Transfer Case Leak Diagnosis

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

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	Inspect for the correct sealer and the correct amount of sealer on the plugs. Install the plugs correctly. Refer to Transfer Case Fluid Replacement .
Input/output or front output seal leaking	Inspect for the following conditions: Overfilled or improper transfer case fluid Blocked vent Seal improperly installed, worn, or damaged Seal bore damaged or cracked Repair or replace the following components if found faulty: Adjust or replace the transfer case fluid. Refer to Transfer Case Fluid Replacement . Replace the case half, or case halves, if the seal bores are damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble . Replace the input/output shaft seal. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Leaking at the vent	Leaking vent or input seal will be noticed from a weep hole between the adapter and the transfer case. Transfer case overfilled Inspect for the correct transfer case fluid level. Refer to Transfer Case Fluid Replacement . Damaged O-ring on the vent Transmission output shaft seal leak will be noticed from a weep hole between the adapter and the transfer case.
Case half seam leak	Disassemble and seal the case halves. Refer to Transfer Case Disassemble and Transfer Case Assemble .
Case leaking	Inspect for a cracked case or case porosity. Replace the faulty case half. Refer to Transfer Case Disassemble and Transfer Case Assemble .