Hummer H3. Manual — part 944

Fig. 12: Identifying Heat Discoloration
Courtesy of GENERAL MOTORS CORP.

Heat discoloration ranges from faint yellow to dark blue. This discoloration results from overload
or an incorrect lubricant. Excessive heat causes softening of the races or the rollers. In order to
inspect for loss of temper on the races and the rollers, perform a file test. A file drawn over a
tempered part will grab and cut the metal. A file drawn over a hard part will glide readily with
no metal cutting. Replace the bearings if overheating damage is indicated. The tempered part will
fail the file test. Inspect the seals and the other related parts.

Misalignment

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

Fig. 13: Identifying Misalignment
Courtesy of GENERAL MOTORS CORP.

A misaligned outer race can be due to a foreign object. Clean the related parts. Replace the
bearing. Ensure the races are properly sealed.

Cracked Inner Race

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

Fig. 14: Identifying Cracked Inner Race
Courtesy of GENERAL MOTORS CORP.

Cracked race can be due to improper fit, cocking or poor bearing seats. Replace the bearing.
Correct the bearing seats.

Fatigue Spalling

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

Fig. 15: Inspecting Bearing Rollers & Races For Pitting, Grooves, Spalling & Excessive
Wear
Courtesy of GENERAL MOTORS CORP.

Flaking of surface metal results from fatigue. Replace the bearing. Clean all related parts.

Brinelling

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3