This is a weird one. Driving home today, I put it to the floor in od. It down shifted as expected and climbed through the rpm range fine until the upper 3k,just before 4k. At that point the truck stopped pulling but the engine quickly redlined, almost as if it popped into neutral with the pedal still to the floor. I let off the gas, it grabbed a gear, and away I went. I put it the floor a couple more times and it had the same behavior.

I just drove the truck a few hundred miles towing with no issues, but I never had it to the floor. I rarely hot rod it, that's what the challenger is for, so it could have been doing this for some time. On the recent trip I did check transmission fluid which was fine, assuming I did it correctly. The transmission was supposed rebuilt right before I bought it, and have only put a few thousand on it since then.

 

You may need to adjust your kick down cable or rod.

 

OK, I'll look into the process. Do you know what is happening in the transmission, is it just popping out if gear?

 

If the transmission shifts into gear when you let off the gas. It maybe a band adjustment or transmission seals.