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 amount of sealer on the plugs.
2. Correctly install the plugs. Refer to Transfer Case Fluid Replacement .

Vehicle speed sensor (VSS) leaking

1. Remove the VSS and inspect for the following conditions:

•	Cross threaded

•	Cut or damaged O-ring seal

•	VSS over tightened causing deformation in the VSS

•	Refer to Transfer Case Front Output Shaft Speed Sensor Replacement or Transfer Case Rear Output Shaft Speed Sensor Replacement - Left Side or Transfer Case Rear Output Shaft Speed Sensor Replacement - Right Side .

2. Replace the VSS O-ring seal if it is faulty. Refer to Transfer Case Front Output Shaft Speed Sensor Replacement or Transfer Case Rear Output Shaft Speed Sensor Replacement - Left Side or Transfer Case Rear Output Shaft Speed Sensor Replacement - Right Side .
3. Replace the VSS if it is faulty. Refer to Transfer Case Front Output Shaft Speed Sensor Replacement or Transfer Case Rear Output Shaft Speed Sensor Replacement - Left Side or Transfer Case Rear Output Shaft Speed Sensor Replacement - Right Side .

Encoder motor area leak

1. Remove the encoder motor and inspect for the following conditions:

•	Inspect the encoder motor insulator for cracks.

•	Inspect for a faulty control actuator lever shaft bearing.

•	Inspect the actuator lever shaft for wear or damage.

•	Refer to Transfer Case Encoder Motor Replacement .

2. Repair or replace the following components if found faulty:

•	Replace the encoder motor insulator if it is cracked. Refer to Transfer Case Encoder Motor Replacement .

•	Replace the control actuator lever shaft bearing if it is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

•	Replace the control actuator lever shaft if the bearing or seal surface is faulty. Refer to Transfer Case Disassemble and Transfer Case Assemble .

Rear output shaft seal leaking

1. Inspect for the following conditions:

•	Overfilled or improper transfer case fluid

•	Blocked vent

•	Seal improperly installed, worn or damaged

•	Seal bore damaged or cracked

•	Rear output shaft bushing for excessive wear

•	Slip yoke seal surface for wear or pitting

2. Repair or replace the following components if found faulty:

•	Adjust or replace the transfer case fluid. Refer to Transfer Case Fluid Replacement .

•	Clean or properly route the vent hose.

•	Replace the slip yoke if the surface could cause leakage. Refer to Rear Propeller Shaft Replacement .

•	Replace the rear bushing if it is worn. Refer to Rear Output Shaft Seal Replacement .

•	Replace the rear case half if the seal bore is damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble .

•	Replace the rear output shaft seal. Refer to Rear Output Shaft Seal Replacement .

Front output shaft seal leaking

1. Inspect for the following conditions:

•	Overfilled or improper transfer case fluid

•	Blocked vent

•	Seal improperly installed, worn or damaged

•	Seal bore damaged or cracked

2. Repair or replace the following components if found faulty:

•	Adjust or replace the transfer case fluid. Refer to Transfer Case Fluid Replacement .

•	Clean or properly route the vent hose.

•	Replace the front case half if the seal bore is damaged. Refer to Transfer Case Disassemble and Transfer Case Assemble .

•	Replace the front output shaft seal. Refer to Front Output Shaft Seal Replacement .

Leaking at the vent

Transfer case to adapter leak

1. Inspect for the following conditions:

•	Loose mounting fasteners

•	Gasket or sealant faulty

•	The transfer case input shaft seal leaking

2. Repair or replace the following components if found faulty:

•	Replace the transfer case input shaft seal. Refer to Input Shaft Seal Replacement .

•	Inspect for the following conditions:

-	Seal improperly installed, worn or damaged

-	Seal bore damaged or cracked

-	Input shaft seal surface worn, grooved or damaged

•	Repair or replace the loose fasteners. Refer to Transfer Case Adapter Replacement .

•	Replace the transfer case gasket. Refer to Transfer Case Adapter Replacement .

Front case half to rear case half seam leak

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

Case leaking

1. Inspect for a cracked case or case porosity.
2. Replace the faulty case half. Refer to Transfer Case Disassemble and Transfer Case Assemble .