Hummer H3. Manual — part 1019

Fig. 123: Identifying Gear Tooth Components
Courtesy of GENERAL MOTORS CORP.

The side of the ring gear tooth which curves outward or is convex, is the drive side (4). The
concave side is the coast side (3). The end of the tooth nearest the center of the ring gear is the toe
end (2). The end of the tooth farthest away from the center is the heel end (1).

Adjustments Affecting Tooth Contact

The following 2 adjustments affect the tooth contact pattern:

Backlash adjustment

Pinion depth adjustment

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3

The effects of bearing preloads are not readily apparent on hand-loaded tooth contact pattern
tests. However, bearing preloads should be within specifications before proceeding with backlash
and pinion depth adjustments.

Backlash Adjustment

The backlash can be adjusted by either varying the thickness of the side bearing shims from side
to side or by moving the adjuster sleeve(s) in or out or both. By adjusting the shim thickness or
moving the adjuster sleeve(s), the case and ring gear assembly will move closer to or further away
from the pinion. In most cases, adjusting the backlash will correct an abnormal contact pattern.
This adjustment will also be used to set the side bearing preload.

If the thickness of the right shim is increased or the adjuster sleeve is moved in (if
applicable), along with an equal decrease in the thickness of the left shim or the adjuster
sleeve is moved out (if applicable), the backlash will increase.

If the thickness of the left shim is increased or the adjuster sleeve is moved in (if applicable),
along with an equal decrease in the thickness of the right shim or the adjuster sleeve is
moved out (if applicable), the backlash will decrease.

Pinion Depth Adjustment

Adjust the position of the pinion by increasing or decreasing the distance between the pinion head
and the centerline of the ring gear. Decreasing the distance moves the pinion closer to the
centerline of the ring gear. Increasing the distance moves the pinion farther away from the
centerline of the ring gear.

Testing Procedure

1. Wipe clean the differential case, the ring gear and the axle housing of lubricant. Carefully

clean each tooth of the ring gear.

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3

Fig. 124: Applying Gear Marking Compound To Ring Gear Teeth
Courtesy of GENERAL MOTORS CORP.

2. Use a medium stiff brush in order to sparingly apply gear marking compound, GM P/N

1052351 (Canadian P/N 10953497) or equivalent, to all of the ring gear teeth.

3. Torque the bearing caps bolts to specification.

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3

4. Apply the park brake until a torque load of 14 N.m (10 lb ft) is required in order to turn the

pinion.

5. Using a wrench, turn the drive pinion flange/yoke so that the ring gear rotates 3 full

revolutions.

6. Turn the drive pinion flange/yoke in the opposite direction so that the ring gear rotates 3 full

revolutions in the opposite direction.

7. Observe the pattern on the ring gear teeth. Compare the pattern with the following

illustrations.

Correct Contact Pattern

Condition

Fig. 125: Identifying Correct Gear Tooth Contact Pattern
Courtesy of GENERAL MOTORS CORP.

The backlash and pinion depth is correct.

IMPORTANT: Performing a test without loading the gears will not produce

a satisfactory pattern.

IMPORTANT: Avoid turning the ring gear excessively.

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3