Hummer H3. Manual — part 1503

12. If scratches are present, replace the affected parts.

Scratches can be caused by the following conditions:

Dust and abrasive particles, including those caused by flank contact, in the lubricating
oil

The sliding action of the flanks

Fig. 149: Abrasive Wear On Gear Teeth
Courtesy of GENERAL MOTORS CORP.

13. Inspect the gear teeth for abrasive wear.

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

The marks left by the machining process are erased from the active flank. Instead, the entire
flank takes on a matte gray appearance. Substantial changes take place in the tooth profile
and clearance once abrasive wear has reached an advanced stage. This not only increases the
noise level, but can also cause secondary damage.

14. If abrasive wear is present, replace the affected parts.

Abrasive wear is caused by the following conditions:

Oil contamination resulting from wear or surface fatigue in other areas of the
transmission

Sand, sludge, etc. penetrating into the transmission from the outside

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

Fig. 150: View Of Rippling Or Brinelling On Gear Teeth
Courtesy of GENERAL MOTORS CORP.

15. Inspect the gear teeth for rippling or brinelling.

The polished tooth flanks show signs of ripple-like alterations in the surface structure, which

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

run perpendicular to the direction of sliding and may resemble a washboard.

16. If rippling or brinelling is present, replace the affected parts.

Rippling or brinelling is caused by the following conditions:

A combination of inadequate lubrication, high flank loads and low peripheral speeds

Friction-induced vibration

Fig. 151: Light Scoring On Gear Teeth
Courtesy of GENERAL MOTORS CORP.

17. Inspect the gear teeth for light scoring.

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3