GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Tools Required

    • J 8433 Universal Puller Bridge
    • J 38611 Crankshaft Sprocket Puller Legs and Center
    • J 38612 Crankshaft Sprocket Installer
  1. Remove the front cover. Refer to Engine Front Cover Replacement .
  2. Retract the timing chain tensioner.
  3. Remove the timing chain tensioner bolts.
  4. Raise the vehicle. Suitably support the vehicle. Refer to General Information.

  5. Object Number: 57237  Size: SH
  6. Remove the timing chain, the crankshaft sprocket, and the intermediate shaft sprocket as an assembly, using the J 8433 and the J 38611 on the crankshaft sprocket.
  7. If the intermediate gear does not slide off easily with the timing chain, rotate the crankshaft back and forth in order to help loosen the tight fit.
  8. Remove the timing chain tensioner.
  9. Inspect the crankshaft alignment key for burrs or marks that could affect the assembly.

Installation Procedure

Tools Required

J 38612 Crankshaft Sprocket Installer


    Object Number: 57237  Size: SH
  1. Make sure that the crankshaft key is installed and fully seated, and that the chain tensioner is installed and the blade retracted.
  2. Slip both sprockets and the chain over the proper shaft and engage the slot in the key. The intermediate shaft may move against the rear cover. Slide the sprocket and chain on the shafts maintaining the parallel alignment of the sprockets.
  3. Make sure that the rubber and tension blade of the tensioner does not become caught, misaligned, or dislodged.
  4. The larger chamfer and the counterbore of the crankshaft sprocket are installed toward the crankshaft. The intermediate sprocket spline sockets are installed away from the case.
  5. The crankshaft sprocket must be pressed on for the final 8 mm (0.31 in) to the seated position using the J 38612 .
  6. Verify that the timing is maintained.
  7. Pull the retaining pin from the tensioner.
  8. Install the front cover. Refer to Engine Front Cover Replacement .