Hummer H3. Manual — part 1018

4. Calculate the average of the 3 measurements for each shim.

Add the average of each of the shim measurements together.

Record the measurement. This is the thickness for the left side shim pack.

5. Assemble a new left side shim pack by decreasing the appropriate amount of thickness

from the original left side shim pack. If the original shim is cast iron production shim,
assemble the shim pack using a service spacer and service shims. For example, to
increase the backlash by 0.05 mm (0.002 in), remove 0.10 mm (0.004 in) of thickness
from the left side shim pack.

6. Measure the thickness of right side shim pack.

Measure the shim or the shim and service spacer in 3 locations.

Measure each shim separately.

7. Calculate the average of the 3 measurements for each shim.

Add the average of each of the shim measurements together.

Record the measurement. This is the thickness for the right side shim pack.

8. Assemble a new right side shim pack by increasing the appropriate amount of thickness

to the original right side shim pack. If the original shim is cast iron production shim,
assemble the shim pack using a service spacer and service shims. For example, to
increase the backlash by 0.05 mm (0.002 in), add 0.10 mm (0.004 in) of thickness to
the right side shim pack.

10. If the backlash is too large, decrease the backlash using the following procedure:

1. Remove the bearing cap bolts and the bearing caps.

Mark the bearing caps left or right.

2. Remove the differential case assembly with the bearing cups and the shims.

Mark the bearing cups and the shims left or right.

3. Measure the thickness of left side shim pack.

Measure the production shim or the shim and service spacer in 3 locations.

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3

Measure each shim separately.

4. Calculate the average of the 3 measurements for each shim.

Add the average of each of the shim measurements together.

Record the measurement. This is the thickness for the left side shim pack.

5. Assemble a new left side shim pack by increasing the appropriate amount of thickness

to the original left side shim pack. If the original shim is cast iron production shim,
assemble the shim pack using a service spacer and service shims. For example, to
increase the backlash by 0.05 mm (0.002 in), add 0.10 mm (0.004 in) of thickness to
the left side shim pack.

6. Measure the thickness of right side shim pack.

Measure the shim or the shim and service spacer in 3 locations.

Measure each shim separately.

7. Calculate the average of the 3 measurements for each shim.

Add the average of each of the shim measurements together.

Record the measurement. This is the thickness for the right side shim pack.

8. Assemble a new right side shim pack by decreasing the appropriate amount of

thickness to the original right side shim pack. If the original shim is cast iron
production shim, assemble the shim pack using a service spacer and service shims. For
example, to decrease the backlash by 0.05 mm (0.002 in), remove 0.10 mm (0.004 in)
of thickness to the right side shim pack.

11. Install the differential case assembly with the bearing cups.

12. Install the left side service spacer between the axle housing and the differential case.

13. Install the right side service spacer between the axle housing and the differential case.

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3

Fig. 122: Installing The Service Shim Using J 25588
Courtesy of GENERAL MOTORS CORP.

14. Install the left side service shim using the J 25588 , if necessary.

The service shim must be installed between the service spacer and the differential bearing
cup.

15. Install the right side service shim using the J 25588 , if necessary.

The service shim must be installed between the service spacer and the differential bearing
cup.

16. Install the bearing caps and bolts.

NOTE:

Refer to Fastener Notice .

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3

Tighten: Tighten the bolts to 75 N.m (55 lb ft).

17. Recheck the backlash and adjust, if necessary.

18. Once backlash is correct, perform a gear tooth contact pattern check in order to ensure

proper alignment between the ring and pinion gears. Refer to Gear Tooth Contact Pattern
Inspection.

GEAR TOOTH CONTACT PATTERN INSPECTION

The gear contact pattern check is not a substitute for adjusting the pinion depth and backlash. Use
this method in order to verify the correct running position of the ring gear and the drive pinion.
Gear sets which are not positioned properly may be noisy and/or have a short life span. A pattern
check ensures that when best contact has been obtained between the ring gear and the drive
pinion, the system will produce low noise and have a long life.

Drive Pinion and Ring Gear Identification

Production drive pinion and ring gears are manufactured by using a 2-cut or a 5-cut method. The
2-cut drive pinions and ring gears can be identified by having a groove cut into the outside edge
of the ring gear and a ring on the stem of the drive pinion. The gear tooth contact patterns that are
produced from each style of gear set differ slightly. A 2-cut gear will produce a pattern that is
bias from the toe to the heel of the tooth (drive side), while a 5-cut gear set will produce a square
pattern from the toe to the heel of the tooth (drive side). When diagnosing the gear tooth contact
pattern, regardless of what type of gear set it is, a correct pattern will be centered within the area
of the tooth, from toe to heel and from top to bottom.

Gear Tooth Nomenclature

2007 Hummer H3

2007 Driveline/Axle Rear Drive Axle - H3