Hummer H2. Manual - part 880

9. Install the bearing cap bolts. 

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

10. Rotate the J 21777-1 within the J 21777-86. The J 21777-1 must rotate back and forth freely within the 

discs. If the J 21777-1 does not rotate freely, disassemble the components, inspect for proper seating 
and/or mis-aligned components and re-assemble. 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

Fig. 112: Aligning Plunger Of J 21777-1 To J 21777-85 
Courtesy of GENERAL MOTORS CORP. 

11. Align the plunger of the J 21777-1 (1) to the J 21777-85 (2). See Special Tools and Equipment .  

12. Install the J 8001-3 to the J 21777-1 as follows: 

1. Loosely clamp the J 8001-2 onto the stem on the J 21777-1. 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

2. Install the J 8001-3 onto the J 8001-2.  

3. Place the contact pad of the J 8001-3 onto the mounting post of the J 21777-1.  

4. With the contact pad of the J 8001-3 touching the mounting post of the J 21777-1, loosen the lock 

nut on the J 8001-2 and push down on the J 8001-3 until the needle the J 8001-3 has turned 3/4 of a 
turn clockwise.  

5. Tighten the clamp on the J 8001-2 finger tight.  

13. Move the plunger of the J 21777-1 back and forth until the needle of the J 8001-3 indicates the greatest 

amount of deflection. 

The greatest amount of deflection is the point where the needle changes direction. 

Fig. 113: Measuring Necessary Shim Thickness 
Courtesy of GENERAL MOTORS CORP. 

14. At the greatest point of deflection, move the housing of the J 8001-3 until the needle indicates ZERO.  

15. Move the plunger of the J 21777-1 back and forth again to verify the zero setting. Adjust the housing of 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

the J 8001-3 as necessary to set the needle to ZERO. 

16. Rotate the plunger of the J 21777-1 away from the J 21777-85 until it no longer touches the J 21777-85.  

17. The value indicated on the J 8001-3 is the thickness of the shim needed in order to set the depth of the 

pinion.  

18. Select the shim that indicates the proper thickness. Measure the shim with a micrometer in order to verify 

that the thickness is correct.  

19. Remove the pinion depth setting tools.  

20. Remove the pinion bearings.  

21. Install the pinion shim between the pinion gear and the inner pinion bearing. Refer to Drive Pinion 

Bearings Replacement .  

DIFFERENTIAL SIDE BEARING PRELOAD ADJUSTMENT 

Tools Required 

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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 .  

1. Disconnect the propeller shaft from the rear axle and support as necessary. Refer to Propeller Shaft 

Replacement - Rear in Propeller Shaft. 

2. Remove the differential assembly from the axle housing, if necessary.  

3. Measure the rotating torque of the drive pinion bearing using an inch-pound torque wrench. 

Specification: The rotating torque of the drive pinion should be 1.7-3.4 N.m (15-30 lb in) for new 
bearings or 1.1-2.3 N.m (10-20 lb in) for used bearings.

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 drive pinion bearing preload must be within specifications before the 
differential side bearing preload adjustment can be performed.  

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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.  

CAUTION: To prevent personal injury and/or component damage, support the 

differential case when removing the case from the axle housing. If 
the case is not supported, the differential case could fall and cause 
personal injury or damage to the differential case.

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2