Camshaft and Bearings Cleaning and Inspection

WARNING: This page is about a different car, the 2003 Pontiac Montana, 2003 Oldsmobile Silhouette, and 2003 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required

J 7872 Magnetic Base Dial Indicator Set

Clean the camshaft with cleaning solvent.
CAUTION: Refer to CLEANING SOLVENT CAUTION in Cautions and Notices.
Inspect the camshaft for the following conditions:
- Scored camshaft bearing journals (1)
- Damaged camshaft lobes (2)
- Damaged camshaft sprocket locator pins (3)
- Damaged threads (4)
- Damage to the camshaft reluctor tooth (5)
Fig 1: Inspecting Camshaft
Courtesy of GENERAL MOTORS CORP.
Measure the camshaft journals using a micrometer.
If the camshaft journals are not within specifications, replace the camshaft.

Fig 2: Measuring Camshaft Journals Using Micrometer
Courtesy of GENERAL MOTORS CORP.
Measure the camshaft runout using the J 7872.
1. 4.1. Mount the camshaft in V-blocks between the centers.
2. 4.2. Use the J 7872 in order to measure the intermediate camshaft journal.
Measure the camshaft lobe lift using the J 7872.
1. 5.1. Lubricate the camshaft using
  GM P/N 12345501 (Canadian P/N 992704) or the equivalent.
2. 5.2. Set the camshaft on V-blocks.
3. 5.3. Use the J 7872 in order to measure the lobe lift.
If the runout or lobe lift is not within specifications, replace the camshaft.

Fig 3: Measuring Camshaft Runout Using J 7872
Courtesy of GENERAL MOTORS CORP.