Long story short. Having a issue with my transmission after a rebuild. It’s at a local shop and has been there for 3 months. Whole transmission has been rebuilt and new pump and after a faulty torque converter a second one is now in its place. The truck is a 03 f250 6.0 bulletproof and after all the mods I is pushing almost 1000 hp. The truck runs great but only moves as it should for the first 10 min of operation. ****s to drive and moves forward at idle and reverse as well. Will command shift as normal for the first 10 min of operation then seams to get stuck in a low gear and must rpm to 3000+ to move forward at all. BUT scan tool says pressures and temp is good. Command gears claim it is shifting. But again feels as tho it is not. After turning its off for an hour or so it will repeat this process. No codes. At all. So I’m lost. I have tried a new pcm and flashed to the truck. Tried unplugging the fan clutch…. All new internals and valve body/ solenoids. What am I missing here. Could it be a second faulty converter?

 

A little skeptical of your std auto trans able to handle that kind of power. Something that is often overlooked when addl power is thrown on a trans that is built for a fraction of that.

Maybe I misunderstood the post, but if you place that kind of demand on a typical trans,,,,,,,,,,,,,,,,,forget it ! All the beefing up will not handle that kind of demand and if it does, it won't be for long.

 

I guess I should have mentioned that the rebuild and new torque converter is all “stage 4” upgraded
the conveyer (rev max) low stall stage 4 triple clutch blah blah blah