Ford YC2Z-4204-AA
Differential Case

The differential carrier requires differential carrier maintenance that starts with an axle steam cleaning to stop abrasive dirt from shortening component life. Before draining off axle lubricant place the parking brake in position and use wheel chocks followed by removing the drain plug to transfer the fluid into an appropriate container and lastly replacing it with the clean plug. The differential carrier service requires disconnecting the rear anti-lock brake sensor electrical connection while marking and removing the driveshaft and requiring hex nut loose tightening before disassembly. The flange of the axle shaft requires careful attention when using a steel hammer to avoid damage and excessive wear, while any attempts at chiseling the hub from the shaft can harm the sealing surface so mark the shaft's orientation before replacement. Mark and measure the position of each bolt before you take out the axle shafts and carrier-to-axle housing retaining bolts except for the two that secure the top of the housing. Position the carrier on a jack while securely fastening it to protect against falling then use a suitable jack underneath to remove it from the axle housing by removing remaining bolts before separating the carrier by 25.4 - 50.8 mm (1 - 2 inches) from the axle housing. Components need cleaning through emulsion cleaners combined with petroleum-based solvents followed by drying with lintless towels. Then coat the parts lightly with rust inhibitor or clean lubricant before storing them in wax paper. An inspection must check for pitting, scoring and wear and damage on gear sets with an additional evaluation of splines for wear and cracking and deformations. Inspect and clean the flange O-ring of the axle before evaluating the interior of the axle housing and all sealing surfaces and threads of the carrier mounting bolt holes for potential thread damage and bending fatigue. The differential case and ring gear specification should be consulted when parts need to be disassembled. A continuous bead of Ford Gasket Maker F8AZ-19B508-AB should be applied to the axle housing mounting flange along with its bolt holes before inserting two studs through the housing at a 180-degree angle to stop the carrier assembly from rotating. The installation process requires first attaching the carrier to a jack before positioning it into the axle housing and cleaning the bolt threads and applying Threadlock 262 E2FZ-19554-B to the threads. Then install the bolts but keep the two alignment studs in place until several bolts are securely installed. Install the axle shafts after the cross pattern bolt tightening then reconnect the driveshaft followed by installing the rear anti-lock brake sensor electrical connection. Install Motorcraft SAE 80W-90 Premium Rear Axle Lubricant XY-80W90-QL until it reaches the fill hole, replace the plug after cleaning, take away wheel chocks and deactivate parking brake.

An axle shaft held in a vise, with the splines extending no more than three inches above the jaws, serves as an effective holding fixture for the differential case.