My guess is any shop or experienced trans guy is going to tell you to figure out your line pressure. This will at least allow you to have more info when figuring it out. Get your hands on a 300psi (or more) gauge and rig up a way to monitor it while shifting.
Good luck. Trans problems suck.
Transmission Line Pressure - TCI® Auto
Good luck. Trans problems suck.
Transmission Line Pressure - TCI® Auto
