Balance Shaft: Service and Repair

Balance Shaft Replacement

Tools Required
* J8092 Universal Driver Handle
* J36660-A Torque Angle Meter
* J36996 Balance Shaft Installer

Removal Procedure
1. Remove the radiator.
2. Remove the Air Conditioning (A/C) condenser.
3. Remove the lifter pushrod guide.
4. Remove the timing chain and camshaft sprocket.





5. Remove the balance shaft drive gear.





6. Remove the balance shaft driven gear bolt
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.





8. Remove the balance shaft retainer bolts and 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, if necessary.

Installation Procedure

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

1. Apply clean engine oil to the balance shaft front bearing.





2. Using J36996 and J8092, install the balance shaft.





Notice: Refer to Fastener Notice in Service Precautions.
Fastener Notice


3. Install the balance shaft retainer and bolts.
Tighten the bolts to 12 Nm (106 inch lbs.).





4. Install the balance shaft driven gear.
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.
6.2.1. Tighten the bolt a first pass to 20Nm(15ft. lbs.).
6.2.2. Tighten the bolt a final pass using the J36660-A 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 camshaft so that the timing mark 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.

Balance Shaft Drive Gear And Balance Shaft Driven Gear Timing Marks (4.3L):

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.
16. Install the valve lifter pushrod guide.
17. Install the A/C condenser.
18. Install the radiator.