GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 7872 Magnetic Base Dial Indicator

  1. Using a soft cloth and clean solvent, clean the camshaft. Do not scratch the camshaft bearing journals or lobes.
  2. Caution: Wear safety glasses in order to avoid eye damage.

  3. Using compressed air, dry the camshaft.
  4. Using a soft cloth and clean solvent, clean the camshaft bearing inserts. Do not scratch the camshaft bearing inserts.
  5. Inspect the camshaft for cracks using the Magnaflux Spot-check dye method or the equivalent.

  6. Object Number: 188095  Size: SH
  7. Inspect the camshaft for the following conditions:
  8. • Scoring (1)
    • Nicks (1)
    • Worn camshaft lobes (2)
    • Damaged sprocket bolt threads (3)
    • Damaged sprocket pin (4)
    • Damage caused by lack of lubrication
  9. Inspect the camshaft bearing inserts for the following conditions:
  10. • Scoring
    • Nicks
    • Damage caused by lack of lubrication

    Object Number: 520254  Size: SH
  11. Inspect the camshaft retainer plate for damage.

  12. Object Number: 35212  Size: SH
  13. Using a suitable measuring device, measure the camshaft journal diameter and taper in several places, approximately 90 degrees apart. Refer to Engine Mechanical Specifications .
  14. Measure for a bent camshaft or excessive camshaft runout using J 7872 .
  15. 9.1. Mount the camshaft in V-blocks at camshaft journals one and five.
    9.2. Using theJ 7872 Magnetic Base Dial Indicator, measure camshaft journal runout at camshaft journal three. Refer to Engine Mechanical Specifications .
  16. Replace the camshaft if runout exceeds specifications.