Hummer H2. Manual - part 2660

TRANSFER CASE WILL NOT SHIFT 

Transfer Case Will Not Shift 

z

Pinion gear bushings worn  

z

Pinion gear thrust washers missing  

z

Seized or binding pinion gears 

Refer to Cleaning and Inspection . 

2. Inspect the planetary differential for deformation. Refer to Cleaning and 

Inspection .  

3. Replace the planetary differential assembly if it is faulty. Refer to Transfer 

Case Disassemble and Transfer Case Assemble .  

Thrust washers

1. Inspect the thrust washers for seizure to the planetary differential.  

2. Replace the thrust washers if they are faulty and the mating component if it is 

damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble . 

Planetary 
differential not 
timed properly

1. Inspect the planetary differential for being timed properly. Refer to Transfer 

Case Assemble .  

2. Properly time the planetary differential gears. Refer to Transfer Case 

Assemble .  

Cause

Correction

DEFINITION: While shifting from HI range to LO range, there is gear clashing, no HI range, or the 
transfer case will not shift from 4HI to 4HI Lock. 
Review the Symptoms - Transfer Case and perform the necessary inspections.
Shift detent lever

z

Inspect for the following conditions: 

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The shift detent lever at the shift fork cams for being worn  

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The shift detent lever torsion spring for being faulty 

Refer to Cleaning and Inspection . 

z

Replace the following components if found faulty: 

z

The shift detent lever cam  

z

The shift detent lever spring 

Refer to Transfer Case Disassemble and Transfer Case Assemble .

High/low range shift 
fork

1. Inspect the high low shift fork for the following conditions: 

z

Worn shift fork pads  

z

The roller on the shift fork for wear or damage  

z

Cracked or bent shift fork 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2

  

Refer to Cleaning and Inspection . 

2. Replace the following components if found faulty: 

z

The shift fork pads  

z

The shift fork 

Refer to Transfer Case Disassemble and Transfer Case Assemble .

Range sleeve

1. Inspect the range sleeve for the following conditions: 

z

Engagement teeth for burrs or damage  

z

Sliding freely on the mainshaft  

z

The range sleeve shift fork collar for excessive wear 

Refer to Cleaning and Inspection . 

2. Replace the range sleeve if it is faulty. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

High/low planetary 
carrier

1. Inspect the high/low planetary engagement teeth for burrs or damage. Refer 

to Cleaning and Inspection .  

2. Replace the high/low planetary carrier if it is faulty. Refer to Transfer 

Case Disassemble and Transfer Case Assemble .  

Mainshaft front 
support bearing

1. Inspect for the following conditions: 

z

Failed front mainshaft support bearing in the input gear  

z

Journal on the mainshaft for excessive wear or damage 

Refer to Cleaning and Inspection . 

2. Replace the bearing if it is faulty. Refer to Transfer Case Disassemble and 

Transfer Case Assemble .  

3. Replace the mainshaft if it is damaged. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

Lockup shift 
assembly

1. Inspect the lockup shift assembly for the following conditions: 

z

Shift assembly hub for binding  

z

Shift assembly sleeve for damage  

z

Burred or damaged engagement teeth 

Refer to Cleaning and Inspection . 

2. Replace the shift assembly if it is faulty. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

Drive sprocket

1. Inspect for the following conditions: 

z

Engagement teeth on the drive sprocket for burrs or damage  

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2

  

TRANSFER CASE JUMPS OUT OF GEAR 

Transfer Case Jumps Out of Gear 

z

Worn bushing in the drive sprocket  

z

Journal on the mainshaft for excessive wear or damage 

Refer to Cleaning and Inspection . 

2. Replace the drive gear if it is damaged. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

3. Replace the mainshaft if it is damaged. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

Cause

Correction

DEFINITION: Loss of the transfer case drive torque during deceleration, acceleration, or under load. 
Review the Symptoms - Transfer Case and perform the necessary inspections.
Shift detent cam worn

1. Inspect for excessive wear on the shift detent cam, not allowing full shift 

fork travel. Refer to Cleaning and Inspection .  

2. Replace the faulty shift detent cam. Refer to Transfer Case Disassemble 

and Transfer Case Assemble .  

High/low shift fork 
pads

1. Inspect the shift fork pads for wear. Refer to Cleaning and Inspection .  

2. Replace the fork pads or other damaged components. Refer to Transfer 

Case Disassemble and Transfer Case Assemble .  

Faulty high speed 
teeth on range sleeve

1. Inspect for the following conditions: 

z

The input gear high speed engagement teeth for wear or damage  

z

The engagement teeth on the range sleeve for wear or damage 

Refer to Cleaning and Inspection . 

2. Replace the range sleeve if the teeth are faulty. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

3. Replace the high/low planetary carrier assembly if the input gear 

engagement teeth are faulty. Refer to Transfer Case Disassemble and 
Transfer Case Assemble .  

High/low planetary 
carrier

1. Inspect the high/low planetary carrier for the following conditions: 

z

Low speed engagement teeth worn or damaged  

z

Cracked carrier housing  

z

Pinion gear bushings worn or out of position  

z

Pinion gears broken or damaged teeth  

z

Pinion gears seized 

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2

  

TRANSFER CASE LEAK DIAGNOSIS 

Transfer Case Leak Diagnosis 

Refer to Cleaning and Inspection . 

2. Replace the high/low planetary carrier if any of the above conditions are 

found. Refer to Transfer Case Disassemble and Transfer Case 
Assemble .  

Faulty high/low range 
fork

1. Inspect the high/low range fork for damage or wear. Refer to Cleaning and 

Inspection .  

2. Replace the high/low range fork if it is faulty. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

Lockup shift 
assembly

1. Inspect the lockup shift assembly for the following conditions: 

z

Worn or damaged sleeve  

z

Lock up collar teeth worn or damaged 

Refer to Cleaning and Inspection . 

2. Replace the lockup shift assembly if it is faulty. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

Planetary differential

1. Inspect the planetary differential for the following conditions: 

z

Cracked carrier housing  

z

Pinion gear bushings worn or out of position  

z

Pinion gears broken or damaged teeth  

z

Pinion gears seized 

Refer to Cleaning and Inspection . 

2. Replace the planetary differential if any of the above conditions are found. 

Refer to Transfer Case Disassemble and Transfer Case Assemble .  

Mainshaft front 
support bearing

1. Inspect the bearing in the input gear and the mainshaft journal for excessive 

wear. Refer to Cleaning and Inspection .  

2. Replace the bearing and the mainshaft if they are faulty. Refer to Transfer 

Case Disassemble and Transfer Case Assemble .  

Sun gears

1. Inspect the sun gears for broken or damaged teeth. Refer to Cleaning and 

Inspection .  

2. Replace the sun gears if they are faulty. Refer to Transfer Case 

Disassemble and Transfer Case Assemble .  

Cause

Correction

DEFINITION: A visible indication of an external fluid leak from the transfer case. 
Review the Symptoms - Transfer Case and perform the necessary inspections.

 

2004 Hummer H2 

2004 DRIVELINE/AXLE Transfer Case - BW 4484 - Hummer H2