Chevrolet Silverado / GMC Sierra. Service manual — part 2131

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 67: Measuring Camshaft Lobe Lift
Courtesy of GENERAL MOTORS CORP.

1. Using the J 8520 , measure camshaft lobe lift. See Special Tools .

2. Remove the valve rocker arms and bolts.

3. Install the dial indicator mounting stud into the valve rocker arm bolt hole.

4. Assemble the components of the J 8520 and position onto the stud. See Special Tools .

5. Position the shaft of the dial indicator onto the end of the pushrod.

6. Rotate the face of the dial indicator to zero.

7. Slowly rotate the crankshaft clockwise, until the dial indicator obtains its highest and lowest

readings.

8. Compare the total to specifications. Refer to Engine Mechanical Specifications (RPO

LY5 VIN J) or Engine Mechanical Specifications (RPO LC9 VIN 3) or Engine
Mechanical Specifications (RPO LY2 VIN C) or Engine Mechanical Specifications
(RPO LH6 VIN M) or Engine Mechanical Specifications (RPO LMG VIN 0) or
Engine Mechanical Specifications (RPO LY6 VIN K) or Engine Mechanical
Specifications (RPO L76 VIN Y) or Engine Mechanical Specifications (RPO L92
VIN 8) .

CAMSHAFT BEARING INSTALLATION

Tools Required

J 33049 Camshaft Bearing Service Set

Installation

IMPORTANT: Measuring camshaft lobe lift is a procedure used to

determine if the camshaft lobes have worn. This test is to be
performed prior to engine disassembly and with the camshaft
and valve train components installed in the engine.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

Fig. 68: Identifying Engine Block Camshaft Bearing Bores
Courtesy of GENERAL MOTORS CORP.

IMPORTANT: The engine block camshaft bearing bores are machined for 3

different outside diameter (OD) size bearings. Position 1 and
5 are the largest diameter bores. Position 3 is the smallest
diameter bore. Position 2 and 4 are the intermediate size
bores. The inside diameter (ID) for all camshaft bearings is
the same size.

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado

1. Measure the engine block camshaft bearing bores (1-5) in order to identify the correct OD

size bearing for each position. Refer to Engine Mechanical Specifications (RPO LY5
VIN J) or Engine Mechanical Specifications (RPO LC9 VIN 3) or Engine Mechanical
Specifications (RPO LY2 VIN C) or Engine Mechanical Specifications (RPO LH6
VIN M) or Engine Mechanical Specifications (RPO LMG VIN 0) or Engine
Mechanical Specifications (RPO LY6 VIN K) or Engine Mechanical Specifications
(RPO L76 VIN Y) or Engine Mechanical Specifications (RPO L92 VIN 8) .

2008 Chevrolet Silverado 1500

2008 ENGINE Engine Mechanical - 4.8L, 5.3L, 6.0L, 6.2L, or 7.0L - Cab & Chassis Sierra, Cab & Chassis Silverado,

Sierra & Silverado