The rear axle on a 2000 Ford F-250 uses an axle seal mounted on the axle shaft. This O-ring stops the fluid held in the axle assembly from leaking out of the axle, which would cause the rear end gears to potentially seize and break. If this seal does go out, you will need to install a new one as soon as possible so that your axle doesn't fail. Installing a new axle seal takes about an hour.
Park the F-250 on a level surface. Position yourself in front of the rear axle seal that's leaking or that you want to replace so that you're facing the tire.
Unbolt the axle shaft in the center of the wheel using the 3/8-inch ratchet and socket and discard the stock bolts. Tap the sides of the axle shaft using the soft-faced hammer to break it free from the axle, then pull the axle shaft out of the axle.
Locate the axle seal, which is an O-ring located on the outside end of the axle shaft. Slide the stock axle seal off the axle shaft using your hands. Install the replacement axle seal onto the axle shaft with your hands.
Slide the axle shaft into the axle housing using both hands. Install the axle shaft replacement bolts using the 3/8-inch ratchet and socket.
