Hummer H2. Manual - part 882

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J 8001 Dial Indicator Set  

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J 22779 Side Bearing Backlash Gauge. See Special Tools and Equipment .  

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J 24429 Side Bearing Backlash Spanner. See Special Tools and Equipment .  

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J 25025 Guide Pins. See Special Tools and Equipment .  

Fig. 115: Measuring Pinion Rotation Torque 
Courtesy of GENERAL MOTORS CORP. 

1. Measure the rotating torque of the drive pinion and differential assembly using an inch-pound torque 

wrench. 

Specification: The rotating torque of the drive pinion and differential assembly should be 3.4-6.2 N.m 
(30-55 lb in) for new bearings or 2.8-5.1 N.m (25-45 lb in) for used bearings. 

2. If the rotating torque is too low, tighten the differential bearing adjuster nut in 1 slot increments until the 

IMPORTANT:

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Ensure that the side bearing surfaces in the axle housing are clean and 
free of burrs. If the original bearings are to be reused, the original bearing 
cups must also be used.  

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The differential side bearings must be initially preloaded in order to 
determine the backlash of the gear set. After the backlash is set, the final 
bearing preload is set.  

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

specified rotating torque is obtained.  

3. If the rotating torque is too high, loosen the differential bearing adjuster nut in 1 slot increments until the 

specified rotating torque is obtained.  

4. If the specification for the rotating torque of the drive pinion and differential assembly cannot be obtained 

by adjusting the differential bearing adjuster nut, remove the differential assembly, measure the rotating 
torque of the drive pinion and adjust as necessary. Refer to Differential Replacement and Drive Pinion 
Bearings Replacement . 

Fig. 116: Installing J 25025-1 & J 8001 
Courtesy of GENERAL MOTORS CORP. 

5. Install the J 25025-1 and the J 8001-3 to the axle housing as shown.  

6. Place the indicator stem of the J 8001-3 at the heel end of a gear tooth.  

7. Set the J 8001-3 so that the stem is aligned with the gear rotation and perpendicular to the tooth angle.  

8. Preload the dial of the J 8001-3 approximately 3/4 of a turn. 

Align the needle and the dial face of the J 8001-3 to ZERO.

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

9. While holding the drive pinion stationary, move the ring gear back and forth. 

Measure and record the backlash. 

10. Repeat the measuring procedure at eight points around the ring gear. 

Specification: The difference between the backlash at all of the measuring points should not vary by 
more than 0.05 mm (0.002 in). 

11. If the difference between the backlash at all of the measuring points varies by more than 0.05 mm (0.002 

in), inspect for the following conditions: 

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Burrs  

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A distorted case flange  

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Uneven bolting  

12. If the difference between all the measuring points is within specifications, the backlash at the minimum 

lash point measured should be: 

Specification: The backlash between the ring gear and the drive pinion should be between 0.08-0.25 mm 
(0.003-0.010 in) with a preferred backlash of 0.13-0.18 mm (0.005-0.007 in). 

13. If the backlash is too small, increase the backlash using the following procedure: 

1. Support the differential assembly in order to prevent the differential assembly from falling out of 

the axle housing.  

2. Loosen the right side bearing cap bolts.  

3. Loosen the left side bearing cap bolts. 

Do not remove the bearing cap bolts. 

4. Loosen the differential bearing adjuster nut using the J 24429 . See Special Tools and 

Equipment .  

5. Remove the differential side bearing shim.  

6. Measure the thickness of the shim. 

Measure the shim in 3 locations. 

7. Calculate the average of the 3 measurements. 

IMPORTANT:

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Do not use the original cast iron production shim to adjust the 
backlash. Use service shims instead.  

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Increasing or decreasing the shim thickness by 0.05 mm (0.002 in) 
will change the backlash adjustment approximately 0.03 mm (0.001 
in).  

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

Record the measurement. 

8. Select a smaller shim than the one that was removed. For example, to increase the backlash by 0.05 

mm (0.002 in), select a shim that is 0.10 mm (0.004 in) thinner than the shim that was removed.  

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

1. Support the differential assembly in order to prevent the differential assembly from falling out of 

the axle housing.  

2. Loosen the right side bearing cap bolts.  

3. Loosen the left side bearing cap bolts. 

Do not remove the bearing cap bolts. 

4. Loosen the differential bearing adjuster nut using the J 24429 . See Special Tools and 

Equipment .  

5. Remove the differential side bearing shim.  

6. Measure the thickness of the shim. 

Measure the shim in 3 locations. 

7. Calculate the average of the 3 measurements. 

Record the measurement. 

8. Select a larger shim than the one that was removed. For example, to increase the backlash by 0.05 

mm (0.002 in), select a shim that is 0.10 mm (0.004 in) thicker than the shim that was removed.  

15. Install the new service shim.  

16. Tighten the differential bearing adjuster nut using the J 24429 until the differential bearing adjuster nut 

contacts the bearing. See Special Tools and Equipment .  

17. Once the differential bearing adjuster contacts the differential bearing, tighten the differential bearing 

adjuster nut using the J 24429 the following additional amounts: 

Tighten:  

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For used bearings, tighten the differential bearing adjuster nut an additional 2 slots.  

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For new bearings, tighten the differential bearing adjuster nut an additional 3 slots.  

18. Tighten the right side differential bearing cap bolts. 

Tighten: Tighten the right side bearing cap bolts to 85 N.m (63 lb ft).

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2