Chevrolet Silverado / GMC Sierra. Service manual — part 2554

period has expired, without damaging the components. Rough peaks produced during
manufacture are worn away or, to some extent, are rolled into the surface. The surface
structure, grinding and shaving marks, are still visible.

Fig. 136: Inspect Gear Teeth For Scratches
Courtesy of GENERAL MOTORS CORP.

3. Inspect the gear teeth for scratches.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (M96) - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

Scratches are linear indentations on the flank, running in the direction of sliding.

4. If scratches are present, replace the affected components.

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. 137: Inspect Gear Teeth For Abrasive Wear
Courtesy of GENERAL MOTORS CORP.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (M96) - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

5. Inspect the gear teeth for abrasive wear.

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 cause secondary damage.

6. If abrasive wear is present, replace the affected components.

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

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (M96) - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado

Fig. 138: Inspect Gear Teeth For Rippling Or Brinelling
Courtesy of GENERAL MOTORS CORP.

7. Inspect the gear teeth for rippling or brinelling.

The polished tooth flanks show signs of ripple-like alterations in the surface structure which
run perpendicular to the direction of sliding, resembling a washboard.

2008 Chevrolet Silverado 1500

2008 TRANSMISSION Manual Transmission - Tremec 5-Speed (M96) - Cab & Chassis Sierra, Cab & Chassis

Silverado, Sierra & Silverado