Transmission Issues

Ok, so a couple years back I was having trans issues. My truck was not shifting properly, was slipping a little, making noise when shifting, just overall not at its best. I took it into my local diesel shop for sh*ts and giggles. They said the best would be to put in a Ford reman. I had called around to the local rebuilders and it was gonna run between $2100 and $2500 depending on what needed to be done. The Ford reman was gonna be $3100 installed. Ended up costing me $3600 with the required flush and rear main seal replaced.


The truck did not pull the same after that. It is weak, revs up but takes forever to get moving. When towing, driving through the mountains I can be going 65 at the base of the hill and it will slow down to 40 before down shifting, that is pedal to the floor. It will not keep pace at 60 like with old trans. Even going up a medium size bridge. It loses speed quickly. I took it back to the shop who installed it and they said there was nothing wrong with it. Computer shows everything is running as it should. It has since overheated on me 3 times in the winter, below 35 deg out. I then took it to Ford and they said the same thing. Nothing wrong with it.
I know this trans is not right. Ford said same trans is used in all trucks 250 to 550. I don't understand how that can be when they are all different capacity trucks. But I am not a diesel tech so I don't know. I had posted on a Ford forum and everyone said torque converter and/or valve body could be the issue.
Any thoughts on how to get Ford to fix the issues at hand? It is still under warranty, the reason I went with it to start with.

Thanks in advance for any assistance.


2002 F-550, 4x4, 7.3L auto