BW4406 Transfer Case Bearing & Seal Rebuild Kit, Ford F150

This is the complete bearing and seal set for rebuilding a Borg-Warner 4406 transfer case. It covers the electric-shift and manual-shift 4406 units found in 1997-2003 Ford F150 and F250 with the 4.2L, 4.6L and 5.4L, 1997-2002 Expedition with the 4.6L and 5.4L, and 1998-2002 Lincoln Navigator with the 5.4L. Check the case half for the cast "44-06" identification before ordering. The 4406 is easy to confuse with the 4404 and 4411 used in the Explorer line, and those take a different bearing set.

The 4406 usually comes apart for one of three reasons: a growling front output bearing, ATF weeping past the rear output seal onto the driveshaft, or a rear case half that has been leaking at the mating surface long enough to run the case low. All three are bearing and seal jobs, not hard-part jobs, which is why this kit gets the unit back together without buying a remanufactured case. If the chain has stretched enough to slap the case, replace the chain at the same time; it is sold separately.

On the bench, split the case, pull the chain and sprockets, then press out the front and rear output bearings and the input bearing. Clean both case halves down to bare metal at the sealing surface, since the 4406 uses RTV rather than a paper gasket at the case split, and any leftover ridge will leak again. Press the new bearings in square, install the new output seals with a proper seal driver so the garter spring stays seated, and torque the case bolts evenly in a crossing pattern. Fill with Motorcraft MERCON V unless the tag on your case specifies otherwise.