For 1990-2009 cars

# SERVICE MANUAL UPDATE CAMSHAFT GEAR REPLACEMENT

#### MODELS AFFECTED: 1989 SKYLARKS WITH 2.5L (VIN CODE U)

SERVICE MANUAL UPDATE

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

#### IMPORTANT: SEE APPROPRIATE SERVICE MANUAL SECTION FOR FASTENER TORQUE SPECIFICATIONS.

#### 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. Body ground strap.

5. Front end sheet metal diagonal brace (R.H.).

6. Install engine support fixture - J28467-A per Service Manual.

7. Upper front engine mount to body bolts (2).

8. Raise vehicle.

9. Right front wheel.

10. Right front brakeline-to-body bracket.

11. Right front wheelhouse engine splash shield.

12. Flywheel/flexplate cover.

13. Crankshaft pulley (have assistant hold flywheel).

14. Rear engine mount to bracket nuts and mount thru bolts.

15. Rear transaxle strut.

16. Lower front engine mount to body bolt (leave mount attached to engine).

17. Retaining bolts from right side front suspension support (6).

18. Retaining bolts from left side front suspension support (6).

19. Drain engine oil (remove oil filter).

20. Lower vehicle.

21. Transaxle mount thru bolt.

22. Lower engine/transaxle assembly with engine support fixture.

23. Raise vehicle.

24. Front cover - do not distort.

Clean

- Front cover and engine sealing surfaces.

25. Align crankshaft/camshaft timing marks on gears.

26. Drill hole on the camshaft centerline (8mm drill, 1/2 inch deep).

#### CAUTION:

WEAR SAFETY GLASSES TO AVOID EYE DAMAGE.

#### IMPORTANT: USE CARE WHEN DRILLING AND TAPPING C M GEAR TO AVOID D W GE TO THE CAMSHAFT.

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

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

#### IMPORTANT: AVOID BUILDUP OF CHIPS. BACK OUT THE TAP EVERY FEW TURNS AND REMOVE CHIPS.

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

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

29. Enlarge pilot holes with 5.5mm drill; 1/4 inch deep.

30. Tap 5.5mm holes with 1/4-28-NF bottoming tap.

31. 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.

32. 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 N. (90 lb in).

#### 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 until camshaft end play is in the range of .0015 in. to .0050 in. (.04mm to .13mm).

2. Front cover seal using J34995 - lubricate seal lip with clean engine oil.

3. Apply RTV sealant to timing gear cover sealing surfaces.

4. Front 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 (with 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.

23. Power steering pump mount bolts to engine.

24. Accessory drive belts.

25. Front end sheet metal diagonal brace (R.H.)

26. Body ground strap.

27. Negative battery cable.

28. 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.

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.