Camshaft Measurement

WARNING: This page is about a different variant/trim than selected.

Fig 1: Supporting Camshaft In Fixture

Courtesy of GENERAL MOTORS CORP.

Fig 2: Measuring Camshaft Journals

Courtesy of GENERAL MOTORS CORP.

Measure the camshaft journals for diameter and out-of-round using an outside micrometer. Refer to Engine Mechanical Specifications .
- If the diameter is smaller than specifications, replace the camshaft.
- If the out-of-round exceeds specifications, replace the camshaft.

Fig 3: Checking Camshaft Runout With J 7872

Courtesy of GENERAL MOTORS CORP.

Measure the camshaft runout using the J 7872 . See Special Tools . Refer to Engine Mechanical Specifications .

Fig 4: Measuring Camshaft Thrust

Courtesy of GENERAL MOTORS CORP.

Measure the camshaft thrust width for wear using a depth micrometer. Refer to Engine Mechanical Specifications .

Fig 5: Identifying J 7872

Courtesy of GENERAL MOTORS CORP.

Measure the camshaft thrust wall surface for runout using J 7872 . See Special Tools . Refer to Engine Mechanical Specifications .
If the camshaft is damaged or worn beyond specifications, replace the camshaft. No machining of the camshaft is allowed.

Fig 6: Measuring Camshaft Lobes For Wear

Courtesy of GENERAL MOTORS CORP.

Fig 7: Identifying Camshaft Lobe Dimensions

Courtesy of GENERAL MOTORS CORP.

Place the J 7872 with the indicator tip on the base circle (1) of the camshaft lobe. See Special Tools .
1. Place the J 7872 at zero. See Special Tools .
2. Rotate the camshaft until the indicator tip is at the highest point (3) on the lobe. This reading is the lift of the camshaft lobe. Refer to Engine Mechanical Specifications .
3. If the indicated measurement is significantly lower than these specifications, replace the camshaft or engine performance will be reduced.