCL. HEATER

ENGINE THERMOSTATS

QUARTS 'I RUCK MODELS

CE40 CS40 PS40 SE, CE50 CG, SG50 CM, SM50 CS, SS50 TE50 TM50 TG50 CE, ME60 CM, TE60 TM60

U.S.

I MP E RI AL m 13% 13% 16%

21.0 16.0 16.0 20.0 29.0 36.0 17.0 28.0 44.0 38.0 33.0 35.0 44.0

24% 30 14X 23% 36% 32 21%

Engine

No. U sed

Mean

Starts to

351C

2

180

177-183

202

250; 292

1

195

192-198

217

350

1

195

192-198

217

366; 427

2

180

177-183

202

DH478

1

180

177-183

202

29% 36%

ENGINE OVERHEAT SWITCH SWITCH CONTACTS CLOSE AT: V6 G asoline Engines

............................................................................... ..... 225°F .

V8 G asoline Engines

............................................................................... ..... 250°F .

D ie se l Engines

Fully

remp. (°F .) Open (°F.) Open ( F.)

........................................................................................ ..... 215°F .

Sec. 6M P age 21

SECTION 6M f y u e l S if d i& Q

a A

o lin e

tn

C '+ U f U te A

GOVERNORS HOLLEY INTERNAL -VA CU U M TYPE GOVERNOR (Refer to Schem atic Figure 1) The Holley Internal-V acuum Type Governor is used on both 366 and 427 engines. The governor is com p rised of two b a sic units; the centrifugal control valve housed in the distributor and the carburetor with its integral governor com ponents.

CARBURETOR

GOVERNOR TEST The following procedure should be used to help locate the cause for lo s s of governor control: 1.

U sing a tachom eter, check engine governed sp eed as sp ecified in ’’Specifications" at end of th is sectio n .

NOTE: Initial overrun m eans that under a c c e l­ eration the engine w ill m om entarily exceed gov­ erned speed by approxim ately 150-250 rpm and

GOVERNOR B Y -P A S S JETS GOVERNOR VACUUM

D IS TR IB U T O R

REAR VIEW S P IN N E R V A L V E G O V E R N O R V A C U U M LIN E G O V E R N O R S P R IN G

G O V E R N O R LEVER

G O V E R N O R V A C U U M LIN E GOVERNOR VACUUM PASSAGE

BOTTOM VIEW

D IA P H R A G M R O D D IA P H R A G M

Figure 1—H o lle y In te rn a l—V acuum Type G overnor

T-m o

S e c . 6M P a ge 22

FUEL SYSTEM— GASOLINE ENGINES then se ttle to governed speed which is a normal condition.

2.

If there is no governor control, perform the following: a. D isconnect the vacuum line (d istrib u tor-togovernor throttle actuating unit). Leave the second­ ary control valve vacuum line connected. Operate the engine at 2200 rpm, then wet your finger and hold it over the opening in the disconnected vacuum lin e. If the engine speed slo w s to near id le, the governor trouble is in the distributor spinner valve or the lin es or connections to the d istributor. If the engine does not slow down p roceed to Step b. fo l­ lowing: b. D isconnect the secondary control valve vacuum line from the governor a ssem b ly . Again, operate the engine at 2200 rpm and p lace a wet fin ger over the p a ssa g e to the governor throttle unit. If the engine now slow s to near id le, the prob­ lem is in the secondary control valve or its vacuum lin e . If the engine does not slow down, the problem is in the governor throttle unit or the vacuum p a s s ­

a g es behind it.

3.

If the engine governs at light load and does not govern at w ide-open throttle the problem is probably in the secondary control valve. C orrect operation of the secondary throttle sy ste m and the governor depends upon proper functioning of the secondary control valve. B e su re the secondary control valve air clean er is cleaned or replaced at regular in tervals depending on sev erity of op er­ ation, then perform the following: When the problem is su sp ected to be in the secondary control valve, operate the v eh icle on the highway and check governor operation. The gov­ ernor should lim it speed to that sp ecified in "Speci­ fications" plus 150-250 rpm initial overrun. If the engine does not govern, rem ove "E" clip, discon­ nect the secondary throttle diaphragm link from the secondary throttle shaft le v e r . Operate the v eh icle again on only the prim ary carburetor ven­ tu r is. If the engine governs now, the problem is in the secondary control valve which must be replaced a s an assem b ly .

ROCHESTER CARBURETORS F igu res 2, 3, and 4 illu str a te the current R och ester carb uretors in sta lled on C hevrolet Truck en gin es. The m ost sign ifican t change in th e se carburetors extern ally, is the addition of p la stic lim ite r caps which are in sta lled over the id le m ixture sc r e w (s).

The p la stic caps prevent unauthorized adjust­

ment of the idle m ixture sc re w (s). T hese caps are not to be rem oved u n less made n ec essa ry by som e m ajor carburetor repair or replacem ents which a ffects idle m ixture adjustm ent. Replacem ent of the p la stic caps is covered in this section under "Re­ placing P la stic L im iter Caps on Idle Mixture S crew s."

CARBURETOR IDENTIFICATION FUEL INLET A N D FILTER

CHOKE ROD IDLE STOP SO LEN O ID

CHOKE RETAINER

FAST IDLE C AM DISTRIBUTOR A D V A N C E LINE PORT

PLASTIC LIMITER CAP (IDLE MIXTURE SCREW) Figure 2 — M o d el M Rochester Carburetor

THROTTLE LEVER

Sec. 6M P age 23

FUEL SYSTEM—GASOLINE ENGINES IDLE VEN T VALVE IDENTIFICATIO N NUMBER

FUEL INLET A N D FILTER

ACCELERATOR PUMP ROD

DISTRIBUTOR LINE PORT

PLASTIC LIMITER CAPS (IDLE MIXTURE SCREW)

C H O K E ROD IDLE SPEED SCREW

THROTTLE LEVER

Figure 3 —M odel 2 G Rochester C arburetor

A lso of im portance on the Model M carburetor (fig. 2) used on In-lin e engines is the addition of an e le c tr ica lly operated idle stop solenoid which functions to prevent engine d ieselin g.

ROCHESTER CARBURETOR ADJUSTMENTS

in stalled , parking brake applied, and driving w h eels blocked.

2. A ir conditioning (when used) must be turned "ON.” 3. Check the distributor dwell reading.

In-L ine Engines 350 V8 Engine

... ...

31 to 34 d egrees 28 to 32 d egrees

NOTE: When setting ignition tim ing, the term BTDC m eans "Before Top Dead C enter."

4. Adjust ignition tim ing to 4°BTDC with P relim in ary Checks (All Engines) 1.

Idle adjustm ents should be perform ed with vacuum advance disconnected and plugged. R econ­ nect vacuum advance hose. the engine at operating tem perature air cleaner IDLE SPEED ADJUSTMENTS

ID ENTIFICA TIO N NUMBER

FUEL INLET A N D FILTER

IDLE V EN T VALVE

IDLE SPEED SCREW

GOVERNOR

LIMITER CAPS (IDLE MIXTURE SCREWS)

ACCELERATOR PUMP ROD

Figure 4 —M odel 2 G Rochester C arburetor w ith G overnor

LEVER

S ec. 6M Page 24

FUEL SYSTEM— GASOLINE ENGINES 9/16" W RENCH

SO L E N O ID

STOP PIN IDLE MIXTURE SCREW

Figure 5 — A djusting Idle Speed (In-Line EngineI

PLASTIC CAP SCREW DRIVER T-9134

5. Adjust idle speed as follow s: In-L ine Engine Idle Speed Adjustment 1. R eferring to figure 5, using a 9 /1 6 -in ch open-end wrench on hexagonal portion of solenoid, rotate solenoid until engine speed reach es 700 rpm.

NOTE: If n e c e ssa r y to rotate solen oid m ore than one full revolution (360°), disconnect e le c ­ tr ic a l connector, straighten w iring and reconnect to solenoid.

2. D isconnect e le c tr ic a l connector from s o le ­ noid with engine idling. Adjust 1 /8 -in c h A llen-head sc r e w on end of solenoid (see fig. 6) to ach ieve

Figure 7 — Rem oval of Plastic Limiter Cap (M odel M Rochester CarburetorI

450 rpm (reduced idle speed).

3.

R econnect e le c tr ica l connector and check for proper idle speed (700 rpm).

350 V8 Engine Idle Speed Adjustment R eferring to figu res 3 or 4, adjust idle speed sc re w until engine speed reaches 600 rpm.

1/8” ALLEN W REN C H

STOP PIN PLASTIC CAP SO LE N O ID

Figure 6 — A djusting Idle Stop Solenoid (Plunger RetractedI

Figure 8 — Rem oving Plastic Limiter C ap (M o d e l M Rochester Carburetor)

Sec. 6M P age 25

FUEL SYSTEM—GASOLINE ENGINES

T-9137

Figure 9 —In sta llin g Plastic Lim iter C a p (M odel M Rochester Carburetor)

REPLACING PLASTIC LIMITER CAPS ON IDLE MIXTURE SCREWS IMPORTANT: P la stic lim iter caps are in sta ll­ ed on the idle m ixture sc r e w s (se e fig s. 2, 3, and 4) of R ochester carburetors to prevent unauthor­ ized adjustm ent. T h ese p la stic caps are not to be rem oved u n less made n e c e ssa r y by som e major carburetor repair or replacem ent which affects the idle m ixture screw adjustm ent.

IN-LINE ENGINES R em oving P la stic L im iter Cap 1. Using a screw d riv er as shown in figure 7, tw ist p la stic cap back and forth until cap begins to fa il. DO NOT u se extrem e p r e ssu r e when tw isting cap to avoid bending stop pin.

2. Then pull p la stic cap straight away from carburetor as shown in figure 8.

CA U TIO N : It is most important to pull plastic cap straight away from ca rb ­ uretor to avoid bending idle mixture screw .

Installing P la stic L im iter Cap NOTE: The carburetor must be in stalled on the engine and properly adjusted p rior to in sta ll­ ation of the p la stic caps.

Figure J 0 —Rem oval of Plastic Lim iter C a p s (M odel 2 C Rochester Carburetor)

2. Check dwell reading and adjust, if n e c e s ­ sa ry . D w ell reading on In-line engines should be 31 to 34 d egrees.

3. Adjust ignition tim ing to 4°BTDC with v a c ­ uum advance hose disconnected and plugged. R e ­ connect vacuum advance hose.

4. Adjust engine idle speed using a 9 /1 6 -in c h open-end wrench as shown in figure 5 until engine speed is 775 rpm.

5. With engine running at idle speed as d e s­ cribed in Step 4, adjust idle m ixture sc re w to give highest steady idle speed.

6. Readjust engine idle speed as d escrib ed in Step 4, to 775 rpm.

7. Turn idle m ixture screw IN by rotating clock w ise to LEAN m ixture until the engine idle sp eed reach es 700 rpm.

8. P osition p la stic lim iter cap as shown in figure 9, so that alignm ent slo t in p la stic cap is aligned with stop pin on carburetor. Then carefu lly push p la stic cap onto idle m ixture sc re w until it snaps into position.

350 V8 ENGINE

R em oving P la stic L im iter Caps 1. U sing a screw d river as shown in figure 10.

T w ist each p la stic cap back and forth until cap 1.

Thoroughly w arm up the engine. Be sure begins to fa il. choke is open.

2. Then with the aid of a screw d riv er as

J

Sec. 6M Page 26

FUEL SYSTEM— GASOLINE ENGINES ------— PLASTIC C A P S 1 B O S S O N THROTTLE BODY PLASTIC CAPS

TANG S _

SCREW DRIVER

_

_

Figure 12— Installing Plastic Limiter Caps (M odel 2 G Rochester Carburetor)

Figure 11 — R em oving Plastic Limiter Caps (M odel 2 C Rochester Carburetor)

shown in figure 11, pry the p la stic lim ite r caps from idle m ixture sc r e w s.

Installing P la stic L im iter Caps NOTE: The carburetor must be in sta lled on the engine and properly adjusted p rior to in sta ll­ ation of the p la stic caps.

1. Thoroughly warm up the engine. B e su re choke is open.

2. Check dwell reading and adjust, if n e c e s ­ sa r y . D w ell reading on the 350 V8 engine is 28 to 32 d eg rees.

3. Adjust ignition tim ing to 4°BTDC with vac-

uum advance hose disconnected and plugged. R e­ connect vacuum advance h ose.

4. Adjust engine idle speed screw (figs. 3 and 4) until idle speed is 650 rpm.

5. With engine running at idle speed, adjust idle m ixture scre w s to give highest steady idle speed.

6. Readjust engine idle speed as describ ed in Step 4, to 650 rpm.

7. Turn id le m ixture sc r e w s IN, equally, by rotating clock w ise to LEAN m ixture until the en­ gine idle speed reaches 600 rpm.

8. P osition p la stic lim ite r caps as shown in figure 12, so that tangs on p la stic cap are located on either sid e of b oss on throttle body. Then c a r e ­ fully push lim iter caps onto idle m ixture scre w s until they snap into position.

HOLLEY CARBURETOR F igu res 13 and 14 illu stra te the H olley Carb­ uretor, Model 4150G in stalled on 366 and 427 en­ g in es. The significant changes in the H olley carb­ u retor are the addition of p la stic lim iter caps which are in stalled on the idle m ixture sc r e w s and also a relocation of governor vacuum control lin e and fittin g s on the carburetor.

HOLLEY CARBURETOR ADJUSTMENTS IDLE SPEED ADJUSTMENT 1. Idle speed adjustm ent should be perform ed with the engine at operating tem perature, air clean ­ er in stalled parking brake applied, and driving w h eels blocked.

2. A ir conditioning (when used) m ust be turned ON.

3. Check the distributor dwell reading. Dwell reading on 366 and 427 engines should be 28 to 32 d eg r ee s.

NOTE: When setting ignition tim ing the term BTDC m eans "Before Top Dead C en ter.”

4. Adjust ignition tim ing to 8°BTDC. 5. Adjust idle speed sc rew (fig. 13) until en­ gine speed reach es 550 rpm.

AIR VENT VALVE ADJUSTMENT (F ig. 15) 1. Back off idle speed screw until throttle v alves are fully clo sed . (Choke valve open and throttle arm off idle screw .)

2. Check clearance between valve and sea t.

C learance should be 0.060".

3. Bend air vent valve rod to adjust, if n e c e s­ sa r y .

Sec. 6M P age 27

FUEL SYSTEM—GASOLINE ENGINES S EC O N D A R Y FUEL B O W L

PRIMARY FUEL B O W L

AIR VEN T VALVE CHOKE PLATE ASSEMBLY

NEEDLE A N D SEAT ASSEMBLY

C O N TR O L VALVE AIR CLEANER

S EC O N D A R Y C O N TR O L VALVE ASSEMBLY

CARBURETOR A N D AIR H O R N PART NUM BER

FUEL TRANSFER TUBE IDLE MIXTURE SCREW

A

FutfL BOW L SIG H T PLUG GOVERNOR ASSEMBLY

CHOKE LEVER

SEC O ND A R Y D IA PH R A G M ASSEMBLY

VACUUM LINE TO DISTRIBUTOR

GOVERNOR VACUUM C O N T R O L LINE

FUEL INLET

PUMP PUMP LEVER

THROTTLE LEVER ED SCREW

PUMP OVERRIDE SPRING

Figure 13—H o lle y C arburetor

4.

Turn idle sc r e w in until contact is made and choke fully clo sed , m easure gap betw een fast idle cam and screw . Gap should be 0.035". with throttle le v e r , then turn screw in 1% addi­ 3. If n ec essa ry , adjust fast idle scr ew to p ro­ tional turns for prelim in ary idle speed adjustm ent. vide correct gap using wrench ( J - 10176).

Adjust engine idle speed as d escribed e a rlier in 4. Connect throttle return spring and in stall th is sectio n . air clean er.

FAST IDLE ADJUSTMENT 5. Check engine rpm with choke c lo se d against (R efer to Figure 16) the fast idle cam and throttle at idle. The fa st idle 1. With engine "OFF” and air clean er rem ov­ "Running" rpm ’s should be 1800-2400 rpm. ed, disconnect throttle return spring.

2. With throttle le v e r in wide open position VENT VALVE ACTUATING ROD BEND HERE TO ADJUST

SECO N D A RY BARRELS

^ rU U M * VAp q r t SECONDARY THROTTLE PLATE SC REW

PO W ER VALVE VACUUM PORTS

IDLE SPEED SCREW

THROTTLE SC R EW S (8) .............. BARRELS

PORT

Figure 14—H o lle y C arburetor (Bottom V iew )

ADJUSTMENT .060" AIR VENT VALVE

THROTTLE LEVER

Figure 15—A ir V ent V a lv e A djustm ent

Se c . 6M P ag e 28

FUEL SYSTEM— GASOLINE ENGINES

Figure 18— Positioning Plastic Limiter Cap For Installation (Holley Carburetor)

Figure 7 7 — R em oving Plastic Limiter Caps (Holley Carburetor)

REPLACING PLASTIC LIMITER CAPS O N IDLE MIXTURE SCREWS IMPORTANT: P la stic lim ite r caps are in sta ll­ ed on the idle m ixture sc r e w s (fig. 13) located on both sid e s of the secondary throttle body to prevent unauthorized adjustm ent. T h ese p la stic caps are not to be rem oved u n less made n e c e ssa r y by som e

Figure 19— Installing Plastic Limiter Cap (Holley Carburetor)

m ajor carburetor repair or replacem ent which affects the idle m ixture screw adjustm ent.

REMOVING PLASTIC LIMITER CAPS (R efer to Fig. 17) 1.

With the aid of two standard scr ew d r iv er s, sim ply in sert tips of screw d riv er blades behind

Sec. 6M Page 29

FUEL SYSTEM—GASOLINE ENGINES 4. Adjust engine idle speed scr ew (fig. 13) p la stic cap, as shown.

2.

Pry p la stic cap from each idle m ixture until engine idle speed is 600 rpm.

5. With engine running at idle speed, adjust screw . idle m ixture scre w s to give highest steady idle speed.

INSTALLING PLASTIC LIMITER CAPS 6. Readjust engine idle speed as d escrib ed in NOTE: The carburetor must be in stalled on Step 4 to 600 rpm. the engine and properly adjusted prior to in sta ll­ 7. Turn idle m ixture screw s IN, equally, by ation of the p la stic caps. rotating clock w ise to LEAN m ixture until the en­ gine idle speed reaches 550 rpm.

1. Thoroughly warm up the engine. B e sure 8. R eferring to figure 18, p la stic caps must choke is open. be in stalled so that ears on cap are aligned with 2. Check dwell reading and adjust, if n e c e s ­ sa ry . D w ell reading on 366 and 427 V8 engines b o ss on secondary throttle body. Then carefully should be 28 to 32 d eg rees. push p la stic cap onto each idle m ixture sc rew (see fig . 19) until it snaps into position.

3. Adjust ignition tim ing to 8°BTDC.

BENDIX—STROMBERG CARBURETOR The B endix-Strom berg carburetor (W W Series) as shown in figure 20, is in stalled on 351C engine.

The m ost significant change externally on the carburetor is the addition of p la stic lim ite r caps which are in stalled over each of the idle m ixture sc r e w s.

BENDIX-STROMBERG CARBURETOR ADJUSTMENTS IDLE AND MIXTURE ADJUSTMENT P relim in a ry Checks 1. Thoroughly warm up the engine. Be sure the choke is open.

2. B e su re the carburetor is properly secu red to the intake manifold, which w ill exclude the p o s­ sib ility of air lea k s. C arburetor-to-m anifold bolts or nuts should be tightened to 20-25 foot-pounds torque.

3. Inspect the manifold heat control valve (if used) for freedom of action and co rrect spring tension.

4. A ir conditioning, when used, should be turned on during the carburetor adjustm ents.

5. Check dwell reading and adjust, if n e c e s ­ sa ry . Dw ell reading on V6 engines should be 31 to 34 d eg rees.

6. Adjust ignition tim ing with vacuum advance hose disconnected and plugged to 7^°BTDC. R e­ connect vacuum advance hose.

CA U TIO N : UN D ER NO CO N D ITIO N SHOULD T H E D IAPHRAGM E X T E N S IO N B E A LLO W E D TO R O T A T E OR IN T E R N ­ A L DAM AGE W IL L R E S U L T TO VACUUM ID L E STO P UN IT. b.

Adjust the plunger with a 3 /8 -in c h open end w rench until the face of the plunger hex contacting the carburetor throttle le v e r resu lts in the idle speed given e a r lie r in Step 1.

2. Rotate idle m ixture screw s cou n terclock ­ w ise until tang on each p la stic cap contacts roll pin in throttle body of carburetor as shown in View B ,figure 20.

3. R eset the idle speed as directed in Step 1.

4. Turn "in" idle m ixture scr ew s equally by rotating clock w ise to LEAN m ixture until the fo l­ lowing idle speed reach es 600 rpm.

5. With engine running, vacuum id le stop hose disconnected, check reduced engine rpm . The r e ­ duced engine speed should be 400 rpm. If n e c e s ­ sa ry , adjust id le speed screw (View A, fig. 20) to obtain 400 rpm. Reconnect vacuum id le stop h ose.

FLOAT LEVEL ADJUSTMENT

1. R em ove air clean er and disconnect choke and a ccelera to r linkage and fuel line from carbur­ etor. D isconnect fast idle link and a cce lera to r pump rod.

2. Rem ove carb u retor-to-m an ifold retaining b olts or nuts, then rem ove carburetor from engine.

3. R eferring to View A, figure 20, rem ove C arburetor Adjustment sc r e w s from top of air horn. Separate a ir horn and 1.

Engine idle speed for the 351C engine should throttle body from main body of carburetor. C are­ be adjusted to 650 rpm by perform ing the following: fully pour fuel from float bowl.

4. Hold main body inverted as shown in figure a.

R eferring to figure 21, place a %-inch open 22. This w ill allow weight of float to hold needle in end wrench on diaphragm extension of vacuum idle the closed p osition. U se float gauge (J-8824) to stop to prevent its rotation w hile adjusting plunger.

S e c . 6M P ag e 30

FUEL SYSTEM— GASOLINE ENGINES

M A IN DISCHARGE JETS VENT TUBE IDLE SPEED SCREW

IDENTIFK TAG

HIGH-SPEED" BLEEDER VIEW A

ACCELERATOR PUMP ROD Figure 21 — A djusting V acuum Idle Stop

FUEL INLET

IDLE MIXTURE SCREW S VIEW B VAC U U M IDLE STOP

THROTTLE LEVER \ VIEW C

CHOKETO-THROTTLE LEVER

Q

Figure 2 0 -B e n d ix -Stro m b e rg Carburetor (W W Series)

Figure 2 2 — Checking Float Level

check relationship of the float to top of the fuel bowl as shown. R efer to "Specifications" for proper float le v e l adjustm ent. Setting is co rrect when the edge of the gauge touches top of the rib on float.

5. U se tool (J-4395) to bend float le v er next to float to change the float settin g. U se bending tool as illu strated in figure 23.

6. A fter checking float le v e l, in stall air horn and throttle body to main body using new g ask ets.

R eferring to View A, fig. 20, in stall sc r e w s. Locate choke control bracket and identification tag in original p o sitio n s. Install carburetor with new gasket on engine. Tighten carburetor-to-in take manifold bolts or nuts to 20-25 foot-pounds torque.

Connect fast idle link, acceleratin g pump rod, fuel lin e s, choke w ire, and a ccelera to r linkage. Install a ir clean er.

Sec. 6M P age 31

FUEL SYSTEM—GASOLINE ENGINES Bending Tool

B ending Tool

Finger H olding Tab V ertic a l

/ B E N D IN G LEVER TO RAISE SETTING

B EN D IN G LEVER TO LOW ER SETTING

Figure 2 3 —Typ ica l Use of B e n d in g Tool To Set Float Level

REPLACING PLASTIC LIMITER CAPS ON IDLE MIXTURE SCREWS

sim p ly in sert tip s of screw d river blades behind p la stic cap, as shown.

IMPORTANT: P la stic lim ite r caps a re in sta ll­ ed on the idle m ixture sc r e w s (see fig. 20) of Bendix Strom berg carburetors to prevent unauthorized adjustm ent. T hese p la stic caps are not to be r e ­ m oved u n less made n ec e ssa r y by som e major carburetor repair or replacem ent which affects the id le m ixture screw adjustm ent.

CAU TIO N : It is most important to use equal pressure on both screw d rive rs when prying off the plastic caps, to p re ­ vent the idle mixture screw (s) from being bent. If idle m ixture screw is bent during removal of plastic cap, the screw must be replaced.

REMOVING PLASTIC LIMITER CAPS (R efer to Fig. 24) 1. With the aid of two standard sc rew d riv ers,

2. screw .

R em ove p la stic cap from each idle m ixture

INSTALLING PLASTIC LIMITER CAPS NOTE: The carburetor must be in sta lled on the engine and properly adjusted p rio r to in sta ll­ ation of the p lastic caps.

1. Thoroughly w arm up the engine. B e su re choke is open.

2. Check dwell reading and adjust, if n e c e s ­ sa ry . D w ell reading on V6 engines should be 31 to 34 d eg rees.

3. Adjust ignition tim ing with vacuum advance hose disconnected and plugged to 7^°BTDC. R e ­ connect vacuum advance h ose.

4. Engine idle speed should be adjusted to 650 rpm by perform ing the following: a.

R eferring to figure 21, place a M-inch open end wrench on diaphragm extension of vacuum idle stop to prevent its rotation w hile adjusting plunger.

Figure 2 4 —Rem oving Plastic Lim iter C a p s (B en dix-Strom berg Carburetor)

CA U TIO N : U N D ER NO CO N D ITIO N SH O U LD T H E D IAPH RAGM E X T E N S IO N B E A LLO W E D TO R O T A T E OR IN T E R N ­ A L DAM AGE W IL L R E S U L T TO VACUUM ID L E STO P UNIT.

S e c . 6M P a ge 32

____________________________________

FUEL SYSTEM— GASOLINE ENGINES b.

Adjust the plunger with a 3 /8 -in c h open end w rench until the face of the plunger hex contacting the carburetor throttle lev er resu lts in the idle speed given e a r lie r in Step 4.

5. Adjust the idle m ixture sc r e w s. With engine running and idling speed set, turn each m ixture sc r e w "in" until engine begins to slow down or run unevenly, then back out sc r e w s until engine runs sm oothly with highest vacuum gauge reading.

NOTE: If vacuum gauge is not available,adjust the id le m ixture sc r e w s to give highest idle speed.

Turning idle m ixture sc r e w s "in" g iv es leaner m ixture; w hile turning sc r e w s "out" g iv es richer m ixture. DO NOT turn sc r e w s in tight against se a ts sin ce sc r e w s or se a ts w ill be damaged.

6. With the aid of a ham m er handle or other su itab le driving tool in sta ll p la stic caps on each id le m ixture sc rew as shown in figure 25. Each p la stic cap is to be installed in fuel RICH position (as shown). Tang on cap should contact roll pin in Figure 2 5 — Installing Plastic Limiter Caps throttle body of carburetor. U se care when in sta ll­ (Bendix-Strom berg CarburetorI ing caps to prevent bending of idle m ixture sc r e w s.

7. R eset the engine idle speed as directed in rotating clockw ise to LEAN m ixture until the idle Step 4. speed is reduced to 600 rpm .

8. Turn "in” idle m ixture screw s equally by

SPECIFICATIONS YARI-SPEED GOVERNOR INTROL PART NO. 901-685 651-735 601-734 651-739 601-738 651-759 601-758

GMC PART NO.

ENGINE MODEL

MAX. GOVERNED SPEED (RPM )* NO LOAD

2472969 3929621 3929623 3929625 3929627 3938709 3938708

351C 250 250 292 292 292 292

3900 2400 3900 2400 3900 2400 3900

* With Engine broken-in. Full load is approximately 300 RPM less than No Load RPM and will vary from engine to engine.

FUEL PUMP ENGINE

PRESSURE

V6 In-Line 350 V8 366 or 427 V8

51/2-6 4-5 7V2-9

71/2-9

VOLUME 1 1 1 1

pint pint pint pint

in in in in

20-25 35-40 20-25 10-15

seconds seconds seconds seconds

TORQUE CHART CARBURETOR TO MANIFOLD

FT. LBS.

Bolts (V6 Engine). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-25 Nuts (V8 Engine). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20-25 Nuts (In-Line Engine). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-30 Nuts (V6 Engine with Vari-Speed Governor). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8

Sec. 6M P a ge 33

FUEL SYSTEM—GASOLINE ENGINES ROCHESTER CARBURETOR SPECIFICATIONS CARBURETOR MODEL NUMBER

“M”

Carburetor N u m b e r.....................

Engine M odel.............................

Float Level ..............................

Float Drop ..............................

Accelerator Pump .....................

Metering R o d .............................

Idle V e n t ..................................

Fast Idle (B e n ch )........................

Fast Idle (R u n n ing).....................

Governed Speed * .....................

(Full Load) Vacuum Spinner Type

“2G" 7042012 292 1 /4

7042011 250 1 /4

7042124 350 23/32 1 9/32

7030699 350 23/32 1 9/3 2 1 1 /2

—

—

7042134 350 23/32 1 9/32

—

—

1 1 /2

1 1 /2

—

—

0.070

0.070 —

0.025

—

0 .1 0 0

0 .1 0 0

2400 RPM —

—

0.025

—

—

—

—

—

—

4000 RPM (Except w/AT475 Transmission) 4100 RPM (w/AT475 Transmission)

* No Load Speed is Approximately 200-250 RPM Higher Than Full Load.

HOLLEY CARBURETOR SPECIFICATIONS 4150G

CARBURETOR MODEL

Engine Displacem ent...........................................

366 427 685982 GM Part Number ..............................................

685981 R-6293A Holley Part N u m b er...........................................

R-6292A Fuel L e v e l........................................................

Bottom of Sight Plug Accelerator P u m p ..............................................

0.015 Min. 0.015 Min. 0.060 0.060 Air V e n t...........................................................

Mechanical Fast Idle 0.035 0.035 1800-2400 RPM Running 1800-2400 RPM Main Metering Jet Primary #56 #56 #71 # 7 1 Secondary 1 9/16 Primary 1 9/16 Throttle Bore 1 9/16 Secondary 1 9/16 Governed Speed * 4000 RPM (Except w/AT475 Transmission) (Full Load) 4100 RPM (w/AT475 Transmission) * No Load Speed is Approximately 200-250 RPM Highter Than Full Load.

BENDIX - STROMBERG CARBURETOR SPECIFICATIONS CARBURETOR SERIES Engine Displacement GM Part No.......................................................

Bendix No.........................................................

Code No............................................................

Venturi Size .....................................................

Main Discharge Jet No..........................................

Main Metering Jet S iz e ........................................

High Speed B le e d e r...........................................

Power By-Pass J e t ..............................................

Accelerator Pump Discharge Jet ........................

Float Level ......................................................

Accelerator Pump Travel ................................... * Excluding California Vehicles. ** California Vehicles Only.

—

0.025

WW 351C*

351C**

685275 381304 23-244 1 3/16 No. 28-36 0.058 No. 70 2 No. 60 No. 70 0.190 0 .4 2 0 -0 .4 5 0

687113 381312 23-248 1 3/16 No. 28-36 0.057 No. 70 2 No. 59 No. 70 0.190 0 .4 2 0 -0 .4 5 0

3000 RPM

Sec. 6M P a ge 34

QMG

ubielel Ctupitte

A ll inform ation in S ervice Manual S T -331-71 pertaining to ENGINE FUEL SYSTEM (SEC. 6M), pages 6M-1 through 6M -26 is applicable to m od els covered by this supplem ent with the exception of the following:

ACCELERATOR LINKAGE ADJUSTMENT (STEEL TILT CAB MODELS)

1. T ilt cab forw ard.

2. With a c celera to r controls in stalled , make su re threads of ball joint "A” are engaged as shown in figure 2.

PLACE A N D SECURE ACCELERATOR PEDAL Z4” FROM FLOOR MAT

ADJUST BALL JOINT " B ” AT INJECTION PUMP TO OBTAIN FULL THROTTLE

3. D ep ress a cc e le ra to r pedal to %" (fig. 2) from floor mat.

4. Adjust ball joint "B" at injection pump throttle le v e r to obtain full throttle.

NOTE: It may be n e c e ssa r y to adjust ball joint "B" (minimum engagem ent at either ball joint no le s s than %").

Aa

T W^ BOOT

£

THREADS OF BALL JOINT " A ” EN G AG ED '/2' CHECK POINTS AT ACCELERATOR PEDAL

ADJUSTMENT POINT AT INJECTION PUMP O N ENGINE

5. Lower cab to operating position.

NOTE: A ccelera to r pedal linkage is properly adjusted when a cceleratin g pedal is contacting floor mat and the fuel injection pump lev er is in full throttle position.

Figure 1— Steel Tilt C ab Acceleration Linkage

A iA . G le a tte te (ALL ENGINES) A ll inform ation in S erv ice Manual ST -331-71 "AIR CLEANERS” p ages 6M -27 through 6M-31 is applicable to m odels covered by this supplem ent with the exception of the following: A ir clea n ers should be inspected and ser v ic ed at in tervals s p e c i­ fied in E m issio n Control booklet, or m ore often under s e v e r e dust conditions; a lso , w henever dirt is v isib le in elem ent or o il. A ir clea n ers on v eh icles operating in dust sto rm s should be cleaned im m ediately a fter such sto rm s occur.

The air clean er should be inspected to make certain that all h oses and ducts are intact and co rrectly in stalled . O perational function should be checked by inspecting position of valve in air intake (when used).

With engine stopped, valve should be open. At underhood tem perature below 100°F ., with engine running, valve should be partially or fully c lo se d . A s engine underhood tem perature r is e s , the valve should open.

Sec. 6T Page 35

SECTION 6T

GosnfLSiedAxM a n d Cj&ue/istosiA, S erv ice inform ation applicable to air co m p re sso r s and governors u sed on v e h ic le s covered by this Supplement rem ains the sam e as covered on p ages 5D -80 through 5D -93 in AIR COMPRESSORS AND GOVERNORS (SEC. 5D) in S ervice Manual S T -331-71 except as follows:

GENERAL INFORMATION

in p r e ssu r e adjusted to 85 PSI and the cut-out p r e ssu r e adjusted to 100-107 p si.

Midland R oss and Bendix W estinghouse air co m p r e sso r s are interchangeable as com plete a s ­ se m b lie s on all m odels covered by this Supplement.

R efer to ,TA ir C om pressor Model Application Chart" la te r in this section .

GOVERNOR ADJUSTMENT Inform ation applicable to governor adjustment rem ain s the sam e as covered on page 5D-92 under “ A ir C om pressor G overnor” in AIR COM­ PRESSORS AND GOVERNORS (SEC. 5D) in Serv­ ic e Manual ST-331-71 except as follows: The Midland R oss N-20856 governor used on the N -5601-R air com p resso r should have the cut-

GOVERNOR ADJUSTMENT CHART C om pressor Model

Governor Model

Cut-In P r e ssu r e

Cut-Out P r e ssu r e

MIDLAND-ROSS N -5601-R N -20856 N -20856-C N -5601-S N -6400-N N -20856-C N -5217-B A N-20856-C

85 105 105 105

P si.

P s i.

P s i.

P s i.

100-107 105-127 105-127 105-127

BENDIX WESTINGHOUSE 281977 276102 282564 276226 282567 276226 282896 276104

105 105 105 105

P s i.

P s i.

P s i.

P si.

125 125 125 125

P s i.

P s i.

P s i.

P s i.

AIR COMPRESSOR MODEL APPLICATION CHART TRUCK MODELS

COMPRESSOR MODEL

MANU­ FACTURER

C U .-F T .

CAPACITY

TYPE COOLING

TYPE DRIVE

TYPE FILTER

STANDARD 50 SERIES CE, SE CG, SG SM TG 60 SERIES CE, ME, TE CM, TM

N -5601-R or 282567 N -5601-S or 282896 281977 or.

N -6400-N N -6400-N or 281977

M-R B-W M-R B-W B-W M-R M-R B-W

1A n n n n

N -5601-R or 282567 N -6400-N or 281977

M-R B-W M-R B-W

TA TA

A ir Air A ir A ir Air Air Air Air

B elt B elt B elt B elt B elt B elt B elt B elt

Paper Foam Paper Foam P aper Paper P aper P aper

n TA n TA

A ir A ir A ir Air

B elt B elt B elt B elt

Paper F ib ers Foam Paper F ib ers Paper

ta

F ib ers F ib ers

F ib ers F ib ers

OPTIONAL 50 SERIES CE, SE 60 SERIES CE, ME, TE

N -5217-B A or 282564

M-R B-W

12 12

Water Water

B elt B elt

Paper F ib ers Foam

N -5217-B A or 282564

M-R B-W

12 12

Water Water

B elt B elt

Paper F ib ers Foam

P si.

P si.

P si.

P si.

Sec. 6T P age 36________________________________________

AIR COMPRESSOR A N D G O V ERN O R

NOTE The air com p resso r is the ONLY sou rce of supply for the veh icle braking sy ste m . Faulty operation of the com p resso r w ill resu lt in im ­ proper function of brakes.

Sec. 6Y Page 37

SECTION 6Y £ n a in e

Z le c t t U

c a l

NOTE: E le c tric a l sy stem inform ation applicable to m odels covered by this supplem ent rem ains the sam e as covered on pages 6Y -1 through 6Y -68 in ENGINE ELECTRICAL (SEC. 6Y) in S ervice Manual ST -331-71 except as follow s: This group, covering “ ON-VEHICLE MAINTENANCE AND RE­ PLACEMENT” of charging sy ste m components is divided into section s shown in the index following:

Subject P age No. B attery .......................................................................................................~ !

37 Model Application Chart ....................................................................

37 B attery Specifications ........................................................................

39 Starting System ...............................................................................................

39 Model Application Chart ....................................................................

39 Starting System Specifications .........................................................

41 Ignition S y s t e m ..................................................................................................

42 Ignition System Specifications .........................................................

42 A lternating Current Generating System (Non-Integral Type) . .

43 Model Application Chart ....................................................................

43

S erv ice inform ation applicable to b a tteries used on v eh icles covered by this supplem ent rem ains the safne as covered under "BATTERY” pages 6Y-1 through 6Y -11, in ENGINE ELECTRICAL (SEC. 6Y) in Serv ice Manual S T -331-71, except as follows:

BATTERY MODEL APPLICATION CHART TRUCK SERIES STANDARD S e r ie s T E /T M -50 (03): T E /T M -60 ( 0 3 - 1 3 ) ...............

S e r ie s C E /C S-40; C E /C M /C S -5 0 .................................

S e r ie s C E /C M /M E -6 0 ..........................................................

S e r ie s S E /S M /S S -5 0 .............................................................

S e r ie s C G /SG /TG -50 ..........................................................

PART NO. 1980030 1980145 1980145 1980149 1980758

MODEL E -5000 E-5000 E-5000 E-5000 20T-4A (Cont’d.)

S e c . 6Y P a g e 38

BATTERY BATTERY MODEL APPLICATION CHART (CONT.) TRUCK SERIES OPTIONAL PART NO. S e r ie s T E /T M -50; T E /T M -60 .........................................1980038 S e r ie s C G /SG /T G -50 .............................................................. ...1980046 S e r ie s C E /C S-40; C E /C M /C S-50 ................................... 1980149 S e r ie s C E /C M /M E -60 .............................................................. ... 1980149

GENERAL On S e r ie s 40 through 60 conventional cab ga so lin e engine m odels, a sin g le 12-volt battery is mounted in the right front corner of the engine com partm ent.

On ste e l tilt cab m odels equipped with the g a so lin e engine, a sin g le 12-volt battery is mounted forw ard of radiator above the cro ssm em b er inside the right-hand fram e ra il, On v eh icles equipped with the Turbium or 6V53 D etroit D ie se l Engine, a sin g le 12-volt battery is mounted on the fram e ra il behind the cab.

USE OF BOOSTER BATTERY A N D JUMPER CABLES CAUTION Any procedure other than the follow­ ing could result in: 1. Personal injury caused by electrolyte squirting out of the battery vents.

2. Personal injury or property damage due to battery explosion.

3. Damage to the charging system of the booster vehicle or of the immobilized vehicle.

DO NOT attempt to jump start a ve­ hicle having a frozen battery because the battery may rupture or explode. If a frozen battery is suspected, examine all fill vents on the battery. If ice can be seen, or if the electrolyte fluid cannot be seen, do not attempt to start the vehicle with jumper cables as long as the battery remains frozen.

Both the booster battery and the d is­ charged battery must be treated carefully when using jumper cables. Follow E X A C T ­ LY the procedure outlined below, being careful not to cause sparks.

MODEL E-3000 8D-250 E -5000 E -5000

2. Rem ove vent caps from both the booster and the discharged b atteries. Lay a cloth over the open vent w e lls of each battery. T hese two actions help reduce the p ossib ility of explosion which is alw ays p resen t when connecting a "live" booster battery to a "dead" battery.

3. Attach one end of one jumper cable to the p o sitiv e term inal of the b ooster battery (identified by a red color, "+" or "P" on the battery ca se , post or clamp) and the other end of the sam e cable to the p o sitiv e term inal of the discharge battery.

DO NOT perm it v eh icles to touch each other as this could estab lish a ground connection and counteract the benefits of this procedure.

4. Attach one end of the rem aining negative (-) cable to the negative term inal (black color, "-" or "N") of the booster battery, and the other end to ground location on the v eh icle being started. DO NOT CONNECT DIRECTLY TO NEGATIVE POST OF DEAD BATTERY - taking care that clam ps from one cable do not inadvertantly touch the clam ps on the other cable. DO NOT lean over the battery when making th is connection.

NOTE: The ground location for m odels having the battery in stalled under the hood is on the engine.

The ground location for m odels having a fram e mounted battery is on the fram e r a il. The ground is to be at le a st 12 inches from the battery fille r cap s, providing good e le c tr ica l conductivity and current carrying capacity, and must avoid moving hot or e le c tr ica l hazards such as fans, m anifolds, and spark plug term in als.

DISCONNECTING BOOSTER BATTERY AND JUMPER CABLES 1. Taking care that clam ps from one jumper cable do not inadvertently touch clam ps on other jumper cable, disconnect jum per lead from ground location on the veh icle being started. DO NOT lean over the battery when disconnecting this lead.

2. Rem ove rem aining end of negative (-) jump­ er cable from the b ooster battery.

3. R em ove one end of the rem aining jumper cable from p ositive term inal of the discharged battery, then rem ove other end of the sam e cable CONNECTING BOOSTER BATTERY from p ositive term inal of the b ooster battery.

AND JUMPER CABLES 4. R em ove cloths, from open vent w ells of 1.

Set parking brake and p lace automatic each battery. D iscard cloths as they may have c o r ­ tra n sm issio n in "PARK" (neutral for manual tra n s­ ro siv e acid on them . Install vent caps on both the m issio n ). Turn off lig h ts, heater and other loads. b ooster and the discharged battery.

Sec. 6Y P age 39

STARTING SYSTEM

BATTERY SPECIFICATIONS i

PART NO. f

Make Model No. Catalog No. Volts No. of Plates Per Cell Cranking Power @ 0°F. (Watts) Amp. Hr. Capacity at 20 Hr. Rate Cranking Ability at 0°F. and 300 Amps.

Load Test Amp Load Voltage and Temperature Chart*

1980030

1980038

1980046

1980145

1980149

1980758

Delco-Remy E-5000 R-59

Delco-Remy E-3000 Y-71

Delco-Remy 8D-250 985

Delco-Remy E-5000 R-89

Delco-Remy E-5000 R-89W

Delco-Remy 20T-4A 759

12

12

12

12

12

12

11

11

11

2900 61 1.6 Min.

3000 70 2.0 Min.

29 5900 205 10.5 Min.

2900 61 1.6 Min.

15 3750 80 2.6 Min.

19 4500 150 6.0 Min.

180 No. 1

No. 1

450 No. 1

180 No. 1

230 No. 1

450 No. 1

210

* Voltage must not drop below minimum listed at given temperature when battery is subjected to proper load for 15 seconds and is 1.200 specific gravity at 80°F. or more.

CHART NO. 1 - VOLTAGE AND TEMPERATURE CHART Electrolyte Temperature

80°F.

70°F.

60°F.

50°F.

40°F.

30°F.

20°F.

10°F.

0°F.

Voltage Minimum 12-Volt

9.6

9.6

9.5

9.4

9.3

9.1

8.9

8.7

8.5

S t a / d in a

S y it e t n

Starting sy stem inform ation applicable to v e h ic le s covered by th is supplem ent rem ains the sam e as covered under "STARTING SYSTEM" p ages 6Y-12 through 6Y -16 in ENGINE ELECTRICAL (SEC. 6Y) in S erv ice Manual ST -331-71 except as follow s:

STARTING MOTOR MODEL APPLICATION CHART STANDARD TRUCK SERIES PART NO. CE-40; C S/SS-50 ...............................................................................

1108360 C E /S E /T E -5 0 ...................................................................................... 1108362 CS-40 (With Autom atic T r a n s m is s io n ).................................. 1108367 CS-40 (With Manual T r a n s m is s io n ) ........................................ 1108368 CM /SM /TM -50; CM /TM -60 .........................................................

1108483 C E /M E /T E -60 ..................................................................................... 1108487 C G /SG /TG -50 ........................................................................................ 1113686 4

OPTIONAL PART NO. CE/CS-40; C E-50 (03-13); C S /S E /S S -5 0 ............................... 1108486 CS-40; CE-50 (02); C S /S E /T E -50 ........................................... 1108485 SE -50 ....................................................................................................... 1108372 C E -50 (03-13); Except With A T-540 Automatic T rans. . . 1108485 C S-40 With L6-292 Engine and Manual T ran sm ission . . 1108360 C E /SE -50 With V 8-366 E n g in e ...................................................... 1108369 T E -50 With V 8-366 Engine . ...........................................................

1108487 C E -60 (03-13); M E /T E -60 With V 8-427 Engine ............ 1108484

Se c . 6Y P age 40

STARTING SYSTEM

€ > j- * 0 0 B L K — ||l> FRAME —

—

(AMMETER. SH UNT)'

STARTER ASM.

FRAME

}

TO AMMETER AND VOLTMETER 110 BLK. (AMMETER SHUNT)'

STARTERASM.

GENERATOR

GENERATOR

TRANSISTORIZED VOLTAGE REGULATOR

\

VOLTAGE REGULATOR

16 BLK --------- 16 BLK-----------------TO ACCESSORY BUS BAR

■16BLKSTARTER MAG. SW.

■H hQQQr-OSTARTER MAG. SW .

CONTROL SW. STARTER CONTROL RELAY

STARTER CONTROL RELAY

I6BLK I6 B L K ' CONTROL SW. ---14 PIN K ---

■12PU RPLE'

•12PURPLE'

WITH M ECHANICAL TRAN SM ISSIO N

TRANSMISSION CONTROL

WITH AUTOMATIC TRANSM ISSION

Figure 1— Starter Automatic D isengagem ent and Lock-Out (Series TG50) (Typical)

STARTER AUTO M ATIC DISENGAGEM ENT A N D LOCK-OUT Information applicable to the Starter Automatic D isengagem ent and Lock-Out sy ste m used on S eries C G /SG /T G -50 rem ain s the sam e as covered under “ Starter Autom atic D isengagem ent and Lock-Out” in ENGINE ELECTRICAL (SEC. 6Y) in S ervice Manual ST -331-71 except as follow s: NOTE: A typ ical sy ste m u sed on S e r ie s TG50 is shown in figure 1, and a typ ical sy stem used on S e r ie s CG /SG -50 is shown in figure 2.

On som e v eh icles equipped with the automatic tra n sm issio n , the sta r te r magnetic sw itch operat­ ing c o il is energized through the combination neu­ tra l safety and back-up lamp sw itch when the tra n s­ m issio n shift lev er is in neutral position.

When tra n sm issio n shift lev er is in neutral p osition and engine control sw itch is placed in ’'START" position, current from the battery w ill en ergize the sta rter m agnetic sw itch operating c o il through the com bination neutral start and back-up lamp sw itch, thus com pleting circuit to the starting m otor. When tra n sm issio n is shifted out of neutral, feed circu it to sta rter m agnetic sw itch operating co il is broken, thus preventing sta rter engagem ent.

»

Figure 2 — Starter Autom atic D isenga ge m en t and Lock-Out (Series C G / S G 5 0 ) (Typical) f

Sec. 6Y P age 41

STARTING SYSTEM STARTING SYSTEM SPECIFICATIONS STARTER MODEL M a ke ..............................

S e r ie s .............................

Type ..............................

Type of D riv e ...................

Rotation (Viewed at Drive End) No Load Test V o lts ...........................

Min. Amps. * ..............

Max. Amps. * ..............

Min. RPM ...................

Max. R P M ...................

Pinion C le a ra n ce ..............

1108360 (a) 1108362 (b)

110836/

1108368

1108369 1108372

Delco-Remy 10MT 125 Overrunning Clutch CW

Delco-Remy 10MT 125 Overrunning Clutch CW

Delco-Remy 10MT 125 Overrunning Clutch CW

Delco-Remy 10MT 125 Overrunning Clutch CW

9 55 80 3500 6000 0.010” -0.140"

9 50 80 5500 10,500 0.010” -0.140”

9 50 80 5500 10,500 0.010” -0.140”

9 35 75 6000 9000 0.010” -0.140”

1114356 (a) 1114344 (b)

1114362

1114356

1114356

12

12

12

12

13-15.5 5

13-15.5 5

13-15.5 5

13-15.5 5

14.5-16.5

14.5-16.5

14.5-16.5

14.5-16.5

10

10

10

10

1108483

1108484

1108485 1108486 1108487

1113686

Delco-Remy 10MT 125 Overrunning Clutch CW

Delco-Remy 10MT 125 Overrunning Clutch CW

Delco-Remy 10MT 125 Overrunning Clutch CW

Delco-Remy 35MT 185 Overrunning Clutch CW

9 55 80 3500 6000 0.010” -0.140"

9 35 75 6000 9000 0.010”-0.140”

9 35 75 6000 9000 0.010” -0.140”

9 130 160 5000 7000 .0.010” -0.140”

1114356

1114359

1114356

1115518

12

12

12

12

13-15.5 5

13-15.5 5

13-15.5 5

26-29 5

14.5-16.5

14.5-16.5

14.5-16.5

18-20

* Includes Solenoid

STARTER SOLENOID MODEL Rated Voltage .................

Current Consumption Pull-In Winding Amps..........................

V o lts .........................

Hold-ln Winding Amps..........................

V o lts .........................

STARTER MODEL M ake..............................

S e r ie s .............................

Type ..............................

Type of D riv e ...................

Rotation (Viewed at Drive End) No Load Test V o lts .........................

Min. Amps. * ..............

Max. Amps. * ..............

Min. RPM.....................

Max. RPM....................

Pinion Clearance .............. * Includes Solenoid

STARTER SOLENOID MODEL Rated Voltage .................

Current Consumption Pull-In Winding Amps..........................

V o lts .........................

Hold-ln Winding Amps..........................

V o lts .........................

10

10

10

10

Sec. 6Y P age 42

9 <

f4 u tiQ

* t

Ignition sy ste m inform ation applicable to v e h ic le s covered by this supplem ent rem ain s the sam e as covered under ‘‘IGNITION SYSTEM” pages 6Y-17 through 6Y-31 in ENGINE ELECTRICAL (SEC. 6Y) in S ervice Manual S T -331-71, except r e fe r to ignition sy ste m sp ecification s following:

IGNITION SYSTEM SPECIFICATIONS

ENGINE DISTRIBUTOR

250

Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Delco-Remy Model No. .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . ..

1110489 Clockwise Rotation (Viewed at R otor).................

Point Opening (In.) N e w ....................................

0.019 Used ............ . . . . . . . . . . . . . . . . . . . . . .

0.016 Cam Angle (Degrees). .. . . .. . .. . .. . . .. . .. . .

31-34 (1) Centrifugal Advance Start D e gree s. . . . . . . . . . . . . . . . . . . . . . . . . . .

0-2 R P M ...................................

650 Intermediate D egre es. . . . . . . . . . . . . . . . . . . .

R P M ...................................

Intermediate D egre es. . . . . . . . . . . . . . . . . . . .

6-8 R P M ...................................

1150 Maximum Advance Degrees . . . . . . . . . . . . .

11-13 Rpm ...................................

2050 Firing O rder. .. . . .. . .. . .. . . .. . .. . .. . . .. . .. .

1-5-3-6-2-4 *(1) Set with vacuum in full retard.

(2) Satisfactory Range When Adjusting Set to 30° Gives .016 Point Ignition Timing Idle Speed (RPM) . .......................

700 Distributor Setting (1 ) . . . . . . . . . . . . . . . . . . . .

4° BTDC (1) With Distributor Vacuum Ports on Carburetor Plugged.

Distributor Vacuum Control Model No. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1973434 Inches of Mercury to Start Advance. . . . . .

7-9 Inches of Mercury for Maximun Advance ..

15.0-16.5 Maximun Advance (Distributor D egrees)*...

11.5 * * Plus or minus one degree.

Ignition Coil Model No. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

115208 Spark Plugs M a k e ...................................

AC R-46-T Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

S iz e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14MM-5/8” Point Gap . .. . . .. . .. . .. . . .. . .. . .. . . .. . ..

0.035 Torque (Ft. L b s.). .......................

15 (1) Use R-42-T on V8-427 Engine and Set Point Gap to 0.035”.

292

351-C

350

350

366 427

Delco-Remy 1110486 Clockwise

Delco-Remy 1110478 Clockwise

Delco-Remy 1111364 Clockwise

Delco-Remy 1112048 Clockwise

Delco-Remy 1111365 Clockwise

0.019 0.016 31-34 (1)

0.019 0.016 31-34 (1)

0.5-2.5 600

0-2 510 4-6 750 6.5-8.5 1100 10-12 1750 1-6-5-4-3-2

700 4° BTDC

—

—

—

—

— —

28-32 (2)

28-32 (2)

28-32 (2)

0-2 550

0-2 600

0-2 625

4-6 850 9-11 1900 1-8-4-3-6-5-7-2

4-6 850 9-11 1900 1-8-4-3-6-5-7-2

7.S-9.5 1200 12-14 2200 1-8-4-3-6-5-7-2

600 7 1/2° BTDC

600 4° BTDC

600 4° BTDC

550 8° BTDC

1973435 8-10 15.5-16.3 9

1973423 3-5 6.25-8.2 7.5

NONE

1973437 7-9 15-16 8

NONE

1115208

1115205

1115293

1115429

1115293

AC R-44-T 14MM-5/8” 0.035 15

AC CR-43-N 14MM-13/16” 0.035 30-34

AC R-44-T 14MM-5/8” 0.035 15

AC R-44-T 14MM-5/8” 0.035 15

AC R-43-T (1) 14MM-5/8” 0.030 (1) 15

7.5-9.5 1050 13-15 2000 1-5-3-6-2-4 Opening.

—

—

—

—

Sec. 6Y Page 43

(NON-INTEGRAL TYPE) A non-integral (generator and separate regulator) or an integral (generator with a so lid state regulator built in) type generating sy stem is used on v e h ic le s covered by this supplem ent.

Inform ation applicable to the non-integral type alternating current generating sy ste m rem ains the sam e as covered under ''ALTERNATING CURRENT GEN­ ERATING SYSTEM” pages 6Y-32 through 6Y-57 in ENGINE ELECTRICAL (SEC. 6Y) in S erv ice Manual S T -331-71 except as follows: NOTE: Inform ation applicable to the integral type alternating current generat­ ing sy stem rem ains the sam e as covered under "ALTERNATING CURRENT GEN­ ERATING SYSTEM - INTEGRAL TYPE” pages 6Y-58 through 6Y -68 in ENGINE ELECTRICAL (SEC. 6Y) in S ervice Manual ST -331-71.

MODEL APPLICATION CHART AMPERAGE STANDARD 37-A M P. 42-A M P. _ 42-A M P. _ 42-A M P. 42-A M P. 61-A M P. _

C E /C S -40 (02); C E /C S-50 (02) C E /C S-40 (03); C E -50 (03-13) ..................

C M /C S /T E /T M -50 (03); C M /TE/TM -60 TG -50 (03-13) ......................................................

C E /M E -60 ............................................................

C G /SE /S G /S M /SS -50 .......................................

GENERATOR ............

1100838 ............

1100842 ............

1100842 ............

1100842 ............

1100547 ............ 1100849

OPTIONAL 42-A M P. 42-A M P. _ 61-AM P. 61-AM P. 61-AM P. _ 61-A M P. 62-A M P. 62-AM P. _ 62-A M P. 100-AM P. -

C E /C S-40 (02); C E /C S-50 (02) ..................

C E -50 (02-0 3 -1 3 ) ................................................

C E /C S -40 (02,03); C E/C M /C S-50 T E /T M -50; C M /T E /T M -60 ........................

TG -50 > .....................................................................

CE-50; C E /M E -60 .......................................

C E /C S - 40; C E /C M /C S/SE /SG /SM /SS - 50 T E /T M -50; T E /T M -60 .................................

TG-50 .....................................................................

S E /S G /SM /SS -50 ................................................

............ ............ ............ ............ ............ ............ .... ............ ............. ............

1100842 1100547 1100849 1100849 1100849 1100548 1117782 1117782 1117782 1117141

USE WITH REGULATOR 1119515 1119515 1119515 1119507 Integral 1119515

1119515 Integral 1119515 1119515 1119507 Integral 1116378 1116378 1116374 Integral

GENERATING SYSTEM GENERAL DESCRIPTION (NON-INTEGRAL TYPE) The b asic charging sy ste m components include the battery, the s e lf-r e c tify in g , alternating current type generator, the voltage regulator, and interconnecting w iring.

An indicator lamp (tell-ta le) which indicates only whether or not the generator is charging is used on s te e l tilt cab m od els. An am m eter or v oltm eter type charge indicator is available on all v e h ic le s covered by this supplem ent.

A typical generating sy ste m used on veh icles

equipped with the tw o-unit type regulator is sch em atically illu strated in figure 1, and a typical generating sy stem used on v eh ic le s equipped with the tran sisto rized type regulator is sch em atically i l ­ lustrated in figure 2.

NOTE: Schem atic diagram s of generating s y s tem s used on veh icles equipped with the integral type generating sy ste m (generator with internal tra n sisto rized type regulator mounted within the generator) are covered la ter in th is section .

S ec . 6Y Page 44

A. C. GENERATING SYSTEM (NON-INTEGRAL TYPE)

Figure 1— Schematic D iagram of A. C. C harging Circuit with Two Unit Type Regulator (Typical)

O - ~ * 0 0 8LK.— ||l' FRAME

FUSIBLE LINK GAS MODELS STARTER ASM.

-(A M M ETER. SH UNT)' TO AMMETER AND VOLTMETER GENERATOR

FUSIBLE LINK DIESEL MODELS

SWITCH OffitfNUSED)

t r a n s is t o r i z e d vo lta g e r e g u l a t o r

TRANSISTORIZED V0LTA6E REGULATOR

GENERATOR 62AMP

AC C ESSO RY

I6BLK

STARTER ASM. TO STARTER MA6.

JCT. BLOCK-DIESEL MODELS

■I6WHT.

I6BLK •

STARTER MAG. SW.

STARTER CONTROL R tLA Y CONTROL SWITCH

I

OT

CONTROL SW. -— 14 PINK — 12 PURPLE

TRANSMISSION CONTROL

WITH 1116374 REGULATOR

12 PURPLE

WITH 1116378 REGULATOR

Figure 2 — Schematic D iagram of A .C . Charging Circuit with Transistorized Type Regulator (Typical)

T-9120

Sec. 7A Page 45

SECTION 7

7\anA M uA A io-n c u iJ l G lu tc h e i

*

A ll inform ation in Service Manual S T -331-71 pertaining to TRANS­ MISSIONS AND CLUTCHES is applicable to m odels covered by this supplem ent with the addition of the following:

SECTION 7A

GanfruU Jlinkacje.

LINKAGE ADJUSTMENT (AT475 TRANSMISSION) MANUAL SHIFT LINKAGE ADJUSTMENT (R efer to Figure 1) The manual shift linkage for the AT475 trans­ m ission should fully engage all tra n sm ission range p osition s just before the lev er hits the "stops” in the shift control tow er. Shift the se le c to r lever (B) through each position w hile feeling for full engage­ ment in the tra n sm issio n . Note the position of the se le c to r lev er after each shift. T ran sm ission should not engage ”D" (Drive) or ”R ” (Reverse) until the se le c to r le v e r on the control tower is com pletely out of the "N" (Neutral) notch. If lever is not properly located or operating, the linkage should be adjusted as follow s: 1. Locate tra n sm issio n se le c to r lev er (B) against stop in "N" position.

2. Check cable for dim ension shown in View A -A , and adjust if n e c e ssa r y . Anchor cable to bracket at point (C).

3. D isconnect c le v is (F) from shift cable (I).

Anchor cable (I) secu rely at point (D).

4. L ocate tra n sm issio n shift le v e r (G) in ”N .”

NOTE: Neutral position of tra n sm ission shift lev er (G) is obtained by rotating le v e r clockw ise com pletely, then back one notch.

5. Adjust c le v is (F) for fr e e -en try of clevis pin, through tra n sm issio n shift le v e r (G). Then shorten cable by rotating c le v is two turns clock­ w ise . Tighten jam nut against clev is; in sta ll clevis pin and secu re with cotter pin.

6. A fter com pleting a ll adjustm ents, operate v eh icle and check operation of the se le c to r lever through all shift ranges. Readjust if n ecessa ry .

NEUTRAL SAFETY AND BACK-UP LAMP SWITCH CHECK AND ADJUSTMENT (R efer to Figure 1) NOTE: -'Manual Shift Linkage Adjustment”

should be perform ed as d escrib ed p reviou sly, p rior to adjustment of the neutral safety sw itch.

1.

B lock driving w h eels, apply parking brake, and perform the following to prevent the vehicle from accidentally starting w hile perform ing ad­ justment.

Sec. 7B P age 46

TRA N SM ISSIO N ON-VEHICLE SERVICE NOTE: Pull secondary w ire out of center sock et in the distributor cap and ground w ire to prevent p o ssib le damage to co il.

2. P osition se le c to r lev er in "N" (Neutral).

Turn ignition sw itch to "START" position. Engine should start but v eh icle must not m ove. Turn ig ­ nition sw itch to "OFF." 3. P osition se le c to r le v e r in "R" (R everse).

Turn ignition sw itch to "START" position. Engine m ust not start.

4. Move se le c to r le v e r to "D" (Drive) p o si­ tion. Engine m ust not sta rt.

5. If the previous conditions are not met for the neutral safety and back-up lamp switch,adjust the sw ivel p osition on rod (H) until operation is as stated in Steps 2 -4 .

DOWNSHIFT SWITCH ADJUSTMENT NOTE: The downshift sw itch mounted at the carburetor is activated by the carburetor throttle le v e r . When the throttle lev er reach es wide open p osition it resu lts in a forced downshift to the tra n sm issio n u n less veh icle is in "LI." 1. Move carburetor throttle lev e r to wide open position.

2. Loosen two adjusting scre w s (at slotted holes) on sw itch bracket.

3. P osition sw itch and bracket assem b ly so that clearan ce between throttle lev er and sw itch plunger (fully depressed) is .05-inch.

4. Tighten the two adjusting sc rew s to 20-30 inch-pounds torque.

5. Road test and check for proper operation.

SECTION 7B

On-Velude Sendee. Op&uuUo-HA, AT475 TRANSM ISSIO N REPLACEMENT The follow ing p rocedures apply to vehicles covered by this supplem ent. However, it may be n e c e ssa r y to rem ove air tanks, fuel tanks, special equipment, e tc ., on som e v eh icles to provide clearan ce before the tra n sm issio n is rem oved.

Overhaul inform ation for the AT475 tran s­ m issio n is contained in 40-60 S eries Truck Chas­ s is Overhaul Manual Supplement S T -334-72.

Figure l - A T - 4 7 5 Flex Plate Installation (In-Line and V8 Engines)

REMOVAL 1. B lock veh icle so that it cannot m ove. D is ­ connect ground strap from battery negative (-) p o st. R em ove the spark plugs so the engine can be turned over manually.

2. R em ove the oil le v e l gauge (dipstick).

Drain tra n sm issio n by disconnecting oil fille r tube at right sid e of tra n sm issio n . R em ove bracket holding oil fille r tube to tran sm ission and rem ove fille r tube from v eh icle. R eplace dipstick in tube and cover the oil pan opening to prevent entry of foreign m aterial.

3. D isconnect oil cooler lin es from fittings on right sid e of tra n sm issio n c a se . Plug line ends and ca se openings with lin t-fr e e m aterial.

4. D isconnect the manual se le c to r cable from shift lev e r at left sid e of tra n sm issio n .

5. D isconnect vacuum modulator line from m odulator.

6. D isconnect the sp eedom eter shaft fitting from adapter at rear of tra n sm issio n .

7. D isconnect the p rop eller shaft from tran s­ m issio n as d escrib ed in "PROPELLER SHAFTS" (SEC. 4D) of S ervice Manual S T -331-71.

8. D isconnect the m echanical parking brake linkage at the right sid e of tran sm ission (if used).

9. Rem ove the sh eet-m eta l under pan from beneath the converter housing. As the flex-p late (fig s. 1 and 2) is rotated, rem ove the three bolts retaining fle x -p la te assem b ly to converter.

10. Support the tra n sm issio n with 500-pound tra n sm issio n floor jack. The jack must be p osition ­ ed so tran sm ission oil pan w ill not support the weight of tra n sm issio n . Fasten a safety chain over top of tra n sm issio n and to both sid e s of jack.

Sec. 7B Page 47

TRANSMISSION ON-VEHICLE SERVICE 11. P la ce a support under rear of engine and rem ove tra n sm issio n exten sio n -to -en g in e rear support bolts (fig. 3). Then rem ove engine rear support from fram e of veh icle.

12. Rem ove the tra n sm issio n c a se-to -fly w h eel housing bolts and w ash ers.

13. C arefully in sp ect tra n sm issio n and sur­ rounding area to be su re no lin e s, h o se s, or w ires w ill in terfere with tra n sm issio n rem oval.

IMPORTANT: When rem oving tran sm ission , keep rear of c a se low er than the front so as not to lo s e the con verter. Install converter holding tool (J-5384) when tra n sm issio n is rem oved from the v eh icle.

14. Move tra n sm issio n a ssem b ly from the engine, low er the assem b ly carefully and move it out from the v eh icle.

INSTALLATION 1.

R aise v eh icle sufficien tly to allow in sta ll­ ation of tra n sm issio n . With tra n sm issio n assem bly mounted on tra n sm issio n jack m ove tra n sm ission into position aligning converter with fle x plate (fig s. 1 and 2). Check for and clean away any for­ eign m aterial in flyw heel pilot hole and flywheel fle x -p la te assem b ly and front face of tran sm ission c a s e . Rotate flyw heel ring gear, as n e c e ssa ry , so that the three bolt h oles in flex plate are aligned with bolt holes in con verter carefu lly m ove trans­ m issio n assem b ly toward engine so fle x -p la te -to con verter bolts can be lo o se ly in sta lled and so that pilot on tra n sm issio n converter en ters pilot

Fig u re 3 —En g in e Rear M ounting with A T -4 7 5 Transm ission

Sec. 7B P age 48

TRA N SM ISSIO N ON-VEHICLE SERVICE hole in center of flyw heel flex-p late assem bly.

2. Install bolts and w ash ers that attach trans­ m issio n c a se to flyw heel housing. Tighten bolts to 25-30 foot-pounds torque.

3. Tighten the three flex -p la te-to -co n v erter b olts.

In-L ine and V8 Engines . 25-30 F t.-L b s.

V6 Engines ........................ 20-30 F t.-L b s.

4. Install engine rear support (see fig. 3).

NOTE: An arrow is stam ped in the center of the engine rear support. This arrow should face the front of veh icle when equipped with 292, 350, or 351C engines. The arrow should face the rear of veh icle when equipped with 366 engine.

5. C arefully low er engine and transm ission assem b ly onto engine rear support. Tighten engine rear su p p o rt-to -tra n sm issio n bolts to torques sp ecified in figure 3. Bend lock tabs down over heads of bolts (where used). Remove lifting equip­ ment from beneath v eh icle.

6. Install the sheet m etal underpan beneath the converter housing.

7. Rem ove plugs from o il cooler lin es and tra n sm issio n c a se fittin gs. Be sure fittings are clean and lin t-fr e e , then connect oil cooler lines to tra n sm issio n .

8. Install o il cooler tube and bracket on right sid e of tra n sm issio n . Install oil le v e l gauge (dip­ stick ).

9. Connect the speedom eter shaft fitting to adapter at rear of tra n sm issio n .

10. Connect p rop eller shaft to transm ission a s describ ed in "PROPELLER SHAFTS" (SEC.4D) of S erv ice Manual S T -331-71.

11. Connect parking brake linkage (if used) at sid e of tra n sm issio n .

12. Connect the manual se le c to r cable to shift le v e r at left sid e of tra n sm issio n .

13. Connect the vacuum modulator line to modulator.

W A R N I N G : TO P R E V E N T A C C I­ DENTAL ST A R T IN G OF V E H IC LE , W H IL E IN A D R IV E RANGE, BE SURE THE IGNITIO N SW ITCH IS IN THE "O F F ” POSITION B E F O R E P R O C E ED IN G TO THE N EXT STEP. 14. Install spark plugs and connect battery ground strap, p reviously disconnected (for safety).

15. Connect any other lin e s, h o ses, or w ires which w ere disconnected to aid in tran sm ission rem oval.

16. R efer to the "TRANSMISSION CONTROL LINKAGE" (SEC. 7A) of this supplem ent for ad­ justm ent of manual shift linkage.

AT475 AUTOMATIC T RA N SM ISSIO N LUBRICATION DETAILS IMPORTANT: For inform ation on lubrication in tervals and type of lubricant for AT475 tra n s­ m issio n , refer to LUBRICATION (SEC. 0) of this manual.

CHECKING FLUID LEVEL If oil lev e l is too high or too low, foam ing of o il w ill occur. This w ill affect lubrication, cooling, and p r e ssu r e build-up.

The dipstick and fille r tube are located on the right sid e of tra n sm ission .

1. Apply parking brake firm ly and block driv­ ing w h eels. Start engine and warm fluid to operat­ ing tem perature.

Move se le c to r le v er through all speed ranges.

2. Run engine at idle rpm with lev er in "N" (N eutral).

3. Clean dipstick and adjacent area, then r e ­ move dipstick, clean, re in ser t, again rem ove and note fluid le v e l.

4. Add one pint of fluid when lev e l reach es "ADD" mark.

DRAINING AND FILLING Drain w hile tran sm ission fluid is at operating tem perature (160°F . m inimum ).

NOTE: This procedure includes replacem ent of the oil filte r elem ent.

1. C arefully rem ove oil pan.

2. R em ove bolt holding o il filte r to control valve body, then pull out o il filte r and oil intake pipe.

3. Install a new se a l ring onto the top of the oil intake pipe, and lubricate the sea l ring with the sa m e oil as used to re fill the tra n sm ission .

4. Insert the intake pipe and sea l ring into the hole at the bottom of the tra n sm issio n . Install new o il filte r assem b ly (includes gromm et) onto the intake pipe. Tighten retaining bolt to 10-13 foot­ pounds torque.

5. Install the oil pan gasket on the o il pan (using o il-so lu b le g rea se to hold the gasket in p lace on the pan, if n ecessa ry ).

CAUTION: DO NOT use gasket-type sealing compounds any place either inside the transm ission or where they might get washed into the transmission. Also, any oil soluble greases may be used for tem­ porarily retaining parts during assembly.

6. Install oil pan and gasket. Tighten oil pan retaining bolts to 10-13 foot-pounds torque.

7. R efill tra n sm issio n with approxim ately 9% pints of recom m ended tran sm ission lubricant.

Check le v e l using dipstick; co rrect as n e c e ssa r y .

Sec. 7C Page 49

AUXILIARY TRANSMISSIONS OIL COOLER, LINES, AND BY-PASS SYSTEM IMPORTANT: The v e h ic le 's radiator not only c o o ls the engine coolant, but also coo ls the trans­ m issio n o il. It is im perative that the coolant be at the proper le v e l at a ll tim e s, otherw ise insufficient heat dissipation from tra n sm issio n oil w ill result.

An oil cooler located in the radiator, through which tra n sm issio n oil is circulated before return­ ing to the oil pan, d issip a tes heat created b y normal operation of the torque converter and tran sm ission .

If a tra n sm issio n failu re occu rs which ca u ses for­ eign m atter to be carried into the o il co oler, the co o ler and all connecting lin es should be thorough­ ly cleaned by flushing before tra n sm issio n is put back into operation.

FLUSHING OIL COOLER AND LINES It is important that follow ing tra n sm ission m alfunctions, the tra n sm issio n oil coo ler be prop­ erly flushed sin ce foreign p a r tic le s lodged in the co o ler eventually becom e free and can cause a r e ­ peated tra n sm issio n failu re. If the oil cooler and lin e s are properly flushed, the p o ssib ility of these trou bles reoccurring after the tra n sm ission has been repaired is elim inated or substantially r e ­ duced.

W henever an internal difficulty occu rs in the tran sm ission which would resu lt in clutch plate m aterial or m etal p a r tic le s being distributed throughout the oil sy stem , the oil cooler should be thoroughly flushed as outlined in the follow ing text, then an auxiliary filte r in stalled in the cooler r e ­ turn line before the veh icle is returned to serv ice: 1. D isconnect both o il cooler lin es at the fit­ tings at sid e of tra n sm issio n ca se, or if an au xil­ iary filter has been p reviou sly in stalled , d iscon ­ nect cooler return line at filte r instead of at the tra n sm issio n . (Change auxiliary filter elem ent.)

2. B ack-flush the o il co o ler and lin e s using clean solvent and co m p ressed air.

CA U TIO N : DO NOT exceed 100 psi a ir pressure.

3. R em ove all rem aining cleaning from the sy ste m with com p ressed air.

solvent

4. Flush the cooling sy stem again with DEXRON® tra n sm issio n fluid. A fter the final flush, test the oil cooler for fre e flow of oil, and if the flow is re stricted , the radiator bottom tank and cooler assem b ly must be replaced.

SECTION 7C A

u

x

j li a

/u

f.

The Spicer 6041 and 7041 A uxiliary T ran sm is­ sio n s have new mountings for this year as shown in figure 2.

A uxiliary tra n sm issio n replacem ent procedures are d escribed as follow s:

AUXILIARY TRANSMISSION REPLACEMENT REMOVAL 1. Drain lubricant from auxiliary tr a n sm is­ sion .

2. D isconnect p rop eller shafts from input and output ends of tra n sm issio n . R efer to "PROPEL­ LER SHAFTS” (SEC. 4D) in this supplem ent.

NOTE: Support p rop eller shafts secu rely to prevent damage from dropping.

3. D isconnect shift control rods from th efron t of the tra n sm issio n .

4. D isconnect speedom eter cable from adap­ ter at rear of the tra n sm issio n .

5. D isconnect parking brake linkage (when used).

6. R em ove a ll connections to the auxiliary tra n sm issio n power tak e-off (when used).

7. P osition a suitable dolly or jack under the tran sm ission and adjust to safely carry the weight of the tra n sm ission .

8. Rem ove attaching parts from auxiliary

AUXILIARY TRANSMISSION

T-6113

Figure J —Front M ount In sta lle d

Se c . 7C Page 50

AUXILIARY TRA N SM ISSIO N S

NOTE: See Chart for Dimension

"A "

T -9 U 9

Figure 2 — Auxiliary Transmission M o u n tin g

AUXILIARY TRANSMISSION APPLICATION AND ALIGNMENT DATA CHART (use in conjunction with Figure 2) TRUCK MODELS M E 6 0 .. . . . . . . . . . . . . . . . . . . .

M E 6 0 .....................

M E 6 0 .....................

M E 6 0 .....................

ENGINE

MAIN TRANSMISSION

AUXILIARY TRANSMISSION

366 366 427 427

NP542 CL285V CL325V SP5652B

SP6041 SP6041 SP7041 SP7041

tran sm issio n front and rear mountings. Lower the tra n sm issio n away from the ch a ssis.

INSTALLATION 1. B e su re the tapered surface of the auxiliary tran sm issio n front mount fa ces the front of the veh icle as shown in figure 1.

2. With tran sm issio n mounted on a suitable dolly or jack,m ove into position under the vehicle.

Adjust front and rear height as listed in "Auxiliary T ran sm issio n Application and Alignment Data Chart."

3. Torque attaching parts to proper sp ecifica ­ tions as shown in figure 2.

4. Reconnect p rop eller shafts to the input and output ends of the tra n sm issio n as described in "PROPELLER SHAFTS" (SEC. 4D) in this supple­ ment.

DIMENSION “A” INCHES

FRONT MOUNTING Fig. Fig. Fig. Fig.

2, 2, 2, 2,

View View View View

A A B B

1-1/8 1-1/8 2-11/16 2-11/16

DIMENSION “A” INCHES

REAR MOUNTING Fig. Fig. Fig. Fig.

2, 2, 2, 2,

View View View View

B B B B

2-1/2 2-1/2 2-11/16 2-11/16

IMPORTANT: The preceding step s, se r v e to locate the auxiliary tran sm ission in relation to the v e h icle's fram e. A lso, it is essen tia l that the aux­ ilia ry tran sm ission be checked for proper d rivelin e angle adjustment as described under "PRO­ PELLER SHAFTS" (SEC. 4D) in this supplem ent, and if n e c e ssa r y , sp a cers added or rem oved from rear mounts.

5. Reconnect power take-off (when used).

6. R econnect parking brake linkage (when used).

7. Connect speedom eter cable to adapter at the rear of the tran sm ission .

8. R econnect shift control rods to the front of the tra n sm ission and adjust linkage if n e c e ssa r y .

9. R efill tra n sm ission with lubricant recom ­ mended in LUBRICATION (SEC. 0) of this supple­ ment.

Sec. 7D & E Page 51

CLUTCHES

SECTION 7D C lu tch Go-nbi&U. MECHANICAL LINKAGE ADJUSTMENT The 1972 m echanical clutch controls used on conventional cab and cowl m odels rem ain the sam e as shown in S T -331-71 pages 7D -1 to 7D -3 with the exception of the r e le a se bearing clea ran ce. R elease bearing clearan ce m easu red at the r e ­ le a s e le v e r or r e le a s e fork is increased from 3 /1 6 " -1 /4 " to the new dim ension of 0.4".

On tilt cab m odels equipped with In-line or V8 engines the r e le a se bearing clearan ce m easured at the r e le a se lev er or fork is in crea sed from 3 /1 6 " -1 /4 " to 0.4". The clearan ce on V6 engines rem ains at 1/2".

SECTION 7E G h d cU & i FRONT DRIVEN DISC

FLYWHEEL H O U S IN G -

REAR DRIVEN DISC

■CLUTCH H O U S IN G

FLYWHEEL

RELEASE BEARING ASSEMBLY

M A IN DRIVE GEAR " BEARING CAP TR A N S M IS S IO N M A IN DRIVE GEAR-

CLUTCH CROSS SHAFT PILOT BEARING

RELEASE YOKE INTERMEDIATE DRIVE PLATE

7 0 -80 FT.LBS:

PRESSURE PLATE A N D CO VER ASSEMBLY

Figure 1—Borg & Beck 12-Inch Dual Disc Clutch

T-9152

S e c . 7E P age 52_____

CLUTCHES

A ll inform ation pertaining to CLUTCHES as d escrib ed in ST -331-71 pages 7E -1 to 7E -5 is applicable to m odels covered by this supplem ent with the addition of the following: It is im portant when installing the B org & Beck 12-Inch Duel D isc Clutch that the driven d isc hubs face the engine as shown in figure 1.

Sec. 9 Page 53

SECTION 9

Steestinxj, S u iiem T his section is divided into two separate sectio n s as shown in the follow ing Index: Section 9A 9B

P age No. M echanical S t e e r i n g ............................................................

53 Power Steering ...................................................................

54

SECTION 9A M

e o

lta

n

ic a

l S

te e A

in

x j

A ll inform ation pertaining to “ MECHANICAL STEERING” (SEC.j 9A) in S ervice Manual ST-331-71 is applicable to m odels covered by this supplem ent. The following information and illu stratio n s a lso apply.

STEERING GEARS On all steering gears covered in this supple­ ment w ill have the side cover attached to the main housing with flange type cap screw s.

On steerin g g ears 553DV, the stub end of the steerin g gear worm shaft (fig. 1) w ill have a cro ss groove and a section of the serration s machined flat. With the steerin g gear centered, the steering interm ediate shaft clamp yoke and clamp bolt can only be installed one way.

STEERING TIE ROD V ehicles covered in this supplement have a th ree-p iece tie rod connecting left and right ste e r ­ ing a rm s. The tie rod assem bly (figs. 2 and 3) co n sists of a tube and two socket end a ssem b lies.

Socket end a ssem b lies are threaded into tube and locked in place with clam ps. Right- and left-hand

threads are provided to fa cilitate to e-in adjustment.

The tie rod ends are non-repairable and r e ­ quire lubrication as sp ecified in LUBRICATION (SEC. 0) and inspection to se e that ball studs are tight. Socket ends should be replaced when e x c e s s ­ ive up and down motion or any lost motion or end play at ball end of stud e x ists.

NOTE: ALL STEERING COMPONENT AT­ TACHMENTS ARE IMPORTANT ATTACHING PARTS IN THAT THEY COULD AFFECT THE PERFORMANCE OF VITAL COMPONENTS AND SYSTEMS, AND/OR COULD RESULT IN MAJOR REPAIR EXPENSE. THEY MUST BE REPLACED WITH PARTS OF THE SAME PART NUMBERS OR WITH EQUIVALENT PARTS IF REPLACEMENT BECOMES NECESSARY. DO NOT USE REPLACE­ MENT PARTS OF LESSER QUALITY OR SUBSTI­ TUTE DESIGN. TORQUE VALUES MUST BE USED AS SPECIFIED DURING REASSEMBLY TO ASSURE PROPER RETENTION OF THESE PARTS.

S T E E R IN G G E A R W O R M S H A F T

Figure 1 S t e e r i n g G ear W orm shaft (Stub End) and Interm ediate Shaft Yoke an d C la m p (S M odels)

Sec. 9B P age 54

POWER STEERING

1 2 3 4 5 6 7

Cotter Pin Nut Steering Arm Stud Rubber Dust Cover B a ll Seat B all Seat Wedge

8 9 10 11 12 13 14

Tie Rod Tube End Clamp and Bolt W asher G rease Cavity Lube Fitting Spring Retaining Plug T-9103

Figure 2 — Tie Rod End (F070 Axle)

1 2 3 4 5 6

Cotter Pin Nut Stud Rubber Dust Cover Socket B earing T ie Rod Tube t-8467

7 8 9 10 11 12

End Clamp G rease Cavity Clamp Bolt End Stud Seat Spring Retaining Plug

Figure 3 — Tie Rod End (All Axles Except F070)

SECTION 9B Paw eA. S te & U n a A ll inform ation pertaining to "POWER STEERING” (SEC. 9B) in S erv ice Manual ST -331-71 is applicable to m odels covered by this supplem ent. The follow ing inform ation and illu stration a lso apply.

2. Rem ove pump drive belt, if pump is driven by a separate belt from the crankshaft. This w ill prevent further p o ssib le damage to the pump w hile NOTE: If for any reason the power steering driving with manual steerin g. sy ste m should fa il, the control valve "locks up" 3. If failed component is not at pump, r e ­ and the steerin g gear operates manually, giving the driver full control of the v eh icle. R esponse of route pump p r e ssu r e line directly back into pump r e se r v o ir . the steerin g gear in effort applied to the steering w heel w ill be in creased .

If at the tim e of final repair it has been de­ term ined the pump has failed or was damaged to Should the power steerin g sy stem becom es inoperative due to the lo s s of power steerin g fluid, the point of replacem ent, the entire steerin g sy stem should be cleaned and flushed out. one of the follow ing step s should be taken before Due to scorin g of the pump at tim e of failu re, the truck is moved under its own power or before running engine: the control valve, and cylinder should be d is a s ­ 1.

Make all n e c e ssa r y rep a irs, fill and bleed sem bled and any p a r ticles of m etal wiped clean steerin g sy ste m . from all p arts. L ines and h oses should be rem oved and blown clea r . Tag all lin es and h oses for proper relocation.

CAUTION: When pump drive belt is also used to drive the fan or other engine POWER STEERING RETURN LINE FILTER components it should not be disconnected.

The pump becomes an idler pulley and if A new disposable type power steerin g return allowed to run dry would burn up bearing line filte r is now available for se r v ic e u se. causing fan to stop and possibly damage U se of th is filte r on v eh icle s which operate engine further. Do not operate pumpwithunder conditions w here considerable dust is p r e s ­ out steering fluid in pump reservoir. ent should extend power steerin g life considerably.

M A IN TEN AN CE

Sec. 9B P age 55

POWER STEERING Actual conditions w ill dictate rep lacem ent inter­ v a ls, how ever, under norm al conditions rep lace­ ment on a sem i-annual b a sis should be sufficient.

To help prevent repeated fa ilu r e s, it is r e c ­ om m ended that th is filter be in sta lled at time of overhaul on any unit experiencing a pow er steering component fa ilu re. When used for this purpose, it should be replaced after the fir s t 500 m iles of s e r v ic e .

INSTRUCTIONS 1. Cut a 3 - inch section from the return line h ose and in sta ll the filte r as shown in figure 1.

(Installation should be made as c lo se to the pump a s p o ssib le.) Care should be taken to ensure hose clam ps are properly positioned behind sealing rin gs of filte r .

NOTE: The direction of flow is indicated on the filte r and, under no circu m sta n ces, should the elem ent be rev ersed .

2. Tape the filte r elem ent and the return line to the p r e ssu r e hose as shown. It is important that the return line be taped on both sid e s of the filter to synchronize vibration.

3. B leed hydraulic sy stem as outlined in cur­ rent S erv ice M anuals.

PUMP DRIVE BELT ADJUSTMENT NOTE: When adjusting a new drive belt, adjust ten sion to "New" belt sp ecifica tio n s, turn engine

over se v e r a l tim e s, then r e se t belt to "New" s p e c i­ fications sp ecified below: Adjusting Ordinary V -B elt Using Strand Gauge (Burroughs B T -3 3 -7 3 -F ) NOTE: Gauge should be placed at the center of the grea test span of the belt. a. L oosen pump mounting b olts. b. If "Used" belt, position pump to obtain 80 to 90 pounds. c. If "New” belt, position pump to obtain 120 to 130 pounds. d. Tighten pump attaching b olts firm ly.

NOTE: A V -b elt is considered "Used" after two hour’s operation or approxim ately 50 to 100 m iles operation.

SPECIFICATIONS POWER STEERING GEAR APPLICATION CHART GEAR MODEL

TRUCK SERIES CE/CS40; C E/C G /C M /C S50; C E /C M /M E 6 0 ..........................................

S E /S G /S M /S S 50..........................................................

T E /TG /T M 50; T E /T M 6 0 ....................................

553-DV 92 and 93 ..................

553-DV 9 3 ..................................

553-DV 9 4 ..................................

RATIO 28.14 to 1 28.14 to 1 28.14 to 1

POWER STEERING FLUID GM APPROVED POWER STEERING FLUID IS AVAILABLE THROUGH WHOLESALE WAREHOUSES AND TRUCK CENTERS. CHECK FLUID LEVEL EVERY 6,000 MILES OR FOUR MONTHS, WHICHEVER OCCURS FIRST. IF GM POWER STEERING FLUID IS NOT AVAILABLE, DEXRON®

AUTO­

MATIC TRANSMISSION FLUID MAY BE USED.

CAUTION: DO NOT USE GM POWER STEERING FLUID IN AUTOMATIC TRANSMISSION.

Sec. 9B Page 56

POW ER STEERING

A satisfactory steerin g sy stem depends upon maintaining components in good condition, with a minimum amount of wear perm itted . Proper align­ m ent, and lubrication w ill pay dividends in driver satisfaction , and in tire econom y.

Sec. 10 Page 57

SECTION 10 'U / h e e li a tu H A ll inform ation pertaining to WHEELS AND TIRES (SEC. 10) of S ervice Man­ ual S T -331-71 is applicable with addition of the following:

GENERAL DESCRIPTION CAST SPOKE MOUNTING C ast spoke w h eels have hub and w heel integral.

Dem ountable rim s are clam ped to w h eels by studs, cla m p s, and nuts. Rim driver blocks at each side of valve stem hole prevent rim slippage and valve ste m dam age. Figure 1 show s positioning of both rim types to w heel with sp a c e r . Depicted a lso are d ifferen ces in tir e and rim c r o s s se c tio n s. Dual rea r tir e spacing is the sum of the w heel offsets plus rim sp a cer width.

BUDD DISC TYPE MOUNTING W heels are secu red to hubs by bolts and ball sea t type nuts. Unique in the dual rear attachment is the inner and outer threaded nut arrangem ent perm ittin g rem oval of outside w heel without inter­ ferin g with inner w heel.

CAST S TEEL SPOKE WHEELS

TU BELESS T IR E

TU BE T Y P E T IR E

WHEEL STUDS OR BOLTS AND NUTS (Refer to F igu res 2 and 3)

BUDD DISC STUDS Stripped threads on the studs may be the r e ­ sult of e x c e ssiv e torquing of the studs, or it may be a resu lt of damage during w heel installation, when placing the w heel over the studs.

Where a damaged thread is discovered , the stud should be replaced.

Broken studs are a direct resu lt of operating with loose cap nuts or im properly seated w h eels.

When a broken stud is found, a ll the studs should be replaced. This is b ecau se the other studs in the a ssem b ly have been subjected to undue strain in carrying all the load and may have b e ­ com e e x c e ssiv e ly fatigued.

BUDD TY P E DISC W HEELS

-Tire Clearance

Figure 1—Wheels and Rim Mounting for Cast Spoke and Budd Type Disc W heels

T-8280

Sec. 10 Page 58

WHEELS A N D TIRES F reezin g of Nut T his condition r e su lts from one of two b a sic causes: 1. C orrosion or galling of the stud and nut a ssem b ly can reach a point w here rem oval of cap nuts is difficult. If this is a p er siste n tp r o b lem , the threads of the stud and the threads of the inner cap nut should be cleaned with a w ire brush.

To further aid in th is problem , u se cadm ium plated cap nuts with a dichrom ate dip.

2. Im proper tightening of the inner cap nuts.

If the inner nut, during assem b ly, is UNDER­ TIGHTENED to only 200-250 foot-pounds, and then the outer tightened co rrectly to 500-550 foot­ pounds, the very act of backing off the outer nut w ill so m etim es turn the inner.

CAST WHEEL STUDS CAUTION: Insufficient wheel stud nut torque can cause rim slippage, result­ ing in broken valve stems, worn parts, wheel shimmy and extreme tread wear.

Excessive mounting torque can cause damage by stripping studs, collapsing spacer bands, out-of-round rim condition or broken studs or cracks in the stud hole area.

WHEEL INSPECTION (DISC TYPE)

Figure 3 — B u d d Type D a m a g e d or Broken Studs

Dam aged Inner or Outer Cap Nuts (Fig. 4) When th is condition is found - it is a definite indication of a lo o se mounting condition. Cap nuts and stu ds, if n e c e ssa r y , m ust be replaced. If wheel ball s e a ts are damaged, the w heel also should be replaced.

Figure 4 — B u d d Type D a m a g e d Inner or Outer Cap Nuts

WORN WHEEL STUD HOLES (F ig. 5) This condition w ill usually be accom panied by appearance of a shiny worn su rface on w heel face, indicating that lo o se w h eels w ere moving against each other. If the stud h oles are out of shape - oval or egg shaped - and w here a build-up of m etal is around them , th ese w heels must be replaced.

CRACKED DISC WHEELS (F ig. 5) C racks running from hand-hole to stud-hole or b olt-h ole to cen ter-h ole or hand-hole to handhole, or hand-hole to rim , or stud hole to stud-hole, are a direct resu lt of overloading. Check working loads of a x le s, discard damaged w h eels, check w heel studs and com plete assem b ly .

The hub assem b ly may have a worn mounting fa ce as a resu lt of moving of the inner w heel on the hub. The studs may have turned in the hub and worn the stud groove or the studs may have actual crack s or breaks resu ltin g from tfiis condition.

The wheel may have worn ball se a ts in the stud h o les. A ll th ese p o ssib ilitie s m ust be checked and a ll damaged p arts replaced.

DAMAGED OR CRACKED RIMS The rim a s shown in figure 6 has cracked from fatigue and overload. This type of failu re is

Sec. 10 Page 59

WHEELS AND TIRES

Figure 5 —W orn W heel Stud Holes and C racked Disc W heels

com m on to overloaded r im s and dangerous. C are­ ful checks should be made for this condition be­ fo re tir e mounting and defective p arts are replaced.

C orrosion so m etim es is a lso ob served (fig. 6) and w here co rro sio n is e x c e ss iv e , may cau se poor seating of lock or sid e rin g s. W here damage of e x c e s s iv e co rrosion is observed, w heel should be rep laced.

Rust Streaks on D isc s Emanating From Stud H oles T his is a p o sitiv e indication that the cap nuts a r e , or have been, lo o se . In this ca se , the a sse m ­ bly should be checked carefully becau se damage to hub, studs, or w heel may have been caused by running in this condition.

Damaged or Sprung Rings Broken or cracked rings as shown in figure 7, are generally caused by rough u se of tir e tools or im proper in itial seating in gutter of rim . When found, the ring should be replaced. Bent or sprung rings are caused by rough and im proper rem oval of this part and cannot be properly sprung back so as to seat accurately in the rim gutter. They should be replaced.

Cracked or Eroded Side R ings (Fig. 8) Cracks through sid e ring, spreading la terally through the entire sectio n . T hese are caused by im proper mounting and demounting techniques, im ­ pact with road obstructions, and e x c e ssiv e clam p­ ing torques.

Figure 6—Cracked or Corroded Rims

Sec. 10 Page 60

WHEELS A N D TIRES Bead sea t a rea s of rim should be fr ee of rust and rubber d ep osits. This is esp ecia lly important for drop-center tu b eless rim s, becau se the 15° bead seat is the a ir -se a lin g elem ent.

Rings should be cleaned with w ire brush. Pay particu lar attention to seatin g su rfa ces and bead sea t a r ea s.

Paint rim by brush or spray with a fast-d ryin g m etal p rim er. Surfaces should be clean and dry p rior to painting. Insure that bare m etal a rea s on outside or tir e sid e of rim are covered. This is e sp e cia lly im portant on d rop-center tu b eless rings, b ecau se warm and som etim es m oist a ir is in con­ stant contact with the m etal surface on the tir e sid e of the rim .

Figure 7— D a m a g e d or Sp rung Rings

INFLATION OF TIRES (R efer to Figure 9)

E rosion and chipping of bead seat of lock ring, resu ltin g from e x c e s s iv e corrosion.

NOTE: Insure that replacem ents are made with the proper s iz e s and types of rim s and rings.

W heel M aintenance Thoroughly rem ove rust, dirt, and other for­ eign m a terials from all su r fa c e s. Hand or electric w ire bru sh es, sand blasting or chem ical baths may be u sed. Gutter of rim b ase should be cleared of rust and other m a teria ls obstructing sa fe, positive seatin g of rin gs.

Inflate to co rrect p r e ssu r e when tir e s are cool.

If tir e s are continually carrying le s s than the r e c ­ om m ended maxim um load, adjust air p ressu r e downward to correspond to the actual load carried.

N ever "bleed" tir e s to reliev e build-up of p r e ssu r e . T ire tem perature w ill in c rea se when the tir e is in se r v ic e and allow s for the norm al build­ up in air p r e ssu r e . T ire tem perature and air p r e s ­ su re w ill rem ain within lim its that are not harmful to the tire when used in accordance with the r e c ­ om m endations for load and a ir p r e ssu r e .

If e x c e ssiv e build-up of air p r e ssu r e occu rs, load, underinflation, speed, or a combination of th ese is resp on sib le. U se the siz e and type of tire that has the capacity to carry the load at reco m ­ mended cold starting p r e ssu r e .

TIRES

Figure 9 — Inflation of Tires

OVERLOAD Overloading is the cause of many kinds of cord body breaks and is the m ost costly of a ll truck tire ab u ses. Such breaks are due to abnormal flexing or overw orking of the cord body of the tir e .

O verload flex breaks occur in the sid ew all or in the shoulder of a tir e and run with the circu m ­ feren ce of the tir e . Som etim es they are only two or three inches long.

Other tim es they w ill extend partly around the tir e , resulting either in a la rg e blowout or a pinch­ ed tube which allow s the tir e to go flat.

N orm al flexing of a tir e can go on indefinitely without causing any appreciable damage to the cord s.

But if the tir e is overw orked or overflexed from overload, abnorm al heat is generated and the cords becom e fatigued and break.

Underinflation w ill cau se this sam e resu lt. In addition, crowned roads, sprung a x les, m ism atched duals and poor load distribution tend to produce fle x breaks; how ever, overloading exceed s all other

Sec. 10 Page 61

WHEELS AND TIRES fo rm s of abuse and c o sts truck ow ners la rg e sums of money annually. This trem endous w aste can be avoided if trucks are equipped with tir e s and rim s of the proper s iz e and type, la rg e enough to carry the load. The rated carrying capacity of a tire can­ not be in crea sed by inflating it beyond the maximum recom m ended p r e ssu r e .

V alve Stem A fter installation of tir e s , make su re valve stem does not r e st on brake drum. If b ra ss stem s a re too c lo se to the brake drum s, e x c e ssiv e heat may damage valve and cause p o ssib le lo s s of air p r e ssu r e .

WHEEL AND TIRE WEAR CORRECTING IRREGULAR TIRE WEAR Heel and Toe Wear - - T his is a saw-toothed effect w here one end of each tread block is worn m ore than the other. The end that w ears is the one that fir s t grips the road when the brakes are applied.

H eel and toe w ear is le s s noticeable on rear tir e s than on front tir e s , because the propelling action of the rear w h eels crea tes a fo rce which tends to w ear the opposite end of the tread blocks.

The two fo r c e s , propelling and braking, make for m ore even w ear of the rear tir e s , w hereas only the braking fo r c e s act on the front w h eels, and the saw -toothed effect is m ore noticeable.

A certain amount of h eel and toe wear is norm ­ a l. E x c e ssiv e w ear is usually due to high speed driving and e x c e s siv e u se of b rakes. The best rem edy, in addition to cautioning the owner on his driving habits, is to interchange tir e s regularly.

Side Wear — This may be caused by incorrect w heel cam ber, under inflation, high cam bered roads or by taking co rn ers at too high a rate of speed.

The fir s t two ca u ses are the m ost common.

Cam ber w ear can be readily identified because it o ccu rs only on one sid e of the trea d s, w hereas underinflation ca u ses w ear on both sid e s. Camber w ear req u ires correctio n of the cam ber fir st and then interchanging t ir e s . T here is , of cou rse, no co rrectio n for high cam bered roads. Cornering w ear is d iscu ssed further on.

M isalignm ent Wear - - This is w ear due to e x c e s s iv e to e -in or to e-o u t. In either c a se , tires w ill revolve with a sid e motion and scrap e the tread rubber off. If m isalignm ent is s e v e r e , the rubber w ill be scraped off of both tires; if slight, only one w ill be affected.

The scraping action against the face of the tire c a u se s a sm a ll feather edge of rubber to appear on one sid e of the tread and th is feather edge is c er ­ tain indication of m isalignm ent. The rem edy is readjusting to e-in , or rechecking the entire front end alignm ent if n e c e ssa r y .

C ornering Wear — When a truck m akes an

extrem ely fa st turn, the weight is shifted from an even loading on all w heels to an abnormal load on the tir e s on the outside of the curve and very light load on the in sid e tir e s , due to centrifugal fo rce.

This unequal loading may have two unfavorable re su lts.

F irst, the rear tire on the inside of the curve may be relieved of so much load that it is no longer geared to the road and it s lip s, grinding off the tread on the inside half of the tir e at the e x c e ssiv e rate. This type of tir e show s much the sam e ap­ pearance of tread w ear as tire w ear caused by negative cam ber.

Second, the tran sfer of weight may also o v er ­ load the outside tir e s so much that they are la te r ­ ally distorted resulting in e x c e ssiv e w ear on the outside half of the tir e , producing a type of w ear like that caused by e x c e ssiv e p o sitiv e cam ber.

Cornering wear can be m ost ea sily distinguish­ ed from abnormal cam ber w ear by the rounding of the outside shoulder or edge of the tir e and by the roughening of the tread surface which denotes abrasion.

Cornering w ear often produces a fin or raised portion along the in sid e edge of each row in the tread pattern. In som e c a se s this fin is alm ost as pronounced as a to e-in fin, and in oth ers, it tapers into a row of tread blocks to such an extent that the tire has a definite "step wear" appearance.

The only rem edy for cornering w ear is proper instruction of operations. D riving m ore slow ly on curves and turns w ill avoid grinding rubber off tir e s . To offset norm al cornering w ear a s much as p o ssib le , tir e s should be interchanged at regular intervals.

Uneven Wear — Uneven or spotty w ear is due to such ir r eg u la ritie s a s unequal ca ster or cam ber, bent front suspension p arts, ou t-of-b alan ce w h eels, brake drums out-of-round, brakes out of adjust­ ment or other m echanical conditions. The rem edy in each ca se c o n sists of locating the m echanical defect and correctin g it.

Powe*r and Speed — E x c e ssiv e speed has a l­ w ays been harmful to tir e s . Speed c r e a te s heat heat softens tir e s .

Stops and Starts — Quick stops and sta r ts grind off tread in a hurry, may cause flat spots which con­ tinue to grow for the life of the tir e.

Tem perature - - C onsiderably le s s m ileage can be e j e c t e d from a tire used in all warm weather driving as com pared to a ll cool weather driving, or from a tire fir st put into se r v ic e in warm w eather.

MECHANICAL IRREGULARITIES (Fig. 10) Following are som e w heel or v eh icle irreg u ­ la r itie s which may cause rapid or uneven tread wear: Toe-In — The w heels on the sam e axle are c lo se r together in the front than they are in the

Sec. 10 Page 62

WHEELS A N D TIRES

Q _

o

l= d

L

m

o

o

E.

TOE-IN

CAMBER

/

/

«

w

SPRUNG OR SA G G IN G AXLE t-8289

TOE-OUT

Figure 10— M echanical Irregularities

re a r . When to e -in is e x c e s siv e the tire wear shows feath ered edges on in sid e edge of the skid design.

Toe-O ut — The w heels on the sam e axle are c lo s e r together in the rear than they are in the front.

T ir e w ear show s feathered edges on outside edge of the skid design.

Cam ber — This design ates the tilt of the wheel.

P o sitiv e cam ber is when w heels are c lo se r together at point of road contact. N egative cam ber is when w h eels a re c lo se r together at top. Too much cam ­ b er re su lts in e x c e s s iv e w ear on one sid e of tire.

C aster — T his is the backward tilt of the axle or inclination of the kingpin at the top. Too little c a ste r ca u ses w heel to wander or weave re su lt, spotty w ear. E x c e ssiv e ca ster may cause w heel "flight” or shim m y w ear. Unequal caster ca u se s w heel to pull to one sid e, resulting in ex­ c e s s iv e and uneven w ear.

Sprung or Sagging A xle - - Either of th ese con­ ditions ca u ses uneven distribution of the load. A sprung or sagging axle w ill cause the inside dual

tir e to carry the greater load.

Tandem and Spread A xle W heels — F ast tir e w ear often occu rs on tandem w heels because of sid e scuffing when the v eh icle rounds a curve and the tir e s are not moving in a straight path. The sa m e thing happens when spread axle tir e s are dragged or pushed sidew ays; for exam ple, w hile spread axle tr a ile r s are being spotted at or pulled away from loading docks.

Sprung or T w isted Fram e — W ill cau se rapid or uneven tread w ear.

Grabbing B rakes - - B rak es out of adjustment and out-of-round brake drum s cause tir e tread s to w ear rapidly in sp o ts. O ut-of-round brake drums u sually wear out tir e s in a sin g le spot. Im properly adjusted brakes produce se v e r a l worn p la c e s.

Worn w heel bearin gs, lo o se radius rods and U -b o lts, unbalanced w h eels, or wobbly w h eels all resu lt in uneven and irregu lar tread w ear.

At fir s t sign of uneven tir e tread w ear, check and co r rect all m echanical ir r e g u la r itie s.

SELECTION OF TIRES TIRE M A T CH IN G (R efer to Figure 11) Unmatched tir e s on eith er Tandem D rive Units or T ridem D rive U nits w ill cause tire w ear and scuffing and p o ssib le dam age to the drive units.

Consequently we recom m end the tir e s be matched to within 1 /8 ” of the sa m e rolling radius, X" of the sa m e rolling circu m feren ce.

TANDEM UNITS IMPORTANT: The four la rg e st tir e s should never be in stalled on one driving axle or the four sm a lle st tir e s on the other driving axle. Such tir e mounting w ill cause an in te r-a x le "fight,"unusually high axle lubricant tem peratures that r esu lt in p r e ­ m ature lubricant breakdown and p o ssib le costly ax le s e r v ic e .

Sec. 10 Page 63

WHEELS AND TIRES

Fig u re 11 —Types of Tire M easurem ent

In addition to matching individual tir e rolling radii or rolling circu m feren ce, we recom m end matching, as nearly as p o ssib le , the total tire circu m feren ce of one driving axle to the total tire circu m feren ce of the other driving a x le. This will u su ally resu lt in sa tisfa cto ry tandem axle lubricant tem p eratu res that lengthen drive unit se r v ic e with higher tir e m ileage.

TRIDEM UNITS When three driving a x les a re "hooked" together in a T ridem S e r ie s, unmatched tir e s w ill compound the problem s describ ed in the preceding paragraphs.

T h erefore, we recom m end m atching, as nearly as p o ssib le , the total tir e circu m feren ce of each of the three driving a x le s.

HOW TO MATCH TIRES TANDEM UNITS The veh icle should be on a le v e l flo or, carry­ ing a co rrectly distributed rated capacity load. Be su re a ll tir e s are the sam e s iz e (m easure new tires to be su re they w ill be co rrectly m atched).

1. Inflate a ll tir e s to the sam e p re ssu re .

2. C arefully m easu re the rolling circum fer­ ence of each tir e with a ste e l tape.

3. Mark the s iz e on each tir e with chalk and arrange them in order of s iz e , la r g e st to sm a llest.

4. Mount the two la r g e st tir e s on one side of

one axle and mount the two sm a lle st on the opposite sid e of the sam e axle.

5. Mount the four other tir e s on the other axle in the sam e m anner.

6. T est run the veh icle to get accurate rear axle lubricant tem perature readings on the two axle lubricant tem perature gauges.

7. Vary tire a ir p r e ssu r e , within the tire manufacturer’s recom m ended range, so the lu b ri­ cant tem perature of both a x les is within 3 0°F ., of each other and not in e x c e ss of 2 2 0 °F. This w ill usually resu lt in uniform tir e loading and good tire life.

Follovy the sam e procedure (Item s 1 thru 7) for matching tir e s on a T ridem Unit. Arrange the tir e s in order of s iz e . The two la rg est and two sm a lle st go on one axle, the next two la rg est and sm a llest on the second axle, and the rem aining four on the third axle.

M easuring the circu m feren ces of the tir e s with a ste e l tape after they are on the rim s and inflated but before they are applied to a v eh icle is the m ost accurate method.

M easuring in th is manner takes into account any irre g u la ritie s in w ear. In checking tir e s a l­ ready on a v eh icle, either a square, sim ila r to but larger than a carp en ter's square, a strin g gauge, a large pair of c a lip er s, or a wooden straigh t-ed ge long enough to lie a c r o ss the tread s of all four tir e s , may be used.

Sec. 10 P age 64

WHEELS A N D TIRES tir e s and by using w ell worn tir e s on th ese w h eels, lo s s on tir e s due to road hazards is m inim ized.

NOTE: When rotating any tir e , follow reco m ­ mendations in " selection of tir es" as covered p r e ­ viou sly.

TWO-AXLE TRUCK T ir e s should be m oved from front w heels to rear w heels (fig. 12) after 1 /3 of the tread design is worn off. If there is uneven front w heel tire w ear, rotate tir e s im m ediately and check veh icle for m echanical ir r e g u la r itie s. When tir e s are moved to the rea r, follow recom m endations in m atching them with other tir e s .

Figure 12— Tire Rotation

TIRE ROTATION G enerally, it is the best practice to "breakin" new tir e s on front w h eels. "Breaking in" on an easy p osition generally in c r e a se s the overall tire life.

The m ovem ent of the tir e s from front to var­ ious rear w heel p osition s depends upon the type of unit being operated. It is generally n ecessa ry to u se tir e s with good non-skid tread design on drive w h eels.

T ir e s with le a st tread design should be used on tr a ile r w h eels, and particularly on the rear of tandem w h eels. This is due to the fact that cuts are found m ore often on the tr a ile r and rear tandem

Figure 13— Tire Rotation

TRUCK WITH TANDEM AXLE DRIVE Follow the sam e p ractice as described for sin g le -d r iv e axle except tir e s must be rem oved from the fronts at le s s se r v ic e in order to provide 8 tir e s for the rear w heels instead of 4 for the sin g le -a x le drive. Since there are 5 tir e s on each sid e of the v eh icle (fig. 12) the front tir e s should be m oved to the rear when 1 /5 of the tread design is worn off. Then match tir e s on each w heel as already d escribed but with an additional precaution - the sum of the circu m feren ces of the four tir e s for the front of the tandem drive a x les should equal the sum of the circu m feren ces of the four tir e s on the rea r of the tandem a x le s. This precaution is n e c essa r y to prevent e x c e ssiv e w ear from slippage.

If there is a third differential between the two drive a x le s, this precaution is unn ecessary.

TRACTOR AND SEMI-TRAILER A fter 1 /5 of the tread design is worn off, tir e s should be moved from the front to the in sid e or outside driving w heels (shown in figure 13), the position being determ ined by matching as reco m ­ mended. Later the tir e s should be m oved to the tr a ile r w h eels. The p o ssib ility of injury from cuts, b r u ise s, e tc ., is greater in the tra iler w heel p o s i­ tion. By follow ing this rotation plan with tir e s , end­ ing their se r v ic e on tr a ile r w h eels, at le a st the g reater portion of the tir e se r v ic e has been ob­ tained even if they are damaged.

TRACTOR WITH TANDEM AXLE DRIVE WITH SEMI-TRAILER WITH TANDEM AXLE Follow sam e procedure as above for tractor and se m i-tr a ile r with sin g le -a x le except tir e s m ust be rem oved from the front w heels at le s s s e r v ic e in order to provide for 16 tir e s instead of 8. Since th ere are 9 tir e s on each sid e of the veh icle, the front tir e s should be moved to the rear when 1 /9 of the tread design is worn off (fig. 13). Then match tir e s on each w heel as already described but with an additional precaution - the sum of the circ u m ­ fe r e n c e s of the 4 tir e s for the front of the tandem

Sec. 10 P age 65

WHEELS AND TIRES drive a x les should equal the sum of the circum fer­ en ces of the 4 tir e s on the rear of the tandem axles.

T h is'p recau tion is n e c e ssa r y to prevent e x c e ssiv e w ear from slippage. If there is a third differential betw een th ese two drive a x le s, d isregard th is r ec­ om m endation. L ikew ise it is to be disregarded for s e m i-tr a ile r tandem tir e s becau se th ese are on fr e e -r o llin g w h eels.

SYNTHETIC TUBES AND FLAPS TUBES CHAFED OR PINCHED

BY FABRIC BREAKS Tubes may fa il as a resu lt of being chafed or pinched by fabric breaks in sid e the tir e . The d irec­ tion and shape of the tube in ju ries have rather c lo se ly follow ed the pattern of the fabric breaks.

A tir e does not n e c e ssa r ily go flat im m ediately when a fabric break o ccu rs on the insid e of the tire b ecau se it may take som e tim e for the injury to chafe com pletely through the tube.

T-8305

TUBES DAMAGED BY MISMOUNTED FLAPS The tube may becom e chafed by a fold at the edge of the flap. In mounting tir e s requiring flaps, it is e sse n tia l that the flaps be properly centered betw een beads to prevent folds or w rin k les. Flaps which have once becom e tw isted, c rea sed , or folded over at ed ges, should not be used again.

TUBES AND CASINGS DAMAGED

BY FOREIGN MATERIALS IN CASINGS Any foreign m aterial between the casin g and tube w ill cause a chafing action. In tim e, one or both w ill becom e badly damaged and fa il. The re ­ sult of grit, pebbles, or other hard sub stances which becom e embedded in the tube w all, w ill chafe tube and finally cause fa ilu re.

TUBES STRETCHED AND CREASED When a tube is la r g e r than the in side of the

Figure 14—Im proper Tube Inflation

casing it has becom e stretched and can becom e crea sed . C reasing can a lso happen to a new tube of proper s iz e when in correctly mounted. If the cr ea se occu rs in the flexing area of the tir e , the resulting additional thickness of the tube where folded ca u ses a hinging action which cuts the tube and frequently dam ages the fabric - resulting in a costly failure.

CREASES CAUSED BY REMOUNTING USED TUBES Tubes usually undergo som e stretch or growth in se r v ic e . This is particularly true of truck tubes because of the high tem peratures which develop.

When a used tube is remounted in a new, or nearly new tire, a folded condition w ill usually resu lt, and eventually w ill cause both tube and tire to fa il.

Figure 15—Proper Tube Inflation

Sec. 10 Page 66

WHEELS A N D TIRES TUBE BREAKS NEXT TO THE VALVE Im proper inflation procedure may cause a c ir ­ cum ferential crack or tear in the valve base at the edge of the bridge w asher. Figure 14, View A shows the position of beads, flap and tube with 4 or 5 lbs. inflation p r e ssu r e . The tube is fully rounded out within the tir e , but the p r e ssu r e is insufficient to m ove the beads on wide base rim s. Depending upon tir e s iz e and condition of the rim , from 20 to 40 lb s. p r e ssu r e is required to push the beads onto the tapered bead se a ts as shown in figure 14, View B. F orced by th is high p r e ssu r e , the tube can stretch only in the rim area. B ecause the r e s is t­ ance to stretch is g rea test at the valve b ase, ten­ sion there is often enough to crack the tube at edge of the valve b ase.

T his can be avoided by proper inflation pro­ cedure as described la ter in this section.

TUBE INSTALLATION 1. Insert tube in tir e and inflate as shown in figu re 15, View 1. rounded out. U se approximately 1 lb. of air or le s s .

2. Using a brush or cloth swab, apply a solu­ tion of neutral vegetab le oil soap in the area of the tir e beads, including flap. Do not allow soap solu­ tion to run down into tir e . Extra ply rated tires may require soap on the rim bead seat area.

3. Mount tir e on rim , center valve and pull it through hole in rim and hold firm ly against the rim . Hold in this position w hile inflating until beads are properly seated.

4. C om pletely deflate by rem oving valve core or using deflating tool. T his is extrem ely im port­ ant to prevent tube buckling.

5. R e-in flate tube to recom m ended p ressu re (fig. 15, View 2). R efer t o ’’Load and Inflation Table” at end of this section .

NOTE: U sed flaps may cause tube failure UN­ LESS mounted with the s iz e tir e and rim originally u sed . When tube and flap are not properly lubri­ cated and mounted, they w ill be stretched thin in the tir e bead and rim region (fig. 15, View 3). This w ill cause prem ature fa ilu re.

A lw ays clean r im s thoroughly to rem ove rust.

C ertain p recautions m ust be taken when mount­ ing used flap s, or damage to the tire and tube will resu lt.

New truck and bus flaps can be used with any one of se v e r a l different tir e and rim s iz e s as r e c­ om m ended. But once u sed , the flap must be r e ­ mounted in the sam e s iz e tir e and on the sam e size rim from which it w as rem oved. Always use flap of adequate width to prevent tube pinching.

A s a precaution against flap failure, mark the tir e and rim s iz e on the flap at the tim e of rem oval - if inspection show s that it is not damaged and can be used again. When the flap is again mounted, this

m arking p ro tects against the danger of m isusing the flap with the wrong s iz e tir e and rim .

New flaps and tubes should be used after tire or rim rep a irs. It is inexpensive insurance sin ce sm a ll w ear spots and im perfections in tubes and flaps are hard to s e e . This could prevent future tire fa ilu r e s.

TUBE RECOMMENDATIONS 1. Long life and high m ileage receiv ed from p resen t day tir e s exhaust the useful se r v ic e life of tubes. T herefore, when a casin g is worn to the point of being unsafe, the tube generally is in the sam e condition and should be replaced with a new one.

2. If valve cap is lo st, clean end of valve be­ fo re applying air hose to prevent dust and dirt from being blown into the tube. Apply new cap.

3. When tubes are inflated for inspection, they should not be inflated to the point of ’’ballooning.”

When a tube is ’’ballooned,’’ it thins out in the stretch ed area, making the tube too large in that area and resulting in folds or w rinkles when r e ­ mounted.

SPACER B A N D S INSTALLATION PROCEDURE 1. Check the sp acer band for concentricity, and a ssu r e yo u rself that it has not been distorted or bent, or otherw ise m ishandled in shipm ent.

2. Do not move v e h ic le s, w h eels, a x le s, or a sse m b lie s by rollin g on sp a c er s.

3. P la ce the in sid e rim over the ca st spoke w heel as far as p o ssib le up to the mounting le v e l.

4. Push the sp acer band over the ca st spoke w heel with a con sisten t p r e ssu r e on both sid e s.

Guard against cocking. The band should fit snugly to the spokes and against the in sid e rim gutter edge. (At this point, the concentricity can be check­ ed by turning the sp acer band on the w heel.)

5. Apply outer rim clam ps. Tighten clam p nuts evenly to the recom m ended range, 5 /8 ” studs from 150-175 foot-pounds, and %" studs from 190-210 foot-pounds torque. Apply torque evenly by grad­ ually tightening nuts in an alternating pattern a c r o ss the diam eter of the w h eels.

6. Check to s e e that clam ps do not bottom out, and be su re the rim edges con sisten tly m eet the sp acer band edges.

7. R echeck torque after assem b ly is used in se r v ic e after 500 and 1,000 m ile s.

M O U N T IN G A N D D E M O U N T IN G RIM S For proper procedures in mounting and de­ mounting different type r im s, refer to figu res 16, 17, 18, 19, and 19a for applicable type.

Sec. 10 Page 67

WHEELS AND TIRES

M O U N T IN G

A fter applying tire and tube in usual manner, place removable side ring (flange) on bead of tire.

Then insert tapered toe of lock ring between side ring and rim base.

To fasten lock ring, hold with foot at one end of split and hammer end of ring into place with rim mallet.

Continue progressively around the rim, holding ring with foot and hammering until entire ring is seated. Check seating of rings and inflate tire to recommended pressure.

D E M O U N T IN G

Completely deflate tire by removing valve core or using deflator cap. Place tapered end of rim tool in depression in lock ring, or between rings, and press down on side ring to free bead. Continue downward pressure on side ring progressively around the tire until the bead is completely freed from the bead seat.

To disengage lock ring from the gutter, insert rim tool in removing notch, near split in the ring, and push downward. If desired, a second similar tool may be used to facilitate removal.

Insert the rim tool between the lock ring and side ring and press downward to pry ring up. Move progressively around the rim until lock ring is fr e e , then lif t o f f lock and sid e r in g s. Turn assembly over, unseat tire bead, stand tire up and remove rim base,

_____________________________________ T-8307 Figure 16—M ounting and Demounting 3-Piece Convertible Rims

Sec. 10 Page 68

WHEELS A N D TIRES

M O U N T IN G

D E M O U N T IN G

To fa s te n side rin g , p lace fo o t a t one end n e a r th e s p lit an d p u sh dow n in to p lace.

C o m p le te ly d eflate tir e , th e n w ith cu rv e d end o f rim to o l a n d h o o k ed -en d rim to o l p r y b e a d loose fro m side rin g by d o w n w a rd p re s s u re on rim to o ls.

C o n tin u e p ry in g o p e ra tio n p ro g re s s iv e ly a ro u n d th e tir e u n til th e rin g is c o m p le te ly fre e d fro m th e b ead se a t.

C o n tin u e p ro g re s s iv e ly a ro u n d th e rim “ w a lk in g ” th e side rin g firm ly in to place.

To d is e n g a g e side rin g fro m th e g u tt e r in s e r t one rim to o l in tool slo t of sidfe rin g a n d p ry rin g u p w a rd an d o u tw a rd . T h is o p e ra tio n c an be a s s is te d (a s sh o w n ) b y in s e rtin g h o o k ed -en d tool b etw ee n th e tir e a n d rin g , p ry in g u p w a rd on rin g an d d o w n w a rd on tir e to fre e rin g fro m tir e b ead.

A bove illu s tra tio n show s side rin g fu lly en g ag ed in rim g u tte r . C heck s e a tin g o f rin g an d in flate t i r e to reco m m en d ed p re s s u re .

C o n tin u e in th is m a n n e r p ro g re s s iv e ly a ro u n d rim u n til rin g is c o m p le te ly rem o v ed . T u rn a sse m b ly o v er, u n s e a t tir e b ead , s ta n d ti r e u p a n d rem o v e rim b a se .

T-8308

Figure 17— Mounting and Demounting 2-Piece Convertible and DT Rims

Sec. 10 P age 69

WHEELS AND TIRES

M O U N TIN G

Be sure right valve is used and is properly installed in the rim. Inspect rim to insure bead seats are clean and smooth. Then place rim on floor w ith wide side down and lubricate first bead of tire and upper bead seat of rim.

Push first bead into well of rim and onto rim as far as possible. U sing straigh t end of tool (with stop resting on rim flange) take small bites to work remaining section of first bead onto rim.

Hold second bead in well by standing on tire and anchor w ith vise-grip pliers (snub side toward tire). U sing sp oon end o f tir e to o l w ith sto p toward rim, use sm all bites until bead slips over flange. If necessary, insert second tire tool and lubricate last 6" of bead before com pleting mounting.

Inflate tire to recommended pressure.

Exam ine valve assem bly occasionally to avoid leaks.

Hold tool in position with one foot and pull second tool toward center of rim.

P rogressively work bead off rim, tak­ ing additional bites if necessary.

Stand assem bly in vertical position.

Lubricate second bead. A t top of a s­ sem bly insert straigh t end of tool be­ tw een bead and back flange of rim at about a 45° angle. Turn tool so that it is perpendicular to rim. Pry second bead off.

D E M O U N T IN G

Deflate tire. W ith tire lyin g flat, loosen both beads by w alking on tire w ith heels close to rim. W ith wide side of rim down, lubricate top bead. With stops toward rim, insert spoon ends of both tools about 10" apart. Holding bead in well w ith foot, pull one tool toward center of rim.

T-8309

Figure 18—Mounting and Demounting 15° Drop-Center Tubeless Rims

Sec. 10 Page 70

WHEELS A N D TIRES

M OUNTING

Place disc portion of wheel on floor with rim gutter up. Apply tire with valve pointing in direction desired.

Place side ring in position with oper­ ating notch located between two em­ bo ssin g s (p o in t B) a p p ro x im a te ly three inches from valve, on either side.

The two cutaway portions opposite each other in the inner diam eter of the ring (points A) are placed so as to span the rim g u tter. A t point C, opposite valve, force h alf of ring into the g u tter as fa r as possible using hand and rim mallet.

Insert straight end of rim tool in operating notch (point B ), then pull in direction indicated by arrow. R e­ tain pressure with tool and strike ring downward with m allet a t point be­ tween tool slot and cutaw ay portion, thereby engaging ring over rim gut­ ter a t th a t point. Remove tool and strike additional blows progressively tow ard other cutaw ay portion until entire toe of ring has passed over the rim gutter. Check seating of ring as shown below and inflate tire to recom­ m ended pressure.

Remove ring by p u ttin g stra ig h t end of rim tool into notch in ring located between embossings (point B). Push ring downward a t point opposite oper­ ating notch. Force tool handle down­ ward as illustrated, causing ring to disengage from rim g u tte r. Continue o p e ra tio n , p ry in g aw a y fro m rim g u tter with flat end of tool until free.

Turn assembly over and unseat tire bead from back flange in same m anner as loosening bead from side ring in first step. Stand tire up and remove rim base.

DEM O UNTING

C A U TIO N : Make certain tire is com­ pletely deflated. To loosen tire bead fro m side rin g , d riv e cu rv ed beadloosening end of above recommended rim tool, or a larg er tire tool, between ring and bead. P ry downward on bead and repeat this operation around the ring until bead is loose.

N O T E : It is unnecessary to free the side ring from the tire bead if tire is to be removed for tube repair and im­ mediately replaced. Simply loosen bead from back (permanent) flange as in third demounting step. Then turn the assembly over arid remove ring, with tire attached, as in second demounting step.

SA F E T Y P R E C A U T IO N S: 1. Before inflating tire, be sure side ring has completely cleared the gu t­ ter of rim base. In this position the side ring can be depressed by hand or will yield to a ligh t hammer blow.

DO NOT INFLATE IF SIDE RING DOES NOT MOVE FREELY.

T-8317

Figure 19— Mounting and Demounting RH5° Rims

Sec. 10 P age 71

WHEELS AND TIRES

MOUNTING

P la ce tire on rim so th a t valve is in lin e w ith rim s lo t and in sert v a lv e th rou gh th e slot.

F orce first bead dow n into w ell o f rim ju st to sid e o f v a lv e w ith foot. M o u n t first bead over rim lip w ith rim tool p rogressin g from each sid e o f foot a p p ro x im a te ly o p p o site foot.

T o a p p ly second bead, start at point op p osite valve an d press tire bead over rim lip and into rim w ell w ith foot pressure. M ount rem ainder o f bead over rim lip by m eans of th in tire tool, b ein g careful not to pinch tube. If n e c es­ sary, in sert second tire tool and lub ricate last 6" of bead before com pleting m ounting.

P la ce h alf of sid e ring under th e rim lip w ith c u taw ay portion s in p osition as show n. Insert th in end of rim tool or heavy screw driver and pull ring outw ard tow ard cen tered position.

Strik e w ith m allet to start ring over rim lip. th en strike rem ainin g portion to force it over rim lip.

DEMOUNTING

F irst rem ove va lv e core to c o m p le te ly deflate tire. P la ce tire an d w h eel on floor w ith sid e ring up. T o lo o sen first bead, d riv e hooked end o f rim tool b etw een tire a nd rim flange a nd p ress d o w nw ard on bead. P ro g ress a round rim, u sin g 2 tools, as show n.

T o rem ove ring, insert tool in notch and force ring (o p p o site of notch) dow n w ith feet; th en pry off. P ry out and up on side ring, c a re ­ fu lly but firmly. B e careful not to bend side ring.

Sta n d a ssem b ly in vertical position . L ubri­ c a te secon d bead. A t top o f assem b ly insert stra ig h t end o f tool betw een bead and back flange of rim a t ab ou t a 45° angle. T urn tool so th a t it is p erp en d icu la r to rim. P ry second bead off.

F orce up per tire bead into w ell o p p osite the valve slo t and w ith tire tool pry o p p o site p or­ tion of bead over edge of rim.

T urn tire over and by m ean s of rim tools, loosen bead on o p p osite bead seat. T h is can be further aided by u sin g foot pressure.

M ake sure on e portion of second bead is s t ill in th e rim w e ll, th e n p r y o p p o s it e portion of be^d over ed ge of rim. T h is w ill free the tire from th e rim.

Figure 19a Mounting and Demounthg XL Rims

T -9 1 0 2

Sec. 10 P age 72

_______________

WHEELS A N D TIRES

TIRE BA LAN CIN G W A R N IN G WARNING: When balancing tir e s on the truck, follow the equipment m anufacturer's instructions carefully.

On trucks which do not have

M aximum T raction, drive wheel spin should be lim ited to 35 mph as indicated on the speedom eter.

T his lim it is n e cessa r y b ecau se the

sp eed om eter only indicates one-half of the actual wheel speed when one drive wheel is spinning and the other drive wheel is stopped. Un­ l e s s ca re is taken in lim iting drive w heel spin, the spinning w heel can reach e x c e ssiv e sp eed s, resulting in p o ssib le tir e disintegration or d ifferential failure, which could cause personal injury or extensive v eh icle damage.

On trucks which do have Maximum T raction, drive w heel spin should be lim ited to 70 mph. On such trucks, do not attempt to balance a tir e on a drive w heel with the other drive w heel on the ground sin ce the truck may drive through this w heel.

WHEELS AND TIRES RIM AND WHEEL SAFETY PRECAUTIONS CAUTION An inflated tir e and rim can be very dangerous. Many accid en ts, som e fatal, have resu lted from improper handling and operation of truck r im s and w h eels. It is , therefore, of the utm ost im portance that the p recau tions outlined in th is section be carefully noted by all p erso n s concerned in order to avoid personal injuries and costly damage.

HOW TO PREVENT RIM ACCIDENTS (R efer to F igure 20)

DURING TIRE DEMOUNTING C om pletely D eflate T ire P r io r to Demounting (R efer to F ig. 20, View A) If either rim or rings a re damaged or ring appears to be unseated, the tir e should be deflated p rio r to rem oval of the tir e and rim assem bly from the veh icle.

F ir st, reduce the p r e ssu r e by pushing the plunger, then rem ove the en tire co re. Keep your ey es away from the valve.

R em ove valve co re to en sure com plete de­ flation.

F ollow R ecom m ended Demounting P roced u res S ee previou s p ages of th is section for demount­ ing in stru ction s.

Check For Dam aged or Worn P a rts Mark d efective p arts for destruction to p re­ clude their future u se .

DURING TIRE MOUNTING R eplace Dam aged P a rts Abuse during road operations or in mounting the tir e can cause dents, crack s or d isto rtion s which weaken the p arts and prevent sa fe , proper a sse m ­ bly.

BEFORE mounting a tir e and a ssem b lin g the rim , in sp ect the rim p arts carefu lly for damage, ru st, and distortion . Avoid the u se of r im s, locking rin gs or flan ges which are out of shape, rusted, o r broken. Avoid the u se of a ring or rim parts of d ifferent manufacture than the rim , or of any dif­ feren t s iz e or type than the rim .

A void the u se of any lubricant which contains w ater or solvent that is injurious to rubber. A com ­ bination lubricant and ru st-p rev en tiv e compound is p refera b le. This p ro tectiv e m easu re is of particular im portance with drop -cen ter tu b eless rim s a s the air in the tir e is contained by the tir e - s id e rim su rfa ce.

Rem ove Rust and Other Foreign Matter Accumulation of such m aterial in the rim gut­ ter can prevent the proper fitting of rin gs. P arts that are e x c e ssiv e ly corroded are weakened and should be replaced. U se of a rust preventive com ­ pound (not containing water) during mounting w ill m inim ize rusting.

Do Not U se O v er-S ize or O ver-Inflated T ires U se only p referred or a lte r n a te -siz e rim s for tires and do not exceed recommended air pressures (see pages 77 and 78). These are common causes of rim failures and accidents.

Follow Recom m ended Mounting P roced u res See previous pages of th is section for mounting instructions.

ADDED PRECAUTION: R e-ch eck a ssem b lie s just prior to inflation, particu larly if they have been rolled a c r o ss the floor or have receiv ed rough handling between mounting and inflation.

Rim Ring Seating (Fig. 20, View B) MAKE CERTAIN the rim ring is seated to the full depth of the groove, fits tightly all around, and is secu rely locked. With certain types of w h eels, however, it is n ec essa ry to sea t the rings while the tire is being inflated. In either c a se BEFORE in ­ flating.

Safety D evice or Cage (Fig. 20, View C & F ig. 21) ATTACH A PORTABLE SAFETY DEVICE, OR USE SAFETY CAGE, MADE ESPECIALLY FOR THE PURPOSE. TO THE ASSEMBLY. This p ort­ able device can be used with a ll types of w heels and rim s.

Or, if the assem b ly is not of the type which requires inflation to seat the rin gs, a SAFETY CAGE can be used. This is recom m ended to p re ­ vent personal injury during inflation. An inflated tir e contains potentially ex p losive energy that can blow rings lo o se . A clip -on type a ir chuck should a lso be used, so that the operator can stand to one sid e during tir e inflation.

Avoid a position w here the face or body is im m ediately over the work being done on any tire

Sec. 10 Page 74

WHEELS A N D TIRES

Figure 20— Rim and Wheel Safety Precautions

)

Sec. 10 P age 75

WHEELS AND TIRES in which there is p r e ssu r e (fig. 20, View D).

U se only a ccu rate, tested gauges to ensure proper air p r e s s u r e . Check a ll gauges regularly with a m aster gauge.

Drop Center W heels (Fig. 20. View E) IN CHANGING TIRES on drop center w heels, rem ove w h eels from the truck and p lace on a wheel holder or tir e changing m achine, rem oving and mounting the tir e s in this way. G reater speed and e a se thus can be obtained than by making the change with the w heel on the v eh icle.

This a lso w ill prevent cuts on hands and w rists from fender edges and w ill make it u nnecessary to u se a ham m er for seating the tir e .

U se only standard tir e mounting to o ls and equipment. The u se of m akeshift tools, screw d riv­ e r s or p lie r s to fo rce tir e s on or off rim s or wheels is dangerous.

A ll Wheel and Rim A sse m b lie s (R efer to F ig. 20, View F) IN THE SERVICING OF ALL TIRES u se cau­ tion not to drop them , or the w h eels or a sse m b lie s, on the feet, hands, or body, or heavily on the floor.

Learn how to lift properly — u se your legs as w ell as your body. T his can help prevent pain­ ful, internal injury or rupture.

T ire Iron Safety (F ig. 20. View D) BE CAREFUL IN USING TIRE IRONS, p artic­ u larly a s to gripping them firm ly and keeping the hands free of oil and g r e a se . The iron s can slip and fly with trem endous fo rce.

Figure 21 —Safety C a g e (Typical)

weight does not exceed the rated load of the tir e s used. R im s are designed to sustain the maximum rated load of the m aximum tir e s iz e recom m ended for that rim .

Do Not Exceed Maximum Inflation P r e ssu r e s This is determ ined by the siz e and ply rating of the tir e . It is a lso im portant to m aintain uni­ form inflation in both tir e s of a dual assem b ly so that weight is equally sustained.

H am m ers (F ig. 20, View G) USE CARE IN HAMMERING RINGS OR RIMS WITH STEEL HAMMERS. Sm all b its of ste e l may be broken off the ham m er or rim , flying into the eye, fa ce, or body.

U se ru bb er-covered steel-h ea d ed ham m ers w h erever p o ssib le .

Do not ham m er on r im s or rings after tire inflation has started.

Do Not Run V ehicle on One T ire of Dual A ssem bly When there is lo s s of air in a dual tire the carrying capability is reduced and the load m ust be sustained by the other tir e and rim . Both tir e s should be inflated to balanced, recom m en d ed p ressu res before further operation.

Changing Equipment (F ig. 20, View H) TIRE SPREADER ARMS CAN BE DANGEROUS. Keep them clo sed when the machine is id le and u se ca re in a ll r e sp e c ts while operating the spreader

N ever R e-Inflate a T ire That Has B een Run Flat Without F ir st Thoroughly Inspecting It and The Rim and Wheel A ssem b ly It is esp ec ia lly im portant to make su re the lock ring is se cu re in the gutter and has not been damaged p rior to re-in flation .

F ace and Eye P rotection ALWAYS WEAR GOGGLES or face shields when buffing r im s or tir e s , or when hammering rin g s.

DURING VEHICLE OPERATION Do Not O verload T ir e s E nsure that the com bination of load and vehicle

P eriod ically Check Clam ps and W heel Nuts Loose clam ps can cau se dangerous rim s lip ­ page or detachment of rim and tir e from the v e ­ hicle while in m otion. L oose w heel nuts can cause dangerous wheel shim m y and lo s s of veh icle con­ tro l. E x c e ssiv e torque is also dangerous in that it can cause stud and ring breakage. R efer to page 77 for torque recommendations.

Sec. 10 Page 76

WHEELS A N D TIRES W HAT HAPPENS WHEN TIRES GET HOT As a tir e b ecom es heated, the air in the tire expands and the a ir p r e ssu r e is raised . This is norm al u n le ss the p r e ssu r e build-up is ex c e ssiv e .

B uild-ups of over 20 lb s. are e x c e ssiv e , indicating underinflation, overload, too much speed, too sm all a tire or, m ore often, a combination of these fac­ to r s. T h erefore, p r e ssu r e build-ups of over 20 lbs. should be studied to determ ine cause and proper c o rr ectiv e action. Norm al p r e ssu r e build-ups (not over 20 lb s.) reduce flexin g. Thus the amount of heat generated allow s the tir e to reach a heat bal­ ance (the tem perature at which the rate of heating equals the rate of cooling) at a low er tem perature than if the inflation p r e ssu r e w ere maintained uni­ form ly by frequently bleeding out air. T ires should never be bled. When the p r e ssu r e builds up ex­ c e s s iv e ly - reduce the speed or the load instead.

A tir e operated for a considerable distance at sustained highway sp eed s, in a sev erely underin­ flated or flat condition, b eco m es extrem ely hot due to internal friction , and this heat transm its to the tir e ’s outer su rfa ce. If and when the outer surface tem perature reach es the com bustion point, the tire b u rsts into flam e. This usually occurs after the v eh icle has stopped. Such an occurrence usually involves a dual a ssem b ly w here one of the tir e s is flat and the other is , th erefore, extrem ely ov er­ loaded (possibly a lso underinflated even for normal load). In such c a s e s , eith er the tire which is s e ­ v erely underinflated or com pletely flat, or the tire which is ex trem ely overloaded, could get so hot as to reach the point of spontaneous com bustion.

CAUSE AND PREVENTION OF TIRE FIRES A m ajor cause of tir e fir e s is heat caused by a dragging brake, particu larly if there is ex c e ssiv e g re a se an d/or o il around the brake drum The heat produced by the dragging brake ignites the grease or oil which in turn can eventually ignite the tire, even though the tir e is not overloaded or under­ inflated.

R eg a rd less of the cause of a tire fir e , the t ir e ’s internal tem perature is so high that even if the flam es are extinguished, repeated spontaneous ignition occu rs until the internal tem perature de­ c r e a s e s su fficien tly . A fir e extinguisher usually w ill not have su fficien t capacity to control the fire until the burning tir e can be rem oved. Operators should carry sp e c ia l a sb e sto s blankets which, in c a se of tir e fir e , are u seful in preventing the fire from spreading to v eh icle and cargo. If p ossib le, a steady strea m of w ater should be placed on the tir e until it is cool enough for rem oval.

The b est p rotection against tire fir e s is to avoid running on a flat tir e , prevent underinflation through regular checking of inflation p r e ssu r e s, and

avoid accum ulation of g rea se or o il around brake drum a r e a s. O perators carrying cargo which is exp losive or readily com bustible should check tir e s at 5 0 -m ile in tervals and should a lso u se a p r e ssu r e warning d evice.

INSTRUCTIONS FOR M A IN TEN AN C E OF TIRES O N OFF-THE-HIGHW AY UNITS IN H IG H W A Y TRANSIT Many O ff-The-H ighway T ires are designed and built to give maximum se r v ic e for mining and con­ struction operations. B ecau se of the extra heavy construction built into th ese tir e s , sp ec ia l p recau ­ tion s must be ob served when equipment is being moved over the highway for d elivery or when tr a n s­ ferrin g to a new job s ite . If th ese precautions are not ob served, the tir e s may build up e x c e ssiv e heat and cause prem ature fa ilu re.

The follow ing recom m endations are made in the in ter est of protecting your investm ent against lo s s and delay. T h ese recom m endations apply to a ll tir e s on v eh icles in tran sit, whether driven or towed.

LOAD AND PRESSURE 1. V eh icles must be empty during tran sit.

2. Inflation p r e ssu r e is determ ined by cold p r e ssu r e checks before starting. P r e ssu r e is not to be reduced by "bleeding” tir e s during tra n sit.

3. Inflation p r e ssu r e s are to be determ ined by u se of the follow ing ch arts. If load cannot be a c ­ curately estim ated, u se the m aximum inflation p r e ssu r e shown for the ply rating in question.

4. T ir e s with "dry" b allast m ust not be used for v eh icle transport p u rp oses.

SPEED R egular Skid Depth T ir e s 1. Maximum highway speed 30 mph.

2. Stop for 3 0 -minute cooling period after each 50 m iles of driving or before 2 hours’ s u s ­ tained operation, w hichever com es fir st.

3. One hour minimum m id-day lunch stop should be observed during full day operations.

Extra Skid Depth and Special Compound T ir es V eh icles equipped with extra skid depth or sp ec ia l compound tir e s are not to be driven in tra n sit over the highway u n less the proposed trip is review ed and approved by qualified p erson n el.

Super Deep Tread T ires Under no circu m stan ces should the Super Deep Tread tir e s be moved (roaded) over the highway.

V eh icles in tran sit m ust be controlled and a c ­ com panied by resp on sib le personnel in a p ilot car to enforce recom m endations and maintain a check on equipment. This is good insurance for a v a l­ uable investm ent.

Sec. 10 P age 77

WHEELS AND TIRES SPECIFICATIONS WHEEL NUT TORQUE

CAST TYPE WHEELS Tighten nuts as d irected in text to: F r o n t ..................................................................................................... 190-210 foot-pounds R ear ..................................................................................................... 190-210 foot-pounds BUDD TYPE (DISC) WHEELS Tighten nuts a s d irected in text to: F r o n t .....................................................................................................

R ear (Inner and Outer N u t s ) ........................................................

500-550 foot-pounds 500-550 foot-pounds*

Aluminum W heels and/or H u b s .................................................

450-500 foot-pounds*

CORPORATION TYPE (DISC) WHEELS Tighten nuts as directed in text to: F r o n t ......................................................................................................

Rear ......................................................................................................

300-400 foot-pounds 300-400 foot-pounds

* L oosen outer nuts, tighten inner nuts, then tighten outer nuts.

NOTE: Wheel hub flan ges, w heels, studs, and stud nuts should be free of ru st, lubricants, dirt, and fin ish color paint on all "faying" su rfa ces to ensure proper torque retention.

TIRES FOR TRUCKS IN HIGHWAY SERVICE LOAD AND INFLATION TAB LE T ir e an d R im A s s o c ia tio n S ta n d a rd T ir e Lo a d s A t V a r io u s In fla tio n P re s s u re s.

TIRES USED AS SING LES T IR E IDENTIFICATION

SIZE

L OA D RANGE

8 .2 5 -2 0 8 .2 5 -2 0 9 .0 0 -1 5 9 .0 0 -1 8 9 .0 0 -2 0 9 .0 0 -2 0 1 0 .0 0 -1 5 1 0.0 0 -1 5 1 0 .0 0 - 2 0 1 0 .0 0 - 2 0 1 0 .0 0 - 2 2 1 0 .0 0 - 2 2 1 1 .0 0 - 2 0 1 1 .0 0 - 2 0 1 1 .0 0 - 2 2 1 1 .0 0 - 2 2 1 1 .0 0 -2 4 1 2 .0 0 - 2 0 1 2 .0 0 -2 4

E F F E E F F G F G F G F G F G F G G

T I R E L O A D L I M I T S AT V A R I O U S I N F L A T I O N P R E S S U R E S 50

55

60

65

70

75

80

85

90

95

100

2800 2800

3010 3010 2950 3320 3560 3560

3190 3190 3150 3530 3770 3770 3580 3580 4290 4290 4560 4560 4670 4670 4960 4960 5270

3370 3370 3330 3730 4000 4000 3780 3780 4530 4530 4820 4820 4940 4940 5240 5240 5570 5620 6330

3560 3560 3500 3920 4210 4210 3980 3980 4770 4770 5070 5070 5200 5200 5520 5520 5860 5920 6660

3730 3730 3660 4120 4410 4410 4170 4170 4990 4990 5310 5310 5450 5450 5790 5790 6140 6200 6980

3890 3890 3830 4300 4610 4610 4370 4370 5220 5220 5550 5550 5690 5690 6040 6040 6420 6480 7280

4050 4050 3980

4210 4140

4350 4210

4500

4970

5150

4710

4880

5050

5640

5840

6040

6000

6210

6430

6140

6370

6590

6530

6770

7000

N O T E : U n d e rlin e d F ig u re s In d ic a te M a xim u m R e co m m e n d e d Load.

4790 4540 4540 5430 5430 5780 5780 5920 5920 6290 6290 6680 6740 7580

7000 7880

Sec. 10 P age 78

WHEELS A N D TIRES SPECIFICATIONS (CONT.)

TIRES USED AS DUALS TIRE LOAD LIMITS AT VARIOUS INFLATION PRESSURES

TIRE IDENTIFICATIO N

SIZE

LOAD RANGE

8.25-20 8.25-20 9.00-15 9.00-18 9.00-20 9.00-20 10.00-15 10.00-15 10.00-20 10.00-20 10.00-22 10.00-22 11.00-20 11.00-20 11.00-22 11.00-22 11.00-24 12.00-20 12.00-24

E F F E E F F G F G F G F G F G F G G

40

45

50

55

60

65

70

75

80

85

90

2460 2460

2640 2640 2590 2910 3120 3120

2800 2800 2760 3100 3310 3310 3140 3140 3760 3760 4000 4000 4100 4100 4350 4350 4620

2960 2960 2920 3270 3510 3510 3320 3320 3970 3970 4230 4230 4330 4330 4600 4600 4890 4930 5550

3 120 3 120 3 070 3440 3 690 3 690 3490 3490 4 180 4180 4 450 4 450 4560 4560 4840 4840 5140 5 190 5840

3270 3270 3210 3610 3870 3870 3660 3660 4380 4380 4660 4660 4780 4780 5080 5080 5390 5440 6120

3410 3410 3360 3770 4040 4040 3830 3830 4580 4580 4870 4870 4990 4990 5300 5300 5630 5680 6390

3550 3550 3490

3690 3630

3820 i M

3950

4360

452a .

4130

4 280

4 430

4950

5120

5300

5260

5450

5640

5390

5590

5780

5730

5940

6140

4 200 3980 3980 4760 4760 5070 5070 5190 5190 5520 5520 5860 5910 6650

6140 6910

N O T E : U n d e rlin e d F ig u re s In d ica te M a x im u m R ecom m ended Load.

LOAD RANGE DESIGNATION LETTER TO PLY RATING NUMBER CONVERSION CHART LOAD RANGE LETTER

PLY RATING

E F

10 12 14

G

CAUTION: DO NOT stand unprotected In front of clamp ring when Inflating tire. If a protective Inflation cage is not available, wrap three lengths of chain, evenly spaced around tire and rim. Secure chains but leave loose enough to permit expansion of tire during inflation. Use an extension gauge with clip on chuck so air pressure build-up can be closely watched and so that you can stand well back from the assembly during the bead seating process to avoid possibility of personal injury.

Sec. 11 Page 79

SECTION 11

S h eet M etal A ll inform ation pertaining to SHEET METAL as d escrib ed in S erv ice Manual S T -3 3 1 -7 1 , pages 11-1 through 11-8 is applicable to m od els covered in th is Supplement with addition of the following: HOOD ALIGNMENT Hood alignm ent blocks (see fig s . 1 and 2) are at­ tached to the hood by sc r e w s. To adjust, loosen hood hinge b o lts. Note that the rearm ost bolt hole in hinge is slotted to allow hood trailin g edge to move up and down. Adjust, so hood and cowl su rfa ces are flush.

NOTE: It may be n e c e ssa r y to perform hood lock adjustm ent as d escrib ed in S ervice Manual S T -3 3 1 -7 1 , page 1 1 -3 .

Fig u re 1 —H o o d A lig n m e n t Blocks

H O O D ASSEMBLY

C O W L GRILLE ASSEMBLY

I

Figure 2—Front End Sheet Metal Components (Typical)

(

S ec . 12 P age 80

SECTION 12

GhadAid, SlectsUccd ana 9MAbiumetiti NOTE: E lectrica l sy stem inform ation applicable to m odels cov­ e red by this supplem ent rem ains the sam e as covered on pages 12-1 through 12-52 in CHASSIS ELECTRICAL AND INSTRUMENTS (SEC. 12) in S erv ice Manual ST-331-71 except as follow s:

INSTRUMENTS A N D G A U G E S Inform ation applicable to instrum ents and gauges rem ains the sam e as covered on pages 12-7 through 12-13 under “ Instrum ents and Gauges” in CHASSIS ELECTRICAL AND INSTRUMENTS (SEC. 12) in S erv ice Manual S T -331-71, except a s e r ie s of ground w ir es have been added to the gauges used on ste e l tilt cab m od els. T hese w ire s m ust be in sta lled in such a manner as to m aintain a continuous ground c ir ­ cuit from gauge to gauge.

SPECIFICATIONS RETARDER BRAKE ALARM RELAY . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . .. . .. . .. . . .. . .. . . .. .. . .. . . .. . .. . .. . . .. . .. . . .. . .. . .. . . .. . .. . . .. . .. .

Air Gap at Core Points Closed (In.). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Point Opening (In.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Closing Voltage (Range) . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . .

BRAKE WARNING BUZZER Delco-Remy 1115811 0.020 0.018 1.5-9.5

STARTER CONTROL OR STARTER INTERLOCK RELAY M a ke ....................................................

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Point Opening (In.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Opening Voltage (Range). .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . .

Delco-Remy 1115848 0.017-0.033 3.7-5.2

STARTER SHUT-OFF RELAY . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . .. . .. . .. . . .. . .. . . .. .. . .. . . .. . .. . .. . . .. . .. . . .. . .. . .. . . .. . .. . . .. . .. .

Point Opening (In.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Opening Voltage (Range). .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . .

Delco-Remy 1115848 0.017-0.033 3.7-5.2

GENERATOR TELL-TALE RELAY M a k e ....................................................

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Point Opening (In.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Opening Voltage (Range).. .. . .. . . .. . .. . . .. . .. . .. . . .. . .. . .

Delco-Remy 1115848 0.017-0.033 3.7-5.2

LOW AIR PRESSURE OR LOW VACUUM ALARM BUZZER M a ke ....................................................

Delco-Remy Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1116882 Point Opening (In.) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

0.017 Closing Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adjust to Buzz at .25 .35 Amperes at 13.5-14.5 Volts

..................................................

Delco-Remy ..................................................

1116882 0.017 Point Opening (In.) . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . .. .

Closing Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Adjust to Buzz at .25 .35 Amperes at 13.5-14.5 Volts ENGINE ALARM BUZZER M ake....................................................

Delco-Remy Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1116914 Point Opening (In.) . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . .. . . .. .

0.015 Closing Voltage . . . . .. . .. . .. . . .. . .. . .. . . .. . .. . Adjust to Buzz at .30 .35 Amperes at 13.5-14.5 Volts TRAILER I.C.C. MARKER LAMP RELAY M ake....................................................

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Air Gap at Core Points Closed (In.) * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Point Opening (In.) .. .. . .. . . .. . .. . .. . . .. . .. . .. . . .. . .. . . ..

Closing Voltage (Range) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sealing Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ‘ Tolerance Plus or Minus 1 0 %

Delco-Remy 1115841 0.012 Min. 0.015-0.025 7-8 10.0 Max.

HORN RELAY Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2480982 12

ELECTRIC HORN M ake....................................................

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Delco-Remy 9000235 357 C.P.S.

)

S e c . 12 P a g e 81

CHASSIS ELECTRICAL AND INSTRUMENTS SPECIFICATIONS (Cont.)

ELECTRIC HORN ....................................................................

Delco-Remy

Freq u e n cy.................................................................

360 C.P.S.

DUAL ELECTRIC HORN VIBRATING HI - NOTE M a k e .......................................................................

Model .....................................................................

Frequency “A” Note ..................................................

Delco-Remy 9000004 444 C.P.S.

FLASHER UNIT Specific Load — 2 Prong .............................. Sig. Stat.

Variable Load — 2 Prong .............................. Sig. Stat.

144 175

LIGHT BULB DATA BULB NO.

CANDLEPOWER

Headlamp Single Sealed Beam U n it ..............

6014

50-60 Watts

Directional Signal Lights ..................

1156

32

Park and Directional Signal Lights

1157

32-3

Front Side Marker Lights ................

193 or 195

2

Tail and Stop Lights ......................

1157

32-3

Tail, Stop, and Rear Directional Lights

1157

32-3

Clearance and Identification Lights . . .

67

4

Marker Lights ................................

1445 or 1895

Back-Up Lights ...............................

1156

32

License L ig h t ..................................

67

4

Cargo Light (when used) ..................

1076

32

Dome Light ...................................

211-1

12

Instrument and Tell-Tale Lights Conventional Cab M o d e ls...............

Series S E / S G / S M / S S -50 ..........

Tilt Cab Models ..........................

Headlamp Hi-Beam Indicator Except Tilt Cab Models ..

Tilt Cab Models ...........

Engine Overspeed Warning Lamp (when used) Except Tilt Cab Models ........................

Tilt Cab Models ..................................

195 1895 57 1445 1090D18 67

1

or

2

BULB NO. Directional Signal Indicator Light Conventional Cab M od els.........

Series S E / S G /S M /S S -50 ...

Tilt Cab Models .....................

168 1445 57

Heater Control Light Conventional Cab M od els.........

Tilt Cab Models .....................

1445 57

Speedometer Light Conventional Cab M od els.........

Series S E / S G /S M /S S -5 0 . . . .

Tilt Cab Models .....................

195 1895 53

Low Vacuum Gauge Warning Light Conventional Cab M o d e ls.........

Series S E / S G /S M /S S -5 0 ....

Tilt Cab Models .....................

195 53 53

Brake Warning L ig h t ...................

1895

Differential Lock Tell-Tale Light . . .

1090D18

Temperature Gauge Light (Tilt Cab

53

Fuel Gauge Light (Tilt Cab Models)

53

Air Pressure Gauge Light ...........

53

Voltmeter L ig h t .........................

53

Tachometer Gauge Light .............

53

Ammeter Gauge Light ................

53

Oil Pressure Gauge Light ...........

53

Vacuum Gauge Light .................

53

CANDLEPOWER

P age 82

9 + id e * .

Page No.

Subject

Subject

H

Hubs and B ea rin g s, Front A ir C leaners .........................................................

A ir S u s p e n s io n .........................................................

Alignm ent, Front End ..........................................

Axle C ontrols ............................................................

Front ..................................................................

R ear .....................................................................

..................................

5

.......................................................

42

34 35 3

I Ignition System

7 3 7

L Linkage, T ran sm issio n ........................................

L u b r ic a t io n ................................................................

B B attery .....................................................................

B attery, Using B oo ster .......................................

B elt T ension ............................................................

B rakes ........................................................................

A ir ........................................................................

Hydraulic ............................................................

B ulbs, Light ............................................................

37 38 20 9 10 9 81

Mountings, Engine

29 26 22 33 51 51 19 18

80 80 37 11 13 14 15 34

F Fluid, Pow er S t e e r i n g ..........................................

Fluid, T r a n s m is s io n .............................................

16

o O il, Engine

................................................................

1

Safety, Rim and W h e e l ...........................................

Sheet M e t a l ................................................................

Springs, F r o n t ..........................................................

Springs, R ear ..........................................................

Starting System .......................................................

Steering, M e c h a n ic a l..............................................

Steering, P o w e r .......................................................

Steering S y s t e m .......................................................

Suspension F r o n t ......................................................................

H endrickson .......................................................

R ear ......................................................................

73 79 5 8 39 53 54 53 3 8 7

T T ir e s ............................................................................

T ire B a la n c in g .................................................... ... • T ire Inflation Table ..............................................

T ire Selection ..........................................................

Torque, A ir Line ....................................................

T ran sm issio n ..........................................................

T ra n sm issio n , A uxiliary .....................................

60 72 77 62 10 45 49

1 2 Vacuum Shift

G Gauge, Vacuum ......................................................

Generating System (A.C.) .................................

Governor, A ir C om pressor ..............................

G overnors, Engine ................................................

.................................................

s

E E le c tr ic a l, C h a s s i s ................................................

E le c tr ic a l Instrum ents .......................................

Engine E lectrica l ...................................................

E ngines, G a s o lin e ...................................................

Engine Tune-Up 16 .........................................................................

V6 ........................................................................

V8 ........................................................................

Engine, Turbium (D iesel) .................................

45 1

M

c C arburetor, Bendix .............................................

C arburetor, H o l l e y ................................................

C arburetor, R ochester .......................................

C arburetor Specifications .................................

Clutch ........................................................................

Clutch Controls ......................................................

Coolant Recom m endations .................................

Cooling S y s t e m .........................................................

P age No.

9 43 35 21

w W heels and T ires

57

MODEL DATA ENGINE

TRUCK SERIES

STD.

OPT.

STD.

CLUTCH OPT.

_

—

FRONT AXLE STD. OPT.

_ —

STD.

REAR AXLE OPT. H-135 H-135 T-150, T-170

SM-465 SM-465 SM-465

STD.

C E -4 0 C S -4 0 C E -5 0

(02-03) (02-03) (02-03)

350 250 350

292 366

12”-1 ir- i 13”-1

12”-1 —

F-050 F-050 F-050

F-070

H-110 H-110 H 150

C E -5 0

(13)

350

366

13”-1

—

F-070

—

H-170

T-170

SM-465

C G -5 0

(03)

DH-478

—

13”-1

—

F-050

F-070

H-150

540 GL

C G -5 0 C M -50

(13) (03)

DH-478 351C

13”-1 13”-1

—

F-070 F-050

—

i3 ”- r

F-070

H-170 H-150

540 GL SM-465

C S -5 0 S E -5 0

(02-03) (02)

292 350

— — —

T-150, H-170, T-170, 17121, 17221 T-170, 17121, 17221 T-150, H-170, T-170

12”-1 13”-1

—

366

F-050 F-055

F-070 F-070

H-150 H-150

T-150, T-170 T-150, H-170, T-170

SM-465 SM-465

S E -5 0

(62)

350

366

13”-1

F-055

F-070

H-170

T-170

SM-465

S G -5 0 S G -5 0 S M -5 0

(02) (62) (02)

DH-478 DH-478 351C

13”-1 13”-1 13”-1

F-070 F-070 F-055

— — F-070

H-150 H-170 H-150

H-170, T-170 T-170 T-150, H-170, T-170

540 GL 540 GL SM-465

S M -5 0 S S -5 0 T E -5 0

(62) (02) (03)

351C 292 350

— — — — —

— — —

F-070 F-090

H-170 H-150 H-150

T-170 T-150, H-170, T-170 T-150, H-170, T-170

SM-465 SM-465 435 GL

T G -5 0

(03)

DH-478

540 GL

T G -5 0 T M -5 0 C E -6 0

(13) (03) (02-0313)

DH-478 351C 366

T-150, H-170, T-170 17121, 17221 T-170, 17121, 17221 T-150, H-170, T-170 T-170, 17121, 17221, 19201

C M -60

(03-13)

M E -60

—

—

13”-1 12”-1 13”-1

— — —

F-070 F-055 F-070

13"-1

i3”-r

F-070

F-090

H-150

in *

427

13”-1 13"-1 13”-1

i3 ”- r 12”-2

F-070 F-070 F-070

F-090 F-090 F-090, F-110

H-170 H-150 H-170

351C

—

13”-1

i3 ”- r

F-070

F-090, F-110

H-170

(03-13)

366

427

13”-1

12”-2

F-070

F-090, F-110

30DSC

T E -6 0

(03-13)

366

427

13”-1

12”-2

F-070

F-090, F-120

H-170

T M -60

(03-13)

351C

13”-1

i3 ”- r

F-070

F-090, F-120

H-170

366

— — —

* Equipped with Cerametalix Clutch Discs.

....

—

540 GL 435 GL SM-465

T-170, 17121, 17221, 18121, 18221 34DSC

SM-465

T-170, 17121, 17221, 19201 T-170, 17121, 17221, 19201

435 GL

SM-465

435 GL

TRANSMISSION OPT. AT-475, AT-540 AT-475 282V, 285V, 542GD/GL, AT-475, AT-540 282V, 285V, 542GD/GL, AT-540 540GD 540 GD 435GL, 540GD/GL, AT-475, AT-540 540GL, AT-475 282V, 285V, 542GD/GL, AT-475, AT-540 282V, 285V, 542GD/GL, AT-475, AT-540

_ _

435GL, 540GL, AT-475, AT-540 540GL, AT-475, AT-540 540GL, AT-475 282V, 285V, 542GD/GL, AT-540 540GD, MT-41 540GD, MT-41 540GL, AT-540 282V, 285V, 325V, 327V, 542GD/GL, AT-540, 5652B, 5756B 282V, 285V, 540GD/GL, ' AT-540 285V, 325V, MT-40, 5652B, 6041 Aux., 7041 Aux. 282V, 285V, 542GD/GL, AT-540, 5752C 282V, 285V, 542GD/GL, 5752C, AT-540

>pv

’ T I " -----

I

CHEVROLET

SERVICE ■ji