Hummer H3. Manual — part 969

Fig. 94: Identifying J 21777-1 & J 44416-3
Courtesy of GENERAL MOTORS CORP.

9. Align the plunger of the J 23597-1 (1) to the J 23597-11 (2).

10. Install the J 8001 to the J 23597-1 as follows:

1. Loosely clamp the J 8001 onto the stem on the J 23597-1. See Special Tools.

2. Place the contact pad of the J 8001 onto the mounting post of the J 23597-1. See

Special Tools.

3. With the contact pad of the J 8001 touching the mounting post of the J 23597-1,

loosen the lock nut on the J 8001 and push down on the J 8001 until the needle the J
8001 has turned 3/4 of a turn clockwise. See Special Tools.

4. Tighten the clamp on the J 8001 finger tight. See Special Tools.

11. Move the plunger of the J 23597-1 back and forth until the needle of the J 8001 indicates

the greatest deflection. See Special Tools.

The deflection is the point where the needle changes direction.

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

Fig. 95: Measuring Necessary Shim Thickness
Courtesy of GENERAL MOTORS CORP.

12. At the greatest point of deflection, move the housing of the J 8001 until the needle indicates

ZERO. See Special Tools.

13. Move the plunger of the J 23597-1 back and forth again to verify the zero setting. Adjust the

housing of the J 8001 as necessary to set the needle to zero. See Special Tools.

14. Rotate the plunger of the J 23597-1 away from the J 23597-11 until it no longer touches the

J 23597-11 or the J 21777-29.

15. The value indicated on the J 8001 is the thickness of the shim needed in order to set the

depth of the pinion. See Special Tools.

16. Select the shim that indicates the proper thickness. Measure the shim with a micrometer in

order to verify that the thickness is correct.

17. Remove the pinion depth setting tools.

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

18. Remove the pinion bearings.

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

Pinion Bearings Replacement .

BACKLASH INSPECTION AND ADJUSTMENT

Tools Required

J 8001 Dial Indicator Set. See Special Tools.

J 25025 Guide Pins. See Special Tools.

J 25588 Side Bearing Shim Installer. See Special Tools.

Adjustment Procedure

Fig. 96: Measuring Ring Gear Backlash
Courtesy of GENERAL MOTORS CORP.

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

1. Install the J 25025-1 and the J 8001 to the axle housing as shown. See Special Tools.

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

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

tooth angle.

4. Preload the dial of the J 8001-3 .

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

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

Measure and record the backlash.

6. 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).

7. 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:

Burrs

A distorted case flange

Uneven bolting

8. 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).

IMPORTANT:

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

Adjust the thickness of the shim pack on each side of
the differential in equal amounts. This will maintain the
correct axle side bearing preload.

Moving 0.05 mm (0.002 in) of shim thickness from one
side of the differential to the other will change the
backlash adjustment approximately 0.03 mm (0.001 in).

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3