4R70W Transmission is slipping momentarily during full throttle downshifts. Normal acceleration is perfect with no slip...even half throttle only slips half the time, if that often. Trans temp runs around 140-160 deg. in 95-100 deg. weather, in town. Any idea of an inexpensive, temporary remedy for this?

I have an 02 King Ranch 4wd F150 with:
*5.4L engine with 03 Harley Supercharger running 6psi of boost
*5.13 gears front and rear
*38x15.50 tires
*2 factory upstream converters (rears removed) with single in/out flowmaster 40 series
*137,000 miles
*STOCK transmission

I know with these mods I need a beefed up tranny, but it's not in the budget right now. Looking for something to do to hold me over till I can.

Any suggestions?

 

Stop cramming it to the floor until you can afford to get it fixed.

 

Flush the fluid and use a premium synthetic fluid such as Amsoil. Get a programmer and talk to a good custom tuner about tunes to tighten up the tranny behavior.