The rear drive shaft of a car wears down with age. When it starts to leak oil, it is time to replace the seal. Seal replacement kits come with most, if not all, of the parts that are needed to change out the gaskets of the seal. Rear drive shaft seals can be replaced in the garage at home.
Remove the side flange of the drive shaft by prying it off with a screwdriver. Pull the flange out. Check the axle flange metal where the seal lip has polished it to see if it is worn or scratched. Replace the axle flange if the metal is in bad condition.
Insert the seal or gasket puller tool, placing it under the gasket and prying it out of the drive shaft. Use the needle-nose pliers to remove the C-clip.
Remove the nuts from the axle flange cups with a socket wrench. Take care when you pry them off with a crowbar to note where each shim is located so that you can put them back in the proper order. Pull off the differential carrier cover. Pull the bearing cup out of it.
Remove the shim on the bearing cup and it set aside. Replace the O-ring by gently prying it off of the cup with a pencil and pulling it off. Slide the new O-ring into place and then rub gear oil onto it.
Place a light layer of gear sealer around the outside of the metal ring of the replacement seal. Tap the seal into place with a seal driver.
Clean off the shim mounting face with the brake cleaner and a gasket scraper. Wipe the surface off with paper towel. Push the bearing cup back into place by lifting up the differential carrier and sliding it over the side bearing.
Put the bolts back on in a crisscross alternating pattern. The torque for the bolts should be 16 foot-pounds of torque.
Insert the new C-clip with the needle-nose pliers. Reattach the axle flange, sliding it into place by gently turning it as you push until the splines fit together and the C-clip locks into place.
Clean off the cover gasket surface with brake cleaner and a gasket scraper. Put the paper cover gasket onto the gasket surface. Run a small bead of RTV silicone gasket maker onto the paper gasket cover. Put the cover back on and secure into place with bolts, installing them in a crisscross pattern at 33 foot-pounds of torque.
