GM Service Manual Online
For 1990-2009 cars only

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.

Drain plug or fill plug leak

  1. Inspect for the correct sealer and the correct amount of sealer on the plugs. Refer to Adhesives, Fluids, Lubricants, and Sealers .
  2. Install the plugs correctly. Refer to Transfer Case Fluid Replacement .

Input seal leaking

  1. Inspect for the following conditions:
  2. • Overfilled or improper transfer case fluid
    • Blocked vent
    • Seal improperly installed, worn or damaged
    • Seal bore damaged or cracked
    • Input flange surface for wear or pitting
  3. Repair or replace the following components if found faulty:
  4. • Adjust or replace the transfer case fluid.
    • Clean or properly route the vent hose.
    • Replace the input seal.
    • Replace the front case half if the seal bore is damaged.
    • Replace the input flange if the surface could cause leakage.

Rear output seal leaking

  1. Inspect for the following conditions:
  2. • Overfilled or improper transfer case fluid
    • Blocked vent
    • Seal improperly installed, worn or damaged
    • Seal bore damaged or cracked
    • Rear needle bearing for excessive wear
    • Rear output flange surface for wear or pitting
  3. Repair or replace the following components if found faulty:
  4. • Adjust or replace the transfer case fluid. Refer to Transfer Case Fluid Replacement .
    • Clean or properly route the vent hose.
    • Replace the rear output seal. Refer to Rear Output Shaft Seal Replacement .
    • Replace the retainer assembly if the seal bore is damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble .
    • Replace the rear needle bearing if worn. Refer to Transfer Case Disassemble and Transfer Case Assemble .
    • Replace the rear output flange if the surface could cause leakage. Refer to Rear Output Shaft Seal Replacement .

Front output seal leaking

  1. Inspect for the following conditions:
  2. • Overfilled or improper transfer case fluid
    • Blocked vent
    • Seal improperly installed, worn or damaged
    • Seal bore damaged or cracked
    • Front output flange surface for wear or pitting
  3. Repair or replace the following components if found faulty:
  4. • Adjust or replace the transfer case fluid. Refer to Transfer Case Fluid Replacement .
    • Clean or properly route the vent hose.
    • Replace the front output seal. Refer to Front Output Shaft Seal Replacement .
    • Replace the front case half if the seal bore is damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble .
    • Replace the front output flange if the surface could cause leakage. Refer to Front Output Shaft Seal Replacement .

Sector bearing leaking

Replace the sector bearing. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Leaking at the vent tube

  1. The transfer case is overfilled.
  2. Inspect for the correct transfer case fluid level. Refer to Transfer Case Fluid Replacement .

  3. Inspect for a damaged or missing vent tube.
  4. Replace a damaged or missing vent and seal the vent tube with the correct sealer. Refer to Transfer Case Assemble .

Case leaking

  1. Inspect for the following conditions:
  2. • A cracked case
    • Case porosity
  3. Replace the faulty case half. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Front case half to rear case half seam leak

Disassemble and seal the case halves. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Retainer assembly to rear case half seam leak

Disassemble and seal the seam leak. Refer to Transfer Case Disassemble and Transfer Case Assemble .