If the tran is sound and the torque converter can be drained, service the tranny and refill with Chrysler ATF+4....it's amazing what that stuff does for Ford transmissions.

I have an AODE (155K miles) and a 4R70W (121K miles) both filled with ATF+4 and the trans work flawlessly.

The 4R70W is in my 97 F150XLT; yesterday it was serviced and refilled with ATF+4 and a significant improvement in performance was immediately noticeable....smooth, firm shifts, no TC clutch shudder. (The 4R70W and AODE are noted for 3-4 synchronous lock of the planetary gear set. That transition is vastly improved in quality with the ATF+4 compared to the standard fluid. )