Engine Mechanical - 7.4l v8 - VIN [J] Chevrolet Chevy Van G1500

ENGINE IDENTIFICATION

Engine is identified by eighth character of Vehicle Identification Number (VIN). VIN is stamped on a metal tag on top left end of instrument panel, near windshield. See ENGINE IDENTIFICATION CODES table.

Engine can also be identified by engine identification (ID) number. Number is stamped on front of cylinder block, immediately forward of right cylinder head or on left side of cylinder block, on engine-to-transmission mating flange.

ENGINE IDENTIFICATION CODES

VALVE CLEARANCE ADJUSTMENT

Note. Although valve clearance adjustment is not usually required (engine uses hydraulic valve lifters), perform the following procedure after servicing valve train.

Tighten rocker arm bolts to specification. See TORQUE SPECIFICATIONS table.

SHIFT CABLE ADJUSTMENT

Note. When installing shift cable, DO NOT pull shift lever ball stud forward of transmission shift lever ball stud.

Express, "C" & "K" Pickup, Savana, Sierra, Suburban

1. Ensure transmission shift lever is in mechanical park position. Rotate control lever clockwise until it reaches it's final stop position. Apply parking brake. Raise and support vehicle.
2. Slide Black retaining clip forward on shift cable end far enough to allow White lock button to be pushed out. Push White lock button on shift cable end out far enough to free metal core adjust body inside cable end. DO NOT push White lock button completely out.
3. Inspect metal core adjust body on shift cable end for dirt or debris that may restrict its travel. If travel of metal core adjust body remains restricted, shift cable assembly must be replaced. Lower vehicle. Ensure parking brake is applied.
4. Turn ignition switch to ON position. Move transmission shift lever from Park to One and back to Park position 10 times. Place shift lever to Park. Turn ignition switch to OFF position. Raise and support vehicle. Ensure transmission control lever is in mechanical park position.
5. Rotate control lever clockwise until it reaches it's final stop position. Push White lock button in to secure core adjuster body inside shift cable end. Slide Black retainer clip rearward over shift cable end until it covers White lock button and locks in place over shift cable end. Ensure parking brake is applied. Lower vehicle.

TROUBLE SHOOTING

Note. To trouble shoot mechanical engine components, see appropriate table in TROUBLE SHOOTING article in GENERAL INFORMATION.

REMOVAL & INSTALLATION

Note. For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

FUEL PRESSURE RELEASE

Disconnect battery terminals. Loosen fuel tank cap to relieve tank pressure. When ignition is turned off, an internal constant bleed in injection unit relieves fuel system pressure. No further pressure relief is required.

COOLING SYSTEM BLEEDING

1. Fill radiator to base of filler neck. Start engine. Place A/C-heater control in any position except MAX. Select highest temperature setting. Idle engine until lower radiator hose is hot.
2. Increase engine speed to 3000 RPM and then back to idle. Do this 5 times to expel any air trapped in system. Fill radiator as necessary. Install radiator cap. Allow engine to cool. Fill coolant recovery reservoir as necessary.
3. Crush and add 2 Coolant Sealant Pellets (GM P/N 3634621) or equivalent to radiator (if reservoir is not pressurized) or coolant reservoir (if reservoir is pressurized).

POWER STEERING BLEEDING

Note. If air was introduced into hydraulic system during servicing, bleed system. Aerated fluid, which appears Light Tan in color, results in poor steering performance and will cause pump damage.

1. Turn ignition off. Raise and support vehicle with front wheels off ground. Using steering wheel, turn wheels fully to left. Add power steering fluid to FULL COLD mark on dipstick. Turn wheels from side to side at least 20 times, but DO NOT touch steering stops. Add fluid as necessary to maintain level at FULL COLD mark.
2. Start engine. With engine idling, check fluid level. Add fluid as necessary to bring fluid level to FULL COLD mark. Return wheels to center position. Lower vehicle. Continue to run engine for 2 to 3 minutes to raise temperature of fluid and eliminate trapped air. Turn steering wheel in both directions.
3. Road test vehicle. Check for leaks. Ensure fluid level is at FULL HOT mark when fluid is stabilized at operating temperature.

Removal ("C" & "K" Pickup, Sierra & Suburban)

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__fuel-pressure-release) . Disconnect battery. Remove hood. Drain cooling system.
2. Remove air cleaner, accessory drive belt, fan and water pump pulley. Remove radiator and fan shroud. Disconnect heater hoses from engine. Disconnect fuel lines, electrical connectors, vacuum hoses, coolant hoses and control cables as necessary.
3. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C compressor and bracket. Remove power steering pump with hoses attached and position aside (if equipped). Raise and support vehicle. Drain crankcase. Disconnect exhaust pipes from manifolds. Remove starter. Remove flywheel cover. Remove torque converter bolts (A/T).
4. Remove bellhousing bolts and engine mount through-bolts. Lower vehicle. Support transmission. Attach engine hoist. Remove engine.

Installation ("C" & "K" Pickup, Sierra & Suburban)

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Removal (Commercial Van)

1. Mark and remove hood. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__fuel-pressure-release) . Drain cooling system. Remove engine cover and floor panel sections from inside vehicle. Disconnect accelerator and cruise control linkage. Disconnect vacuum hoses. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C compressor and bracket.
2. Remove air cleaner, duct and exhaust heat stove pipe. Remove distributor cap and position aside. Disconnect all engine harness electrical connectors and position harness aside. Disconnect fuel lines from injection unit. Remove starter motor. Remove fuel line clamps from transmission and position fuel lines aside.
3. Disconnect hydraulic line from clutch slave cylinder. Disconnect ground strap from rear end of left cylinder head. Disconnect all transmission harness electrical connectors and position harness aside. Remove transmission shift lever (M/T).
4. Remove upper radiator hose, all accessory drive belts, fan, fan pulley, fan shroud, lower radiator hose and radiator. Remove engine oil filler tube. Raise and support vehicle. Disconnect exhaust pipes from manifolds. Disconnect battery cable from clamp on cylinder block.
5. Remove flywheel cover (M/T). Remove flywheel-to-torque converter bolts (A/T). Lower vehicle and support transmission. Support engine. Disconnect drive shaft from transmission. Remove transmission mount. Disconnect oil cooler lines from oil filter adapter. Disconnect oil cooler line clamps from engine. Attach engine hoist.
6. Remove engine mount through-bolts. Remove engine and transmission assembly through side door.

Installation (Commercial Van)

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary, adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Removal (Express & Savana)

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__fuel-pressure-release) . Remove engine cover. Drain crankcase and cooling system.
2. Remove air intake duct and air cleaner. Disconnect fuel lines, electrical connectors, vacuum hoses, coolant hoses and control cables as necessary. Remove fuel supply lines at rear of engine. Remove 2 ground straps. Remove distributor cap, distributor and ignition coil.
3. Remove transmission and engine oil dipstick tubes. Remove EGR purge valve. Remove 2 A/C compressor brackets. Remove injection unit. Remove headlight bezels, grille, bumper filler panel and cruise control servo (if equipped). Remove hood latch, coolant reservoir and upper radiator brackets.
4. Remove front end sheet metal cross panel. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment. Remove A/C condenser, windshield washer fluid reservoir and washer pump. Remove upper fan shroud, engine oil cooler and transmission oil cooler. Remove radiator, lower fan shroud, fan, serpentine drive belt and water pump pulley. Remove heater hoses.
5. Disconnect A/C refrigerant line from accumulator and generator bracket. Remove A/C compressor and idler pulley. Remove generator and belt tensioner. Remove power steering pump. Remove oil fill tube. Remove upper and lower intake manifold. Remove exhaust crossover pipe from manifolds. Remove starter. Disconnect drive shaft and shift linkage from transmission.
6. On A/T, remove torque converter to flywheel bolts. Remove engine mount through-bolts. Support transmission. Remove transmission crossmember. Lower vehicle. Attach engine hoist. Remove transmission to engine bolts. Remove engine.

Installation (Express & Savana)

To install, reverse removal procedure. Fill crankcase and cooling system. Bleed cooling system. See COOLING SYSTEM BLEEDING . Evacuate and charge A/C system. Bleed power steering. See POWER STEERING BLEEDING . If necessary adjust shift cable. See SHIFT CABLE ADJUSTMENT . Tighten bolts to specification. See TORQUE SPECIFICATIONS table.

Removal (VIN "J" - Upper)

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__fuel-pressure-release). Remove engine cover or floor panel (if equipped). Remove air cleaner.
2. Disconnect and remove fuel lines. Remove wiring harness connectors and brackets. Remove throttle and cruise control linkage and bracket. Disconnect throttle body electrical connectors. Remove PCV valve and hose. Remove EGR inlet tube. Remove purge solenoid and connectors. Remove ignition coil and coil bracket. Disconnect No. 8 spark plug wire. Remove upper intake manifold. (Scheme 26)

Scheme 26

Installation (VIN "J" - Upper)

Always use NEW "O" rings when reconnecting fuel lines at rear of engine. To install, reverse removal procedure using NEW gaskets. (Scheme 26) Tighten upper intake manifold bolts to specification in sequence. (Scheme 27) See TORQUE SPECIFICATIONS table.

Scheme 27

Removal (VIN "J" - Lower)

1. Remove upper intake manifold. See «REMOVAL (VIN J - UPPER)»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__removal-vin-j-upper).
2. Remove distributor cap. Mark distributor rotor in relation to distributor housing. Mark base of distributor housing in relation to intake manifold. Remove distributor. DO NOT rotate crankshaft while engine is apart.
3. Drain cooling system. Remove upper radiator hose at thermostat housing. Remove water pump by-pass hose and heater hose. Remove fuel line brackets and rail.
4. Remove lower intake manifold bolts, lower intake manifold and gaskets. (Scheme 26)

Installation (VIN "J" - Lower)

Note. Lower intake manifold gaskets are reusable. Replace gaskets only if damaged.

1. Apply a 3/16" (5 mm) bead of RTV (GM P/N 1052289) or equivalent to 4 sealing corners of block. (Scheme 26) Extend bead 1/2" (13 mm) up each cylinder head.
2. Apply Loctite® 242 (GM P/N 12345382) or equivalent to lower intake manifold bolt threads. Tighten bolts in sequence to specification. (Scheme 27) See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table.
3. To complete installation, reverse removal procedure. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__cooling-system-bleeding).

Removal (VIN "N")

1. Release fuel system pressure. See «FUEL PRESSURE RELEASE»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__fuel-pressure-release). Remove engine cover or floor panel (if equipped). Remove air cleaner.
2. Drain cooling system. Disconnect upper radiator hose and water pump by-pass hose. Disconnect heater hose at rear of intake manifold. Disconnect engine wiring harness connectors as necessary.
3. Disconnect accelerator and cruise control cables at Throttle Body Injection (TBI) unit (if equipped). Remove PCV and hose. Disconnect vacuum hose at rear of intake manifold. Disconnect vacuum hoses and fuel lines at TBI unit. Remove TBI unit.
4. Remove distributor cap. Mark distributor rotor in relation to distributor housing. Mark base of distributor housing in relation to lower intake manifold. Remove distributor, ignition coil and bracket. DO NOT rotate crankshaft while engine is apart. Remove EGR electronic vacuum regulator solenoid valve and bracket.
5. Remove MAP sensor and bracket. Remove A/C compressor rear braces (with hoses attached). Remove front generator bracket stud at front of intake manifold. Remove generator front bracket, intake manifold bolts and intake manifold. (Scheme 28)

Scheme 28

Installation (VIN "N")

1. To install, reverse removal procedure. (Scheme 28) Tighten bolts in sequence to specification. (Scheme 29) See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table.
2. Fill and bleed cooling system. See «COOLING SYSTEM BLEEDING»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__cooling-system-bleeding). Set ignition timing to specification. See «IGNITION TIMING»(ref-20056-S04836819302001010200000) in ON-VEHICLE ADJUSTMENTS - 7.4L article in ENGINE PERFORMANCE.

Scheme 29

Removal

Remove engine cover or floor panel. Remove negative battery cable. Remove oil level indicator tube and EGR inlet pipe. Remove spark plugs and spark pug heat shields. Remove exhaust pipe at manifold. Remove exhaust manifold bolts and exhaust manifold.

Installation

Install manifold. Tighten bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

CYLINDER HEAD

Note. Exhaust valve push rods are longer than intake valve push rods.

1. Remove negative battery cable. Remove engine cover or floor panel. Remove intake manifold. See appropriate intake manifold article. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C compressor and bracket (if equipped). Remove generator and brackets. Remove spark plugs.
2. On VIN J, remove temperature sensor connector. On VIN N, remove knock sensor connector. Remove pushrods. See «ROCKER ARMS AND PUSHRODS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) . Remove exhaust manifold. See «EXHAUST MANIFOLD»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) . Remove cylinder head bolts. Remove cylinder head.

1. Clean gasket surfaces, bolt threads and bolt holes. If using steel head gasket, thinly coat both sides of gasket with sealant. DO NOT apply sealant to composite (steel/asbestos) head gaskets. Position head gasket on cylinder block. Ensure all holes align. Coat head bolt threads with GM Sealant (1052080).
2. Install cylinder head with bolts finger-tight. Tighten head bolts in sequence to specification. (Scheme 30) See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. Lubricate valve tip, rocker arm pivot and push rod socket with Molykote.
3. To complete installation, reverse removal procedure. Adjust valves. See «VALVE CLEARANCE ADJUSTMENT»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__valve-clearance-adjustment) under ADJUSTMENTS.

Scheme 30

1. Remove negative battery cable. On Commercial Van, remove engine cover of floor panel. Remove PCV valve and tube. Remove EGR inlet tube. Remove purge solenoid and spark plug wires. Remove valve cover. Remove rocker arm bolts. If pushrods are to be replaced only, back off valve rocker arm bolts until valve rocker arm can be swung away from pushrod and remove pushrod.
2. Intake and exhaust pushrods are different lengths. Exhaust valve pushrods are longer than intake valve pushrods. If removing both rocker arms and pushrods, remove rocker arm with ball. Remove pushrods and pushrod guides.

Coat bearing surfaces with High Viscosity Oil/Zinc (GM P/N 12345501). Valve cover gaskets are reusable. Replace gaskets only if damaged. Tighten to specification. See TORQUE SPECIFICATIONS table. To install remaining components, reverse removal procedure.

Remove negative battery cable. If equipped, remove engine cover or floor pan. Remove engine cooling fan. Remove accessory drive belt(s) and pulley. Remove crankshaft damper bolt. Using Damper Puller/Installer (J-23523-F), remove crankshaft damper. Pry seal from cover.

1. Coat seal lip with engine oil. Using Seal Installer (J-22102), install NEW seal in front cover with seal lip facing engine. Apply RTV sealant to Woodruff keyway in crankshaft damper.
2. Using Damper Puller/Installer (J-23523-F), install crankshaft damper. Tighten crankshaft damper bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. To install remaining components, reverse removal procedure.

Note. DO NOT distort front cover when prying cover loose.

1. Remove negative battery cable. If equipped, remove engine cover or floor pan. Remove engine cooling fan. Remove accessory drive belt(s) and pulley. Remove crankshaft damper bolt.
2. Using Damper Puller/Installer (J-23523-F), remove crankshaft damper.
3. Remove water pump. See «WATER PUMP»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__water-pump) .
4. Disconnect Crankshaft Position (CKP) sensor harness connector. Remove CKP sensor bolt and CKP sensor. Loosen or remove oil pan as necessary for removal of front cover. See «OIL PAN»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__oil-pan) .
5. Remove front cover bolts, front cover and gasket. Inspect front cover for distortion and damage. Replace cover if necessary.

Note. On VIN J, front cover gasket is reusable. Replace only if damaged.

Install cover seal with open end of oil seal facing inside of engine. Coat seal with engine oil. Install crankshaft damper using Damper Puller/Installer (J-23523-F). Tighten to specification. See TORQUE SPECIFICATIONS table. To install remaining components, reverse removal procedure.

1. Remove front cover and gasket. See «FRONT COVER»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j).
2. Remove CKP sensor reluctor ring using Puller (J-8433-1) and Puller Plate (J-41371). (Scheme 31)
3. Rotate crankshaft until timing marks on camshaft and crankshaft sprockets are aligned. (Scheme 32) Remove camshaft sprocket and timing chain. To remove crankshaft sprocket, use Crankshaft Sprocket Puller (J-28509-A).

Scheme 31

Scheme 32

1. Install Woodruff key in crankshaft (if removed). Using Crankshaft Sprocket/Reluctor Ring Installer (J-22102), install crankshaft sprocket. Install camshaft sprocket and timing chain. Ensure timing marks on sprockets are aligned. (Scheme 32)
2. Balance shaft drive gear, driven gear and gear bolt are serviced as a set. Install and tighten camshaft sprocket bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. Install CKP sensor reluctor ring using crankshaft sprocket/reluctor ring installer. Install gasket to front cover with gasket sealant. Install front cover and gasket.
3. Apply RTV sealant to Woodruff keyway in crankshaft damper. Install crankshaft damper using Damper Puller/Installer (J-23523-F). Install crankshaft damper bolt and tighten to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. To complete installation, reverse removal procedure.

ROCKER ARM STUDS

VALVE LIFTERS

Note. Exhaust valve push rods are longer than intake valve push rods.

Remove intake manifold. See INTAKE MANIFOLD . Remove valve covers. Remove push rods. See ROCKER ARMS & PUSH RODS . Remove stuck valve lifter using Valve Lifter Remover (J-9290-01).

Coat lifter base or roller (if equipped) and body with High Viscosity Oil/Zinc (12345501) or equivalent. Install lifters in original location. To complete installation, reverse removal procedure. Replace oil and filter, and add High Viscosity Oil/Zinc (GM P/N 12345501) or equivalent.

Removal (VIN "J")

1. Remove negative battery cable. On Commercial Van, remove engine cover or floor panel. Remove generator and bracket. Remove upper and lower intake manifold. See «INTAKE MANIFOLD»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j). Remove valve covers. Remove push rods. See «ROCKER ARMS & PUSH RODS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j). Remove valve lifters. See «VALVE LIFTERS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__valve-lifters). Remove front cover. See «FRONT COVER»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j).
2. Remove CKP sensor reluctor ring using Puller (J-8433-1) and Puller Plate (J-41371). (Scheme 31)
3. Align timing chain timing marks. Remove camshaft sprocket bolts, camshaft sprocket and timing chain. Using Crankshaft Sprocket Puller (J-28509-A), remove crankshaft sprocket. Install three 5/16 X 18" bolts (4-5 inches long) into camshaft threaded holes. Use bolts to remove and install camshaft.

1. Remove negative battery cable. Remove hood and remove engine cover. Drain engine oil and coolant. Remove air cleaner assembly, PCV tube and PCV valve, and air vent tube. Remove accelerator cable at throttle body. Discharge A/C system (if equipped) using approved refrigerant recovery/recycling equipment and remove A/C compressor and bracket (if equipped).
2. Disconnect horn wiring, oil fill tube and clip, transmission oil level indicator tube. If equipped, remove right and left strut rods from cowl bracket. If equipped, remove cruise control from upper radiator hose support. Remove radiator, condenser, coolant recovery reservoir and upper and lower radiator mounting bracket as an assembly.
3. Remove evaporative emission hoses from charcoal canister. Remove engine fan and fan clutch. Remove power steering pump. Remove generator and engine wiring harness. Remove intake manifold. See appropriate intake manifold section. Remove valve lifters. Remove front cover. See «FRONT COVER»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) .
4. Remove camshaft sprocket bolts, camshaft sprocket and timing chain. Install three 5/16" X 18 bolts (4-5 inches long) into camshaft threaded holes. Use bolts to remove and install camshaft.

Installation (All Models)

Coat camshaft lobes and bearing journals with High Viscosity Oil/Zinc (12345501). Ensure bearing oil holes align with oil holes in block. On engines where oil holes are difficult to see, use a piece of 3/32" rod to check alignment. Install outer camshaft bearing first. Install camshaft. To complete installation, reverse removal procedure. On VIN N, bleed power steering pump. See POWER STEERING BLEEDING . Fill and bleed cooling system. See COOLING SYSTEM BLEEDING . Replace oil and filter, and add High Viscosity Oil/Zinc (12345501) or equivalent.

Remove transmission. On A/T see TRANSMISSION REMOVAL & INSTALLATION - A/T article in TRANSMISSION SERVICING. On M/T see CLUTCH article in M/T. Remove flywheel. Pry seal from housing.

1. Lubricate inner and outer diameter of seal with engine oil. Place seal on Seal Installer (J-38841). Position seal against crankshaft as indicated in illustration. (Scheme 33)
2. Thread attaching screws into crankshaft flange and tighten with screwdriver. This squares seal with crankshaft. Rotate seal installer handle until it bottoms. Remove seal installer. Install flywheel, clutch (M/T) and transmission.

Scheme 33

WATER PUMP

Note. DO NOT immerse water pump in solvent. Solvent may cause premature bearing failure.

Disconnect battery. Drain cooling system. Remove all drive belts, coolant hoses and mounting brackets attached to water pump. If necessary, remove fan shroud. Remove fan and pulley. Remove water pump and gaskets.

Install water pump with NEW gaskets. Tighten water pump bolts to specification. See TORQUE SPECIFICATIONS table. To complete installation, reverse removal procedure.

OIL PAN

Removal ("C" & "K" Pickup, Commercial Van & Suburban)

1. Disconnect battery. Remove fan shroud bolts. Move shroud rearward. Remove air cleaner and distributor cap. Raise and support vehicle. Drain crankcase. Remove starter (M/T). Remove flywheel cover and oil filter.
2. Disconnect oil pressure line from side of cylinder block. Remove front engine mount through-bolts. Raise and support engine. Remove oil pan bolts, oil pan and gasket.

Removal (Express & Savanna)

1. Disconnect battery. Remove engine cover. Raise and support vehicle. Drain crankcase. Remove starter. Remove exhaust crossover pipe from exhaust manifolds and front catalytic converter. Remove transmission. For A/T, see «TRANSMISSION REMOVAL & INSTALLATION»(ref-54679) article in TRANSMISSION SERVICING. For M/T, see «CLUTCHES»(ref-43071) article. Remove flywheel and engine oil dipstick tube. Remove oil cooler line. Disconnect front drive shaft from differential (if equipped).
2. Remove front engine mount through-bolts. Raise engine enough to allow room for oil pan removal. Remove oil pan bolts (DO NOT remove oil pan). Remove oil pump and allow to rest in oil pan. Remove oil pump and oil pan.

1. Apply RTV sealant to 4 corners or gasket sealing surface oil pan gasket. Oil pan gasket is reusable. Replace gasket only if damaged.
2. Install oil pan. Tighten oil pan bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. To complete installation, reverse removal procedure. Fill crankcase.

Valve Springs

1. Measure valve spring free length, installed height and pressure (tension). Replace valve spring if measurement is not within specification. See «VALVES & VALVE SPRINGS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table under ENGINE SPECIFICATIONS.
2. Measure installed height between cylinder head spring seat (or top of shim, if shimmed) and top of spring. If installed height exceeds specification, install shims as necessary to bring installed height to specification.

Valve Stem Oil Seals

1. Intake and exhaust valves use lower umbrella seal.
2. When installing umbrella seal, seat seal against valve guide boss on cylinder head. If equipped, coat upper "O" ring seal with engine oil before installation and ensure seal is not twisted when installed. A gap of.040-.080" (1-2 mm) must exist between edge of oil seal and valve guide. (Scheme 34)

Valve Guides

Valve guides are part of cylinder head (not replaceable). Measure valve guide oil clearance. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. If not within specification, ream valve guide and install valves with oversize stems.

Valves

Replace valve if margin is less than .031" (.8 mm).

Scheme 34

Rocker Arm Assembly

Clean push rods, rocker arms, balls and nuts with solvent and blow dry. Inspect rocker arms and balls at mating surface. Surface should be smooth and free of damage. Inspect push rods for bends or wear. Ensure oil passages are clear.

Piston & Rod Assembly

1. Mark piston in relation to cylinder bore before removal. Piston pin is press-fit in connecting rod. Mark piston in relation to connecting rod before separating components.
2. Replace piston and piston pin as matched set. Install piston in bore with dimple on top of piston toward front of engine.

Fitting Pistons

1. Measure piston diameter at 90-degree angle to piston pin, on piston pin center line. Measure cylinder bore diameter 2 1/2" below cylinder block deck. Determine piston clearance.
2. If piston clearance is not within specification, replace piston and/or machine cylinder bore as necessary. See «CYLINDER BLOCK»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) and «PISTONS, PINS & RINGS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) tables under ENGINE SPECIFICATIONS. Position pistons so that valve cutout is pointing to centerline of engine, or dimple is facing front of engine.

Piston Rings

Measure piston ring end gap and side clearance. If measurement is not within specification, replace piston and/or rings as necessary. See PISTONS, PINS & RINGS table under ENGINE SPECIFICATIONS. Install rings with mark on ring facing upward. Position ring end gaps around circumference of piston as shown. (Scheme 35)

Scheme 35

Rod Bearings

1. Measure rod bearing journal out-of-round, taper and oil clearance. If measurement is not within specification, replace rod bearings and/or machine crankshaft. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table under ENGINE SPECIFICATIONS.
2. Ensure rod side play is within specification. See «CONNECTING RODS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table under ENGINE SPECIFICATIONS. Tighten inside bearing cap bolts first, then outside bearing cap bolts.

Crankshaft & Main Bearings

Note. If rear main bearing cap is removed, replace rear crankshaft oil seal (transmission must be removed to replace seal).

1. Mark bearing caps for reassembly. Measure journal diameter, out-of-round, taper and oil clearance. If measurement is not within specification, replace main bearings and/or machine crankshaft. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table under ENGINE SPECIFICATIONS.
2. Align thrust bearing surfaces, and measure crankshaft end play. See «THRUST BEARING»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__thrust-bearing) . Main bearing caps are press fit. Using Tool (J-6125-B and J-41348), carefully remove caps for service. Install main bearings and main caps. Tap bearing caps into cylinder block cavity using a brass, lead, or leather mallet before installing attaching bolts.
3. DO NOT use cap bolts to pull crankshaft bearing caps into seats. Tighten NEW main cap bolts evenly.

Thrust Bearing

1. Install main bearing caps (except rear), and tighten cap bolts to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. Apply anaerobic sealant to cap-to-cylinder block mating surfaces. On all engines, Install rear main bearing cap and tighten cap bolts to 10 ft. lbs. (14 N.m).
2. Tap crankshaft rearward then forward to align thrust surfaces. Tighten rear main bearing cap bolts to specification. Measure crankshaft end play at forward thrust surface of rear main bearing cap. See «CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table under ENGINE SPECIFICATIONS.

Cylinder Block

Measure cylinder bore out-of-round and taper. If measurement is not within specification, machine cylinder bore and/or replace piston. See CYLINDER BLOCK table under ENGINE SPECIFICATIONS. Finish bore with a 45-65 degree cross-hatch pattern.

ENGINE LUBRICATION SYSTEM

Gear-type oil pump delivers full pressure lubrication through full-flow oil filter to main oil gallery. Main oil gallery feeds crankshaft and camshaft bearings through drilled passages in block.

Valve lifter oil gallery feeds valve lifters. From lifters, oil is routed through hollow push rods to upper valve train components. Timing chain and sprockets are lubricated by oil drainage from No. 1 camshaft bearing. Pistons and piston pins are lubricated by oil splash. Non-adjustable oil pressure regulator is located in oil pump body.

Crankcase Capacity

Crankcase capacity is 7.0 quarts (6.6L), including oil filter.

Oil Pressure

Measure oil pressure with engine at operating temperature and specified RPM. See OIL PRESSURE SPECIFICATIONS table.

OIL PRESSURE SPECIFICATIONS (1)

Removal & Disassembly

Note. Pick-up tube and pump are serviced as an assembly and must be replaced if oil pick-up tube and screen are damaged or loose.

1. Remove oil pan. See «OIL PAN»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j__oil-pan) under REMOVAL & INSTALLATION. Remove oil pump bolt. Remove pump and extension shaft.
2. Remove pump cover. Mark relationship between gears at a meshing point for reassembly. Remove gears. Remove pressure regulator valve retaining pin. Remove pressure regulator valve and spring. Remove oil pump-to-rear crankshaft bearing cap bolt. Remove oil pump, retainer and driveshaft from rear crankshaft bearing cap.

Inspection

Inspect pump body and cover for cracks or excessive wear. Inspect pump gears for damage or wear. Check drive gear shaft for looseness in pump body. Check pressure regulator valve for fit in bore. Replace entire pump assembly if damaged. Inspect inlet tube and screen assembly for damage.

Reassembly & Installation

1. Install pump gears into pump body with marked gear teeth indexed. If pick-up tube was removed, apply sealant to tube end. Tap tube end into pump using plastic hammer. Reassemble remaining components in reverse order of disassembly. If reusing oil pump, replace pressure relief valve spring.
2. Prime oil pump with engine oil. Install pump and extension shaft, ensuring slot on top of extension shaft engages with drive tang on end of distributor shaft. Tighten oil pump bolt to specification. See «TORQUE SPECIFICATIONS»(/chevrolet/chevy-van-g1500/1996-1998/remont/mechanical/#engine-mechanical-74l-v8-vin-j) table. Install oil pan.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL SPECIFICATIONS

GENERAL SPECIFICATIONS

CRANKSHAFT, MAIN BEARINGS & CONNECTING ROD BEARINGS SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CONNECTING RODS SPECIFICATIONS

CONNECTING RODS

PISTONS, PISTON PINS & PISTON RINGS SPECIFICATIONS

PISTONS, PINS & RINGS

CYLINDER BLOCK SPECIFICATIONS

CYLINDER BLOCK

ENGINE VALVES & VALVE SPRINGS SPECIFICATIONS

VALVES & VALVE SPRINGS

CYLINDER HEAD SPECIFICATIONS

CYLINDER HEAD

CAMSHAFT SPECIFICATIONS

CAMSHAFT

See also:
• ENGINE IDENTIFICATION CODES
• FUEL PRESSURE RELEASE
• COOLING SYSTEM BLEEDING
• POWER STEERING BLEEDING
• SHIFT CABLE ADJUSTMENT
• REMOVAL (VIN J - UPPER)
• VALVE CLEARANCE ADJUSTMENT
• WATER PUMP
• OIL PAN
• VALVE LIFTERS
• THRUST BEARING