Transfer case is overfilled with transfer case oil.

Drain the transfer case to the proper oil level. Refer to Transfer Case Fluid Replacement .

The vent hose is kinked or plugged.

1. Inspect the vent hose for kinks or plugging.
2. Reroute or unplug the vent hose as necessary.

Output shaft seal is damaged or improperly installed.

Replace the leaking output shaft seal.

For the front output shaft seal, refer to Front Output Shaft Seal Replacement .

For the rear output shaft seal, refer to Rear Output Shaft Seal Replacement .

Loose transfer case bolts

Tighten the transfer case bolts. Refer to Fastener Tightening Specifications .

Plug is loose or missing a thread sealant.

Perform the following procedures:

Bearing or chain worn

Inspect the inside of the transfer case for worn parts.

Low oil level

1. Check the oil level.
2. Add oil if necessary. Refer to Transfer Case Fluid Replacement .

Front or rear propeller shaft is bent or out of balance

1. Inspect the propeller shaft for damage.
2. Balance or replace the propeller shaft if necessary.

For front propeller shaft replacement, refer to Front Propeller Shaft Replacement in Propeller Shaft.

For vehicles equipped with the one piece rear propeller shaft, refer to One-Piece Propeller Shaft Replacement in Propeller Shaft.

For vehicles equipped the two piece rear propeller shaft, refer to Two-Piece Propeller Shaft Replacement in Propeller Shaft.

Front propeller shaft CV-joint is worn or damaged

1. Inspect the propeller shaft for damage.
2. Replace the front propeller shaft if necessary.

Refer to Front Propeller Shaft Replacement in Propeller Shaft.