Chevrolet Silverado / GMC Sierra. Service manual — part 155

Fig. 520: Camshaft Inspection Areas
Courtesy of GENERAL MOTORS CORP.

6. Inspect the engine camshaft for the following:

Worn, scored, or damaged bearing journals (1)

Worn engine camshaft lobes (2)

Damaged bolt hole threads (3)

Damaged camshaft sprocket locator pin (4)

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

Fig. 521: Measuring Engine Camshaft Journals
Courtesy of GENERAL MOTORS CORP.

7. Measure the engine camshaft journals with a micrometer.

If the camshaft journals are more than 0.025 mm (0.0010 in) out-of-round, then replace the
engine camshaft.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

Fig. 522: Measuring For Bent Engine Camshaft Or Excessive Engine Camshaft
Runout
Courtesy of GENERAL MOTORS CORP.

8. Measure for a bent engine camshaft or excessive engine camshaft runout using the J 7872 .

1. Mount the engine camshaft in a suitable stand between centers.

2. Use the J 7872 in order to check the intermediate engine camshaft journals.

If the runout exceeds 0.065 mm (0.0026 in), the engine camshaft is bent and must be
replaced.

9. Measure the engine camshaft lobe lift using the J 7872 .

1. Place the engine camshaft on the V-blocks.

2. Use the J 7872 in order to measure the engine camshaft lobe lift.

10. Replace the engine camshaft if the engine camshaft lobe lift is not within specifications.

Refer to Engine Mechanical Specifications.

CAMSHAFT BEARING REMOVAL

Tools Required

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado

J 33049 Camshaft Bearing Service Kit. See Special Tools.

Removal

Fig. 523: View Of J 33049 Camshaft Bearing Service Kit Components
Courtesy of GENERAL MOTORS CORP.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.3L - Sierra & Silverado