4R70W Transmission Master Rebuild Kit, 1997-2003 Ford

A master rebuild kit for the Ford 4R70W family - 4R70W, 4R70E, 4R75W and 4R75E - built for the 1997-2003 units found behind the 4.6L and 5.4L in F-150s, Expeditions, Crown Victorias, Grand Marquis and Mustangs. It carries the sealing side of an overhaul: gaskets, lip seals, sealing rings and O-rings for the pump, drums, servos and case.

Worn seals and hardened rings are where a 4R70W loses line pressure. The symptoms are the familiar ones: a slip on the 2-3 shift, delayed engagement into drive or reverse after the truck sits, a soft or flared 1-2, and fluid weeping from the front pump seal or the rear extension housing. Once the clutch pistons cannot hold apply pressure, the frictions start to burn, so resealing during a teardown is cheap insurance.

On the bench, soak every lip seal and O-ring in ATF before installing, drive the front pump and extension seals in square with a seal driver instead of a punch, and size the Teflon scarf-cut rings on the shafts before sliding the drums back over them. Clean the case and pump mating surfaces completely before laying down new gaskets. Match the tag on your case to the listed fitment before you start.