Hummer H3. Manual — part 191

3. Remove the piston pin.

PISTON, CONNECTING ROD, AND BEARINGS CLEANING AND INSPECTION

Tools Required

J 8087 Cylinder Bore Gage. See Special Tools.

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3

Fig. 397: View Of Piston Pin & Connecting Rod
Courtesy of GENERAL MOTORS CORP.

1. Clean and soak the following components in a carburetor cleaning solution to remove

carbon, sludge, and varnish:

Piston

Piston pin

Connecting rod

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3

Fig. 398: Identifying Twisted Connecting Rod
Courtesy of GENERAL MOTORS CORP.

2. Install the connecting rod cap.

3. Place the connecting rod assembly on a checking fixture.

4. Inspect the connecting rod assembly for bending or twisting.

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3

5. Replace any bent or twisted connecting rods.

6. If the connecting rod large bore contains minor scratches or abrasions, clean the bore in a

circular direction with light emery paper. DO NOT scrape the connecting rod or cap.

7. Measure the piston pin to connecting rod bore using the following procedure:

Using an outside micrometer, take two measurements of the piston pin in the area of
the connecting rod contact.

Using an inside micrometer, measure the connecting rod piston pin bore.

Subtract the piston pin diameter from the piston pin bore diameter.

The clearance should not be more than 0.018 mm (0.0007 in).

8. If there is excessive clearance, replace the piston pin.

9. If there is still excessive clearance, replace the connecting rod.

10. If there is evidence of pin bore or pin scoring, replace the rod and pin assembly.

Fig. 399: Inspecting Connecting Rod Cap Bolts
Courtesy of GENERAL MOTORS CORP.

11. Inspect the connecting rod bearings for the following conditions:

Craters or pockets

2006 Hummer H3

2006 ENGINE Engine Mechanical - 3.5L (L52) - H3