Fluid Leak Detection - AWD

The following procedure is for detecting transaxle fluid leaks from the area between the transaxle and the Power Transfer Unit (PTU). When transaxle fluid is leaking form the weep hole in the area of the PTU, the seals around the differential output shaft and the differential side gear is most likely faulty. The large seal around the differential output shaft is serviceable without removing the transaxle. The seal around the inner differential side gear is serviceable after the differential unit is removed from the transaxle. The following procedure is recommended to determine which seal is leaking.

1. Disconnect the transaxle vent tube from the adaptor nipple on the top of the valve body pan.
2. Adapt a compressed shop air coupling and a length neoprene hose onto the vent nipple.
3. Attach a 48 kPa (7 psi) regulated shop air source to the air coupling on the vent nipple.
4. Raise the vehicle on a suitable hoist.
5. Remove the PTU from the vehicle. Refer to REMOVAL .
6. Apply a soapy solution to the seals inside and around the differential output shaft.
7. Observe over several minutes to see if air bubbles form in the leak area.

Test Results 

• If bubbles are emanating from the inner differential side gear seal, remove the differential unit and replace the inner seal.
• If bubbles are emanating from the outer output shaft seal, replace the seal.
• If bubbles are emanating from the transaxle housing casting, replace the porous component.