GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • EN 46330 Timing Chain Tensioner Retaining Pin
    • J 41478 Crankshaft Front Oil Seal Installer
    • J 41665 Crankshaft Balancer and Sprocket Installer
    • J 45059 Angle Meter

Installation Procedure


    Object Number: 1954159  Size: SH
  1. Install the crankshaft sprocket key (1) if removed.

  2. Object Number: 1954143  Size: SH
  3. Tap the key (1) into the key way until both ends of the key bottom onto the crankshaft (2).

  4. Object Number: 1954158  Size: SH
  5. Install the crankshaft sprocket (1) onto the front of the crankshaft. Align the crankshaft key with the crankshaft sprocket key way.

  6. Object Number: 1954145  Size: SH
  7. Use the J 41478 (1) and the J 41665 (2) in order to install the crankshaft sprocket. Install the sprocket onto the crankshaft until fully seated against the crankshaft flange.

  8. Object Number: 1954146  Size: SH
  9. Compress the timing chain tensioner guide (2) and install the EN 46330  (1).

  10. Object Number: 1954147  Size: SH
  11. Install the timing chain tensioner (2) and bolts (1).
  12. Tighten
    Tighten the bolts to 25 N·m (18 lb ft).


    Object Number: 1954149  Size: SH
  13. Position the camshaft sprocket (2) so the timing mark is in the 6 o'clock position.
  14. Important: The sprocket teeth and timing chain must mesh.

    Important: The camshaft and the crankshaft sprocket alignment marks MUST be aligned correctly.

  15. Install the camshaft sprocket (2), timing chain (3) and bolt (1).

  16. Object Number: 1954161  Size: SH
  17. Inspect the sprockets for correct alignment. The mark on the camshaft sprocket (1) should be located in the 6 o'clock position and the mark on the crankshaft sprocket (2) should be located in the 12 o'clock position.

  18. Object Number: 1954151  Size: SH
  19. Remove the EN 46330  (1).

  20. Object Number: 1954152  Size: SH
  21. Tighten the camshaft sprocket bolt.
  22. Tighten
    Tighten a first pass to 75 N·m (55 lb ft).

    Tighten an additional 50 degrees using J 45059 .