GM Service Manual Online
For 1990-2009 cars only

Cause

Correction

DEFINITION: A faulty internal transfer case component that causes a growl or grinding noise in the transfer case, usually while the vehicle is turning.

Review the Symptoms - Transfer Case and perform the necessary inspections.

Planetary carrier

  1. Inspect the planetary carrier pinion gears for the following conditions:
  2. • Chipped, bent or deformed teeth
    • Pinion gear bushings worn
    • Pinion gear thrust washers missing
    • Seized or binding pinion gears
  3. Inspect the planetary carrier for deformation. Refer to Transfer Case Cleaning and Inspection.
  4. Replace the planetary carrier assembly if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble.

Annulus gear

  1. Inspect the annulus gear for teeth damage or wear. Refer to Transfer Case Cleaning and Inspection.
  2. Replace the annulus gear if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble.

Sun gear

  1. Inspect the sun gear for the following conditions:
  2. • Gear tooth failure
    • Worn or galled thrust surfaces
  3. Replace the sun gear if faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble.

Thrust washer

  1. Inspect the thrust washer for seizure to the planetary carrier.
  2. Inspect the thrust washer for galling.
  3. Replace the thrust washer if faulty, and the mating component if damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble.