How are you monitoring the transmission temp? I have never gone for a drive then set the level, it will get too hot and then you are trying to set the level with it cooling off which is not how it works. Start with it cold, let it idle in your driveway and it will come up to temp pretty quick. Follow the procedure, you will probably have to add some fluid at this point which is easy with a pump, just put it in until it starts to come out. You have to move fast though, often the trans temp will rise quickly and then be out of the window. Go with what the FSM wants for temps. Does it all make sense?