GM Service Manual Online
For 1990-2009 cars only

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.

Broken high/low range shift fork pads

Replace the high/low range shift fork pads or other damaged components. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Faulty high/low range shift fork

  1. Inspect the high/low range shift fork for being damaged. Refer to Transfer Case Cleaning and Inspection .
  2. Replace the shift fork if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Faulty high speed teeth on the range sleeve

  1. Inspect for the following conditions:
  2. • The input gear high speed engagement teeth for wear or damage
    • The engagement teeth on the range sleeve for wear or damage
  3. Replace the range sleeve if the teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .
  4. Replace the input gear if the engagement teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

High/low range shift fork bushing and springs

  1. Inspect the high/low range shift fork springs for being faulty.
  2. Inspect the range fork shaft bushing for wear.
  3. Refer to Transfer Case Cleaning and Inspection .

  4. Replace the high/low range shift fork if the springs or bushings are faulty. Refer to Transfer Case Assemble .

High/low planetary carrier

  1. Inspect the high/low planetary carrier for the following conditions:
  2. • Low speed engagement teeth worn or damaged
    • Cracked carrier housing
    • Pinion gear worn or out of position
    • Pinion gears broken or damaged teeth
    • Pinion gears seized
  3. Replace the high/low planetary carrier if any of the above conditions are found. Refer to Transfer Case Disassemble and Transfer Case Assemble .

2/4 Wheel drive synchronizer gear

  1. Inspect the 2/4 wheel drive synchronizer gear for worn engagement teeth.
  2. Replace the synchronizer gear if faulty. Refer to Transfer Case Assemble .