Hummer H2. Manual — part 1857

4. Tighten the M8 bolts to 25 N.m (18 lb ft).

Tighten the bolt on one side of the bearing cap and then tighten the bolt on the opposite side of the
same bearing cap.

Fig. 591: CKP Sensor & Bolt
Courtesy of GENERAL MOTORS CORP.

11. Install the CKP sensor.

1. Inspect the CKP sensor O-ring seal. If the O-ring seal is not cut or damaged, it may be used.

2. Coat the O-ring seal with clean engine oil.

3. Install the sensor. Align the notch in the sensor retaining bracket with the bolt hole in the block.

4. Install the sensor bolt.

2004 Hummer H2

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

Tighten: Tighten the CKP sensor bolt to 25 N.m (18 lb ft).

Fig. 592: Measuring Crankshaft End Play
Courtesy of GENERAL MOTORS CORP.

12. Measure the crankshaft end play.

1. Thrust the crankshaft forward or rearward.

2. Insert a feeler gauge between the center crankshaft bearing and the bearing surface of the

crankshaft and measure the bearing clearance.

The proper crankshaft end play clearance is 0.04-0.2 mm (0.0015-0.0078 in).

3. If the bearing clearance is not within specifications, inspect the thrust surfaces for nicks, gouges or

raised metal. Minor imperfections may be removed with a fine stone.

PISTON, CONNECTING ROD, AND BEARING INSTALLATION

Tools Required

z

J 8037 Piston Ring Compressor. See Special Tools and Equipment .

z

J 8087 Cylinder Bore Gauge. See Special Tools and Equipment .

2004 Hummer H2

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

z

J 41556 Connecting Rod Guide. See Special Tools and Equipment .

z

J 45059 Angle Meter. See Special Tools and Equipment .

Piston Selection

Fig. 593: Measuring Piston
Courtesy of GENERAL MOTORS CORP.

1. With a micrometer at a right angle, measure the piston outside diameter (OD). Measure the diameter 43

mm (1.69 in) from the top of the piston. Refer to Engine Mechanical Specifications .

IMPORTANT: Measurements of all components should be taken with the components at

normal room temperature. For proper piston fit, the engine block cylinder
bores must not have excessive wear or taper. A used piston, pin, and
connecting rod assembly may be installed if, after inspection is within
specifications.

2004 Hummer H2

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

2. Record the piston OD.

Fig. 594: Measuring J 8087 Dimension
Courtesy of GENERAL MOTORS CORP.

3. Adjust the micrometer to the recorded piston OD.

4. Insert the J 8087 into the micrometer and zero the gauge dial. See Special Tools and Equipment .

2004 Hummer H2

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