Ford XW4Z-4204-AA
Differential Case

The Ford 8.8-inch rear differential requires repair and maintenance after vehicle lifting and wheel support followed by tire removal. Drain the lubricant after removing the brake drum (1126) as well as the differential housing cover (4033). You must discard the bolt and extract the shaft of the differential pinion (4211). When removing the U-washer (4N237) through the rubber O-ring (4A332) groove of the U-washer you should avoid pushing the axle shaft (4234) towards the inside of the assembly. Perform the extraction of the axle shaft while you keep the wheel bearing oil seal (1177) from any kind of damage. The wheel bearing oil seal requires greasing before installation while positioning the U-washer on the axle shaft button end and extending the axle shaft outward but avoiding damage to the rubber O-ring in the U-washer groove. The existing bolt should have its threads coated with threadlock as an alternative to obtaining a new bolt when installing the differential pinion shaft by positioning the bolt hole on the shaft to match the case and tightening it with the new bolt. After filling the differential housing with proper lubricant one should install the brake drum and differential housing cover and put on the rear wheel and tire assembly while lowering the vehicle.

Begin repairs and servicing of the Ford 7.5-inch rear differential by first lifting the vehicle and securing it. Then remove the wheel along with the tire from the assembly. You need to place lubricant drainage into clean storage and then separate the differential housing cover (4033) through its 10 bolts which need removal. The lubricant draining process of the 4010 rear axle housing must be completed before proceeding to remove both differential housing cover and rear brake drums. Under the following step remove the differential pinion shaft while using the lock bolt removal method to pull out the shaft. It is crucial to maintain caution during U-washer removal because damaging the rubber O-rings inside axle shaft grooves can occur when pushing the axle shafts inside. Extract the wheel bearing oil seal without damaging it while removing the two axle shafts. Wash the machined areas on the rear axle housing and differential housing cover while keeping the inside of the rear axle (4001) shielded from contaminants during the procedure. The axle shafts should get installed while using grease to lubricate the lip of the wheel bearing oil seal and avoiding damage to the rubber O-rings. Position the U-washers at the end of axle shaft buttons then extend the shafts outward. Threadlock and sealer should be applied to new pinion shaft lock bolt threads when no alternative bolt is available to secure the differential pinion shaft by aligning it with the case lock bolt hole. The differential housing cover needs a new continuous bead of specified thickness sealant which must be installed within 15 minutes after application to prevent needing new sealant. Filling the rear axle housing with 2.4 liters (5 pints) of lubricant should be done after installing the differential housing cover which must be secured with all ten bolts. Reinstall the wheels and tires and lower the vehicle.

Reinstall the rear brake drums for drum brake vehicles or the rear brake disc and caliper for disc brake vehicles.

Align the hole in the shaft with the case lock bolt hole and secure it with a new lock bolt.

Lubricate the lip of the wheel bearing oil seal with grease.

Lubricate the lip of the wheel bearing oil seal with Premium Long-Life Grease XG-1-C or an equivalent meeting Ford specification ESA-MIC75-B.