Hummer H3. Manual — part 945

Fig. 16: Identifying Brinelling
Courtesy of GENERAL MOTORS CORP.

Surface indentations in the race way can be caused by the rollers under impact loading or can be
caused from vibration while the bearing is not rotating. Replace a rough or noisy bearing.

FRONT AXLE LUBRICANT LEAK DIAGNOSIS

Front axle lubricant leaks can occur at the following locations:

Axle shaft oil seals

Differential carrier assembly mating surface

Drain plug

Fill plug

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

Inner axle tube assembly to differential carrier assembly mating surface

Pinion yoke oil seal

Vent tube

Determining the Cause

While most front axle leaks may be easy to find, determining the cause may not be. A thorough
inspection of the area around the leak may assist in determining the cause of the leak.

Oil Seals

Lubricant leaks from a oil seal may be caused by any of the following:

An improperly installed seal

A distorted seal

A worn seal

A worn shaft

A brittle seal lip

A hardened seal lip

To determine the actual cause of the leak, clean the area around the leak. Observe the area of the
leak and determine the if the seal or another component is causing the leak. A worn seal surface
will cause a leak at the sealing lip while a misaligned seal or a seal installed into a housing with
an excessive bore will cause the seal to leak at the outside surface of the seal. Hardened or
cracked seal lips usually indicate the axle is operating beyond the normal temperature limits for
the axle. A seal whose sealing surface has been nicked or cut may indicate that the shaft has a
rough, burred or gouged surface and will need to be inspected before the seal can be replaced.

Sealing Surfaces

Front axles components are assembled using specific sealers. A leak at a surface sealed with
sealant is usually caused by a poor fit of the components but can also be caused by the use of the
wrong sealant. When correcting a sealant leak, inspect each component for distortion and for
nicks or gouges that may prohibit the sealant from sealing properly and when re-assembling the
component, use the proper sealant.

Differential Carrier Assembly

Lubricant leaks at the differential carrier assembly can occur at the following locations:

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

Drain Plug

Fill Plug

Vent tube

Drain and fill plug leaks are usually caused by a loose plug. A vent tube leak can be cause by a
loose fitting vent hose or by a vent tube assembly whose interior shield is stuck in the upside
down position. Inspect the vent plug's interior shield for unrestricted movement, repair or replace
the plug as necessary. Drain or fill plug leaks can be repaired by either tightening the plug or by
using an approved sealer on the threads on the plug.

REPAIR INSTRUCTIONS

FRONT AXLE LUBRICANT REPLACEMENT

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .

2. Ensure that the vehicle is level.

3. Remove the Engine Protection Shield (EPS), if equipped. Refer to Engine Shield

Replacement .

4. Remove the drain plug.

5. Drain axle fluid into a suitable container.

6. Install the drain plug.

Tighten: Tighten the drain plug to 32 N.m (24 lb ft).

7. Remove the fill plug.

8. Fill the drive axle with the proper fluid. Refer to Fluid and Lubricant

Recommendations .

9. Inspect the fluid level. Refer to Front Axle Lubricant Level Inspection.

10. Install the fill plug.

Tighten: Tighten the fill plug to 32 N.m (24 lb ft).

11. Install the EPS, if equipped. Refer to Engine Shield Replacement .

12. Lower the vehicle.

NOTE:

Refer to Fastener Notice .

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3

VENT HOSE REPLACEMENT

Removal Procedure

Fig. 17: View Of Engine Protection Shield
Courtesy of GENERAL MOTORS CORP.

1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .

2. Remove the engine protection shield (EPS), if equipped. Refer to Engine Shield

Replacement .

2007 Hummer H3

2007 Driveline/Axle Front Drive Axle - H3