The hub and bearing assembly cannot be fixed; you must replace it whenever it's faulty. When changing the rear hub/bearing assembly on Expedition/Navigator models with independent rear suspension, just follow the same steps as for fronts hubs/bearing units. First, activate Drive and apply the parking brake. Loosen the drive-axle/hubnut with a socket and large breaker bar. Turn the air suspension system off if your vehicle has it by using the switch below the right kick panel. Before you start working, free up the wheel lug nuts, lift the car, and place it on stable jackstands. Then remove the wheel, along with the driveaxle/hub nut. Carefully take off the brake caliper and secure its wire to hang on the side. After that, remove the caliper anchor bracket and brake disc. Before removing the driveaxle in models with 4-wheel ABS, take off the splash shield from the steering knuckle, unscrew the sensor bolt from the knuckle, and place the sensor and wires in a safe location. Split the driveaxle ends from the wheel hub on Expedition/Navigator models with independent rear suspension by using a puller tool. Pull the bolt connecting the hub to steering knuckle, then wiggle the hub while holding it side to side to loosen it from the steering knuckle, carefully taking the hub away from the driveaxle. Wrap a rag around the driveaxle's free end to protect it from getting scratched. If the hub won't move off the splines, grab a puller to help get it going. To put it back in, make sure you use multi-purpose grease on the driveaxle splines and tighten all fasteners. Also, replace the O-ring at the hub-to-knuckle joint if your vehicle has one.