Hummer H2. Manual - part 1799

Fig. 380: Inspecting Connecting Rod Bearings For Excess Scoring Or Discoloration
Courtesy of GENERAL MOTORS CORP.

16. Inspect the crankshaft bearings for excessive scoring or discoloration.

17. Inspect the crankshaft bearings for dirt or debris imbedded into the bearing material.

2004 Hummer H2

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

Fig. 381: Inspecting Bearings For Improper Seating
Courtesy of GENERAL MOTORS CORP.

18. Inspect the crankshaft bearings for improper seating indicated by bright, polished sections of the bearing.

If the lower half of the bearing is worn or damaged, both upper and lower halves should be replaced.

Generally, if the lower half is suitable for use, the upper half should also be suitable for use.

Measuring Main Bearing Clearance - Gaging Plastic Method

2004 Hummer H2

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

Fig. 382: Bearing Cap Bolts & Studs
Courtesy of GENERAL MOTORS CORP.

1. Remove the bearing cap M8 side bolts.

IMPORTANT:

The crankshaft main bearings are a precision insert type. Main
bearing caps are machined with the engine block for proper
clearance and cannot be shimmed or filed for bearing fit. If the
clearances are found to be excessive, new bearings and/or engine
block and cap repair or replacement may be required.

Do not rotate the crankshaft while gaging plastic is between the
crankshaft journal and the bearing surface.

The crankshaft bearing clearances are critical. Excessive bearing
clearance may effect crankshaft position sensor signals and may
effect On-Board Diagnostics (OBD) II system operation.

Remove the bearing cap side bolts prior to cap removal.

2004 Hummer H2

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

Fig. 383: View Of Bearing Caps
Courtesy of GENERAL MOTORS CORP.

2. Remove the bearing cap M10 bolts and studs.

2004 Hummer H2

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

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