Hummer H3. Manual — part 1501

Fig. 143: Identifying Inspection Areas On Gears
Courtesy of GENERAL MOTORS CORP.

1. Clean the 1st gear (110), the 2nd gear (120), the 3rd gear (130) and the 5th countershaft

gear (450) in a suitable solvent and air dry all the parts.

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

Fig. 144: View Of Inspection Areas On Thrust Surfaces Of Gears
Courtesy of GENERAL MOTORS CORP.

2. Inspect the thrust surfaces (a) on both sides of the gears for the following conditions:

Wear

Galling

Scoring

3. Replace any gears that have faulty thrust surfaces. Worn thrust surfaces may cause gear

clashing or hard shifting, by not allowing full engagement of the synchronizer blocking
rings. Worn thrust surfaces may also cause gear noise or may cause clunking during

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

acceleration or deceleration.

4. Inspect the synchronizer blocking ring surface (b) for the following conditions:

Grooves

Excessive wear

Heat marks

Scoring

5. Replace any gear that has a faulty blocking ring surface.

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

Fig. 145: View Of Gear Change Damage On Selector Teeth
Courtesy of GENERAL MOTORS CORP.

6. Inspect the selector teeth of the gears for gear change damage.

If there is gear change damage, the tooth edges are worn and chipped and, in some cases,

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3