I have comments on several transmission problem on this forum, and can't say it enough if you have a transmission problem before you drain the pan or pull it out, hook up a transmission gauge and check the pressures, Torqueflites have several test ports and you can get clues to what is going on, clues that can be very helpful, if you have to take it back apart. You can buy gauges reasonable at harbor freight. Read the service manual on what pressures to expect. If you have a race valvebody you need to call the company and they can give you the test pressures that are normal for your valvebody. I have worked on automatic transmissions since 1975, a pressure test can save so much time on those weird problems.