Diesel Bombers - E4OD Trans Problems

I have a 1996 ford f350, has the 7.3 with the E4OD, had the transmission out about 2 weeks ago to replace front main seal, after we replaced the seal and re-installed the transmission everything was working proplerly. after about a week i came to a stop and went to accelerate and the transmission acted as if it had a stall and did not take off until higher rpms. took the truck home and check fluid and too see that all electrical connections are seated properly and everything checked out. also the transmission threw a code for the (transmission range sensor) but after the code was cleared it never came back. Any ideas would be greatly appreciated.