Hummer H3. Manual — part 1679

Excessively worn gear surfaces

Slight wear marks are normal.

Debris embedded in the root of the teeth

4. Replace the lockup shift collar assembly if it is faulty. The lockup shift collar assembly

components are not serviced separately.

Drive Chain and Sprockets

Fig. 86: Drive Chain and Sprockets
Courtesy of GENERAL MOTORS CORP.

1. Clean the drive chain (1), drive sprocket (2) and driven sprocket (3) in cleaning solvent and

air dry.

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3

2. Inspect the drive chain (1) for the following conditions:

Loose link pins

Binding or stiff links

Debris embedded in the links

Worn teeth surfaces

3. Replace the chain if any of the above conditions are found.

4. Inspect the driven sprocket (3) and the drive sprocket (2) for the following conditions:

Chipped teeth

Excessively worn gear surfaces

Slight wear marks are normal.

Debris embedded in the root of the teeth

5. Inspect the drive sprocket (2) for the following conditions:

Lockup shift engagement teeth for chipping

Lockup shift engagement teeth for excessive wear

6. Inspect the drive sprocket bushing for the following conditions:

Excessive wear

Scoring

7. Replace the sprockets if any of the above conditions are found. The chain and sprockets may

be replaced separately.

Mainshaft

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3

Fig. 87: Mainshaft
Courtesy of GENERAL MOTORS CORP.

1. Clean the mainshaft in cleaning solvent.

2. Clean the mainshaft oil galleries (1) and air dry.

3. Inspect the front support bearing (2), drive gear bushing (4), front output sun gear (5) and

the rear support bushing (6) bearing journals on the mainshaft for the following conditions:

Scoring

Pitting

Brinelling

Excessive wear

4. Inspect the mainshaft range collar splines (3) for damage or excessive wear. Witness marks

at the location of the gear is normal.

5. Replace the mainshaft if any of the above conditions are found.

Front Output Shaft

IMPORTANT: Do not attempt to smooth any roughness in the bearing

journals.

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3

Fig. 88: Front Output Shaft
Courtesy of GENERAL MOTORS CORP.

1. Clean the front output shaft in cleaning solvent and air dry.

2. Inspect for spun bearings at the front output shaft bearing areas.

3. Inspect the front output internal splines and driven gear splines for damage or excessive

wear.

4. Replace the front output shaft if it is damaged.

Rear Output Shaft

Fig. 89: Rear Output Shaft
Courtesy of GENERAL MOTORS CORP.

1. Clean the rear output shaft, with rear output shaft bearing, in cleaning solvent.

2. Air dry and ensure all solvent is removed from the bearing.

3. Inspect the speed sensor tone wheel for damage.

2007 Hummer H3

2007 TRANSMISSION Transfer Case - BW 4493/4494 - H3