Hummer H2. Manual — part 1820

Fig. 458: Measuring Camshaft Lobe Lift
Courtesy of GENERAL MOTORS CORP.

1. Measure camshaft lobe lift using J 8520 . See Special Tools and Equipment .

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 and Equipment .

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 lift shown to specifications:

z

The proper lobe lift for 6.0L intake lobes is 6.96 mm (0.274 in).

z

The proper lobe lift for 6.0L exhaust lobes is 7.13 mm (0.281 in).

CAMSHAFT BEARING INSTALLATION

Tools Required

J 33049 Camshaft Bearing Service Set. See Special Tools and Equipment .

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.

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Fig. 459: Engine Block Camshaft Bearing Bores
Courtesy of GENERAL MOTORS CORP.

1. Measure the engine block camshaft bearing bores (1-5) to identify the correct OD size bearing for each

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

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

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

position. Refer to Engine Mechanical Specifications .

Fig. 460: J 33049 Camshaft Bearing Service Kit Components
Courtesy of GENERAL MOTORS CORP.

2. Select the expanding driver (4-8) and washer (2 or 3) from the J 33049 . See Special Tools and

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2

Equipment . Refer to Camshaft Bearing Removal .

3. Assemble the tool.

Fig. 461: Driving Bearing From Block Bore
Courtesy of GENERAL MOTORS CORP.

4. Insert the tool through the front of the engine block and into the bearing.

5. Tighten the expander assembly nut until snug.

6. Push the guide cone into the front camshaft bearing to align the tool.

7. Drive the bearing into the block bore.

8. Repeat the above procedures to install the remaining bearings.

TIMING CHAIN AND SPROCKETS CLEANING AND INSPECTION

2004 Hummer H2

2004 ENGINE Engine Mechanical - 4.8L, 5.3L, and 6.0L - Hummer H2