A Ford pinion seal is located in front of the vehicle's differential, where the driveshaft meets the differential. The pinion seal holds the differential fluid inside the differential. As the driveshaft rotates, it transfers the engine torque to the differential, where the ring and pinion gears then send the torque outward to the rear wheels. Over time, this power transfer can wear out a pinion seal, causing it to leak; should the seal begin to leak, you'll need to change it. Anyone with good auto-repair skills can change a Ford pinion seal in under an hour.
Set the drain pan under the front of the Ford's differential. Clean the area around the pinion seal with brake cleaner and rags.
Place the jack stand off to the side of the Ford's driveshaft. Unbolt the driveshaft from the pinion yoke with the socket set. Move the driveshaft over, and support it on the jack stand. Pull the pinion yoke out, by hand.
Remove the Ford's old pinion seal with the seal puller, which you can purchase at most auto parts stores or tool retailers. Set the old seal aside. Wipe the area clean with a rag.
Hold the Ford's new pinion seal in place and tap it in with the rubber mallet until the lip of the seal is flush with the differential.
Slide the pinion yoke onto the new seal, by hand. Move the driveshaft over and bolt it back in place, using the socket set.
Remove the fill plug from the side of the Ford's differential, using the socket wrench. Fill the differential until the fluid reaches the bottom lip of the filler hole. Reinstall the filler plug, using the socket wrench.
