Is it possible that the torque converter is not locking up? This has been seen by a few folks with the AW-4. One possible cause is the brake switch. The torque converter is supposed to disengage when you apply the brakes, so there's a switch on the peddle arm to send the signal. This may be out of adjustment.
Eract shifting can also sometimes be the culprit of the little 10 or 15 amp mini-blade fuse in the engine compartement fuse box. I'd check that first just because its easiest.