GM Service Manual Online
For 1990-2009 cars only

    Object Number: 412470  Size: SH
  1. Inspect the timing chain guides for cracking or wear.
  2. Replace the timing chain guides if wear exceeds 1.12 mm (0.045 in) depth on the chain guide surface.
  3. Inspect the timing chain tensioner shoe for wear.
  4. Replace the timing chain tensioner shoe if wear exceeds 1.12 mm (0.045 in) depth on the chain guide surface.
  5. Inspect the timing chain and sprockets for wear.
  6. Inspect the camshaft sprocket faces for signs of movement.
  7. Inspect the camshaft sprocket teeth and chain for signs of excessive wear, chipping, or seizure of the timing chain links.
  8. Inspect the oil nozzle body for collapse or cracks at the bolt boss. Discard and replace the oil nozzle body if it is damaged.
  9. Remove the old oil from the timing chain tensioner.
  10. Inspect the timing chain tensioner for the scoring or free movement.
  11. Inspect the timing chain washer and O-ring for damage. If damaged, replace the timing chain tensioner.