Camshaft and Bearings Cleaning and Inspection

Tools Required 

J 7872  Magnetic Base Dial Indicator

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 retainer plate for damage.
4. Inspect the camshaft for the following conditions:
   • Camshaft bearing journals (1) that are:
     • Worn
     • Scored
     • Damaged
   • Worn camshaft lobes (2)
   • Damaged sprocket bolt threads (3)
   • Damaged sprocket pin (4)
   Fig 1: Camshaft Inspection Areas

   Courtesy of GENERAL MOTORS CORP.
5. Measure the camshaft journals with a micrometer. Refer to Engine Mechanical Specifications .
6. Measure for excessive camshaft runout using J 7872  .
   1. 6.1. Mount the camshaft in a suitable fixture.
   2. 6.2. Use the J 7872  in order to measure for a bent camshaft. Refer to Engine Mechanical Specifications .
7. Replace the camshaft if runout exceeds specifications.
   Fig 2: Measuring Camshaft Runout

   Courtesy of GENERAL MOTORS CORP.
8. Inspect the camshaft bearings, 1-5, for serviceability.
9. Replace the camshaft bearings if necessary. Refer to Camshaft Bearing Removal  and Camshaft Bearing Installation .
   Fig 3: Camshaft Bearing Bore

   Courtesy of GENERAL MOTORS CORP.