What are Transmission Seals?
The input shaft seal, also called the front transmission seal, prevents fluid from slipping past the input shaft. The input shaft inserts into the torque converter or clutch disk, depending on whether the vehicle is equipped with an automatic or manual transmission.
The output shaft seal, sometimes called the rear transmission seal or driveshaft seal, prevents fluid from escaping where the driveshaft yoke slips into the transmission. Front-wheel drive vehicles have two “rear” transmission seals, one for each axle.