Tools Required

1. Remove the radiator. Refer to Radiator Replacement in Engine Cooling.
2. Remove the A/C condenser. Refer to Condenser Replacement in Heating, Ventilation and Air Conditioning.
3. Remove the valve lifter pushrod guide. Refer to Valve Lifter Replacement .
4. Remove the timing chain and camshaft sprockets. Refer to Camshaft Timing Chain, Sprocket, and Tensioner Replacement .



5. Remove the balance shaft drive gear.




Important: The balance shaft drive and balance shaft driven gears are serviced as a set. The set includes the balance shaft driven gear bolt.

6. Remove the balance shaft driven gear bolt from the balance shaft.

6.1.	Use a wrench in order to secure the balance shaft.

Place the wrench onto the balance shaft near to the balance shaft front bearing.

6.2.	Remove the balance shaft bolt.

6.3.	Remove the wrench from the balance shaft.

7. Remove the balance shaft driven gear from the balance shaft.



8. Remove the bolts and the balance shaft retainer.




Important: The balance shaft and the balance shaft front bearing are serviced only as a package. Do not remove the balance shaft front bearing from the balance shaft.

9. Use a soft-faced hammer in order to remove the balance shaft from the engine block.
10. Clean and inspect the balance shaft. Refer to Balance Shaft Cleaning and Inspection .

Important: The balance shaft and the balance shaft front bearing are serviced only as an assembly. Do not remove the balance shaft front bearing from the balance shaft.

1. Apply clean engine oil GM P/N 12345610 (Canadian P/N 993193) or equivalent to the balance shaft front bearing.
2. Use the J 36996 and the J 8092 in order to install the balance shaft.

Notice: Refer to Fastener Notice in the Preface section.




3. Install the balance shaft retainer and bolts.

Tighten
Tighten the bolts to 12 N·m (106 lb in).




4. Install the balance shaft driven gear onto the balance shaft.
5. If reusing the fastener, apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the threads of the balance shaft driven gear bolt.
6. Install the balance shaft driven gear bolt.

6.1.	Use a wrench to secure the balance shaft.

Place the wrench onto the balance shaft near to the balance shaft front bearing.

6.2.	Install the balance shaft driven gear bolt.

Tighten
Tighten the balance shaft driven gear bolt to 20 N·m (15 lb ft). Using the J 36660-A rotate the balance shaft driven gear bolt an additional 35 degrees.

7. Remove the wrench from the balance shaft.
8. Rotate the balance shaft by hand in order to ensure that there is clearance between the balance shaft and the valve lifter pushrod guide. If the balance shaft does not rotate freely, check to ensure that the retaining ring on the balance shaft front bearing is seated on the case.



9. Install the balance shaft drive gear. DO NOT install the camshaft sprocket bolts at this time.



10. Rotate the engine camshaft so that the timing mark on the balance shaft drive gear is in the 12 o'clock position.



11. Remove the balance shaft drive gear.



12. Rotate the balance shaft so that the timing mark on the balance shaft driven gear is in the 6 o'clock position.



13. Position the balance shaft drive gear onto the engine camshaft.
14. Look to ensure that the balance shaft drive gear and the balance shaft driven gear timing marks are aligned.
15. Install the timing chain and the camshaft sprocket. Refer to Camshaft Timing Chain, Sprocket, and Tensioner Replacement .
16. Install the engine front cover. Refer to Engine Front Cover Replacement .
17. Install the valve lifter pushrod guide. Refer to Valve Lifter Replacement .
18. Install the A/C condenser. Refer to Condenser Replacement in Heating, Ventilation and Air Conditioning.
19. Install the radiator. Refer to Radiator Replacement in Engine Cooling.