Hummer H2. Manual - part 883

Fig. 117: Left Side Differential Bearing Cap Bolts 
Courtesy of GENERAL MOTORS CORP. 

19. Tighten the left side differential bearing cap bolts. 

Ensure that the locking differential coil assembly wires are routed away from the differential bearing cap. 

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

20. Measure the drive pinion and differential case side bearing preload and adjust, if necessary. Refer to 

Differential Side Bearing Preload Adjustment .  

21. Recheck the backlash and adjust, if necessary.  

22. Once backlash and bearing preload 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 .  

23. Complete the installation of the differential into the axle housing. Refer to Differential Replacement . 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

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 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

Fig. 118: Gear Tooth Nomenclature 
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: 

z

Backlash adjustment  

z

Pinion depth adjustment  

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.

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2

  

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. 

z

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.  

z

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. 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Rear Drive Axle - Hummer H2