Auto-Trans Rear Seal Replacement

Curing leaks at the driveshaft

Automatic transmissions are one of the least self-serviceable components on a vehicle. The complexity of these transmission's internal parts requires specialized knowledge to rebuild them. However, a few auto-trans woes can be cured at home.

A few auto-trans woes can be cured at home. One such problem is a leak where the driveshaft couples to the transmission on rear-drive cars and trucks. A puddle under this area and the associated fluid around the transmission's output shaft mean that the seal is likely bad. Armed with a few hand tools, the average mechanic can often fix the problem in less time than is required to deliver and pick up the vehicle from a repair shop.

Notes

> Consult a service manual for procedures specific to your vehicle.

> Park the vehicle with the front facing slightly downhill to minimize the amount of fluid that seeps out during seal replacement.

> Allow the vehicle to cool before working on it.

> After disconnecting the driveshaft, secure it out of the way with wire or other suitable restraint.

> The old seal might need to be severely disfigured in order to remove it. However, avoid gouging the transmission's output shaft and tailhousing.

> Verify that the replacement seal is the proper size before attempting to install it.

> After all components are reinstalled and the vehicle is lowered, move to level ground and check the transmission fluid level following the procedure in the owner's manual or service manual. Top off as necessary.

> Test-drive the vehicle. The leak should be fixed. If not, some other transmission and/or driveshaft component might be damaged.