Reaction Gear and Carrier Inspection

WARNING: This page is about a different car, the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Inspecting Areas Of Reaction Carrier/Support Thrust Bearing Assembly

Courtesy of GENERAL MOTORS CORP.

Inspect the reaction carrier/support thrust bearing assembly (683) for wear or damage.
Inspect the reaction gear support to case bearing (692) for wear or damage.

Fig 2: View Of Reaction Gear & Carrier Inspection Areas

Courtesy of GENERAL MOTORS CORP.

Inspect the internal reaction gear (684) and the internal reaction gear support (685) for proper assembly, stripped splines, cracks, teeth, and lug damage.

Fig 3: Checking Reaction Carrier Pinion End Play With Feeler Gage

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Inspect all pinions, either 4 or 5 depending on model.

Check the reaction carrier pinion end play. The end play must not exceed 0.61 mm (0.024 in).
Inspect the reaction carrier for the following conditions:
- Pinion gear damage
- Proper pinion staking
- Excessive pinion washer wear
- Keystoned pinion gears
Ensure that the pinions turn freely.

Fig 4: Illustrating Proper Inspection Of Reaction Carrier Captive Thrust Bearing

Courtesy of GENERAL MOTORS CORP.

Inspect the reaction carrier captive thrust bearing for wear or damage.
1. Without touching the pinion gears, place a bushing or an output shaft sleeve (690) onto the bearing race, and turn it with the palm of your hand.
2. Any imperfections will be felt through the bushing.