Hummer H2. Manual - part 902

differential coil plate.  

3. Install the differential bearing retainer. 

Ensure the differential bearing retainer is evenly and fully seated in the differential bearing retainer 
slot before releasing the differential bearing race. 

18. Install the ring gear. Refer to Drive Pinion and Ring Gear Replacement in Rear Drive Axle.  

19. Install the differential side bearings. Refer to Differential Side Bearings Replacement in Rear Drive 

Axle.  

DESCRIPTION AND OPERATION 

LOCKING DIFFERENTIAL DESCRIPTION AND OPERATION 

The electronic locking differential consists of the following components: 

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Differential Bearing Retainer Race  

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Differential Bearing Race  

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Differential Bearing Assembly  

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Locking Differential Coil Assembly  

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Locking Differential Coil Plate  

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Locking Differential Ball Bearing Plate - Outboard  

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Locking Differential Ball Bearing Assembly  

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Locking Differential Ball Bearing Plate - Inboard  

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Locking Differential Clutch Spring  

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Locking Differential Clutch Spring Retainer  

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Differential Carrier Lock Pins  

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Differential Case  

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Differential Pinion Gears and Thrust Washers  

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Locking Differential Side Gear and Thrust Washer  

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Differential Side Gear and Thrust Washer  

The electronic locking differential is a combination of an open differential and an electrically energized coil 
assembly. When the coil is not energized, the differential operates in the same manner as an open differential. 
The locking differential coil assembly is located on the left side of the differential case. The locking differential 
coil is held stationary within the differential case housing through the lock tab on the coil and the hold down 
lock that attaches to the differential bearing cap. The remainder of the locking components: the locking 
differential coil plate, the locking differential ball bearing plates, the clutch springs and the lock pins are located 
within the differential case and rotate at the same speed as the differential case. The locking function of the 
differential is accomplished by a combination of vehicle and user inputs. In order to the differential coil to 
energize, the vehicle must be operating under the following conditions:

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Drive Axle - Locking/Limited Slip - Hummer H2

  

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The transfer case indicator switch indicates 4 LO.  

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The vehicle's speed must be less than 4.8 km/h (3 mph).  

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The differential lock switch is turned ON.  

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The left to right rear wheel speed difference is less than 50 RPM.  

Once the above conditions are met, the automatic transfer case shift control module sends a signal to energize 
the coil. The energized coil creates a magnetic field that allows the outboard locking differential ball bearing 
plate to rotate at a slower speed than inboard locking differential ball bearing plate and the differential case. The 
difference in the 2 speeds causes the ball bearings that are between the outboard and the inboard ball bearing 
plate to move along their respective ramps and separate the 2 ball bearing plates. The separation increases the 
width of the plates and allows the differential lock pins to be pushed through the differential case towards the 
locking differential side gear. The locking differential side gear has 6 notches that accept the differential lock 
pins. Once the differential lock pins are engaged, the locking differential side gear can no longer rotate 
independently of the differential case. Since the locking differential side gear is now apart of the differential 
case and turning at the same speed as the ring gear, the pinion gears that are perpendicular to the locking 
differential side gear, cannot rotate within the differential case. This causes the bell-side differential side gear to 
rotate at the same speed as the locking differential side gear. The driving force generated by the ring gear, is 
transmitted through the locking differential side gear, through the pinion gears, to the bell-side differential side 
gear. The axle shafts, which are splined to each side gear, receive the force and rotate together at the same speed 
along with the differential case and ring gear. The will remain the locked position until the vehicle's speed 
exceeds 32 km/h (20 mph) or the operator turns OFF the differential lock switch or the transfer case is shifted 
into 4 HI, 2 HI or NEUTRAL. The locking differential coil will de-energize and the differential will function as 
an open differential. 

SPECIAL TOOLS AND EQUIPMENT 

SPECIAL TOOLS 

Special Tools 

Illustration

Tool Number/Description

J 7872 

Magnetic Base Dial Indicator

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Drive Axle - Locking/Limited Slip - Hummer H2

  

2004 DRIVELINE/AXLE

Front Drive Axle - Hummer H2 

SPECIFICATIONS 

FASTENER TIGHTENING SPECIFICATIONS 

Fastener Tightening Specifications 

AXLE PRELOAD AND BACKLASH SPECIFICATIONS 

Axle Preload and Backlash Specifications 

SEALERS, ADHESIVES, AND LUBRICANTS 

Sealers, Adhesives, and Lubricants 

Application

Specification

Metric

English

Differential Adjuster Lock Nut Bolt

20 N.m

15 lb ft

Differential Carrier Assembly Case Bolts

78 N.m

58 lb ft

Differential Carrier Assembly Mounting Bolts and Nuts

100 N.m

75 lb ft

Differential Carrier Assembly Hole Plug

28 N.m

21 lb ft

Inner Axle Shaft Housing to Frame Mounting Bolt and Nut

100 N.m

75 lb ft

Inner Axle Shaft Housing to Differential Carrier Assembly Bolts

40 N.m

30 lb ft

Pinion Shaft Lock Bolt

53 N.m

39 lb ft

Plug, Drain and Fill

33 N.m

24 lb ft

Ring Gear Bolts

138 N.m

102 lb ft

Stabilizer Link Nut

18 N.m

13 lb ft

Vent Connector

20 N.m

15 lb ft

Wheel Drive Shaft Inboard Flange Bolts

79 N.m

58 lb ft

Yoke Retainer Bolts

25 N.m

18 lb ft

Application

Specification

Metric

English

Backlash

0.08-0.25 mm

0.003-0.010 in

Backlash (Preferred)

0.13-0.18 mm

0.005-0.007 in

Pinion Bearing Preload, New Bearings

1.7-3.4 N.m

15-30 lb in

Pinion Bearing Preload, Used Bearings

1.1-2.3 N.m

10-20 lb in

Pinion and Differential Case Bearing Preload, New Bearings

3.4-6.2 N.m

30-55 lb in

Pinion and Differential Case Bearing Preload, Used Bearings

2.8-5.1 N.m

25-45 lb in

Application

Type of 

Material

GM Part Number

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Front Drive Axle - Hummer H2

  

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Front Drive Axle - Hummer H2

  

COMPONENT LOCATOR 

FRONT DRIVE AXLE DISASSEMBLED VIEWS 

Fig. 1: Front Drive Axle Component Views 
Courtesy of GENERAL MOTORS CORP. 

Callouts For Fig. 1 

Differential Carrier Assembly Case 
Mating Surfaces

Sealant

1052942 (Canadian P/N 10953466) or 

equivalent

Differential Carrier Assembly Hole Plug

Sealant

12346004 (Canadian P/N 10953480) or 

equivalent

Front Drive Axle

Lubricant

12378261 (Canadian P/N 10953455) or 

equivalent meeting GM Specification 9986115

Front Drive Axle Inner Shaft Housing to 
Differential Carrier Assembly

Sealant

1052942 (Canadian P/N 10953466) or 

equivalent

Pinion Yoke Splines

Sealant

12346004 (Canadian P/N 10953480) or 

equivalent

Callout

Component Name

1

Front Drive Axle Inner Shaft

2

Front Drive Axle Inner Shaft Retaining Ring

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Front Drive Axle - Hummer H2