4R100 Transmission Dipstick Fill Tube XC3Z-7A160-AA

This is a replacement transmission dipstick fill tube for Ford Super Duty and E-Series trucks with the 7.3L, 6.0L or 6.4L Powerstroke diesel, covering the E4OD, 4R100 and 5R110 automatics from 1989 to 2010. It replaces Ford XC3Z-7A160-AA. The tube has a machined aluminum base that plugs into the transmission case and three oil-resistant O-rings on the sealing end.

The factory tube seals to the case with a single O-ring that hardens with heat. Once it shrinks, ATF weeps out at the base of the tube and runs down the side of the pan, which is easy to mistake for a pan gasket or cooler line leak. Clean the case around the tube and check whether the wet trail starts at the tube base before buying a pan gasket.

On most trucks the tube can be changed without dropping the transmission. Remove the dipstick and the bracket bolt that holds the tube, twist and pull the old tube out of the case bore, and clean any old O-ring material out of the bore. Lube the new O-rings with clean ATF, push the tube straight in until it seats, refit the bracket bolt, then check the fluid level with the engine running and the transmission at operating temperature.