Inspection Procedure
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Clean the components in solvent.
- Dry the components with compressed air.
- Inspect the camshaft bearing journals (1) for scoring or excessive wear.
- Inspect the camshaft valve lifter lobes (2) for scoring or excessive wear.
- Inspect the threaded bolt hole (3) in the front of the camshaft for damaged threads or debris.
- Inspect the camshaft sprocket pin (204) for damage.
- Inspect the camshaft retainer plate for wear or a damaged sealing gasket.
If the camshaft retainer plate sealing gasket is not cut or damaged, it may be used again.
- Inspect the camshaft bearings for the following:
- Excessive wear or scoring. The presence of the copper color bearing material should be considered normal and not a guideline for bearing replacement. Measure the bearing inside diameter (ID) as required for an over-sized condition. Refer to Engine Mechanical Specifications (RPO LY5 VIN J)Engine Mechanical Specifications (RPO LC9 VIN 3)Engine Mechanical Specifications (RPO LY2 VIN C)Engine Mechanical Specifications (RPO LH6 VIN M)Engine Mechanical Specifications (RPO LMG VIN 0)Engine Mechanical Specifications (RPO LY6 VIN K)Engine Mechanical Specifications (RPO L76 VIN Y)Engine Mechanical Specifications (RPO L9H) .
- Proper fit in the engine block. Camshaft bearings have an interference fit to the engine block and should not be loose in the engine block bearing bores.
- Oil lubrication hole plugged by debris.
Bearings with excessive wear or scoring must be replaced.
- Using a micrometer, measure the camshaft journals for wear and out-of-round.
- If the camshaft bearing journals are greater than 0.025 mm (0.001 in) out-of-round, replace the camshaft.
- If the camshaft bearing journal diameter is less than 54.99 mm (2.164 in), replace the camshaft.
- Using a micrometer, measure the camshaft lobes for wear. Refer to Engine Mechanical Specifications (RPO LY5 VIN J) , Engine Mechanical Specifications (RPO LC9 VIN 3) , Engine Mechanical Specifications (RPO LY2 VIN C) , Engine Mechanical Specifications (RPO LH6 VIN M) , Engine Mechanical Specifications (RPO LMG VIN 0) , Engine Mechanical Specifications (RPO LY6 VIN K) , Engine Mechanical Specifications (RPO L76 VIN Y) or Engine Mechanical Specifications (RPO L9H) .
- Measure the camshaft runout.
- Mount the camshaft in wooden V-blocks or between centers on a fixture.
- Using the J 7872: set , measure the runout of the intermediate camshaft bearing journals.
- If camshaft runout exceeds 0.05 mm (0.002 in), the camshaft is bent and should be replaced.
WARNING:
Refer to Safety Glasses and Compressed Air Warning
.