GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 8092 Driver Handle
    • J 36996 Balance Shaft Installer
    • J 45059 Angle Meter

Removal Procedure


    Object Number: 9847  Size: SH
  1. Remove the lifter pushrod guide. Refer to Valve Lifter Replacement.
  2. Remove the timing chain and camshaft sprocket. Refer to Camshaft Timing Chain, Sprocket, and Tensioner Replacement.
  3. Remove the balance shaft drive gear.

  4. Object Number: 5136  Size: SH
  5. Remove the balance shaft driven gear bolt.
  6. 4.1. Use a wrench in order to secure the balance shaft.

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

    4.2. Remove the balance shaft bolt.
    4.3. Remove the wrench from the balance shaft.
  7. Remove the balance shaft driven gear.

  8. Object Number: 188031  Size: SH
  9. Remove the balance shaft retainer bolts and retainer.

  10. Object Number: 5139  Size: SH

    Note: 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.

  11. Use a soft-faced hammer in order to remove the balance shaft from the engine block.
  12. Clean and inspect the balance shaft, if necessary. Refer to Balance Shaft Cleaning and Inspection.

Installation Procedure

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


    Object Number: 869750  Size: SH
  1. Apply clean engine oil to the balance shaft front bearing.
  2. Using J 36996 and J 8092 , install the balance shaft.
  3. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 188031  Size: SH
  4. Install the balance shaft retainer and bolts and tighten to 12 N·m (106 lb in).

  5. Object Number: 5136  Size: SH
  6. Install the balance shaft driven gear.
  7. If reusing the fastener, apply threadlocker to the threads of the balance shaft driven gear bolt. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  8. Install the balance shaft driven gear bolt.
  9. 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 20 N·m (15 lb ft).
             6.2.2. Tighten the bolt a final pass an additional 35 degrees using J 45059
  10. Remove the wrench from the balance shaft.
  11. 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.

  12. Object Number: 9847  Size: SH
  13. Install the balance shaft drive gear. DO NOT install the camshaft sprocket bolts at this time.

  14. Object Number: 9848  Size: SH
  15. Rotate the camshaft so that the timing mark on the balance shaft drive gear is in the 12 o'clock position.

  16. Object Number: 9847  Size: SH
  17. Remove the balance shaft drive gear.

  18. Object Number: 9849  Size: SH
  19. Rotate the balance shaft so that the timing mark on the balance shaft driven gear is in the 6 o'clock position.

  20. Object Number: 5144  Size: SH
  21. Position the balance shaft drive gear onto the engine camshaft.
  22. Look to ensure that the balance shaft drive gear and the balance shaft driven gear timing marks are aligned.
  23. Install the timing chain and the camshaft sprocket. Refer to Camshaft Timing Chain, Sprocket, and Tensioner Replacement.
  24. Install the valve lifter pushrod guide. Refer to Valve Lifter Replacement.