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