Tools Required

1. Recover the refrigerant. Refer to SECTION 1B.
2. Remove the radiator with the A/C condenser. Refer to Radiator Replacement in Engine Cooling.
3. Remove the rear oil seal housing.
4. Remove the upper intake manifold. Refer to Intake Manifold Replacement .
5. Remove the lower intake manifold. Refer to Intake Manifold Replacement .
6. Remove the valve lifter guide retainer.
7. Remove the engine front cover. Refer to Engine Front Cover Replacement .



8. Remove the balance shaft gear bolt.
9. Remove the camshaft sprocket.
10. Remove the balance shaft driven gear.
11. Remove the balance shaft retainer bolts.
12. Remove the balance shaft retainer.
13. Remove the balance shaft gear.

Important: The balance shaft, front bearing, and rear bushing are serviced as a complete package. Use only the correct tools for bearing, bushing, and shaft installation.

14. Remove the balance shaft. Use the J 6125-1B .
15. Remove the balance shaft rear bushing. Use J 36995-5, J 36995-3A and J 36995-2A.
16. Inspect the balance shaft gear and camshaft gear for nicks and burrs.

1. Dip the balance shaft rear bushing in clean engine oil before installation.

Important: Install the bushing with the lubrication hole facing the flywheel side. The J 36995 assures that the rear bushing is installed in the engine block to the correct depth. The bushing will be installed properly when the J 36995 fully contacts the balance shaft bore or the cylinder block transaxle mounting flange.




2. Install the balance shaft rear bushing. Use the J 36995 .
3. Remove the J 36995 assembly.
4. Apply clean engine oil to the balance shaft inner race and front balance shaft bearing before installation.



5. Install the balance shaft. Use the J 36996 and the J 36996 .
6. Temporarily install the balance shaft retainer.
7. Temporarily install the balance shaft retainer bolts.
8. Install the balance shaft gear.
9. Apply thread lock compound GM P/N 12345493 or equivalent to the bolt threads.
10. Install the balance shaft gear bolt.

Tighten
Tighten the balance shaft gear bolt to 22 N·m (16 lb ft). Use the J 36660-A in order to rotate an additional 70 degrees.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.




11. Measure the balance shaft end play.



12. Measure the front balance shaft radial play. Refer to specifications.
13. Measure the rear balance shaft radial play. Refer to specifications.



14. Turn the camshaft, with the camshaft sprocket temporarily installed, so that the timing mark is straight down.
15. With the camshaft sprocket and the balance shaft driven gear removed, turn the balance shaft so that the timing mark on the balance shaft gear points straight down.
16. Align the marks on the balance shaft gear and the balance shaft driven gear by turning the balance shaft.
17. Install the balance shaft driven gear.
18. Turn the crankshaft so that the number one piston is at top dead center.
19. Install the camshaft sprocket. Refer to Camshaft Replacement.
20. Install the timing chain.



21. Measure the balance shaft gear lash at four places, every 1/4 turn. The lash should be 0.050 to 0.127 mm (0.002 to 0.005 in).
22. Install the balance shaft retainer.
23. Install the balance shaft retainer bolts.

Tighten
Tighten the balance shaft retainer bolts to 30 N·m (22 lb ft).

24. Install the engine front cover. Refer to Engine Front Cover Replacement .
25. Install the lifter guide retainer.
26. Install the lower intake manifold. Refer to Intake Manifold Replacement .
27. Install the upper intake manifold. Refer to Intake Manifold Replacement .
28. Install the rear oil seal housing.
29. Install the radiator with the A/C condenser. Refer to Radiator Replacement in Engine Cooling.
30. Charge the A/C system. Refer to SECTION 1B.