GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 5825-A Crankshaft Gear Remover
    • J 5590 Pinion Bearing Race Installer - Rear

Removal Procedure


    Object Number: 45986  Size: SH
  1. Remove the engine front cover. Refer to Engine Front Cover Replacement .
  2. Remove the crankshaft position sensor reluctor ring.

  3. Object Number: 480575  Size: SH

    Notice: In order to rotate the engine install a bolt with the same threads as the crankshaft, but do not use the crankshaft balancer bolt or a bolt longer than 1 inch, in the crankshaft. Failing to do so will cause damage to the bolt threads and the crankshaft threaded hole when removing the bolt.

  4. Install a 7/16-20 x 1 inch bolt into the end of the crankshaft.
  5. Notice: Align the timing marks before removing the timing chain. If it is necessary to turn either the camshaft or the crankshaft with the timing chain removed, loosen or remove the valve rocker arms. Turning either the crankshaft or camshaft with the timing chain removed may cause the pistons to contact the valves, resulting in damage.

  6. Rotate the crankshaft until:
  7. 4.1. The timing marks on both sprockets line up.
    4.2. The number four cylinder is at top dead center (TDC) of the compression stroke.

    Object Number: 480544  Size: SH
  8. Remove the camshaft sprocket bolts.

  9. Object Number: 480546  Size: SH
  10. Remove the camshaft sprocket and the camshaft timing chain.

  11. Object Number: 480547  Size: SH

    Caution: Wear safety glasses in order to avoid eye damage.

  12. Remove the crankshaft sprocket using the J 5825-A .

  13. Object Number: 387761  Size: SH
  14. Remove the crankshaft balancer key.
  15. Clean and inspect the timing chain and sprockets. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection in Engine Unit Repair.

Installation Procedure


    Object Number: 387766  Size: SH
  1. Install the crankshaft balancer key into the crankshaft keyway.
  2. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.


    Object Number: 480574  Size: SH
  3. Align the keyway of the crankshaft sprocket with the crankshaft balancer key.
  4. Caution: Wear safety glasses in order to avoid eye damage.

  5. Use the J 5590 in order to install the crankshaft sprocket.

  6. Object Number: 480546  Size: SH
  7. Rotate the crankshaft until the crankshaft sprocket alignment mark is at the 12 o'clock position.
  8. Important: Install the camshaft sprocket with the alignment mark at the 6 o'clock position.

  9. Install the camshaft sprocket and the camshaft timing chain.

  10. Object Number: 480575  Size: SH
  11. Look to ensure that the crankshaft sprocket is aligned at the 12 o'clock position and camshaft sprocket is aligned at the 6 o'clock position.

  12. Object Number: 480544  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Important:  Do not use a hammer to install the camshaft sprocket onto the camshaft. To do so may dislodge the expansion cup plug (camshaft rear bearing hole).

  13. Install camshaft sprocket bolts.
  14. Tighten
    Tighten the camshaft sprocket bolts to 25 N·m (18 lb ft).


    Object Number: 480576  Size: SH
  15. Install the crankshaft position sensor reluctor ring.
  16. 8.1. Align the keyway on the crankshaft position sensor reluctor ring with the crankshaft balancer key in the crankshaft.
    8.2. Use the in order to push the crankshaft position sensor reluctor ring onto the crankshaft until completely seated against the crankshaft sprocket.
    8.3. Remove the bolt from the end of the crankshaft.
    8.4. Install the engine front cover. Refer to Engine Front Cover Replacement .