ENGINE IDENTIFICATION
Note. For engine repair procedures not covered in this article, see ENGINE OVERHAUL PROCEDURES - GENERAL INFORMATION article in the GENERAL INFORMATION section.
Engine code number is 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 eighth character of the VIN.
| Application | Engine Code | VIN Code |
|---|---|---|
| Light Duty | LH6 | C |
| Heavy Duty | LL4 | J |
ENGINE IDENTIFICATION CODES
VALVE ARRANGEMENT
Note. Adjustment information not available at time of publication.
- 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).
TROUBLE SHOOTING
Note. See TROUBLE SHOOTING - BASIC PROCEDURES article in the GENERAL TROUBLE SHOOTNG section.
ENGINE
See ENGINE REMOVAL in ENGINE section.
ENGINE OVERHAUL
Note. See ENGINE OVERHAUL PROCEDURES article for basic procedures not covered in this article.
Removal
- 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.
- Loosen vacuum pump hold-down clamp and rotate pump to gain access to intake manifold bolt (if equipped). Label and disconnect vacuum and electrical connections at manifold. Remove intake manifold bolts and fuel line clips. Remove intake manifold.
| CAUTION | Proper intake manifold gaskets must be used according to vehicle emission rating. |
Installation
- Clean all gasket surfaces. Install new manifold gaskets. Ensure proper gasket is used. Light duty emissions use gasket with an open EGR passage. Heavy duty emissions use closed passages.
- Install intake manifold. Tighten bolts in proper sequence to specification. (Scheme 8) Reverse removal procedure to complete installation.
Scheme 8
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)
- Remove intake manifold as previously described. 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.
- 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.
- Raise vehicle. Disconnect exhaust pipe from manifold. Lower vehicle. Remove A/C compressor (if equipped) for left cylinder head. Do not disconnect refrigerant lines.
- Remove alternator and disconnect glow plug wires. Remove glow plug relay (if required). Remove valve covers. Remove rocker arm assemblies and push rods. Mark rocker arm assemblies and push rod location for reassembly reference.
- 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.
- 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, rear head bolt may need to remain in cylinder head during removal.
Removal (Van)
- Remove intake manifold as previously described. 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.
- Seal injection lines, nozzles and fuel injection pump openings. Remove transducer on cruise control models. Remove upper fan shroud and A/C belt if equipped.
- 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.
- Disconnect glow plug temperature switch. Remove rear A/C brace from exhaust manifold (if equipped). Remove upper power steering brackets, transmission detent cable, glow plug controller, bracket and glow plug relay.
- 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.
- Remove dipstick tube front bracket from stud. Remove oil fill tube upper bracket. Disconnect fuel return line bracket. Remove valve cover bolts and valve cover.
- 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.
- Mark push rod hardened area if not previously marked. Drain cooling system. Remove air cleaner resonator and bracket. Disconnect temperature inhibit switch connector at crossover. Disconnect heater, radiator and by-pass hoses at crossover.
- 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)
- Inspect head for cracks and 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.
- Prechamber installed depth must be checked. Measure prechamber depth at seating point on head gasket shield and sealing ring. Measurement must be taken at 2 or more locations.
- Measure difference between prechamber flat surface and cylinder head flat surface. Prechamber must not protrude more than .002" (.05 mm) from cylinder head or be recessed in cylinder head.
- Inspect prechamber for facial cracks. Replace Prechamber if facial crack length exceeds 3/16".
Installation (All Models)
- Remove prechambers from cylinder head if replacement is required. Install small nylon punch through injector hole and drive prechamber from cylinder head.
- 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.
- Ensure gasket surfaces, cylinder head bolt threads and threads in block are clean. Head gasket requires no sealer. Coat cylinder head bolt threads and underside of bolt heads with Sealant (1052080).
- 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.
- Tighten head bolts in proper sequence. (Scheme 9) Tighten head bolts in 3 steps to specification. Install push rods with hardened end upward. Hardened end should be indicated by paint mark.
- Install rocker arm shafts. See «ROCKER ARM SHAFT ASSEMBLY»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj). Special procedure must be used to prevent damage to pistons and valves.
- Reverse removal procedure to complete reassembly. Use new gaskets and tighten all bolts to specification. Evacuate and recharge A/C system if equipped.
Scheme 9
- Remove intake manifold as previously described. Remove fuel injection lines. Remove glow plug wires. Remove rocker covers.
- 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.
| CAUTION | Proper installation procedure must be used to prevent piston and valve damage. |
- 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.
- 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 vibration damper.
- This distance can be estimated by aligning vibration damper mark with first lower water pump bolt. (Scheme 10) Proper positioning ensures that valves will not contact piston.
- Tighten rocker arm bolts to specification. Reverse removal procedure to complete reassembly. Use new gaskets and tighten all bolts to specification.
Scheme 10
VALVE SPRING INSTALLED HEIGHT
Note. Valve spring tension should be checked prior to installation. See VALVES & VALVE SPRINGS under ENGINE SPECIFICATIONS. Replace springs not within specification.
Installed valve spring height must be checked. If installed height is not to specification of 1.8" (46 mm), shim to meet specifications.
VALVE GUIDES
Check valve stem-to-guide clearance. Oversize valves must be used if not within specification. See CYLINDER HEAD 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.
- Remove intake manifold, rocker covers, rocker arm shafts and push rods as previously described. On Van models cylinder head must be removed as previously described.
- 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 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
- 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.
- Replace lifters if not within specification. Refer to «VALVE LIFTERS»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj) under ENGINE SPECIFICATIONS. An oversize lifter can be used to obtain correct clearance.
| CAUTION | New lifters must be primed prior to installation to prevent damage to components. |
- For priming lifters, submerge lifter in clean kerosene or diesel fuel. Operate plunger several times. Coat roller and bearings with Assembly Lube (1052365).
- 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.
- 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. See «ROCKER ARM SHAFT ASSEMBLY»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj) .
Scheme 11
- Remove water pump. See «WATER PUMP»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj). Drain coolant system. Rotate engine and align marks on injection pump gear and camshaft gear. (Scheme 11) Scribe an alignment mark on injection pump flange and on front cover. Remove crankshaft pulley. Remove vibration damper using a puller.
- Remove 4 front cover-to-oil pan bolts. Remove 2 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.
- Clean sealing surfaces. Apply a 3/32" bead of anaerobic sealant on front cover-to-cylinder block surface. Apply a 3/16" bead of RTV sealant to oil pan mating surface of front cover.
- 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. See MARKING TDC ON FRONT COVER.
- 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 11) Tighten gear retaining bolt to specification.
- 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
- 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.
- 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.
- Remove engine front cover as previously described. Remove fuel injection pump gear and camshaft gear. Align timing marks on camshaft and crankshaft sprockets. (Scheme 13) Prior to removal, timing chain and sprocket should be checked for wear.
- Position dial indicator on front of cylinder block. Dial indicator tip must contact center of timing chain between timing sprockets. Pull chain outward and adjust dial indicator to zero.
- 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.
- Install crankshaft sprocket, camshaft sprocket and timing chain. Ensure timing marks on sprockets are aligned. Install camshaft gear. Tighten camshaft gear bolts to specification.
- Install front cover. Tighten bolts to specification. Align marks on fuel injection pump gear and camshaft gear. (Scheme 11) Install pump gear and tighten bolt to specification.
- Fuel injection pump timing must be adjusted whenever timing chain, sprockets or gears are replaced.
Scheme 12
- 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 6 o'clock position. (Scheme 12)
- 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.
- Install nut finger tight on upper housing stud to secure timing fixture. Tighten 18 mm large bolt to 35 ft. lbs. (48 N.m). Tighten nut on upper housing stud.
- 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. Reinstall injection pump.
FUEL INJECTION PUMP TIMING
- Check alignment of injection pump timing marks on top of engine front cover and injection pump flange (half circles on California models and scribe marks on Federal models).
- If timing marks are not aligned, loosen 3 retaining nuts, and align mark on injection pump with mark on front cover. Tighten nuts to 30 ft. lbs. (41 N.m) and adjust throttle linkage.
- Disconnect batteries. Drain cooling system. Remove alternator, grille, A/C compressor and condenser, radiator and power steering (if necessary). Remove vacuum pump (if equipped).
- Remove intake manifold as previously described. Remove valve covers. Remove rocker arm shaft assembly as previously described. Remove push rods. Ensure that components are marked for reassembly reference.
- Remove engine front cover, timing chain, lifters, guide plates and clamps as previously described. Mark components location for reassembly reference. Remove front engine mount through bolts. Raise engine to ease camshaft removal. Block engine. Remove camshaft thrust plate and spacer (if equipped). Remove camshaft.
Scheme 13
- Disconnect batteries. Drain cooling system. Remove grille, bumper, lower valance, coolant bottle, upper tie bar, A/C compressor, condenser, radiator, shroud and fan. Remove vacuum pump and oil pump drive. Remove cylinder heads as previously described.
- Remove engine front cover, timing chain, lifters, guide plates and clamps as previously described. Mark components location for reassembly reference. Remove camshaft thrust plate and spacer (if equipped). Remove camshaft.
Cleaning & Inspection
Inspect camshaft lobes for signs of flaking or flat spots. Measure camshaft runout and journal O.D. Replace camshaft if not within specification. See CAMSHAFT under ENGINE SPECIFICATIONS.
Note. Replace hydraulic lifters if new camshaft is installed.
- 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.
- Check camshaft end play. Camshaft end play must be within specification. See «CAMSHAFT»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj) under ENGINE SPECIFICATIONS.
- Ensure that all timing marks are aligned. (Scheme 11)and (Scheme 13). To complete installation, reverse removal procedure. Use new gaskets and tighten bolts to specification.
CAMSHAFT BEARINGS
| CAUTION | Camshaft bearing bores are different sizes. Ensure that proper bearing is installed in bearing bore. |
- Using Bearing Remover/Installer (J-6098-01) and Adapter (J-6098-10), remove camshaft bearings. Rear inner bearing must be removed with pilot fitted in rear camshaft bearing.
- Install front and rear camshaft bearings first, to act as guides for remover/installer pilot. Seam of camshaft bearings must be installed in upper half of cylinder block face.
- Notch on front bearing must face 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 OIL PAN REMOVAL in ENGINE section.
Remove intake manifold and cylinder head as previously described. 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.
- Properly position rings on piston. (Scheme 14) Ensure depression in piston crown is toward outside of engine. Connecting rod bearing tangs must also face outside of engine.
- Check connecting rod side clearance once connecting rod cap is tightened to specification. See «CONNECTING ROD SPECIFICATIONS»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj). Ensure crankshaft turns smoothly.
Scheme 14
FITTING PISTONS
Determine cylinder taper, wear, out-of-round and piston clearance. For specifications see CYLINDER BLOCK under ENGINE SPECIFICATIONS. If taper or out-of-round are not within limits, hone or bore cylinders for installation of new pistons.
Note. Bohn or Zollner pistons are used in 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.
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 under ENGINE SPECIFICATIONS.
Lubricate piston pin holes in piston and connecting rod with engine oil. When Installing piston on connecting rod, ensure depression in piston crown is toward outside of engine. Connecting rod bearing tangs must also face outside of engine. Press piston pin into piston and connecting rod. Install snap rings. Check piston for freedom of movement on piston pin.
CONNECTING ROD BEARINGS
- Ensure rod caps are marked for cylinder identification. Remove rod cap and bearings. Inspect bearings for wear or damage and replace as necessary.
- Check crankshaft rod bearing journal for out-of-round or taper. Crankshaft out-of-round or taper must not exceed .00019" (.005 mm).
- Measure bearing clearance using Plastigage method. Install new bearings and tighten rod cap to specification. Refer to the «CRANKSHAFT MAIN & CONNECTING ROD BEARINGS»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj) table under ENGINE SPECIFICATIONS for bearing clearance. 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.
- 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 6.2L.
- 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.
- Check connecting rod side clearance. Side clearance should be within specification. See «CONNECTING ROD SPECIFICATIONS»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj) .
- Main bearings may be replaced with crankshaft installed in engine. Mark main bearing caps to cylinder block before removing caps. Replace one main bearing at a time only.
- 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 15
- Coat upper main bearing with engine oil. Install bearing in cylinder block. Bearing end without tang fits in notched location of cylinder block.
- Install main bearing remover/installer in crankshaft oil hole. Slowly rotate crankshaft and install bearing. Check bearing clearance using Plastigage method.
- Install lower main bearing and cap. Ensure 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.
- 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.
- Apply anaerobic sealant on No. 5 main bearing cap in specified area. (Scheme 15) Do not allow sealant to contact seal area. Coat seal lip area with engine oil. Install bearing cap and bearing.
- Tighten all main bearing caps to specification except No. 3. Tighten No. 3 to 10 ft. lbs. (14 N.m). Crankshaft end play must be checked.
CRANKSHAFT END PLAY
- Ensure all other main bearing caps have been properly tightened. Tap crankshaft rearward, then forward. Tighten No. 3 main bearing cap to specification.
- Pry crankshaft toward front of engine and check crankshaft end play. Check for proper thrust bearing if end play is not within specification. See «CRANKSHAFT MAIN & CONNECTING ROD BEARING»(/gmc/cab-chassis-v3500/1987-1991/remont/mechanical/#62l-v8-diesel-vins-cj) under ENGINE SPECIFICATIONS.
- 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.
- Lubricate crankshaft seal lips with engine oil. Install upper seal half into block seal groove until one end of seal extends 1/2" from block.
- Install remaining seal half into 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.
- Coat seal groove of main bearing cap with Loctite (414) or equivalent. Apply a thin film of anaerobic sealant to bearing cap. (Scheme 15) Lightly oil bolt threads. Tap main bearing cap into place. Install bolts and tighten to specification. Install oil pump and oil pan.
- 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.
- 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 as an assembly. Remove water pump from plate.
- Install plate and gasket on water pump. Tighten bolts to specification. Apply anaerobic sealant to sealing surface of plate. Sealant must be wet to touch when installing water pump.
- Coat water pump retaining bolts threads with Sealant (1052080). Install water pump and tighten all bolts to specification. Reverse removal procedure to complete installation.
Note. For further information on cooling systems, see ENGINE COOLING SYSTEMS in ENGINES section.
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 rocker arms.
Remove oil pan. See OIL PAN REMOVAL article. Remove pump-to-rear main bearing cap bolt. Remove oil pump and extension shaft.
Disassembly
- 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.
- 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 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.
On van models oil pump and oil pan must be installed at 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 pump drive or vacuum pump. Install oil pump and bolts. Tighten to specification. Install oil pan.
TORQUE SPECIFICATIONS
| Application | Ft. Lbs. (N.m) | |
|---|---|---|
| Bellhousing Bolt | 30 (40) | |
| Camshaft Gear Bolt | 75 (102) | |
| Camshaft Thrust Plate Bolt | 17 (23) | |
| Connecting Rod Nut | 48 (65) | |
| Crankshaft Pulley Bolt | 30 (40) | |
| Cylinder Head Bolt (1) | ||
| Step 1 | 20 (27) | |
| Step 2 | (2) 50 (68) | |
| Exhaust Manifold Bolt | 26 (35) | |
| Flywheel Bolt | 65 (88) | |
| Front Cover Bolt | 33 (45) | |
| Glow Plugs | 10 (14) | |
| Injection Lines | 19 (25) | |
| Injection Nozzle | 50 (68) | |
| Injection Pump Retaining Nut | 30 (40) | |
| Injection Pump Gear Bolt | 20 (26) | |
| Injection Pump Gear Baffle Bolt | 33 (45) | |
| Intake Manifold Bolt (3) | 31 (42) | |
| Lifter Guide Plate Bolt | 18 (26) | |
| Main Bearing Cap Bolt | ||
| Inner | 110 (150) | |
| Outer | 100 (135) | |
| Oil Pump Drive Clamp Bolt | 31 (42) | |
| Oil Pump Retaining Bolt | 65 (88) | |
| Rocker Arm Cover Bolt | 16 (22) | |
| Rocker Arm Shaft Bolt | 40 (55) | |
| Thermostat Housing Bolt | 35 (48) | |
| Vibration Damper Bolt | 200 (270) | |
| Water Crossover-to-Head Bolt | 31 (42) | |
| Water Pump-to-Cover Bolt | 31 (42) | |
| Water Pump Plate-to-Cover Bolt | 16 (22) | |
| Water Pump Plate-to-Pump Bolt | 16 (22) | |
| Vacuum Pump Retaining Bolt | 31 (42) | |
| INCH Lbs. (N.m) | ||
| Oil Pan Bolt | ||
| Rear 2 Bolts | 84 (10) | |
| All Others | 204 (23) | |
| (1) Tighten in sequence. (Scheme 9) (2) All bolts are then tightened an additional 90 degrees. (3) Tighten in sequence. (Scheme 8) | ||
| (1) | Tighten in sequence. (Scheme 9) |
| (2) | All bolts are then tightened an additional 90 degrees. |
| (3) | Tighten in sequence. (Scheme 8) |
TORQUE SPECIFICATIONS
GENERAL ENGINE SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Displacement | ||
| Cubic Inches | 378 | |
| Liters | 6.2 | |
| Fuel System | Diesel | |
| HP @ RPM | 130 @ 3600 | |
| Torque Ft. @ RPM | 240 @ 2000 | |
| Compression Ratio | 21.3:1 | |
| Bore | 3.98 (101) | |
| Stroke | 3.82 (973 | |
GENERAL ENGINE SPECIFICATIONS (LIGHT DUTY)
| Application | In. (mm) | |
|---|---|---|
| Displacement | ||
| Cubic Inches | 378 | |
| Liters | 6.2 | |
| Fuel System | Diesel | |
| HP @ RPM | 148 @ 3600 | |
| Torque Ft. @ RPM | 246 @ 2000 | |
| Compression Ratio | 21.3:1 | |
| Bore | 3.98 (101) | |
| Stroke | 3.82 (973 | |
GENERAL ENGINE SPECIFICATIONS (HEAVY DUTY)
PISTON/PIN/RING SPECIFICATIONS
| Application | In. (mm) | |||
|---|---|---|---|---|
| Pistons | ||||
| Both Pistons | ||||
| Piston Clearance | ||||
| Journal Nos. 1-6 | (1) .0035-.0045 (.089-.115) | |||
| Journal Nos. 7-8 | (2) .0040-.0054 (.102-.128) | |||
| Piston Diameter | N/A | |||
| Zollner Rings | ||||
| Piston Clearance | ||||
| Journal Nos. 1-6 | .0044-.0054 (.112-.138) | |||
| Journal Nos. 7-8 | .0049-.0059 (.125-.151) | |||
| Piston Diameter | N/A | |||
| Pins | ||||
| Diameter | 1.2203-1.2206 (30.996-31.004) | |||
| Piston Fit | N/A | |||
| Rod Fit | .00031-.00121 (.0081-.0309) | |||
| Rings | ||||
| Ring No. 1 | ||||
| End Gap | .012-.023 (.30-.55) | |||
| Side Clearance | .003-.0070 (.076-.178) | |||
| Ring No. 2 | ||||
| End Gap | .030-.039 (.25-1.00) | |||
| Side Clearance | .002-.003 (.039-.076) | |||
| Oil Ring | ||||
| End Gap | .010-.020 (.25-.51) | |||
| Side Clearance | .0016-.0038 (.040-.096) | |||
| (1) Journals No. 1,2,3,4,5 & 6. (2) Journals No. 7 & 8. | ||||
| (1) | Journals No. 1,2,3,4,5 & 6. |
| (2) | Journals No. 7 & 8. |
PISTONS, PINS & RINGS SPECIFICATIONS
BEARING SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Crankshaft | ||
| Crankshaft End Play | .003-.010 (.10-.25) | |
| Runout | N/A | |
| Journal Taper | .0002 Max. (.005) | |
| Journal Out-Of-Round | .0002 Max. (.005) | |
| Main Bearings | ||
| Journal Diameter | (1) 2.9495-2.9504 (74.917-74.951) | |
| (2) 2.9493-2.9502 (74.912-75.936) | ||
| Oil Clearance | (1) .0018-.0033 (.045-.083) | |
| (2) .0022-.0037 (.055-.093) | ||
| Connecting Rod Bearings | ||
| Journal Diameter | 2.3981-2.3991 (60.913-60939) | |
| Oil Clearance | .0018-.0039 (.045-.100) | |
| (1) Journals No. 1,2,3,4. (2) Journal No. 5 | ||
| (1) | Journals No. 1,2,3,4. |
| (2) | Journal No. 5 |
CRANKSHAFT MAIN & CONNECTING ROD BEARINGS SPECS
CONNECTING ROD SPECIFICATIONS
| Application | In. (mm) |
|---|---|
| Side Play | .007-.025 (.17-.63) |
| Maximum Bend & Twist | N/A |
| Pin Bore Diameter | N/A |
| Large Bore Diameter | N/A |
| Center-to-Center Length | N/A |
CONNECTING ROD SPECIFICATIONS
CYLINDER HEAD SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Maximum Cylinder Head Warp | (1) * | |
| Valve Seat Angle | ||
| Intake | 46° | |
| Exhaust | 46° | |
| Valve Seat Maximum Runout | ||
| Intake | .002 (.05) | |
| Exhaust | .002 (.05) | |
| Valve Seat Width | ||
| Intake | .035-.060 (.89-1.53) | |
| Exhaust | .061-.093 (1.57-2.36) | |
| Valve Seat Bore Diameter | ||
| Intake | N/A | |
| Exhaust | N/A | |
| Valve Stem Oil Clearance | ||
| Intake | .0010-.0027 (.026-.069) | |
| Exhaust | .0010-.0027 (.026-.069) | |
| Valve Guide Inside Diameter | ||
| Intake | N/A | |
| Exhaust | N/A | |
| Valve Guide Bore | ||
| Intake | N/A | |
| Exhaust | N/A | |
| (1) Warpage should not exceed .006" (.15 mm), longitudinally or .003" (.08 mm) transversely. Resurfacing is not recommended. | ||
| (1) | Warpage should not exceed .006" (.15 mm), longitudinally or .003" (.08 mm) transversely. Resurfacing is not recommended. |
CYLINDER HEAD SPECIFICATIONS
CYLINDER BLOCK SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Maximum Block Warp | N/A | |
| Cylinder Bore | ||
| Standard Diameter | 3.9758-3.9789 (100.987-101.065) | |
| Maximum Taper | .0008 (.020) | |
| Maximum Out-of-Round | .0008 (.020) | |
CYLINDER BLOCK SPECIFICATIONS
VALVE/VALVE SPRING SPECIFICATIONS
| Application | In. (mm) | |
|---|---|---|
| Valves | ||
| Head Diameter | N/A | |
| Stem Diameter | N/A | |
| Face Angle | 45° | |
| Minimum Margin | N/A | |
| Maximum Refinish | N/A | |
| Valve Spring | ||
| Free Length | 1.981 (50.32) | |
| Out of Square | .0625 (1.59) | |
| Installed Height | 1.8 (46) | |
| Lbs. @ In. (Kg @ mm) | ||
| Pressure | ||
| Valve Closed | 80 @ 1.81 (356 @ 46) | |
| Valve Open | 230 @ 1.38 (1025 @ 35.3) | |
VALVES & VALVE SPRINGS SPECIFICATIONS
CAMSHAFT SPECIFICATIONS
| Application | In. (mm) |
|---|---|
| Journal Diameter | 2.1641-2.1663 (54.970-55.025) |
| 2.0066-2.0088 (50.970-51.025) | |
| Oil Clearance | .0010-.0046 (.025-.118) |
| .0009-.0044 (.020-.113) | |
| Bearing Bore | N/A |
| Runout | N/A |
| End Play | .0020-.0120 (.051-.305) |
| Lobe Lift | 2808 (7.133) |
| Lobe Height | N/A |
CAMSHAFT SPECIFICATIONS
VALVE LIFTER SPECIFICATIONS
| Application | In. (mm) |
|---|---|
| Diameter | .921-.922 (23.39-23.41) |
| Bore Diameter | .923-.924 (23.45-23.47) |
| Oil Clearance | .0016-.0031 (.040-.080) |
VALVE LIFTERS SPECIFICATION