97 f-150 4.2 4r70w
when accelerating from stop truck shifts from first thru fourth in a few seconds causing the truck to lug. when reaching fourth it downshifts - upshifts constantly until reaching highway speeds where it seems ok. when decelerating it does not downshift causing the truck to die sometimes when stopping unless shifting to neutral where lo and behold it all begins again. the problem was intermittent at first but now the tranny likes this mode full time.
had a local auto supply run the fault code, (forgot the number,
too many brews) but something about converter clutch sensor.
what's up ? any help would be appreciated, thanks.

 

I would try replacing the Torque Converter Clutch soleniod first, with a fluid and filter change(drain the converter too). If you find alot of contamination (which could cause the TCC solenoid to stick) you will need to just replace the transmission and flush the cooler good.
Alan

 

great call, took the truck to a local tranny shop and had it fixed.
combination of the solenoid and a short to ground in the harness behind the block. thanks again, you know your stuff.