GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 8433-1 Puller Bar
    • J 41558 Crankshaft Sprocket Remover
    • J 41665 Crankshaft Balancer and Sprocket Installer
    • J 41816-2 Crankshaft End Protector

Removal Procedure


    Object Number: 1528299  Size: SH
  1. Remove the oil pump. Refer to Oil Pump, Screen, and Crankshaft Oil Deflector Replacement.
  2. Notice: Do not turn the crankshaft assembly after the timing chain has been removed in order to prevent damage to the piston assemblies or the valves.

  3. Rotate the crankshaft until the timing marks on the crankshaft and the camshaft sprockets are aligned.
  4. Remove the camshaft sprocket bolts (1).
  5. Remove the camshaft sprocket (2) and timing chain (3).

  6. Object Number: 63189  Size: SH
  7. Use J 8433-1 , J 41816-2 and J 41558 in order to remove the crankshaft sprocket.

  8. Object Number: 156150  Size: SH
  9. Remove the crankshaft sprocket.

  10. Object Number: 156149  Size: SH
  11. Remove the crankshaft sprocket key, if required.
  12. Clean and inspect the timing chain and sprockets. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection.

Installation Procedure


    Object Number: 156149  Size: SH
  1. Install the key into the crankshaft keyway, if previously removed.

  2. Object Number: 490871  Size: SH
  3. Tap the key (1) into the keyway until both ends of the key bottom onto the crankshaft.

  4. Object Number: 156150  Size: SH
  5. Install the crankshaft sprocket onto the front of the crankshaft. Align the crankshaft key with the crankshaft sprocket keyway.

  6. Object Number: 63199  Size: SH
  7. Use J 41665 in order to install the crankshaft sprocket.
  8. Install the sprocket onto the crankshaft until fully seated against the crankshaft flange.

  9. Rotate the crankshaft sprocket until the alignment mark is in the 12 o'clock position.

  10. Object Number: 1528299  Size: SH

    Important: 

       • Properly locate the camshaft sprocket locating pin with the camshaft sprocket alignment hole.
       • The sprocket teeth and timing chain must mesh.
       • The camshaft and the crankshaft sprocket alignment marks MUST be aligned properly.
            Locate the camshaft sprocket alignment mark in the 6 o'clock position.

  11. Install the camshaft sprocket (2) and timing chain (3).
  12. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1528298  Size: SH
  13. If necessary, rotate the camshaft or crankshaft sprockets in order to align the timing marks.
  14. Install the camshaft sprocket bolts.
  15. Tighten
    Tighten the bolts to 35 N·m (26 lb ft).

  16. Install the oil pump. Refer to Oil Pump, Screen, and Crankshaft Oil Deflector Replacement.