GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 1403675  Size: SH
  1. Remove the crankshaft rear oil seal housing. Refer to Crankshaft Rear Oil Seal and Housing Replacement.
  2. Note: Every 11-crankshaft rotations, 3 of the 5 dark links on the timing chain will line up with the timing marks.

  3. Rotate the crankshaft until the correct timing chain and timing marks align:
  4. • The left-hand balance shaft sprocket timing mark (1) is at the 12:00 position.
    • The right-hand balance shaft sprocket timing mark (2) is at the 2:30 position.
    • The crankshaft sprocket timing mark (3) is at the 4:30 position.
    • The 3 timing marks (1-3) on the sprockets line up with a dark link on the chain.

    Object Number: 953994  Size: SH
  5. Remove the balance shaft chain tensioner bolts.
  6. Remove the balance shaft chain tensioner.

Installation Procedure


    Object Number: 240843  Size: SH
  1. Collapse the balance shaft chain tensioner using the following procedure:
  2. 1.1. Rotate the ratchet release lever (2) clockwise and hold.
    1.2. Collapse the tensioner shoe (1) and hold.
    1.3. Release the ratchet lever.
  3. Slowly release the pressure on the shoe, until the ratchet lever moves to the first detent and a "click" is heard and felt.

  4. Object Number: 52989  Size: SH
  5. Insert a pin through the hole in the release lever in order to lock the tensioner shoe in the collapsed position.
  6. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 953994  Size: SH

    Note: Ensure the tensioner release lever is facing outward.

  7. Install the balance shaft chain tensioner and bolts and tighten the bolts to 10 N·m (89 lb in).
  8. Remove the pin holding the tensioner to tighten any slack in the balance shaft drive chain.

  9. Object Number: 1403675  Size: SH
  10. Verify the correct timing chain and timing mark alignments:
  11. • The left-hand balance shaft sprocket timing mark (1) is at the 12:00 position.
    • The right-hand balance shaft sprocket timing mark (2) is at the 2:30 position.
    • The crankshaft sprocket timing mark (3) is at the 4:30 position.
    • The 3 timing marks (1-3) on the sprockets line up with a dark link on the chain.
  12. Install the crankshaft rear oil seal housing. Refer to Crankshaft Rear Oil Seal and Housing Replacement.