Page 2: Table Of Contents
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical TABLE OF CONTENTS Drive Belt Falls Off and Excessive Wear Diagnosis ..60 Drive Belt Tensioner Diagnosis ........64 8.1L (L18) ENGINE .............4 Engine Component Description (LQ4/LR4) ....64 Fastener Tightening Speciﬁ cations L18 (8.1L) Engine ...4 Lubrication Description ..........67...
Page 3 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Cylinder Leakage Test ..........108 Oil Consumption Diagnosis ......... 110 Oil Pressure Diagnosis and Testing ......111 Oil Leak Diagnosis ............113 Crankcase Ventilation System Inspection/Diagnosis LQ4/LR4 Engine ............116 Drive Belt Chirping, Squeal, and Whine Diagnosis ..
Page 4: 8.1L (L18) Engine
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 8.1L (L18) ENGINE FASTENER TIGHTENING SPECIFICATIONS Speciﬁ cation L18 (8.1L) ENGINE Metric English Application Air Cleaner Outlet Duct Clamp 4 N·m 35 lb in Air Conditioning (A/C) Belt Tensioner Bolt 50 N·m...
Page 5 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Drive Belt Tensioner Bolt 50 N·m 37 lb ft Engine Block Coolant Drain Hole M28 Plug - Left Front 60 N·m 44 lb ft Engine Block Coolant Drain Hole Plug - Side 30 N·m...
Page 6 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Flywheel Bolt - Final Pass 100 N·m 74 lb ft Front Cover Bolt - First Pass 6 N·m 53 lb in Front Cover Bolt - Final Pass 12 N·m...
Page 7 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Power Steering Pump Bracket Stud 20 N·m 15 lb ft Spark Plug 30 N·m 22 lb ft Throttle Body Nu 10 N·m 89 lb in Throttle Body Stud 12 N·m...
Page 8: Engine Mechanical Speciﬁ Cations L18 (8.1L) Engine
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE MECHANICAL SPECIFICATIONS Speciﬁ cation Metric English L18 (8.1L) ENGINE L18 Engine Application General • Engine Type • Displacement 8.1L 496 CID • RPO • VIN - Light Duty •...
Page 9 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Cylinder Bore Taper - Production 0.018 mm 0.0007 in • Cylinder Bore Taper - Service Thrust Axis 0.05 mm 0.002 in • Cylinder Bore Taper - Service Pin Axis 0.05 mm...
Page 10 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Connecting Rod Journal Out-of-Round - Production 0.0102 mm 0.0004 in • Connecting Rod Journal Taper - Production 0.0102 mm 0.0004 in • Crankshaft End Play 0.127-0.35 mm 0.005-0.0138 in...
Page 11 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Oil Capacity - Without Filter 5.7L 6.0 Qts • Oil Capacity - With Filter 6.15L 6.5 Qts • Oil Pressure - Minimum 34 kPa @ 1,000 RPM 5 psi @ 1,000 RPM •...
Page 12 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Pin-Piston Pin Fit in Connecting Rod Bore-Production 0.010-0.023 mm 0.0004-0.0009 in • Pin-Piston Pin Fit in Connecting Rod Bore-Service 0.010-0.023 mm 0.0004-0.0009 in • Pin-Piston Pin Clearance-to-Piston Pin Bore-Production 0.003-0.011 mm...
Page 13 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Valve Stem Diameter - Exhaust 9.431-9.449 mm 0.3713-0.372 in • Valve Stem Diameter - Intake 9.436-9.454 mm 0.3715-0.3722 in • Valve Stem-to-Guide Clearance - Exhaust - Production 0.03-0.079 mm...
Page 14: Diagnostic Starting Point - Engine Mechanical - (8.1L/ L18 Engine)
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DIAGNOSTIC STARTING POINT - ENGINE MECHANICAL — (8.1L/ L18 ENGINE) Begin the system diagnosis by reviewing the Disassembled Views, Engine Component Description , Lubrication Description , New Product Information , and the Drive Belt System Description. Reviewing the description and operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists.
Page 15 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Intermittent Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly. Symptom List Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom: •...
Page 16 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Cause Correction Abnormalities, such as severe cracking, bumps, or missing areas in the Replace the drive belt. Refer to Drive Belt Replacement - Accessory accessory drive belt Abnormalities in the accessory drive system and/or components may cause engine RPM variations and lead to a misﬁ...
Page 17 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Worn or bent push rods Replace the push rods. Sticking valves Repair or replace, as required. Carbon buildup on the valve stem and/or seat can cause the valve to not close properly.
Page 18: Base Engine Misﬁ Re With Abnormal Valve Train Noise
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical A damaged crankshaft reluctor wheel Replace the sensor and/or crankshaft reluctor wheel, as required. A damaged crankshaft reluctor wheel can result in different symptoms, depending on the severity and location of the damage.
Page 19: Base Engine Misﬁ Re With Coolant Consumption
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical BASE ENGINE MISFIRE WITH COOLANT CONSUMPTION Cause Correction Faulty cylinder head gaskets and/or cracking or other damage to the 1. Inspect for spark plugs saturated by coolant. Refer to Spark Plug cylinder heads and engine block cooling system passages Inspection .
Page 20: Engine Noise On Start-Up, But Only Lasting A Few Seconds
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE NOISE ON START-UP, BUT ONLY LASTING A FEW SECONDS Cause Correction Incorrect oil level Add or remove oil, as required, to achieve the proper level. An oil level that is overfull causes aeration within the oil.
Page 21: Upper Engine Noise, Regardless Of Engine Speed
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical UPPER ENGINE NOISE, REGARDLESS OF ENGINE SPEED Cause Correction Plugged oil ﬁ lter Replace the oil ﬁ lter. Low oil pressure 1. Verify proper oil level. 2. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .
Page 22 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Stuck valves 1. Inspect the valves and valve guides. Carbon on the valve stem or valve seat may cause the valve to stick. 2. Repair, as required 3. Use GM top engine cleaner GM P/N 1050002, (Canadian P/...
Page 23: Lower Engine Noise, Regardless Of Engine Speed
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical LOWER ENGINE NOISE, REGARDLESS OF ENGINE SPEED Cause Correction Low oil pressure 1. Verify proper oil level. 2. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing .
Page 24 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Excessive crankshaft bearing clearance 1. Inspect the crankshaft bearings and crankshaft journals. 2. Repair, as required. Incorrect piston, piston pin, and connecting rod installation 1. Verify the pistons, piston pins, and connecting rods are installed correctly.
Page 25: Engine Noise Under Load
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE NOISE UNDER LOAD Cause Correction Low oil pressure 1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . 2. Repair or replace, as required.
Page 26: Engine Will Not Crank - Crankshaft Will Not Rotate
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE WILL NOT CRANK - CRANKSHAFT WILL NOT ROTATE Cause Correction Seized accessory drive system component or starter motor 1. Remove the accessory drive belt or belts and/or starter motor.
Page 27: Coolant In Combustion Chamber
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical COOLANT IN COMBUSTION CHAMBER Cause Correction DEFINITION: Excessive white smoke and/or a coolant type odor coming from the exhaust pipe may indicate coolant in the combustion chamber. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an overtemperature condition, which may cause engine component damage.
Page 28: Coolant In Engine Oil
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical COOLANT IN ENGINE OIL Cause Correction DEFINITION: Foamy or discolored oil or an engine oil overﬁ ll condition may indicate coolant entering the engine crankcase. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an overtemperature condition, which may cause engine component damage.
Page 29: Engine Compression Test
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE COMPRESSION TEST 1. Disconnect the ignition coil wire harness connector at the front of the engine on the left cylinder bank and at the rear of the engine at the right cylinder bank.
Page 30: Cylinder Leakage Test
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical CYLINDER LEAKAGE TEST Tools Required: J 35667-A Cylinder Head Leakdown Tester or equivalent Important: A leakage test may be performed in order to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate 1 or more of the following conditions: •...
Page 31 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Important: It may be necessary to hold the crankshaft balancer bolt to prevent the crankshaft from rotating. 5. Apply shop air pressure to the J 35667-A and adjust according to the manufacturers instructions.
Page 32: Oil Consumption Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical OIL CONSUMPTION DIAGNOSIS Excessive oil consumption, not due to leaks, is the use of greater than 0.95 liter (1 quart) of engine oil within 379 liters (100 gallons) of fuel used. However, during initial engine break-in periods 5 000-6 500 kilometers (3,000-4,000 miles) oil consumption may exceed 1.9 liters (2 quarts) or greater per 379 liters (100 gallons) of fuel used.
Page 33: Oil Pressure Diagnosis And Testing
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical OIL PRESSURE DIAGNOSIS AND TESTING With the vehicle on a level surface, allow adequate drain down time, 2-3 minutes, and measure for the proper engine oil level. An overfull oil level causes aeration within the oil.
Page 34: Oil Leak Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical OIL LEAK DIAGNOSIS Step Action Important: You can repair most ﬂ uid leaks by ﬁ rst visually locating the leak, repairing or replacing the component, or by resealing the gasket surface.
Page 35 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 1. Completely clean the entire engine and surrounding components. 2. Apply an aerosol-type powder, baby powder, foot powder, etc., to the suspected area. 3. Operate the vehicle for several kilometers, miles, at normal operating temperature and at varying speeds.
Page 36 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Repair or replace all damaged or modiﬁ ed components. Go to System Does the engine still leak oil? Step 1 © 2006 WorkhorseCustom Chassis — All Rights Reserved...
Page 37: Drive Belt Chirping, Squeal, And Whine Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT CHIRPING, SQUEAL, AND WHINE DIAGNOSIS Diagnostic Aids • A chirping or squeal noise may be intermittent due to moisture on the drive belts or the pulleys. It may be necessary to spray a small amount of water on the drive belts in order to duplicate the customers concern.
Page 38 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 12. Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
Page 39 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of chirping: • A high pitched noise that is heard once per revolution of the drive belt or a pulley.
Page 40 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Inspect for bent or cracked brackets. Did you ﬁ nd any bent or cracked brackets? Go to Step 9 Go to Step 10 Replace any bent or cracked brackets.
Page 41 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Replace the drive belt. Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning . Go to Diagnostic Did you complete the repair? Go to Step 20 Aids Operate the system in order to verify the repair.
Page 42: Diagnostic Aids
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DIAGNOSTIC AIDS The accessory drive components can have an affect on engine vibration. Vibration from the engine operating may cause a body component or another part of the vehicle to make rumbling noise. Vibration can be caused by, but not limited to the air conditioning (A/C) system over charged, the power steering system restricted or the incorrect ﬂ...
Page 43 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 12. Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate. © 2006 WorkhorseCustom Chassis — All Rights Reserved...
Page 44 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of drive belt rumbling: • A low pitch tapping, knocking, or thumping noise heard at or just above idle.
Page 45 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Clean the drive belt pulleys using a suitable wire brush. Reinstall the drive belts. Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning .
Page 46: Drive Belt Falls Off And Excessive Wear Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT FALLS OFF AND EXCESSIVE WEAR DIAGNOSIS Diagnostic Aids If the drive belt repeatedly falls off the drive belt pulleys, this is because of pulley misalignment. An extra load that is quickly applied on released by an accessory drive component may cause the drive belt to fall off the pulleys.
Page 47 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 7. Inspection of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed. Missing, loose, or the wrong fasteners may cause pulley misalignment from the bracket moving under load. Over tightening of the fasteners may cause misalignment of the accessory component bracket.
Page 48 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The drive belt falls off the pulleys or may not ride correctly on the pulleys.
Page 49 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Operate the system in order to verify the repair. Did you correct the condition? System OK Go to Step 2 Inspect the drive belt for the proper installation. Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning .
Page 50: Base Engine Misﬁ Re With Abnormal Valve Train Noise
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical BASE ENGINE MISFIRE WITH ABNORMAL VALVE TRAIN NOISE Cause Correction Worn or loose rocker arms Repair or replace the valve rocker arms, as required. Worn or bent push rods Replace the push rods.
Page 51: Crankcase Ventilation System Description L18 (8.1L) Engine
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical CRANKCASE VENTILATION SYSTEM DESCRIPTION L18 (8.1L) ENGINE The crankcase ventilation system utilizes a ﬁ xed oriﬁ ce in the intake manifold and has no serviceable components so routine maintenance of the system is not required.
Page 52 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Symptom Correction External oil leak Inspect for any of the following conditions: • Restricted or kinked PCV hose or engine vent hose • Damaged, incorrect, or incorrectly installed PCV hose •...
Page 53: Drive Belt System Description
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT SYSTEM DESCRIPTION The drive belt system consists of the following components: • The drive belt • The drive belt tensioner • The drive belt idler pulley •...
Page 54: Drive Belt Chirping, Squeal, And Whine Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT CHIRPING, SQUEAL, AND WHINE DIAGNOSIS Diagnostic Aids • A chirping or squeal noise may be intermittent due to moisture on the drive belts or the pulleys. It may be necessary to spray a small amount of water on the drive belts in order to duplicate the customers concern.
Page 55 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Test Description The numbers below refer to the step numbers on the diagnostic table. 2. The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table.
Page 56 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action .Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of chirping: • A high pitched noise that is heard once per revolution of the drive belt or a pulley.
Page 57 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Inspect for bent or cracked brackets. Did you ﬁ nd any bent or cracked brackets? Go to Step 9 Go to Step 10 Replace any bent or cracked brackets.
Page 58 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Replace the drive belt. Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning . Go to Diagnostic Did you complete the repair? Go to Step 20 Aids Operate the system in order to verify the repair.
Page 59: Drive Belt Rumbling And Vibration Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT RUMBLING AND VIBRATION DIAGNOSIS Diagnostic Aids The accessory drive components can have an affect on engine vibration. Vibration from the engine operating may cause a body component or another part of the vehicle to make rumbling noise. Vibration can be caused by, but not limited to the air conditioning (A/C) system over charged, the power steering system restricted or the incorrect ﬂ...
Page 60: Drive Belt Falls Off And Excessive Wear Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT FALLS OFF AND EXCESSIVE WEAR DIAGNOSIS Diagnostic Aids If the drive belt repeatedly falls off the drive belt pulleys, this is because of pulley misalignment. An extra load that is quickly applied on released by an accessory drive component may cause the drive belt to fall off the pulleys.
Page 61 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 6. Accessory drive component brackets that are bent or cracked will let the drive belt fall off. 7. Inspection of the fasteners can eliminate the possibility that a wrong bolt, nut , spacer, or washer was installed. Missing, loose, or the wrong fasteners may cause pulley misalignment from the bracket moving under load.
Page 62 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The drive belt falls off the pulleys or may not ride correctly on the pulleys.
Page 63 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Replace the drive belt tensioner. Refer to Drive Belt Tensioner Replacement - Accessory or Drive Belt Tensioner Replacement - Air Conditioning . Does the drive belt continue to fall off? Go to Step 11 System OK Inspect for failed drive belt idler and drive belt tensioner pulley bearings.
Page 64: Drive Belt Tensioner Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT TENSIONER DIAGNOSIS Notice: Allowing the drive belt tensioner to snap into the free position may result in damage to the tensioner. Remove the drive belt(s). Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning.
Page 65 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Camshaft A steel camshaft is supported by 5 bearings pressed into the engine block. The camshaft sprocket is mounted to the front of the camshaft and is driven by the crankshaft sprocket through the timing chain.
Page 66 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Valve Train The valve train is a ball pivot type. Motion is transmitted from the camshaft through the hydraulic roller valve lifters and tubular valve push rods to the valve rocker arms. The valve rocker arm pivots on a ball in order to open the valve.
Page 67: Lubrication Description
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical LUBRICATION DESCRIPTION The gear-type oil pump is driven through an extension driveshaft. The extension driveshaft is driven by the oil pump drive, which is gear driven by the camshaft. The oil is drawn from the oil pan through a pickup screen and tube, into the oil pump.
Page 68: Separating Parts
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical SEPARATING PARTS Important: Many internal engine components will develop speciﬁ c wear patterns on their friction surfaces. When disassembling the engine, internal components MUST be separated, marked or organized in a way to ensure reinstallation to original location and position.
Page 69: Replacing Engine Gaskets
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical REPLACING ENGINE GASKETS Gasket Reuse and Applying Sealant • Do not reuse any gasket unless speciﬁ ed. • Gaskets that can be reused will be identiﬁ ed in the service procedure.
Page 70 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Assembling Components • Assemble components using only the sealant (or equivalent) that is speciﬁ ed in the service procedure. • Sealing surfaces must be clean and free of debris or oil.
Page 71: Use Of Room Temperature Vulcanizing (Rtv) And Anaerobic Sealer
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical USE OF ROOM TEMPERATURE VULCANIZING (RTV) AND ANAEROBIC SEALER Sealant Types Important: The correct sealant and amount of sealant must be used in the proper location in order to prevent oil leaks, coolant leaks, or the loosening of the fasteners.
Page 72 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Notice: Refer to Sealant Notice in Cautions and Notices. • The surfaces to be sealed must be clean and dry. • Use an RTV sealant bead size as speciﬁ ed in the service procedure.
Page 73 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Threadlock Sealant Anaerobic type threadlock sealant cures in the absence of air. This type of sealant is used for threadlocking and sealing of bolts, ﬁ ttings, nuts, and studs. This type of sealant cures only when conﬁ ned between 2 close ﬁ tting metal surfaces.
Page 74 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Notice: Refer to Sealant Notice in Cautions and Notices. • Apply the pipe sealant bead to the inside of any bolt hole areas. • Apply a continuous bead of pipe sealant to 1 sealing surface.
Page 75: 4.8L/6.0 (Lr4/Lq4) Engines
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 4.8L/6.0 (LR4/LQ4) ENGINES FASTENER TIGHTENING SPECIFICATIONS (LR4 VIN V/LR4 VIN U) Speciﬁ cation Application Metric English Air Cleaner Outlet Duct Clamp Screw 7 N·m 62 lb in Air Conditioning (A/C) Belt Tensioner Bolt 50 N·m...
Page 76 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Crankshaft Bearing Cap M10 Studs - First Pass in Sequence 20 N·m 15 lb ft Crankshaft Bearing Cap M10 Studs - Final Pass in Sequence 51 degrees Crankshaft Oil Deﬂ ector Nut 25 N·m...
Page 77 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Flywheel Bolts - First Pass 20 N·m 15 lb ft Flywheel Bolts - Second Pass 50 N·m 37 lb ft Flywheel Bolts - Final Pass 100 N·m 74 lb ft Front Cover Bolts 25 N·m...
Page 78 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Oil Level Sensor 13 N·m 115 lb in Oil Pan Bafﬂ e Bolts 12 N·m 106 lb in Oil Pan Closeout Cover Bolt - Left Side 12 N·m...
Page 79 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Transmission Cover Bolt 12 N·m 106 lb in Transmission Nut - RPO HP2 12 N·m 106 lb in Transmission Oil Level Indicator Tube Nut 18 N·m 13 lb ft Valley Cover Bolts 25 N·m...
Page 80: Engine Mechanical Speciﬁ Cations (Lr4 Vin V)
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE MECHANICAL SPECIFICATIONS (LR4 VIN V) Speciﬁ cation Application Metric English General • Bore 96.0-96.018 mm 3.779-3.78 in • Compression Ratio 9.5:1 • Displacement 4.8L 293 CID • Engine Type •...
Page 81 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Crankshaft Main Journal Diameter - Production 64.992-65.008 mm 2.558-2.559 in • Crankshaft Main Journal Diameter - Service 64.992 mm 2.558 in • Crankshaft Main Journal Out-of-Round - Production 0.003 mm...
Page 82 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Oil Pan • Front Cover Alignment - at Oil Pan Surface 0.0-0.5 mm 0.0-0.02 in • Rear Housing Alignment - at Oil Pan Surface 0.0-0.5 mm 0.0-0.02 in •...
Page 83 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Valves - Valve Lift - Exhaust 11.82 mm 0.465 in • Valves - Valve Lift - Intake 11.58 mm 0.456 in • Valves - Valve Seat Angle 46 degrees •...
Page 84: Engine Mechanical Speciﬁ Cations (Lq4 Vin U)
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE MECHANICAL SPECIFICATIONS (LQ4 VIN U) Speciﬁ cation Application Metric English General 101.618-101.636 • Bore 4.0007-4.0014 in • Compression Ratio 9.4:1 • Displacement 6.0L 364 CID • Engine Type •...
Page 85 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Camshaft Lobe Lift - Intake 6.96 mm 0.274 in • Camshaft Runout - Measured at the Intermediate Journals 0.05 mm 0.002 in Connecting Rod • Connecting Rod Bearing Clearance - Production 0.023-0.065 mm...
Page 86 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Crankshaft Thrust Surface Runout 0.025 mm 0.001 in Cylinder Head • Cylinder Head Height/Thickness - Measured from the Cylinder Head Deck to the Valve Rocker Arm Cover Seal Surface 120.2 mm...
Page 87 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Piston Ring End Gap - Oil Control Ring - Measured in Cylinder Bore - Service 0.31-0.94 mm 0.0122-0.037 in • Piston Ring to Groove Clearance - First Compression Ring - Production 0.04-0.08 mm...
Page 88 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Valves - Stem-to-Guide Clearance - Production - Intake 0.025-0.066 mm 0.001-0.0026 in • Valves - Stem-to-Guide Clearance - Service - Intake 0.093 mm 0.0037 in • Valves - Stem-to-Guide Clearance - Production - Exhaust 0.025-0.066 mm...
Page 89: Engine Identiﬁ Cation
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE IDENTIFICATION The vehicle identiﬁ cation number (VIN) is located on the left side rear of the engine block (1) and is typically a 9 digit number stamped or laser-etched onto the engine at the vehicle assembly plant.
Page 90 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Visual/Physical Inspection • Inspect for aftermarket devices which could affect the operation of the engine. Refer to Checking Aftermarket Accessories. • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
Page 91 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Engine Compression Test • Cylinder Leakage Test • Oil Consumption Diagnosis • Oil Pressure Diagnosis and Testing • Oil Leak Diagnosis • Drive Belt Chirping, Squeal, and Whine Diagnosis •...
Page 92: Base Engine Misﬁ Re Without Internal Engine Noises
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical BASE ENGINE MISFIRE WITHOUT INTERNAL ENGINE NOISES Cause Correction Fuel injector harness connectors are connected to the incorrect fuel Relocate the fuel injector harness connectors, as necessary. injectors/cylinders Abnormalities, such as severe cracking, bumps, or missing areas in the Replace the drive belt.
Page 93 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Sticking valves Repair or replace, as required. Carbon buildup on the valve stem can cause the valve to not close properly. Excessively worn or mis-aligned timing chain Repair or replace the timing chain and sprockets, as required Worn camshaft lobes Replace the camshaft and valve lifters.
Page 94 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical A damaged crankshaft reluctor wheel Replace the sensor and/or crankshaft as required. A damaged crankshaft reluctor wheel can result in different symptoms, depending on the severity and location of the damage.
Page 95: Base Engine Misﬁ Re With Abnormal Internal Lower Engine Noises
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical BASE ENGINE MISFIRE WITH ABNORMAL INTERNAL LOWER ENGINE NOISES Cause Correction Abnormalities, such as severe cracking, bumps, or missing areas in the Replace the drive belt. Refer to Drive Belt Replacement - Accessory .
Page 96: Base Engine Misﬁ Re With Abnormal Valve Train Noise
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical BASE ENGINE MISFIRE WITH ABNORMAL VALVE TRAIN NOISE Cause Correction Worn or loose rocker arms Replace the valve rocker arms, as required. The rocker arm bearing end caps and/or needle bearings should be intact within the rocker arm assembly.
Page 97: Base Engine Misﬁ Re With Coolant Consumption
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical BASE ENGINE MISFIRE WITH COOLANT CONSUMPTION Cause Correction Faulty cylinder head gaskets and/or cracking or other damage to the 1. Inspect for spark plugs saturated by coolant. Refer to Spark Plug cylinder heads and engine block cooling system passages Inspection .
Page 98: Engine Noise On Start-Up, But Only Lasting A Few Seconds
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE NOISE ON START-UP, BUT ONLY LASTING A FEW SECONDS Cause Correction Incorrect oil ﬁ lter without anti-drainback feature Install the correct oil ﬁ lter. Incorrect oil viscosity 1.
Page 99: Upper Engine Noise, Regardless Of Engine Speed
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical UPPER ENGINE NOISE, REGARDLESS OF ENGINE SPEED Cause Correction Low oil pressure 1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . 2. Repair or replace, as required.
Page 100 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Worn valve guides or valve stems 1. Inspect the valves and valve guides. 2. Repair, as required. Stuck valves 1. Inspect the valves and valve guides. Carbon on the valve stem or valve seat may cause the valve to stick.
Page 101: Lower Engine Noise, Regardless Of Engine Speed
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical LOWER ENGINE NOISE, REGARDLESS OF ENGINE SPEED Cause Correction Low oil pressure 1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . 2. Repair or replace damaged components, as required.
Page 102: Engine Noise Under Load
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE NOISE UNDER LOAD Cause Correction Low oil pressure 1. Perform an oil pressure test. Refer to Oil Pressure Diagnosis and Testing . 2. Repair or replace, as required.
Page 103: Engine Will Not Crank - Crankshaft Will Not Rotate
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE WILL NOT CRANK - CRANKSHAFT WILL NOT ROTATE Cause Correction Seized accessory drive system component or starter motor 1. Remove the accessory drive belts. 2. Conﬁ rm that the engine will rotate. Rotate the crankshaft by hand at the balancer or ﬂ...
Page 104 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Material in cylinder: 1. Inspect the cylinder for damaged components and/or foreign materials. • Broken valve 2. Repair or replace the components, as required. • Broken piston rings •...
Page 105: Coolant In Combustion Chamber
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical COOLANT IN COMBUSTION CHAMBER Cause Correction DEFINITION: Excessive white smoke and/or a coolant type odor coming from the exhaust pipe may indicate coolant in the combustion chamber. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an overtemperature condition, which may cause engine component damage.
Page 106: Coolant In Engine Oil
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical COOLANT IN ENGINE OIL Cause Correction DEFINITION: Foamy or discolored oil or an engine oil overﬁ ll condition may indicate coolant entering the engine crankcase. Low coolant levels, an inoperative cooling fan, or a faulty thermostat may lead to an overtemperature condition, which may cause engine component damage.
Page 107: Engine Compression Test
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical ENGINE COMPRESSION TEST 1. Charge the battery if the battery is not fully charged. 2. Disable the ignition system. 3. Disable the fuel injection system. 4. Remove all the spark plugs.
Page 108: Cylinder Leakage Test
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical CYLINDER LEAKAGE TEST Tools Required J 35667-A Cylinder Head Leakdown Tester or equivalent Important: A leakage test may be performed in order to measure cylinder/combustion chamber leakage. High cylinder leakage may indicate 1 or more of the following conditions: •...
Page 109 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Important: It may be necessary to hold the crankshaft balancer bolt to prevent the crankshaft from rotating. 5. Apply shop air pressure to the J 35667-A and adjust according to the manufacturers instructions.
Page 110: Oil Consumption Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical OIL CONSUMPTION DIAGNOSIS Excessive oil consumption, not due to leaks, is the use of greater than 1l (1 quart) of engine oil within 3 200 Kilometers (2,000 Miles) The causes of excessive oil consuption may include the following conditions: •...
Page 111: Oil Pressure Diagnosis And Testing
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical OIL PRESSURE DIAGNOSIS AND TESTING Tools Required • EN-47971 Oil Pressure Gage Adapter • J 21867 Pressure Gage 1. With the vehicle on a level surface, run the vehicle for a few minutes. Allow adequate drain down time, 2-3 minutes, and measure the oil level.
Page 112 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical • Excessive bearing clearance • Cracked, porous, or restricted oil galleries • Oil gallery plugs missing or incorrectly installed • Refer to Engine Block Plug Installation . • Broken valve lifters •...
Page 113: Oil Leak Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical OIL LEAK DIAGNOSIS Step Action Important: You can repair most ﬂ uid leaks by ﬁ rst visually locating the leak, repairing or replacing the component, or by resealing the gasket surface.
Page 114 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 1. Completely clean the entire engine and surrounding components. 2. Apply an aerosol-type powder, baby powder, foot powder, etc., to the suspected area. 3. Operate the vehicle for several kilometers, miles, at normal operating temperature and at varying speeds.
Page 115 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Repair or replace all damaged or modiﬁ ed components. Go to System Does the engine still leak oil? Step 1 © 2006 WorkhorseCustom Chassis — All Rights Reserved...
Page 116: Crankcase Ventilation System Inspection/Diagnosis Lq4/Lr4 Engine
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical CRANKCASE VENTILATION SYSTEM INSPECTION/DIAGNOSIS LQ4/LR4 ENGINE Crankcase Ventilation System Description The crankcase ventilation system has no serviceable components so routine maintenance of the system is not required. A closed crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors.
Page 117 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Symptom Correction External oil leak Inspect for any of the following conditions: • Restricted or kinked PCV hose or engine vent hose • Damaged, incorrect, or incorrectly installed PCV hose •...
Page 118: Drive Belt Chirping, Squeal, And Whine Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT CHIRPING, SQUEAL, AND WHINE DIAGNOSIS Diagnostic Aids • A chirping or squeal noise may be intermittent due to moisture on the drive belts or the pulleys. It may be necessary to spray a small amount of water on the drive belts in order to duplicate the customers concern.
Page 119 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 14. This test is to verify that the drive belt tensioner operates properly. If the drive belt tensioner is not operating properly, proper belt tension may not be achieved to keep the drive belt from slipping which could cause a squeal noise.
Page 120 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of chirping: • A high pitched noise that is heard once per revolution of the drive belt or a pulley.
Page 121 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Inspect for bent or cracked brackets. Did you ﬁ nd any bent or cracked brackets? Go to Step 9 Go to Step 10 Replace any bent or cracked brackets.
Page 122 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Operate the system in order to verify the repair. Did you correct the condition? System OK Go to Step 3 © 2006 WorkhorseCustom Chassis — All Rights Reserved...
Page 123: Drive Belt Rumbling And Vibration Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT RUMBLING AND VIBRATION DIAGNOSIS Diagnostic Aids The accessory drive components can have an affect on engine vibration. Vibration from the engine operating may cause a body component or another part of the vehicle to make rumbling noise. Vibration can be caused by, but not limited to the air conditioning (A/C) system over charged, the power steering system restricted or the incorrect ﬂ...
Page 124 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 9. Inspecting of the fasteners can eliminate the possibility that the wrong bolt, nut, spacer, or washer was installed. 11. This step should only be performed if the water pump is driven by the drive belt. Inspect the water pump shaft for being bent.
Page 125 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of drive belt rumbling: • A low pitch tapping, knocking, or thumping noise heard at or just above idle.
Page 126 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Install a new drive belt. Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning . Did you complete the replacement? Go to Step 8 Go to Step 9 Operate the system in order to verify the repair.
Page 127: Drive Belt Falls Off And Excessive Wear Diagnosis
WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical DRIVE BELT FALLS OFF AND EXCESSIVE WEAR DIAGNOSIS Diagnostic Aids If the drive belt repeatedly falls off the drive belt pulleys, this is because of pulley misalignment. An extra load that is quickly applied on released by an accessory drive component may cause the drive belt to fall off the pulleys.
Page 128 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical 7. Inspection of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed. Missing, loose, or the wrong fasteners may cause pulley misalignment from the bracket moving under load. Over tightening of the fasteners may cause misalignment of the accessory component bracket.
Page 129 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Step Action Notice: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The drive belt falls off the pulleys or may not ride correctly on the pulleys.
Page 130 WORKHORSE CUSTOM CHASSIS W Series Chassis PAGE SECTION Service Manual Engine Mechanical Operate the system in order to verify the repair. Did you correct the condition? System OK Go to Step 2 Inspect the drive belt for the proper installation. Refer to Drive Belt Replacement - Accessory or Drive Belt Replacement - Air Conditioning .

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