My 4R70W is making me pull the hair out of my head! I own a 1999 F150 4X4 5.4L and last week my OD light started flashing. When this began, my transmission would SLAM hard on the downshifts (not sure which gears) when slowing down from speeds of over 55mph. When braking hard, it almost felt like my ABS brakes were kicking in for a brief second when I was coming to a complete stop.

I took it to my local Ford dealer, and they diagnosed it with the following:
"Trans tested, code p0781 found also noted burnt fluid. SSA and SSB found, would command on/off. Concern is internal, would have to dissassemble trans to diagnose further."

Last night the OD light was flashing and I turned the OD on & off and also noted a hard clunking that was similar to that I was feeling when braking. I changed the 1-2 accumulator piston and springs, and the shift solenoids with no results. Also changed with fresh Mercon V fluid and filter (drained the TC too).

I ordered a VSS for the tailshaft area and will put that in tomorrow after work. Has anybody experienced anything like this or can anybody offer help??
I don't want to change the tranny as the Ford dealer wants to because I feel this is electrical. When the OD light stays off, the truck is fine (like the way home from work today).

Please help!

Dago

 

Are you just going to ignore the 781 code?
It's a 1 to 2 shift error causing all the problems.
Until some one finds what the error is, you will keep having the problem.

 

I am not going to ignore the code.....just looking for advice if someone else has been through this battle. I bought a VSS today, but I don't see it on the transmission-must be sharing the rear diff. sensor with the ABs system.

Please help....


Dago

 

With the 5.4 engine I don't think you have a 4R70W. I was to believe the 5.4 came with an E40D or something like that.