bad torque converter??
 

rpms go way high when going into 3rd gear, cant drive over like 30 mile per hr, just put this tranny in, the last tranny was doin the same thing thats why we changed trannys!!!!!

Bet you wish you put in a new torque converter...

Did you use the torque converter from the original transmission that was in your truck?

yes because the one that came with the tranny looked a little rusted

could it be the 3-4 clutch???

If you used the same torque converter from your original transmission and it is doing the same thing as it was doing before, I think it is likely your torque converter.

It would not be a 3-4 clutch if it does it going into 3rd gear. It would be something with the 2-3 transfer.

I just really doubt that you would have gotten another transmission that would do the exact same thing.