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.

Shift linkage worn

Inspect the shift linkage for correct adjustment or for being worn. Refer to Transfer Case Control Lever Replacement and Transfer Case Control Rod Replacement .

Melted 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 shaft if the input gear engagement teeth are faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble.

High/low range shift fork

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

  4. Replace the high/low range shift fork if 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 bushings 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 Cleaning and Inspection.