Hummer H2. Manual — part 1810

Fig. 421: Measuring Piston Pin Bore
Courtesy of GENERAL MOTORS CORP.

10. To determine the piston pin-to-bore clearance, use an inside micrometer and measure the piston pin bore

inside diameter (ID).

11. Subtract the piston pin OD measurement from the piston pin bore ID measurement to determine pin-to-

bore clearance.

Refer to Engine Mechanical Specifications .

Measuring Piston Ring End Gap

2004 Hummer H2

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

Fig. 422: Upper & Lower Compression Rings & Marks
Courtesy of GENERAL MOTORS CORP.

1. Identify the NEW upper and lower compression rings. The upper compression ring can be identified by a

paint mark (3) located 180 degrees from the end gap. The lower compression ring can be identified by a
paint mark (3) located 90 degrees from the end gap. Both rings should be installed with the orientation
marks (1, 2) facing the top of the piston.

IMPORTANT:

z

Do not attempt to file the end of the piston ring to achieve the proper
end gap clearance.

z

Measure the piston ring in the cylinder in which it will be used.

2004 Hummer H2

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

Fig. 423: Measuring Piston Compression Ring End Gap
Courtesy of GENERAL MOTORS CORP.

2. Place the piston ring into the cylinder bore 6.5 mm (0.25 in) below the top of the ring travel area.

3. Insert a feeler gauge and measure the piston ring end gap. Refer to Engine Mechanical Specifications .

Connecting Rod and Bearings

2004 Hummer H2

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

Fig. 424: Piston & Connecting Rod Components
Courtesy of GENERAL MOTORS CORP.

1. Clean the connecting rod (2) and cap (4) in solvent.

IMPORTANT:

z

The powdered metal connecting rod and cap are machined for
proper clearances. The connecting rod and cap must be used as an
assembly with no repair or modifications to either mating surface.
Do not attempt to repair the rod or cap. If service is required, replace
the first design press-fit piston, pin, and connecting rod as an
assembly.

z

Do not attempt to repair the bolt hole threads of the connecting rod.

2004 Hummer H2

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