I have a 1989 ford f150 with 94,000 miles on it. It has been shifting fine and running smooth. Yesterday I decided to change the transmission fluid and filter. When I put it all back together it won't shift and just revs high at 20 m.p.h. I torqued the filter bolts with a inch pound torque wrench first to 100 inch pounds. Still didn't work. So I removed the pan and torqued it with my foot pound torque wrench to 8 foot pounds. Still nothing. I am not really a mechanic and I'm out of ideas. I have pulled the pan 5 times and still come up with nothing. Anyone have and suggestions or advice? Thanks.