The rear transmission seal is located between the transmission housing and the transmission extension. The extension covers the overdrive gear. To change a leaky seal, you must disconnect the drive shaft from the Ranger. Although labor intensive, the task of replacing the rear transmission seal is relatively straightforward. Ford does not install a gasket between the two mating surfaces. Rather, they use RTV gasket maker for the seal.
Remove the bolts that secure the driveshaft to the rear differential union located on the rear axle. Use a socket and ratchet to remove the bolts.
Pull down on the driveshaft to remove it from the differential union. Slide the driveshaft backwards to remove the driveshaft spline from the transmission.
Remove the bolts that secure the transmission extension to the back of the transmission housing using a socket and ratchet.
Scrape the old seal off the mating surfaces of the transmission housing and the transmission extension using a scraper and shop towels.
Place a bead of RTV gasket sealer onto the mating surface of the transmission housing. Allow the RTV 20 minutes time to cure.
Place the transmission extension onto the transmission housing and secure it using the bolts, socket and ratchet.
Slide the driveshaft spline into the end of the transmission and but the other end of the driveshaft up against the rear differential union. Secure the driveshaft to the union using the socket and ratchet.
