Wheel Hubs and Bearings
The rear hub (1109) is supported or floats on the axle spindle on two opposed tapered roller bearings. The rear hub is retained on the spindle by a ratcheting nut that is tabbed to a slot on the spindle. A seal is installed inboard of the inner rear wheel bearing to keep the rear axle and wheel bearing lubricant from the brake components. The full-floating rear axles (4001) on E-350 vehicles have the brake discs mounted outboard of the rear hub, permitting brake disc removal for brake inspection without the need to remove the rear hub.
The rear wheel bearings are packed with a lithium-base grease, Premium Long-Life Grease XG-1-C or equivalent meeting Ford specification ESA-M1C75-B, to provide initial lubrication until axle lubricant flows into the rear hubs and rear wheel bearing inner cone and rollers (1244) during vehicle operation.