6.2l v8 Diesel - Vins [c,j] GMC Cab & Chassis R2500

ENGINE IDENTIFICATION

Note. For engine repair procedures not covered in this article, see ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article in GENERAL INFORMATION.

Engine code number is the suffix of engine identification number. Code number is located on label of right valve cover. The Vehicle Identification Number (VIN) is located on a metal plate on top left side of instrument panel. Engine can be identified by the 8th character of the VIN.

ENGINE IDENTIFICATION CODES

ENGINE

See ENGINE REMOVAL article.

ENGINE OVERHAUL

Note. See ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article for detailed information on performing basic engine overhaul and checking procedures.

Removal

1. Disconnect batteries. Remove engine cover on van models. Remove air cleaner. Disconnect PCV and EGR hoses. Remove fuel line bracket and ground strap. Remove EPR/EGR valve bracket and A/C bracket (if equipped). On van models remove crankcase depression relief valve.
2. Loosen vacuum pump hold-down clamp and rotate pump to gain access to intake manifold bolt (if equipped). Remove intake manifold bolts and fuel line clips. Remove intake manifold.

Installation

1. Clean all gasket surfaces. Install new manifold gaskets. Ensure that proper gasket is used. Light duty emissions use gasket with an open EGR passages while heavy duty emissions use closed passages.
2. Install intake manifold. Tighten bolts in proper sequence to specification. (Scheme 40) Reverse removal procedure to complete installation.

Scheme 40

Disconnect batteries. Raise vehicle. Disconnect exhaust pipe from manifold flange. Lower vehicle. Disconnect glow plug wires and remove glow plugs. Remove air cleaner duct bracket (if equipped). Remove dipstick tube when removing left manifold on pickup models. Remove air conditioning bracket (if equipped). Remove manifold bolts and manifold.

To install, reverse removal procedure. Tighten bolts to specification.

Removal (Pickup)

1. Remove intake manifold. Remove injection line clips from brackets. Remove injection lines from injector nozzles. Remove injection lines at injection pump and mark for reassembly reference. Remove fuel supply line from injection pump.
2. Seal injection lines, nozzles and fuel injection pump openings. Remove wiring harness and bracket from engine. Drain coolant. Remove dipstick tube for left cylinder head removal. Disconnect ground wire from cowl at right side of engine.
3. Raise vehicle. Disconnect exhaust pipe from manifold. Lower vehicle. Remove A/C compressor (if equipped) for left cylinder head. Do not disconnect refrigerant lines.
4. Remove alternator and disconnect glow plug wires. Remove glow plug relay (if required). Remove rocker cover. Remove rocker arm assemblies and push rods. Mark rocker arm assemblies and push rod location for reassembly reference.
5. Note location of hardened end of push rod. Hardened end should be indicated by painted area and fit in rocker arm assembly. Mark push rod if not previously marked for hardened area.
6. Disconnect radiator, heater and by-pass hoses. Disconnect ground strap. Remove thermostat crossover and thermostat housing. Remove head bolts and cylinder head. On left cylinder head removal, head bolt may need to remain in cylinder head during removal.

Removal (Van)

1. Remove intake manifold. Remove injection line clips from brackets. Remove injection lines from injector nozzles. Remove injection lines at pump and mark for reassembly reference. Remove fuel supply line from injection pump.
2. Seal injection lines, nozzles and fuel injection pump openings. Remove transducer on cruise control models. Remove upper fan shroud and A/C belt on A/C equipped models.
3. Disconnect glow plug wires. Raise vehicle. Disconnect exhaust pipes from manifolds. For left head removal, remove left exhaust manifold and power steering lower adjusting bolts.
4. Disconnect glow plug temperature switch. Remove rear A/C brace from exhaust manifold on A/C equipped models. Remove upper power steering brackets, transmission detent cable, glow plug controller, bracket and glow plug relay.
5. Remove wiring loom bracket and vacuum line clip bolt from cylinder head. Disconnect fuel return line bracket. Lower vehicle. Discharge A/C system. Disconnect A/C lines at compressor and remove compressor from brackets.
6. Remove dipstick tube front bracket from stud. Remove oil fill tube upper bracket. Disconnect fuel return line bracket. Remove rocker cover bolts and rocker cover.
7. Remove rocker arm assemblies and push rods. Mark rocker arm assemblies and push rod location for reassembly reference. Note location of hardened end. Hardened end should be indicated by painted area and fit in rocker arm.
8. Mark push rod hardened area if not previously marked. Drain cooling system. Remove air cleaner resonator and bracket. Disconnect heater, radiator and by-pass hoses at crossover.
9. Remove alternator upper bracket, coolant crossover and cylinder head bolts. Disconnect transmission dipstick from rear of right head and remove tube. Remove head bolts and cylinder head.

Cleaning & Inspection (All Models)

1. Inspect head for cracks and warpage. For complete cleaning and inspection see «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Check cylinder head for warpage. Replace cylinder head if warpage exceeds .006" (.15 mm) longitudinally or .003" (.08 mm) transversely. NOTE: Cylinder head should not be resurfaced. Replace cylinder head if not within specification or damaged.
2. Prechamber installed depth must be checked. Measure prechamber depth at the seating point on the head gasket shield and sealing ring. Measurement must be taken at 2 or more locations.
3. Measure the difference between the prechamber flat surface and the cylinder head flat surface. Prechamber must not protrude more than .002" (.05 mm) from cylinder head or be recessed in cylinder head.
4. Inspect prechamber for facial cracks. Replace prechamber if facial crack length exceeds 3/16".

Installation (All Models)

1. Remove prechambers from cylinder head if replacement is required. Install small nylon punch through injector hole and drive prechamber from cylinder head.
2. Align new prechamber with alignment notch in cylinder head. Using an 1 1/4" socket and hammer, tap prechamber in place. Check prechamber installed depth.
3. Ensure gasket surfaces, cylinder head bolt threads and threads in block are clean. Head gasket require no sealer. Coat cylinder head bolt threads and underside of bolt heads with Sealant (1052080).
4. Left rear head bolt must be installed in cylinder head prior to installation. Install cylinder head. Ensure that head is seated on dowel pins. Install head bolts.
5. Tighten head bolts in proper sequence. (Scheme 41) Tighten head bolts in 3 steps to specification. Install push rods with hardened end upward. Hardened end should be indicated by paint mark.
6. Install rocker arm shafts. See «ROCKER ARM SHAFT ASSEMBLY»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj). Special procedure must be used to prevent damage to pistons and valves.
7. Reverse removal procedure to complete reassembly. Use new gaskets and tighten all bolts to specification.

Scheme 41

VALVE ARRANGEMENT

Left Bank - I-E-I-E-I-E-I-E (Front-to-rear).

Right Bank - E-I-E-I-E-I-E-I (Front-to-rear).

1. Remove intake manifold as previously described. Remove fuel injection lines. Remove glow plug wires. Remove rocker covers.
2. Remove bolts and rocker arm shafts. Mark component location for reassembly reference. If push rods are to be removed note location of hardened end. Hardened end should be indicated by painted end and fit in rocker arm.

1. Install push rods with hardened end upward (if removed) in original location. Hardened end should be indicated by paint mark. Install rocker arm assemblies in original location. Install bolts, but do not tighten at this time.
2. Ensure that push rods are seated in rocker arms. Rotate engine to align vibration damper timing mark with "O" TDC mark on timing tab. Rotate engine counterclockwise 3 1/2" measured at the vibration damper.
3. This distance can be estimated by aligning vibration damper mark with the first lower water pump bolt. (Scheme 42) Proper positioning ensures that valves will not contact piston.
4. Tighten rocker arm bolts to specification. Reverse removal procedure to complete reassembly. Use new gaskets and tighten all bolts to specification.

Scheme 42

VALVE SPRINGS & OIL SEALS

See ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article for removal and installation procedures. Valve spring tension should be checked prior to installation. See VALVE SPRING SPECIFICATIONS table under ENGINE SPECIFICATIONS. Replace springs not within specification.

VALVE SPRING INSTALLED HEIGHT

Installed valve spring height must be checked. Refer to ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article. If installed height exceeds specifications, shim to meet specifications. See VALVE SPRING INSTALLED HEIGHT SPECIFICATIONS table.

VALVE SPRING INSTALLED HEIGHT SPECIFICATIONS

VALVE GUIDES

Check valve stem-to-guide clearance. See ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION . Oversize valves must be used if not within specification. See VALVE SPECIFICATIONS table under ENGINE SPECIFICATIONS. Valves with .003" (.08 mm) and .015" (.38 mm) oversize stems are available. Ream guides to proper dimension using Reamer Set (J-7049).

HYDRAULIC VALVE LIFTERS

Note. Hydraulic lifters used are roller type. Lifters are serviced as complete assemblies only. Parts are not interchangeable between lifters.

1. Remove intake manifold, rocker covers, rocker arm shafts and push rods as previously described. On Van models, cylinder head must be removed. See «CYLINDER HEAD»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) .
2. On other models, lifters can be removed through access holes using Lifter Remover (J-29834) and a magnet. Remove lifter guide clamps and guide plates. Remove lifters using lifter remover. Mark lifters for location.

Note. Lifters are available in an .010" oversize diameter. Oversize lifter can be identified by a "10" etched on the side. Cylinder block will be stamped "O.S." on pad adjacent to lifter bore and on top rail of cylinder case above lifter bore.

Inspection

1. Check for nicks, burrs or scoring on parts. Ensure lifter roller operates smoothly without excessive play and contains no flat spots. Measure lifter and lifter bore diameter to ensure proper clearance.
2. Replace lifters if not within specification. See «LIFTER SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) table. An oversize lifter can be used to obtain correct clearance.

LIFTER SPECIFICATIONS

1. For priming lifters, submerge lifter in clean kerosene or diesel fuel. Operate plunger several times. Coat roller and bearings with Assembly Lube (1052365).
2. Install lifters into their original position in block. Install lifter guide plate and clamp. Tighten clamp bolts to specification. Rotate crankshaft 2 full turns while checking to see that lifters are not binding against guide plates.
3. Reverse removal procedure to complete reassembly. Use new gaskets and tighten all bolts to specification. Rocker arm assemblies must be installed in proper sequence to prevent piston and valve damage.

Scheme 43

1. Drain coolant system. Disconnect negative battery cables. Remove fan belts, fan, fan shroud and pulley. Remove A/C hose bracket nuts. Remove oil fill tube. Remove alternator pivot bolt and drive belt. Remove alternator lower bracket.
2. Remove power steering belt and pump. Remove A/C compressor. Do not disconnect hoses or lines. Remove A/C compressor belt. Disconnect by-pass and lower radiator hose. Remove water pump bolts. Remove water pump plate and water pump.
3. Rotate engine and align marks on injection pump gear and camshaft gear. (Scheme 43) Scribe an alignment mark on injection pump flange and on front cover. Remove crankshaft pulley. Remove vibration damper using a puller.
4. Remove front cover-to-oil pan bolts. Remove fuel return line clips. Remove fuel injection pump gear. Remove fuel injection pump retaining nuts from front cover. Remove baffle and remaining front cover bolts. Remove front cover.

Scheme 44

1. Clean sealing surfaces. Apply a 3/32" bead of anaerobic sealant on the front cover-to-cylinder block surface. Apply a 3/16" bead of RTV sealant to oil pan mating surface of front cover.
2. Install front cover, baffle and oil pan bolts. Tighten bolts to specification. If front cover was replaced TDC timing mark must be located on replacement front cover.
3. Rotate engine to TDC on No. 1 cylinder. Install Timing Fixture (J-33042) in fuel injection pump location. Do not install gasket. Slot in fuel injection pump timing gear should be located at the 6 o'clock position. (Scheme 44)
4. Remove timing fixture and rotate engine 360 degrees if gear slot is not at 6 o'clock position. Fasten timing fixture to fuel injection pump gear.
5. Install nut finger tight on upper housing stud to secure timing fixture. Tighten the 18 mm large bolt to 35 ft. lbs. (48 N.m). Tighten nut on upper housing stud.
6. Check that crankshaft did not rotate. Check that timing fixture is not binding. Strike scriber to mark TDC indicator on front housing. Remove timing fixture.
7. Install fuel injection pump and gasket. Align scribe marks. Install injection pump drive gear. Align timing marks on fuel injection pump gear and camshaft gear. (Scheme 43) Tighten gear retaining bolt to specification. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__torque-specifications).
8. Check clearance between fuel injection pump gear and baffle. Clearance must be a minimum of.040" (1.01 mm). To complete installation, reverse removal procedure. Use new gaskets and tighten bolts to specification.

Removal & Installation

1. Disconnect negative battery cable. Remove drive belts, crankshaft pulley and vibration damper. Pry seal from cover using a screwdriver. Note direction of seal lip. Ensure seal area is free of burrs.
2. Coat seal lips and crankshaft with engine oil. Install new seal using Seal Installer (J-22101). To complete installation, reverse removal procedure. Tighten bolts to specification.

1. Remove engine front cover. Remove fuel injection pump gear and camshaft gear. Align timing marks on camshaft and crankshaft sprockets. (Scheme 45) Prior to removal, timing chain and sprocket should be checked for wear.
2. Position dial indicator on the front of cylinder block. Dial indicator tip must contact center of timing chain between timing gears. Pull chain outward and adjust dial indicator to 0 (zero).
3. Push timing chain inward and note indicator reading. Timing chain deflection must not exceed.800" (20.32 mm) on used parts or.500" (12.70 mm) on new parts. Replace components as necessary. Remove camshaft and crankshaft sprocket and timing chain.

1. Install crankshaft sprocket, camshaft sprocket and timing chain. Ensure timing marks on sprockets are aligned. Install camshaft gear. Tighten camshaft gear bolts to specification.
2. Install front cover. Tighten bolts to specification. Align marks on fuel injection pump gear and camshaft gear. (Scheme 43) Install pump gear and tighten bolt to specification.
3. Fuel injection pump timing must be adjusted whenever timing chain, sprockets or gears are replaced. See appropriate FUEL SYSTEMS article.

1. Disconnect batteries. Drain cooling system. Remove grille, A/C compressor and condenser, radiator and power steering (if necessary). Remove vacuum pump (if equipped).
2. Remove intake manifold and rocker covers. Remove rocker arms and push rods. See «ROCKER ARM SHAFT ASSEMBLY»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) . Ensure that components are marked for reassembly reference.
3. Remove engine front cover and timing chain. See «ENGINE FRONT COVER»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) and «TIMING CHAIN & SPROCKETS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) . Remove lifters, guide plates and clamps. Mark components location for reassembly reference. Remove camshaft thrust plate and spacer (if equipped). Remove camshaft.

Scheme 45

1. Disconnect batteries. Drain cooling system. Remove grille, A/C compressor and condenser, radiator, shroud and fan. Remove vacuum pump. Remove cylinder heads. See «CYLINDER HEAD»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) .
2. Remove engine front cover and timing chain as previously described. Remove lifters, guide plates and clamps. Mark components location for reassembly reference. Remove camshaft thrust plate and spacer (if equipped). Remove camshaft.

Cleaning & Inspection

Clean all components with clean solvent. Inspect camshaft lobes for signs of flaking or flat spots. Measure camshaft runout and journal O.D. See ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article. Replace camshaft if not within specification. See CAMSHAFT SPECIFICATIONS table under ENGINE SPECIFICATIONS.

Note. Replace hydraulic lifters if new camshaft is installed.

1. Install spacer (if equipped) with inside chamfer toward camshaft. Lubricate camshaft journals with engine oil and lobes with Molykote. Install camshaft and thrust plate. Tighten screws to specification.
2. Check camshaft end play. See «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Camshaft end play must be within specification. See «CAMSHAFT SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) table under ENGINE SPECIFICATIONS.
3. Ensure that all timing marks are aligned. (Scheme 43)and (Scheme 45). To complete installation, reverse removal procedure. Use new gaskets and tighten bolts to specification.

CAMSHAFT BEARINGS

1. Using Bearing Remover/Installer (J-6098-01) and Adapter (J-6098-10), remove camshaft bearings. See «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Rear camshaft bearing must be removed with pilot fitted in the rear camshaft bearing.
2. Install front and rear camshaft bearings first, to act as guides for remover/installer pilot. Seam of camshaft bearings must be installed in the upper half of cylinder block face.
3. Notch on the front bearing must face the front of cylinder block. Front bearing contains 2 oil holes. Ensure that all oil holes align in bearings. Coat rear bore plug with Loctite Sealer (592). Install plug even to 1/32" below block surface.

OIL PAN

See PAN REMOVAL article.

Remove intake manifold and cylinder head. See INTAKE MANIFOLD and CYLINDER HEAD . Remove oil pan and oil pump. Ensure that rods and rod caps are marked for cylinder location. Remove cylinder ridge and piston and rod assembly. See ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article.

For complete cleaning and inspection see ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article.

1. For ring end clearance, side clearance, and rod side clearance see «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Properly position rings on piston. Ensure that depression in piston crown is toward the outside of the engine. Bearing tangs must be opposite the camshaft.
2. Check connecting rod side clearance once connecting rod cap is tightened to specification. See «CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) table under ENGINE SPECIFICATIONS. Ensure crankshaft turns smoothly.

FITTING PISTONS

Determine cylinder taper, wear and out-of-roundness and piston clearance. See ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article. For cylinder specifications, see CYLINDER & PISTON WEAR SPECIFICATIONS table. If taper or out-of-round are not within limits, hone or bore cylinders for installation of new pistons.

Note. Bohn and Zollner pistons are used in the 6.2L. Each require different clearance specification. Piston can be identified by letter stamped inside of piston skirt area. Letters "B" or "Z" are used for piston identification.

CYLINDER & PISTON WEAR SPECIFICATIONS

With piston and rod assembly removed from engine, remove piston pin retaining rings. Slide pin from piston and connecting rod. Note location of piston crown indent and bearing tangs.

Measure piston pin diameter, piston pin bore diameter and connecting rod pin bore. Determine piston pin clearance for piston and connecting rod. Replace piston, piston pin or connecting rod if not within specification. See PISTONS, PINS & RINGS SPECIFICATIONS table under ENGINE SPECIFICATIONS.

Lubricate piston pin holes in piston and connecting rod with engine oil. Install piston on connecting rod with piston crown indent on the same side as bearing tangs. Press piston pin into piston and connecting rod. Install snap rings. Check piston for freedom of movement on piston pin.

CONNECTING ROD BEARINGS

1. Ensure rod caps are marked for cylinder identification. Remove rod cap and bearings. Inspect bearings for wear or damage, and replace as necessary.
2. Check crankshaft rod bearing journal for out-of-round or taper. Crankshaft out-of-round or taper must not exceed .00019" (.005 mm).
3. Measure bearing clearance using Plastigage method. See «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Install new bearings and tighten rod cap to specification. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__torque-specifications) . For bearing clearance, see «CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) table under ENGINE SPECIFICATIONS. NOTE: Some engines with VIN Code C may contain both standard and .003" (.08 mm) oversize connecting rod bearings. Oversize connecting rod bearings can be identified by "O.S." stamped on bearing cap lower end.
4. If clearance exceeds specifications, undersize bearings possibly can be used in combination to produce correct clearance. If clearance is still excessive, crankshaft must be replaced. Do not recondition a rolled fillet crankshaft used on the 6.2L.
5. Clean crankshaft journal and bearing surface in rod. Insert bearings in rod and cap, then lubricate bearing surfaces with oil. Pull piston and rod assembly down onto crankshaft. Install cap and tighten cap to specification.
6. Check connecting rod side clearance. See «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Side clearance should be within specification. See «CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) table under ENGINE SPECIFICATIONS.

1. Main bearings may be replaced with crankshaft installed in the engine. Mark main bearing caps to cylinder block before removing caps. Replace one main bearing at a time only.
2. Remove main bearing cap and main bearing. Position Main Bearing Remover/Installer (J-8080) in crankshaft oil hole. Bearing must be removed so that tang area rotates from cylinder block. Rotate crankshaft and remove upper bearing. This procedure can be used to remove remaining bearings.

Scheme 46

1. Coat upper main bearing with engine oil. Install bearing in cylinder block. Bearing end without tang fits in the notched location of cylinder block.
2. Install main bearing remover/installer in crankshaft oil hole. Slowly rotate crankshaft and install bearing. Check bearing clearance using Plastigage method. See «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article.
3. Install lower main bearing and cap. Ensure that bearing caps are installed in proper location. Tap main bearing cap in position. Lightly oil bolts with engine oil. Tighten all main bearing caps to specification.
4. Once bearing clearance is checked, remove cap and coat bearing and journals with engine oil. Install all bearing caps except No.5 rear bearing cap.
5. Apply anaerobic sealant on No. 5 main bearing cap in specified area. (Scheme 46) Do not allow sealant to contact seal area. Coat seal lip area with engine oil. Install bearing cap and bearing.
6. Tighten all main bearing caps to specification except No. 3. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__torque-specifications). Tighten No. 3 to 10 ft. lbs. (14 N.m). Crankshaft end play must be checked. See «CRANKSHAFT END PLAY»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__crankshaft-end-play).

CRANKSHAFT END PLAY

1. Ensure all other main bearing caps have been properly tightened. Tap crankshaft rearward, then forward. Tighten No. 3 main bearing cap to specification. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__torque-specifications) .
2. Pry crankshaft toward front of engine and check crankshaft end play. See «ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION»(/gmc/cab-chassis-r2500/1987-1987/remont/engine/#engine-overhaul-procedures-general-information) article. Check for proper thrust bearing if end play is not within specification. See «CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj) table under ENGINE SPECIFICATIONS.

1. Remove oil pan and oil pump. Mark rear bearing cap location. Remove rear main bearing cap and lower half of seal. Remove upper half of seal from block. Clean block surface and seal grooves.
2. Lubricate crankshaft seal lips with engine oil. Install upper seal half into block seal groove until one end of seal extends from 1/2" from block.
3. Install remaining seal half into the opposite block seal groove. Contact ends of seal halves will be at 4 and 10 o'clock, or 8 and 2 o'clock positions. This provides proper alignment of main cap with seal lips.
4. Coat seal groove of main bearing cap with Locktite (414) or equivalent. Apply a thin film of anaerobic sealant to bearing cap. (Scheme 46) Lightly oil bolt threads. Tap main bearing cap into place. Install bolts and tighten to specification. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__torque-specifications). Install oil pump and oil pan.

1. Remove oil filler retaining nuts and oil filler. Remove studs used to mount oil filler. Disconnect by-pass hose. Remove water pump retaining bolts. Remove water pump and plate. Remove plate retaining bolts and plate.

1. Install plate and gasket on water pump. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-r2500/1987-1987/remont/mechanical/#62l-v8-diesel-vins-cj__torque-specifications) . Apply anaerobic sealant to sealing surface of plate. Sealant must be wet to touch when installing water pump.
2. Coat water pump retaining bolts threads with Sealant (1052080). Install water pump and tighten all bolts to specification.

Note. For further information on cooling systems, see ENGINE COOLING SYSTEM article.

CRANKCASE CAPACITY

Crankcase capacity is 7 qts. (6.6L) including oil filter change.

OIL FILTER

Replace oil filter every oil change.

NORMAL OIL PRESSURE

Normal oil pressure should be 40-45 psi (2.81-3.16 kg/cm 2 ) at 2000 RPM.

OIL PRESSURE REGULATOR VALVE

Oil pressure regulator valve is located in oil pump body. Valve is nonadjustable.

ENGINE OILING SYSTEM

Pressurized lubrication is provided by vacuum pump or gear driven gear-type oil pump. Lubrication flows through a radiator mounted oil cooler then into a full-flow oil filter.

Main oil gallery supplies oil through drilled passages to camshaft and crankshaft bearings. Oil flows through galleries to valve lifters then through hollow push rods to the rocker arms.

Remove oil pan. Remove pump-to-rear main bearing cap bolt. Remove oil pump and extension shaft.

Disassembly

1. Remove pump cover attaching screws and pump cover. Mark gears so they may be reassembled with same tooth indexing. Remove idler gear, drive gear and shaft from pump housing.
2. Remove pressure regulator valve retaining pin from pump cover. Remove regulator valve from pump cover. Do not disassemble pick-up screen and pipe. Screen and pipe are only serviced as an assembly with the pump.

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

Install pump gears into pump body, with marked gear teeth indexing. Reassemble remaining components in reverse order of disassembly. Tighten cover screws to specification. See TORQUE SPECIFICATIONS .

On Van models, oil pump and oil pan must be installed at the same time. Position oil pump in oil pan and install in place. Assemble pump and extension shaft to engine. Ensure slot on top of extension shaft engages with drive tang on end of distributor shaft. Install oil pump and bolts. Tighten to specification. See TORQUE SPECIFICATIONS . Install oil pan.

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS

GENERAL ENGINE SPECIFICATIONS (LIGHT DUTY)

GENERAL ENGINE SPECIFICATIONS (HEAVY DUTY)

VALVE SPECIFICATIONS

VALVE SPECIFICATIONS

PISTON/PIN/RING SPECIFICATIONS

PISTONS, PINS & RINGS SPECIFICATIONS

BEARING SPECIFICATIONS

CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECIFICATIONS

VALVE SPRING SPECIFICATIONS

VALVE SPRING SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

CAMSHAFT SPECIFICATIONS

See also:
• ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION
• ROCKER ARM SHAFT ASSEMBLY
• TORQUE SPECIFICATIONS
• CRANKSHAFT END PLAY