Tool Required

J 7872  Magnetic Base Dial Indicator. See Special Tools and Equipment .

1. Clean the camshaft in solvent.
CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.
2. Dry the camshaft with compressed air.
3. Inspect the camshaft for the following conditions:
   • Worn, scored, or damaged bearing journals
   • Worn camshaft lobes
   • Damaged sprocket pin
Fig 1: Measure Camshaft Journals With Micrometer
Courtesy of GENERAL MOTORS CORP.
4. Measure the camshaft journals with a micrometer 27.939-27.960 mm (1.099-1.101 in).
5. Measure for a bent camshaft or excessive camshaft runout using J 7872  . See Special Tools and Equipment .
   1. Mount the camshaft in V-blocks between centers.
   2. Use the J 7872  in order to measure for a bent camshaft. See Special Tools and Equipment . Radial runout 0.06 mm (0.0023 in).
6. Replace the camshaft if runout exceeds specifications.
7. Inspect the camshaft bearings and bearing cap surfaces for the following:
   • Wear
   • Scoring
   • Overheating from lack of lubrication
8. Inspect the bearing clearances with gaging plastic.

   Refer to Engine Mechanical Specifications (LY9)  or Engine Mechanical Specifications (LA3) .

9. Inspect the camshaft for excessive end play 0.038-0.051 mm (0.001-0.002 in) 0.04-0.144 mm (0.002-0.006 in).
10. The camshaft bearing surfaces are machined into the cylinder head and are not serviceable.