GM Service Manual Online
For 1990-2009 cars only
  1. Remove the engine front cover. Refer to Engine Front Cover Removal .
  2. Remove the left secondary timing chain. Refer to Secondary Timing Chain Removal - Left Side .
  3. Remove the primary timing chain. Refer to Primary Timing Chain Removal .

  4. Object Number: 648347  Size: SH
  5. Remove the 2 bolts and the timing chain guide (1).

  6. Object Number: 648133  Size: SH
  7. Remove the camshaft bearing cap bolts in the proper sequence.
  8. Remove the camshaft bearing caps.
  9. Remove the camshafts and secondary timing chain as a set.

  10. Object Number: 648349  Size: SH
  11. Remove the 2 bolts and the timing chain tensioner (1).