SERVICE MANUAL UPDATE-REVISED CAM GEAR REPLACEMENT PROCEDURE

REVISED CAM GEAR REPLACEMENT SERVICE PROCEDURE (NEW PROCEDURE) SERVICE MANUAL UPDATE

VEHICLES AFFECTED: 1982-88 A/N/P CARS W/2.5L L4 ENGINES

SERVICE MANUAL UPDATE

THIS BULLETIN SUPERSEDES CURRENT AND PAST SERVICE MANUAL PROCEDURES. THIS BULLETIN ALSO SUPERSEDES PRODUCT SERVICE BULLETIN # 86-625-113.

The above bulletin should be discarded and replaced with this bulletin.

A set of revised service procedures has been developed for replacement of camshaft timing gears. The revised methods do not require the complete removal of the engine from the vehicle. Cam gear replacement is generally accomplished by partially lowering the engine/cradle assembly to gain access to the cam gear.

This bulletin contains three separate and complete procedures for servicing cam gears on A, N, and P cars.

NOTICE: SEE APPROPRIATE SERVICE MANUAL SECTION FOR FASTENER TORQUE SPECIFICATIONS.

A CAR SERVICE PROCEDURE

Tools Required:

J28467-A Engine Support Fixture J24420-B Cam Gear Removal Tool J25033-B Cam Gear Installation Tool J34995 Crankshaft Front Cover Oil Seal Installer J8001 Universal Dial Indicator w/Magnetic Base

Remove or Disconnect 1. Negative battery cable. 2. Drain coolant. 3. Belt tensioner and belt, or drive belts, as applicable. 4. Upper engine torque strut. 5. Timing pointer plate (as applicable). 6. Both forward hood bumpers. 7. Install engine support fixture - J28467-A per Service Manual. 8. Raise Vehicle. 9. Both front wheels. 10. Drain engine oil (remove oil filter). 11. Steering shaft pinch bolt at steering gear. 12. Right front lower ball joint. 13. Right front brakeline-to-body bracket. 14. Right front wheelhouse engine splash shield. 15. Flywheel/flexplate cover. 16. Crankshaft pulley (have assistant hold flywheel) 17. Frame (cradle) bolts and insulators (4). 18. Lower vehicle. 19. Timing gear cover bolts (8). 20. Lower the passenger side of the cradle/powertrain assembly 4 inches with support fixture (may require lowering of driver's side). 21. Raise vehicle. 22. Timing gear cover - do not distort.

Clean - Timing gear cover and engine sealing surfaces.

23. Align crankshaft/camshaft timing marks on gears. 24. Drill and tap hole on the camshaft centerline (8mm drill, 12.7mm (1/2 inch) deep.

CAUTION:

WEAR SAFETY GLASSES TO AVOID EYE DAMAGE. USE CARE WHEN DRILLING AND TAPPING CAM GEAR TO AVOID DAMAGE TO THE CAMSHAFT.

IMPORTANT! COVER OIL PAN OPENING WITH RAGS TO PREVENT CHIPS FROM FALLING INTO PAN.

25. Tap the 8mm hole with a 3/8-16-NC bottoming tap.

IMPORTANT! AVOID BUILD-UP OF CHIPS. BACK OUT THE TAP EVERY FEW TURNS AND REMOVE CHIPS.

26. Center punch and drill (2) 3mm pilot holes in the metal hub of the cam gear (180 degrees apart).

IMPORTANT! USE CARE TO AVOID DRILL WANDER THAT CHOULD DAMAGE CAMSHAFT.

27. Enlarge pilot holes with 5.5mm drill; 6.35mm (1/4") deep. 28. Tap 5.5mm holes with 1/4-28-NF bottoming tap. 29. Drill a hole no larger than lmm (.040 in.) in the front oil gallery This provides improved lubrication to the timing gears.

Clean - Oil pan of debris.

30. Cam gear with J24420-B - do not move cam or crank.

Inspect - Thrust plate for scuffing and/or grooving. If evident, install new thrust plate, spacer ring, and key. Thrust plate-to-block bolts torque - 10 Nm.(90 in.lb.)

IMPORTANT! LUBRICATE FRONT THRUST PLATE SURFACE WITH CLEAN ENGINE OIL.

Install or Connect

1. Cam gear using J25033-B - align timing marks.

Measure - Camshaft end play using dial indicator - J8001 or equivalent. Push cam gear onto camshaft until camshaft end play is in the range of .0015 in. to .0050 in. (.04mm to .13mm).

2. J34995 into front cover - lubricate seal lip with clean engine oil. 3. Apply RTV sealant to timing gear cover sealing surfaces. 4. Timing gear cover to engine. 5. Brakeline bracket to frame. 6. Crank pulley and bolt. 7. Flywheel/flexplate cover and bolts. 8. Lower vehicle. 9. Raise frame assembly with support fixture. 10. Install (4) frame (cradle) bolts finger tight. 11. Remove engine fixture. 12. Raise vehicle. 13. Cradle bolts. 14. Lower ball joint; use new pinch bolt. 15. Steering shaft pinch bolt. 16. Engine splash shield. 17. Both front wheels. 15. Steering shaft pinch bolt. 16. Engine 17. Both front wheels. 18. Lower vehicle 19. Front hood bumpers. 20. Engine torque strut. 21. Tensioner - as applicable.

Clean - Tensioner and block sealing surfaces. Do not remove molded seal ring. Apply RTV around molded seal.

22. Timing pointer plate (as applicable). 23. Accessory drive belt(s). 24. Engine oil (replace oil filter). 25. Coolant. 26. Negative battery cable. 27. Check front end toe-in and adjust if necesssary.

Inspect - For oil and coolant leaks with engine running at operating temperature - For proper completion of repairs.

Labor Operation Number: J0840

For 1987-88 Labor Time : 3.9 Hours To Replace Crankshaft Gear - Add .1 Hours Locking Wheel Covers and/or Nuts - Add .2 Hours

For 1982-86 Labor Time : 4.2 Hours A/C - Add: .1 Hours

N-CAR SERVICE PROCEDURE ----------------------- Tools Required:

J28467-A Engine Support Fixture (with long hooks) J24420-B Cam Gear Removal Tool J25033-B Cam Gear Installation Tool J34995 Crankshaft Front Cover Oil Seal Installer J8001 Universal Dial Indicator w/Magnetic Base

Remove or Disconnect 1. Negative battery cable. 2. Accessory drive belts. 3. Power steering pump mount bolts - lay pump aside. 4. Drain coolant (1985-86 only). 5. Timing pointer plate (1985-86 only). 6. Body ground strap. 7. Front end sheet metal diagonal brace (R.H.). 8. Install engine support fixture - J28467-A per Service Manual. 9. Upper front engine mount to body bolts (2). 10. Raise vehicle. 11. Right front wheel. 12. Right front brakeline-to-body bracket. 13. Right front wheelhouse engine splash shield. 14. Flywheel/flexplate cover. 15. Crankshaft pulley (have assistant hold flywheel). 16. Rear engine mount to bracket nuts and mount thru bolts. 17. Rear transaxle strut - automatic transaxle only (as applicable). 18. Lower front engine mount to body bolt (leave mount attached to engine). 19. Retaining bolts from right side front suspension support (6). 20. Retaining bolts from left side front suspension support (6). 21. Drain engine oil (remove oil filter). 22. Lower vehicle. 23. Transaxle mount thru bolt. 24. Lower engine/transaxle assembly with engine support fixture. 25. Raise vehicle. 26. Timing gear cover - do not distort.

Clean - Timing gear cover and engine sealing surfaces.

27. Align crankshaft/camshaft timing marks on gears. 28. Drill and tap hole on the camshaft centerline (8mm drill, 12.7mm (.5")deep).

CAUTION:

WEAR SAFETY GLASSES TO AVOID EYE DAMAGE. USE CARE WHEN DRILLING AND TAPPING CAM GEAR TO AVOID DAMAGE TO THE CAMSHAFT.

IMPORTANT! COVER OIL PAN OPENING WITH RAGS TO PREVENT CHIPS FROM FALLING INTO PAN.

29. Tap the 8mm hole with a 3/8-16-NC bottoming tap.

IMPORTANT! AVOID BUILD-UP OF CHIPS. BACK OUT THE TAP EVERY FEW TURNS AND REMOVE CHIPS.

30. Center punch and drill (2) 3mm pilot holes in the metal hub of the cam gear (180 degrees apart).

IMPORTANT! USE CARE TO AVOID DRILL WANDER THAT COULD DAMAGE CAMSHAFT.

31. Enlarge pilot holes with 5.5mm drill; 6.35mm(.25")deep. 32. Tap 5.5mm holes with 1/4-28-NF bottoming tap. 33. Drill a hole no larger than lmm (.040 in.) in the front oil gallery plug. This provides improved lubrication to the timing gears.

Clean - Oil pan of debris.

34. Cam gear with J24420-B - do not move cam or crank.

Inspect - Thrust plate for scuffing and/or grooving. If evident, install new thrust plate, spacer ring, and key. Thrust plate-to-block bolts torgue - 10 N. (90 in.1b).

IMPORTANT: LUBRICATE FRONT THRUST PLATE SURFACE WITH CLEAN ENGINE OIL

Install or Connect 1. Cam gear using J25033-B - align timing marks.

Measure - Camshaft end play using dial indicator - J8001 or equivalent. Push cam gear onto camshaft until camshaft end play is in the range of .0015 in. to .0050 in. (.04mm to .13mm) 2. J34995 into front cover - lubricate seal lip with clean engine oil 3. Apply RTV sealant to timing gear cover sealing surfaces. 4. Timing gear cover to engine. 5. Lower vehicle. 6. Raise engine assembly with support fixture. 7. Thru bolt in rear transaxle mount. 8. Retaining bolts (2) in front engine mount. 9. Raise vehicle. 10. Retaining nuts (2) and thru bolts (2) in right front engine mount. 11. Retaining bolt (1) in left front engine mount. 12. Place axle stand under right front suspension support, raise into position and fasten with retaining bolts (6). 13. Place axle stand under left front suspension support, raise into position and fasten with retaining bolts. 14. Crankshaft pulley and bolt (w/assistant). 15. Flywheel/flexplate cover and bolts. 16. Engine splash shield. 17. Brakeline-to-body bracket. 18. Right front wheel. 19. Lower vehicle. 20. Transaxle bracket to transaxle mount long bolt. 21. Remove engine support fixture. 22. Timing pointer plate (1985-86 only). 23. Engine coolant (1985-86 only). 24. Engine oil (replace oil filter). 25. Power steering pump mount bolts to engine. 26. Accessory drive belts. 27. Front end sheet metal diagonal brace (R.H.). 28. Body ground strap. 29. Negative battery cable. 30. Check front end toe-in and adjust if necessary.

Inspect - For oil and coolant leaks with engine running at operating temperature. - For proper completion of repairs.

Labor Operation Number: J0840

For 1987-88 Labor Time : 4.7 Hours A/C - Add : .2 Hours To Replace Crankshaft Gear - Add: .1 Hour Automatic Transmission (1987 only) - Add: .1 Hour Locking Wheel Covers and/or Nuts - Add: .1 Hour

For 1985-86 Labor Time : 5.1 Hours A/C - Add : .2 Hour To Replace Crankshaft Gear - Add: .1 Hour Automatic Transmission - Add: .1 Hour Locking Wheel Covers and/or Nuts - Add: .1 Hour

P-CAR SERVICE PROCEDURE

Tools Required:

J28467-A Engine Support Fixture J28467-60 Support Foot (GT Fastback Only) J24420-B Cam Gear Removal Tool J25033-B Cam Gear Installation Tool J34065 Parking Brake Cable Retainer Compressor J34995 Crankshaft Front Cover Oil Seal Installer J8001 Universal Dial Indicator w/Magnetic Base.

Remove or Disconnect

1. Rear compartment lid and "battery-side" cover.

IMPORTANT! DO NOT REMOVE THE TORSION ROD RETAINING BOLTS.

2. Negative battery cable. 3. Left side cover and mounting bracket. 4. Accessory drive belt(s). 5. Upper engine torque strut. 6. Air cleaner assembly. 7. Braided body ground strap - below right hinge of rear compartment lid. 8. Trim piece on battery side. 9. Install engine support fixture - J28467-A per Service Manual. 10. Raise vehicle. 11. Both rear wheels. 12. Brakeline-to-body brackets (both sides). 13. Retaining bolt from right rear brakeline junction block. 14. Inner fender well and splash shield (right side). 15. Push pins (3) from left rear splash shield. 16. Rear suspension strut bolts - mark struts for realignment. See Section 3D in Service Manual. 17. Drain coolant partially. 18. Timing pointer plate (as applicable). 19. Drain engine oil (remove oil filter). 20. Starter - let hang. 21. Flywheel/flexplate cover. 22. Crankshaft pulley (have assistant hold flywheel). 23. Parking brake cable through cradle - J34065. 24. Front frame (cradle) bolts. 25. Rear frame (cradle) bolts 26. Lower vehicle. 27. Lower engine assembly with engine support fixture. 28. Heater hose from intake manifold. 29. Belt tensioner (where applicable). 30. Raise vehicle. 31. Timing gear cover - do not distort.

Clean - Timing gear cover and engine sealing surfaces.

32. Align crankshaft/camshaft timing marks on gears. 33. Drill and tap hole on the camshaft centerline (8mm drill, 12.7mm(.5") deep.

CAUTION:

WEAR SAFETY GLASSES TO AVOID EYE DAMAGE. USE CARE WHEN DRILLING AND TAPPING CAM GEAR TO AVOID DAMAGE TO THE CAMSHAFT.

IMPORTANT! COVER OIL PAN OPENING WITH RAGS TO PREVENT CHIPS FROM FALLING INTO PAN. 34. Tap the 8mm hole with a 3/8-16-NC bottoming tap.

IMPORTANT! AVOID BUILD-UP OF CHIPS. BACK OUT THE TAP EVERY FEW TURNS AND REMOVE CHIPS.

35. Center punch and drill (2) 3mm pilot holes in the metal hub of the cam gear (180 degrees apart).

IMPORTANT! USE CARE TO AVOID DRILL WANDER THAT COULD DAMAGE CAMSHAFT.

36. Enlarge pilot holes with 5.5mm drill; 6.35mm(.25"). 37. Tap 5.5mm holes with 1/4-28-NF bottoming tap. 38. Drill a hole no larger than lmm (.040 in.) in the front oil gallery plug. This provides improved lubrication to the timing gears.

Clean - Oil pan of debris.

39. Cam gear with J24420-B - do not move cam or crank.

Inspect - Thrust plate for scuffing and/or grooving. If evident, install new thrust plate, spacer ring, and key. Thrust plate-to-block bolts torque - 10 Nm. (90 in. lb).

IMPORTANT! LUBRICATE FRONT THRUST PLATE SURFACE WITH CLEAN ENGINE OIL

Install or Connect

1. Cam gear using J25033-B - align timing marks.

Measure - Camshaft end play using dial indicator - J8001 or equivalent. Push cam gear onto camshaft until camshaft end play is in the range of .0015 in. to .0050 in. (.04mm to .13mm).

2. J34995 into front cover - lubricate seal lip with clean engine oil. 3. Apply RTV sealant to timing gear cover sealing surfaces. 4. Timing gear cover to engine. 5. Lower vehicle. 6. Raise engine with engine support fixture. 7. Install cradle bolts - finger-tight. 8. Remove engine support fixture. 9. Heater hose. 10. Belt tensioner (where applicable).

Clean - Tensioner and block sealing surfaces. Do not remove molded seal ring. Apply RTV aroung molded seal.

11. Raise vehicle.

12. Tighten front cradle bolts. 13. Tighten rear cradle bolts. 14. Crank pulley and bolt - have assistant hold flywheel. 15. Parking brake cable - J34065. 16. Flywheel/flexplate cover and bolts. 17. Starter and bolts

IMPORTANT: REPLACE ANY SHIMS REMOVED.

18. Left rear splash shield. 19. Inner fender well and splash shield - right side. 20. Brakeline-to-body brackets. 21. Rear suspension strut bolts.

IMPORTANT! ALIGN TO MARKS PREVIOUSLY SCRIBED.

22. Right rear brakeline junction block. 23. Rear wheels. 24. Lower vehicle. 25. Upper engine torque strut. 24. Lower vehicle. 25. Upper engine torque strut.

IMPORTANT! SEE SECTION 6A1.

26. Body ground strap. 27. Left side cover and mounting bracket. 28. Timing pointer plate (as applicable). 29. Accessory drive belt(s). 30. Air cleaner assembly. 31. Trim piece on battery side. 32. Engine oil (replace filter). 33. Engine coolant. 34. Negative battery cable. 35. Rear compartment lid and battery side cover. 36. Set rear end toe-in and adjust if necessary.

Inspect - For oil and coolant leaks with engine running at operating temperature. - For proper completion of repairs.

Labor Operation Number: J0840

For 1987-88 Labor Time : 5.6 Hours To Replace Crankshaft Gear - Add: .1 Hour Locking Wheel Covers and/or Nuts - Add: .2 Hour

For 1984-86 Labor Time : 5.8 Hours A/C - Add : .1 Hour To Replace Crankshaft Gear - Add: .1 Hour Locking Wheel Covers and/or Nuts - Add: .2 Hour

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.