Ford Transmission Help (Sorry My Truck Is Not A Mopar At This Time...)

Ford Transmission Help

The transmission in my 1997 Ford F150 4x4 with 158,000 miles was fluttered between 1st and 2nd gear and had very dark brown transmission fluid. A friend of mind recommended someone he knew that does transmission work on the side and after specking with him he appeared to be very knowledgeable. He removed the transmission and replaced the clutches (finding a damaged one), installed a new torque convertor, replaced all seals and gaskets. After reinstalling the transmission and road testing it he discovered the overdrive no longer worked, throws itself into neutral after 40 miles instead of overdrive. When driving it out of overdrive the transmission slips (example: when driving 25mph at roughly 2000 thousand rpm then attempting to accelerating the rpms go to 3000 before the truck starts the accelerate).

The person that did the work told me he pulled the transmission out again and could not find what is causing these issues and told me I should take it to a transmission shop that will diagnose this issue.

Does anyone have any ideas of suggestion to correct these issues?