Chevrolet 40 Series 1972, Service Manual

Page 1: ...40 60 SERIES TRUCK SUPPLEMENT SERVICE MANUAL ...

Page 2: ... 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 6M ENGINE FUEL SYSTEM 6T AIR COMPRESSOR AND GOVERNOR 6Y ENGINE ELECTRICAL 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 thi...

Page 3: ... and each oil change thereafter to filter sm all particles which could affect valve lifters or PCV valve action RECOMMENDATIONS The oil industry markets various types of en gine oil under certain service designations and specification numbers The selection of a reliable supplier with close attention to his oil and filter element change rec ommendations can provide satisfactory lubrication and long...

Page 4: ...usual condi tions such as off road construction or constant stop and go driving pickup and delivery fluid should be changed at 12 000 m ile intervals It is important that transm ission fluid level be main tained at the full mark and NOT OVERFILLED ENGINE AN D ACCESSORY LUBRICATION The following additional information applies to Lubrication Chart fig 4 on page 7 of ST 331 71 Service Manual CARBURET...

Page 5: ...been updated 1 Steering Knuckle 9 Axle Center Spindle 10 Stop Bolt and Lock 2 Kingpin Bushing Nut Upper 11 Draw Key 3 Kingpin 12 Thrust Bearing 4 Cap Screw 13 Tie Rod End Assy 5 Kingpin Bearing Cap 14 Kingpin Bearing Cap Upper Lower 6 Gasket 15 Gasket 7 Lube Fitting 16 Kingpin Bushing 8 Shim Lower t 8793 1 Steering Knuckle Spindle 2 Steering Knuckle Bushing 3 Kingpin Bushing Upper 4 Kingpin 5 Dust...

Page 6: ...m 1 1090 1 1094 1 2492 1 2496 1 14330 1 14340 1 4330 1 4340 KING PIN BUSHING Length 1 9063 1 9063 Diameter Outer 1 4330 1 4340 1 4330 1 4340 Inner 1 1870 1 1880 1 1870 1 1880 STEERING KNUCKLE BUSHING Length Upper 1 3438 1 875 1 709 1 729 1 760 Lower 1 3438 1 875 1 990 2 010 2 150 I D When Installed 1 1094 1 1124 1 2496 1 2526 1 4365 1 4375 1 434 1 437 STEERING KNUCKLE TO AXLE CENTER CLEARANCE 0 00...

Page 7: ...und Pin Retainer Bolt 20 25 Spring Rear Rebound Bolt N u t 7 5 9 5 Shock Absorber Bracket to Frame Bolt Nut 4 0 5 0 65 95 Shock Absorber Upper and Lower Eye Bolt Nut 65 95 40 50 Shock Absorber Stud to Frame N u t 130 190 9 000 and 11 000 lb Axles Only 366 and 427 V8 Gas Engines SECTION 3D c Jlu b i a n d QeasUnGA All information in Service Manual ST 331 71 FRONT HUBS AND BEARINGS SEC 3D is applica...

Page 8: ... Hub Cap Screw Washer Bearing Cone and Roller A ssy Outer Bearing Retainer Adjusting Nut Washer Adjusting Nut Hub Cap Cotter Pin Backing Plate Inner Oil Seal Bearing Cone and Roller A ssy Inner Spindle 10 11 12 13 14 15 16 17 18 1 2 3 4 5 6 7 8 9 Figure 4 Front Hub and Bearing with Demountable W heel and Drum ...

Page 9: ...d cleaned at regular intervals SERVICING AIR CLEANERS Refer to Figure 1 The air cleaner used on Conventional and S50 Models is the metal cup type which uses a hog s hair type elem ent This cup is a friction fit on the air intake pipe and can be removed by pulling straight off It can be cleaned by rinsing in a suit able solvent and reused Refer to LUBRICATION SEC 0 in this supplement for service in...

Page 10: ...n EQUALIZING BEAM BUSHING REPLACEMENT P ress old bushing out using a suitable driver or press to exert force on bushing outer sleeve P ress new bushing into place exerting force on bushing outer sleeve until outer sleeve extends an equal distance through beam at both sides EQUALIZING BEAM INSTALLATION Refer to Fig 9 1 Position beam s with cross tube and thrust washers in place at spring saddles an...

Page 11: ...andard equipment on all school buses dual split brake system and optional on all other vehicles equipped with dual split brake system s These gauges are mounted on a special bracket below the center of the dash panel One gauge is connected to one vacuum system of the dual brake system and the other gauge is connected to the other vacuum system Vacuum gauge readings may differ during operation of t...

Page 12: ...g 2 remove two screw s and lift cover and filter off housing To install set filter in place on housing and attach cover Filters can be cleaned and reused but breather cannot If removed breather must be replaced with new parts AIR LINE TORQUE Refer to page 5B 53 of Service Manual ST 331 71 and change the following torque values 3 8 inch from 30 50 to 50 75 inch from 90 115 to 120 150 5 8 inch from ...

Page 13: ...n oper ation one hour or approximately 50 m iles it is considered used Belt dressing can be used to ex tend belt life When V belts are worn they should be replaced as excessive tightening w ill not pre vent slippage and can cause damage to bearings SPARK PLUGS Replace spark plugs at 12 000 m ile intervals Use of leaded fuels results in lead deposits on spark plugs and can cause m isfiring at m ile...

Page 14: ... warmed up POSITIVE CRANKCASE VENTILATION SYSTEM HOSES AND CONNECTIONS The PCV system should be checked for sa tis factory operation at 12 month or 12 000 m ile in tervals using a tester such as the AC Tester CT 3 POSITIVE CRANKCASE VENTILATION BREATHER OR FLAME ARRESTER The breather or flame arrester should be re moved and cleaned at 12 000 mile intervals Im m erse in cleaning solvent to remove a...

Page 15: ...6 M in this manual ENGINE IDLE SPEED Refer to appropriate chart in Gasoline Engine Fuel Systems 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 lts 6 8 Main Bearing Cap ...

Page 16: ...CATIONS V6 ENGINE Torque wrench specifications listed below apply to clean dry threads except as otherwise indicated IT E M Rocker Arm Adjusting Screw Rocker Arm Shaft Bracket Bolts Rocker Arm Shaft Cover Bolts Valve Lifter Cover Bolts Distributor Clamp B o lt Cylinder Head Bolts Intake Manifold Bolts Exhaust Manifold B olts Water Outlet Manifold Bolts Thermostat Housing Bolts Front Cover Bolts Co...

Page 17: ...PRESSURE PSD 7 W CYLINDER HEAD BOLT TORQUE FT LBS 350 Eng 60 70 Dwell Angle Degrees 28 32 366 427 75 85 TORQUE WRENCH SPECIFICATIONS V8 ENGINE ITEM FT LBS ITEM FT LBS Rocker Arm Cover B o lt 3 5 Camshaft Sprocket 15 20 Rocker Arm Stud 366 and 427 Only 45 55 Connecting Rod Caps Distribute Clamp Boit 20 25 W H e a d Bolt c Main Bearing Caps 350 Engine 350 60 70 D 7n on 366 and 427 Engines 75 85 tolf...

Page 18: ... 11 18 130 140 3 4 10 16 180 200 7 8 9 14 240 270 1 8 14 325 380 GM 280 M BOLT FT LBS e BOLT HEAD IDENTIFICATION GM 300 M BOLT FT LBS 10 15 25 30 35 45 70 80 85 105 90 110 170 180 300 320 400 430 700 730 BOLT HEAD IDENTIFICATION NUT TORQUE FT LBS 5 8 8 12 15 20 25 30 40 50 50 60 70 80 110 130 210 230 320 350 40 50 55 65 60 70 Torque for aluminum casting ENGINE FRONT MOUNT WITH AT475 TRANSMISSION A...

Page 19: ...Sec 6D Page 17 ENGINE MOUNTINGS WASHER BOLT NUT WASHER LOCK V FRONT V BOLT WASHER NUT M O U N TIN G Figure 1 Engine Front Mount with AT475 Transmission Typical ...

Page 20: ...NG SYSTEM PRESSURE CHECK Several types of cooling system pressure checking devices are available locally and manu facturer s instructions should be followed for proper use A typical tester is illustrated in figure 1 and procedures are given below for testing the pressure cap and cooling system 1 Testing Radiator Cap CAUTION The radiator cap should not be removed while the engine is at normal opera...

Page 21: ...ystem Capacities Chart at the end of this section for system ca pacities ENGINE COOLING SYSTEM COOLING SYSTEM CORROSION PREVENTION NOTE Addition of supplemental additives and other available m aterials which have not been spec ifically approved by GM are not normally required Use of these m aterials will result in unwarranted operating expense Every two years the cooling system should be serviced ...

Page 22: ...tening will not pre vent slippage and can cause damage to bearings SPECIFICATIONS The cooling system capacities listed below apply to vehicles with standard equipment only Because of some optional equipment which may be used air conditioning larger engine water filter increased cooling etc the capacity of cooling system will vary For the purpose of obtaining an accurate cooling system capacity bef...

Page 23: ...lp locate the cause for loss of governor control 1 Using a tachometer check engine governed speed as specified in Specifications at end of this section NOTE Initial overrun means that under accel eration the engine will momentarily exceed gov erned speed by approximately 150 250 rpm and G O V E R N O R LEVER G O V E R N O R V A C U U M LINE D IA P H R A G M ROD D IA P H R A G M T mo CARBURETOR G O...

Page 24: ...alve air cleaner is cleaned or replaced at regular intervals depending on severity of oper ation then perform the following When the problem is suspected to be in the secondary control valve operate the vehicle on the highway and check governor operation The gov ernor should lim it speed to that specified in Speci fications plus 150 250 rpm initial overrun If the engine does not govern remove E cl...

Page 25: ...m inary Checks All Engines 1 Idle adjustments should be performed with the engine at operating temperature air cleaner installed parking brake applied and driving wheels blocked 2 Air conditioning when used must be turned ON 3 Check the distributor dwell reading In Line Engines 31 to 34 degrees 350 V8 Engine 28 to 32 degrees NOTE When setting ignition timing the term BTDC means Before Top Dead Cen...

Page 26: ... reconnect to solenoid 2 Disconnect electrical connector from so le noid with engine idling Adjust 1 8 inch Allen head screw on end of solenoid see fig 6 to achieve Figure 7 Removal of Plastic Limiter Cap Model M Rochester CarburetorI 450 rpm reduced idle speed 3 Reconnect electrical connector and check for proper idle speed 700 rpm 350 V8 Engine Idle Speed Adjustment Referring to figures 3 or 4 a...

Page 27: ... warm up the engine Be sure choke is open FUEL SYSTEM GASOLINE ENGINES Sec 6M Page 25 T 9137 Figure J 0 Removal of Plastic Limiter Caps Model 2 C Rochester Carburetor 2 Check dwell reading and adjust if n eces sary Dwell reading on In line engines should be 31 to 34 degrees 3 Adjust ignition timing to 4 BTDC with vac uum advance hose disconnected and plugged R e connect vacuum advance hose 4 Adjus...

Page 28: ... caps as shown in figure 12 so that tangs on plastic cap are located on either side of boss on throttle body Then care fully push lim iter caps onto idle mixture screw s until they snap into position HOLLEY CARBURETOR Figures 13 and 14 illustrate the Holley Carb uretor Model 4150G installed on 366 and 427 en gines The significant changes in the Holley carb uretor are the addition of plastic lim it...

Page 29: ...dle speed as described earlier in this section FAST IDLE ADJUSTMENT Refer to Figure 16 1 With engine OFF and air cleaner remov ed disconnect throttle return spring 2 With throttle lever in wide open position and choke fully closed measure gap between fast idle cam and screw Gap should be 0 035 3 If necessary adjust fast idle screw to pro vide correct gap using wrench J 10176 4 Connect throttle ret...

Page 30: ...rottle body to prevent unauthorized adjustment These plastic caps are not to be removed unless made necessary by som e Figure 18 Positioning Plastic Limiter Cap For Installation Holley Carburetor Figure 19 Installing Plastic Limiter Cap Holley Carburetor major carburetor repair or replacement which affects the idle mixture screw adjustment REMOVING PLASTIC LIMITER CAPS Refer to Fig 17 1 With the a...

Page 31: ...used should be turned on during the carburetor adjustments 5 Check dwell reading and adjust if neces sary Dwell reading on V6 engines should be 31 to 34 degrees 6 Adjust ignition timing with vacuum advance hose disconnected and plugged to 7 BTDC Re connect vacuum advance hose Carburetor Adjustment 1 Engine idle speed for the 351C engine should be adjusted to 650 rpm by performing the following a R...

Page 32: ...float level adjustment Setting is correct when the edge of the gauge touches top of the rib on float 5 Use tool J 4395 to bend float lever next to float to change the float setting Use bending tool as illustrated in figure 23 6 After checking float level install air horn and throttle body to main body using new gaskets Referring to View A fig 20 install screw s Locate choke control bracket and ide...

Page 33: ...laced BENDING LEVER TO RAISE SETTING Bending Tool REMOVING PLASTIC LIMITER CAPS Refer to Fig 24 1 With the aid of two standard screw drivers 2 Remove plastic cap from each idle mixture screw INSTALLING PLASTIC LIMITER CAPS NOTE The carburetor must be installed on the engine and properly adjusted prior to install ation of the plastic caps 1 Thoroughly warm up the engine Be sure choke is open 2 Chec...

Page 34: ...t roll pin in throttle body of carburetor Use care when install ing caps to prevent bending of idle mixture screw s 7 Reset the engine idle speed as directed in Step 4 8 Turn in idle mixture screw s equally by SPECIFICATIONS YARI SPEED GOVERNOR Sec 6M Page 32 ____________________________________ INTROL PART NO GMC PART NO ENGINE MODEL MAX GOVERNED SPEED RPM NO LOAD 901 685 2472969 351C 3900 651 73...

Page 35: ...rator Pum p Air V ent 366 685981 R 6292A Bottom of 0 015 Min 0 060 427 685982 R 6293A Sight Plug 0 015 Min 0 060 Fast Idle Mechanical 0 035 0 035 Running 1800 2400 RPM 1800 2400 RPM Main Metering Jet Primary 5 6 56 Secondary 7 1 71 Throttle Bore Primary 1 9 16 1 9 16 Secondary 1 9 16 1 9 16 Governed Speed 4000 RPM Except w AT475 Transmission Full Load 4100 RPM w AT475 Transmission No Load Speed is...

Page 36: ... AIR CLEANERS pages 6M 27 through 6M 31 is applicable to models covered by this supplement with the exception of the following Air cleaners should be inspected and serviced at intervals sp eci fied in Em ission Control booklet or more often under severe dust conditions also whenever dirt is visible in element or oil Air cleaners on vehicles operating in dust storm s should be cleaned immediately a...

Page 37: ... COOLING DRIVE FILTER STANDARD 50 SERIES CE SE N 5601 R or M R 1A Air Belt Paper Fibers 282567 B W n Air Belt Foam CG SG N 5601 S or M R n Air Belt Paper Fibers 282896 B W n Air Belt Foam SM 281977 or B W n Air Belt Paper N 6400 N M R ta Air Belt Paper Fibers TG N 6400 N or M R TA Air Belt Paper Fibers 281977 B W TA Air Belt Paper 60 SERIES CE ME TE N 5601 R or M R n Air Belt Paper Fibers 282567 B...

Page 38: ...RNOR Sec 6T Page 36________________________________________ NOTE The air com pressor is the ONLY source of supply for the vehicle braking system Faulty operation of the com pressor will result in im proper function of brakes ...

Page 39: ...Model Application Chart 39 Starting System Specifications 41 Ignition S y ste m 42 Ignition System Specifications 42 Alternating Current Generating System Non Integral Type 43 Model Application Chart 43 Service information applicable to batteries used on vehicles covered by this supplement remains the safne as covered under BATTERY pages 6Y 1 through 6Y 11 in ENGINE ELECTRICAL SEC 6Y in Service Ma...

Page 40: ...ls of each battery These two actions help reduce the possibility of explosion which is always present when connecting a live booster battery to a dead battery 3 Attach one end of one jumper cable to the positive terminal of the booster battery identified by a red color or P on the battery case post or clamp and the other end of the sam e cable to the positive terminal of the discharge battery DO N...

Page 41: ...TAGE 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 ta d in a S y it e t n Starting system information applicable to vehicles covered by this supplement remains the same as covered under STARTING SYSTEM pages 6Y 12 through 6Y 16 in ENGINE ELECTRICAL SEC 6Y in Service Manual ST 331 71 except as ...

Page 42: ...ition When transm ission shift lever is in neutral position and engine control switch is placed in START position current from the battery will energize the starter magnetic switch operating coil through the combination neutral start and back up lamp switch thus completing circuit to the starting motor When transm ission is shifted out of neutral feed circuit to starter magnetic switch operating c...

Page 43: ...n Winding Amps 13 15 5 13 15 5 13 15 5 13 15 5 V o lts 5 5 5 5 Hold ln Winding Amps 14 5 16 5 14 5 16 5 14 5 16 5 14 5 16 5 V o lts 10 10 10 10 STA RTER M O D EL 1108483 1108484 1108485 1108486 1108487 1113686 M ake Delco Remy Delco Remy Delco Remy Delco Remy Serie s 10MT 10MT 10MT 35MT Type 125 125 125 185 Type of D rive Overrunning Overrunning Overrunning Overrunning Clutch Clutch Clutch Clutch ...

Page 44: ...M 1150 1050 1100 850 850 1200 Maximum Advance Degrees 11 13 13 15 10 12 9 11 9 11 12 14 Rpm 2050 2000 1750 1900 1900 2200 Firing Order 1 5 3 6 2 4 1 5 3 6 2 4 1 6 5 4 3 2 1 8 4 3 6 5 7 2 1 8 4 3 6 5 7 2 1 8 4 3 6 5 7 2 1 Set with vacuum in full retard 2 Satisfactory Range When Adjusting Set to 30 Gives 016 Point Opening Ignition Timing Idle Speed RPM 700 700 600 600 600 550 Distributor Setting 1 4...

Page 45: ... 42 AMP _ CE 50 02 03 13 1100547 Integral 61 AMP CE CS 40 02 03 CE CM CS 50 1100849 1119515 61 AMP TE TM 50 CM TE TM 60 1100849 1119515 61 AMP _ TG 50 1100849 1119507 61 AMP CE 50 CE M E 60 1100548 Integral 62 AMP CE CS 40 CE CM CS SE SG SM SS 50 1117782 1116378 62 AMP _ TE TM 50 TE TM 60 1117782 1116378 62 AMP TG 50 1117782 1116374 100 AMP SE SG SM SS 50 1117141 Integral GENERATING SYSTEM GENERAL...

Page 46: ...TMETER TO STARTER MA6 JCT BLOCK DIESEL MODELS SWITCH OffitfNUSED t r a n s is t o r iz e d voltage r e g u l a t o r GENERATOR GENERATOR 62AMP TRANSISTORIZED V0LTA6E REGULATOR I6WHT AC CESSO RY I6BLK I6BLK STARTER MAG SW STARTER CONTROL RtLAY CONTROL SWITCH I O T CONTROL SW 14 PINK TRANSMISSION CONTROL 1 2PURPLE 1 2PURPLE WITH 1116374 REGULATOR WITH 1116378 REGULATOR T 9120 Figure 2 Schematic Diag...

Page 47: ...e transm ission selector lever B against stop in N position 2 Check cable for dimension shown in View A A and adjust if necessary Anchor cable to bracket at point C 3 Disconnect clevis F from shift cable I Anchor cable I securely at point D 4 Locate transm ission shift lever G in N NOTE Neutral position of transm ission shift lever G is obtained by rotating lever clockwise completely then back one...

Page 48: ...ide clearance before the transm ission is removed Overhaul information for the AT475 trans m ission is contained in 40 60 Series Truck Chas sis Overhaul Manual Supplement ST 334 72 Figure l A T 4 7 5 Flex Plate Installation In Line and V8 Engines REMOVAL 1 Block vehicle so that it cannot move D is connect ground strap from battery negative post Remove the spark plugs so the engine can be turned ov...

Page 49: ... the engine lower the assem bly carefully and move it out from the vehicle INSTALLATION 1 Raise vehicle sufficiently to allow install ation of transm ission With transm ission assembly mounted on transm ission jack move transm ission into position aligning converter with flex plate figs 1 and 2 Check for and clean away any for eign material in flywheel pilot hole and flywheel flex plate assem bly ...

Page 50: ...m oval 16 Refer to the TRANSMISSION CONTROL LINKAGE SEC 7A of this supplement for ad justment of manual shift linkage AT475 AUTOMATIC TRANSMISSION LUBRICATION DETAILS IMPORTANT For information on lubrication intervals and type of lubricant for AT475 trans m ission refer to LUBRICATION SEC 0 of this manual CHECKING FLUID LEVEL If oil level is too high or too low foaming of oil will occur This will ...

Page 51: ...ne before the vehicle is returned to service 1 Disconnect both oil cooler lines at the fit tings at side of transm ission case or if an auxil iary filter has been previously installed discon nect cooler return line at filter instead of at the transm ission Change auxiliary filter element 2 Back flush the oil cooler and lines using clean solvent and com pressed air CAUTION DO NOT exceed 100 psi air...

Page 52: ... 1 2 With transm ission mounted on a suitable dolly or jack move into position under the vehicle Adjust front and rear height as listed in Auxiliary Transm ission Application and Alignment Data Chart 3 Torque attaching parts to proper specifica tions as shown in figure 2 4 Reconnect propeller shafts to the input and output ends of the transm ission as described in PROPELLER SHAFTS SEC 4D in this s...

Page 53: ...e new dimension of 0 4 On tilt cab models equipped with In line or V8 engines the release bearing clearance measured at the release lever or fork is increased from 3 16 1 4 to 0 4 The clearance on V6 engines remains at 1 2 SECTION 7E G h d cU i FRONT DRIVEN DISC FLYWHEEL HOUSING FLYWHEEL TRANSMISSION M A IN DRIVE GEAR PILOT BEARING INTERMEDIATE DRIVE PLATE REAR DRIVEN DISC 70 80 FT LBS CLUTCH H O ...

Page 54: ...S as described in ST 331 71 pages 7E 1 to 7E 5 is applicable to models covered by this supplement with the addition of the following It is important when installing the Borg Beck 12 Inch Duel D isc Clutch that the driven disc hubs face the engine as shown in figure 1 ...

Page 55: ...g left and right steer ing arm s The tie rod assembly figs 2 and 3 consists of a tube and two socket end assem blies Socket end assem blies are threaded into tube and locked in place with clamps Right and left hand threads are provided to facilitate toe in adjustment The tie rod ends are non repairable and re quire lubrication as specified in LUBRICATION SEC 0 and inspection to see that ball studs...

Page 56: ...e running engine 1 Make all necessary repairs fill and bleed steering system CAUTION When pump drive belt is also used to drive the fan or other engine components it should not be disconnected The pump becomes an idler pulley and if allowed to run dry would burn up bearing causing fan to stop and possibly damage engine further Do not operate pumpwith out steering fluid in pump reservoir 2 Remove p...

Page 57: ...cur rent Service Manuals PUMP DRIVE BELT ADJUSTMENT NOTE When adjusting a new drive belt adjust tension to New belt specifications turn engine SPECIFICATIONS POWER STEERING GEAR APPLICATION CHART TRUCK SERIES GEAR MODEL RATIO CE CS40 CE CG CM CS50 CE CM M E60 SE SG SM SS50 TE TG TM50 T E T M 6 0 553 DV 92 and 93 553 DV 9 3 553 DV 9 4 28 14 to 1 28 14 to 1 28 14 to 1 POWER STEERING FLUID GM APPROVE...

Page 58: ...e 56 A satisfactory steering system depends upon maintaining components in good condition with a minimum amount of wear perm itted Proper align ment and lubrication will pay dividends in driver satisfaction and in tire economy ...

Page 59: ...r attachment is the inner and outer threaded nut arrangement permitting removal of outside wheel without inter fering with inner wheel WHEEL STUDS OR BOLTS AND NUTS Refer to Figures 2 and 3 BUDD DISC STUDS Stripped threads on the studs may be the re sult of excessive torquing of the studs or it may be a result of damage during wheel installation when placing the wheel over the studs Where a damage...

Page 60: ... 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 Figure 4 Budd Type Dam aged Inner or Outer Cap Nuts WHEEL INSPECTION DISC TYPE WORN WHEEL STUD HOLES Fig 5 This condition will usually be accompanied by appearance of a shiny worn surface on wheel face indicating that loose wheels were mo...

Page 61: ...assem bly should be checked carefully because damage to hub studs or wheel 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 use of tire tools or improper initial seating in gutter of rim When found the ring should be replaced Bent or sprung rings are caused by rough and improper removal of this part...

Page 62: ... air pressure downward to correspond to the actual load carried Never bleed tires to relieve build up of pressure Tire temperature will increase when the tire is in service and allows for the normal build up in air pressure Tire temperature and air p res sure will remain within lim its that are not harmful to the tire when used in accordance with the rec ommendations for load and air pressure If e...

Page 63: ...ront end alignment if necessary Cornering Wear When a truck makes an WHEELS AND TIRES extremely fast turn the weight is shifted from an even loading on all wheels to an abnormal load on the tires on the outside of the curve and very light load on the inside tires due to centrifugal force This unequal loading may have two unfavorable results First the rear tire on the inside of the curve may be rel...

Page 64: ...cuffing when the vehicle rounds a curve and the tires are not moving in a straight path The sam e thing happens when spread axle tires are dragged or pushed sideways for example while spread axle trailers are being spotted at or pulled away from loading docks Sprung or Twisted Frame Will cause rapid or uneven tread wear Grabbing Brakes Brakes out of adjustment and out of round brake drums cause ti...

Page 65: ...er of size largest to sm allest 4 Mount the two largest tires on one side of one axle and mount the two sm allest on the opposite side of the same axle 5 Mount the four other tires on the other axle in the same manner 6 Test run the vehicle to get accurate rear axle lubricant temperature readings on the two axle lubricant temperature gauges 7 Vary tire air pressure within the tire manufacturer s r...

Page 66: ...the vehicle fig 12 the front tires should be moved to the rear when 1 5 of the tread design is worn off Then match tires on each wheel as already described but with an additional precaution the sum of the circum ferences of the four tires for the front of the tandem drive axles should equal the sum of the circum ferences of the four tires on the rear of the tandem axles This precaution is necessar...

Page 67: ...hich have once become twisted creased or folded over at edges should not be used again TUBES AND CASINGS DAMAGED BY FOREIGN MATERIALS IN CASINGS Any foreign m aterial between the casing and tube will cause a chafing action In tim e one or both will become badly damaged and fail The re sult of grit pebbles or other hard substances which become embedded in the tube wall will chafe tube and finally c...

Page 68: ...it was removed Always use flap of adequate width to prevent tube pinching As a precaution against flap failure mark the tire and rim size on the flap at the time of removal if inspection shows that it is not damaged and can be used again When the flap is again mounted this marking protects against the danger of m isusing the flap with the wrong size tire and rim New flaps and tubes should be used ...

Page 69: ...seating of rings and inflate tire to recommended pressure 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 free then lift o ff lock and side rings Turn assembly over unseat tire bead stand tire up and remove rim base _____________________________________ T 8307 M OUNTING After applying tire and tube in us...

Page 70: ... Check seating of ring and inflate tire to recom m ended pressure C ontinue in this m anner progressively around rim until rin g is com pletely rem oved T urn assem bly over u n seat tire bead stand tire up and rem ove rim base T 8308 Continue progressively around the rim w alking the side ring firm ly into place To disengage side ring from the g u tte r in sert one rim tool in tool slot of sidfe ...

Page 71: ...rt straight end of tool be tween bead and back flange of rim at about a 45 angle Turn tool so that it is perpendicular to rim Pry second bead off T 8309 Hold tool in position with one foot and pull second tool toward center of rim Progressively work bead off rim tak ing additional bites if necessary MOUNTING Be sure right valve is used and is properly installed in the rim Inspect rim to insure bea...

Page 72: ...to notch in ring located between embossings point B Push ring downward at point opposite oper ating notch Force tool handle down ward as illustrated causing ring to disengage from rim gutter Continue operation prying aw ay from rim gutter with flat end of tool until free Turn assembly over and unseat tire bead from back flange in same manner as loosening bead from side ring in first step Stand tir...

Page 73: ...m Place tire on rim so that valve is in line with rim slot and insert valve through the slot Force first bead down into well of rim just to side of valve with foot M ount first bead over rim lip with rim tool progressing from each side of foot approxim ately opposite foot Place half of side ring under the rim lip with cutaway portions in position as shown Insert thin end of rim tool or heavy screw...

Page 74: ...e half of the actual wheel speed when one drive wheel is spinning and the other drive wheel is stopped Un le ss care is taken in limiting drive wheel spin the spinning wheel can reach excessive speeds resulting in possible tire disintegration or differential failure which could cause personal injury or extensive vehicle damage On trucks which do have Maximum Traction drive wheel spin should be lim...

Page 75: ...ound is preferable This protective m easure is of particular importance with drop center tubeless rim s as the air in the tire is contained by the tire sid e rim surface Remove Rust and Other Foreign Matter Accumulation of such m aterial in the rim gut ter can prevent the proper fitting of rings Parts that are excessively corroded are weakened and should be replaced Use of a rust preventive com po...

Page 76: ...Sec 10 Page 74 WHEELS AND TIRES Figure 20 Rim and Wheel Safety Precautions ...

Page 77: ...ammer on rim s or rings after tire inflation has started Changing Equipment Fig 20 View H TIRE SPREADER ARMS CAN BE DANGEROUS Keep them closed when the machine is idle and use care in all respects while operating the spreader Face and Eye Protection ALWAYS WEAR GOGGLES or face shields when buffing rim s or tires or when hammering rings DURING VEHICLE OPERATION Do Not Overload Tires Ensure that the...

Page 78: ...ets which in case of tire fire are useful in preventing the fire from spreading to vehicle and cargo If possible a steady stream of water should be placed on the tire until it is cool enough for removal The best protection against tire fires is to avoid running on a flat tire prevent underinflation through regular checking of inflation pressures and avoid accumulation of grease or oil around brake...

Page 79: ...D LIM IT S AT VARIOUS IN F L A T IO N PRESSURES SIZE LOAD RANGE 50 55 60 65 70 75 80 85 90 95 100 8 25 20 E 2800 3010 3190 3370 3560 3730 3890 4050 8 25 20 F 2800 3010 3190 3370 3560 3730 3890 4050 4210 4350 4500 9 00 15 F 2950 3150 3330 3500 3660 3830 3980 4140 4210 9 00 18 E 3320 3530 3730 3920 4120 4300 9 00 20 E 3560 3770 4000 4210 4410 4610 9 00 20 F 3560 3770 4000 4210 4410 4610 4790 4970 51...

Page 80: ...5450 5640 11 00 20 F 4100 4330 4560 4780 4990 5190 11 00 20 G 4100 4330 4560 4780 4990 5190 5390 5590 5780 11 00 22 F 4350 4600 4840 5080 5300 5520 11 00 22 G 4350 4600 4840 5080 5300 5520 5730 5940 6140 11 00 24 F 4620 4890 5140 5390 5630 5860 12 00 20 G 4930 5190 5440 5680 5910 6140 12 00 24 G 5550 5840 6120 6390 6650 6910 N O TE Underlined Figures Indicate M axim um Recommended Load LOAD RANGE ...

Page 81: ...s see figs 1 and 2 are at tached to the hood by screw s To adjust loosen hood hinge bolts Note that the rearm ost bolt hole in hinge is slotted to allow hood trailing edge to move up and down Adjust so hood and cowl surfaces are flush NOTE It may be necessary to perform hood lock adjustment as described in Service Manual ST 331 71 page 11 3 I Figure 2 Front End Sheet Metal Components Typical H O O...

Page 82: ...R CONTROL OR STARTER INTERLOCK RELAY M ake Delco Remy Model 1115848 Point Opening In 0 017 0 033 Opening Voltage Range 3 7 5 2 STARTER SHUT OFF RELAY Delco Remy 1115848 Point Opening In 0 017 0 033 Opening Voltage Range 3 7 5 2 GENERATOR TELL TALE RELAY M ake Delco Remy Model 1115848 Point Opening In 0 017 0 033 Opening Voltage Range 3 7 5 2 LOW AIR PRESSURE OR LOW VACUUM ALARM BUZZER M ake Delco ...

Page 83: ...Models Engine Overspeed Warning Lamp when used Except Tilt Cab Models Tilt Cab Models BU LB N O 6014 1156 1157 193 or 195 1157 1157 67 1445 or 1895 1156 67 1076 211 1 195 1895 57 1445 1090D18 67 C A N D LEP O W ER 50 60 Watts 32 32 3 2 32 3 32 3 4 1 or 2 32 4 32 12 Directional Signal Indicator Light Conventional Cab M odels Series SE SG SM SS 50 Tilt Cab Models Heater Control Light Conventional Ca...

Page 84: ...e Tune Up 16 13 V6 14 V8 15 Engine Turbium Diesel 34 F Fluid Power S te e r in g 1 Fluid T r a n sm issio n 2 G Gauge Vacuum 9 Generating System A C 43 Governor Air Com pressor 35 Governors Engine 21 Hubs and Bearings Front 5 I Ignition System 42 L Linkage Transm ission 45 L u b rica tio n 1 M Mountings Engine 16 o Oil Engine 1 s Safety Rim and W h e e l 73 Sheet M e t a l 79 Springs F r o n t 5 S...

Page 85: ... 13 1 F 070 H 170 T 170 540 GL _ SM 5 0 02 351C 13 1 F 055 F 070 H 150 T 150 H 170 T 170 SM 465 435GL 540GL AT 475 AT 540 SM 5 0 62 351C 13 1 F 070 H 170 T 170 SM 465 540GL AT 475 AT 540 SS 50 02 292 12 1 F 055 F 070 H 150 T 150 H 170 T 170 SM 465 540GL AT 475 T E 5 0 03 350 366 13 1 F 070 F 090 H 150 T 150 H 170 T 170 435 GL 282V 285V 542GD GL AT 540 T G 50 03 DH 478 13 1 i3 r F 070 F 090 H 150 T...

Page 86: ... pv I T ji CHEVROLET SERVICE I ...