GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Remove the engine front cover. Refer to Engine Front Cover Replacement .

  2. Object Number: 4899  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.

  3. Install a bolt in the end of the crankshaft.
  4. 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.

  5. Rotate the crankshaft until the number 1 piston is at Top Dead Center (TDC) of the compression stroke.
  6. Make sure the camshaft sprocket alignment mark, which is an 8 mm (0.31  in) hole, and the stamped circle in the crankshaft sprocket align with the tabs on the timing chain tensioner.

  7. Remove the timing chain and sprockets. Refer to Timing Chain and Sprockets Removal .
  8. Clean and inspect the timing chain and sprockets. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection .

Installation Procedure


    Object Number: 4899  Size: SH

    Important: If any of the camshaft drive components are being replaced to correct a noise condition, replace all of the components in the camshaft drive system.

  1. Install the timing chain and the sprockets. Refer to Timing Chain and Sprockets Installation .
  2. Remove the bolt from the end of the crankshaft.
  3. Install the engine front cover. Refer to Engine Front Cover Replacement .