tranny problems cant figure out

[97internationalstroker]

My e4od in my 97 f250 will shift fine through all the gear then at 40 it will go into od then unlock the tq converter, and jump Rpms then at 45 it will lock back up and drive normal the rest of the way until I drop back down into 2nd gear and then it redoes the above actions

I have checked all the sensors on the transmission and under the brake booster and changed out the vss

I don't know what else to check. I'm thinking the valve body possibly?? The transmission has less than 100 miles on it, new tq converter also

Please help. College student and need my truck running

Truck has intake exhaust and that's it never had a chip on it

 

[zilla68]

if it has less than 100 miles on it, isn't it under warranty?

 

[Mark Kovalsky]

I can only think of one sensor on the transmission and one sensor inside the transmission. How did you check them?

If a scan doesn't show codes then you will need to find someone with a scan tool capable of live data (you may need that same scan tool to read codes - auto parts stores that read codes free CANNOT read these codes) to see what the PCM is seeing from the sensors and what it is telling the transmission to do.

With this description I can't tell if the problem is internal or external to the transmission.

 

[speedracer7c]

I had a similar problem here. It turned out to be a bad speedo cluster. It wasn't outputting speed to the pcm. Truck didnt think it was moving caused the trans to do all sorts of wacky stuff. I had it hooked to a snap on verus and watched what it was doing while I drove.