Chevrolet Silverado / GMC Sierra. Manual — part 353

Eroded areas at the top of the piston (1)

Scuffed or damaged skirts (2)

Scoring to the piston pin bore (3) or piston pin

Fig. 424: Inserting Piston Ring Into Ring Groove
Courtesy of GENERAL MOTORS CORP.

6. Insert the edge of the piston ring into the piston ring groove.

Roll the piston ring completely around the piston. If binding is caused by a distorted ring
groove, MINOR imperfections may be removed with a fine file. If binding is caused by a

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

distorted piston ring, replace the rings, as required.

Fig. 425: Measuring Piston Ring Side Clearance
Courtesy of GENERAL MOTORS CORP.

7. Measure the piston ring side clearance with a feeler gage. If side clearance is not within

specifications, try another piston ring. If the proper ring-to-groove clearance cannot be
obtained, replace the piston and pin as an assembly. Refer to Engine Mechanical
Specifications.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 426: Measuring Piston Pin Diameter
Courtesy of GENERAL MOTORS CORP.

8. To determine piston pin-to-bore clearance, use a micrometer and measure the piston pin

outside diameter (OD).

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2