It talked about the over drive a lot. But this doesn’t have an over drive. It has the lock up clutch. Is that what they are talking about?
And if that’s the case....maybe it needs to be replaced. I’ve already got the information how to electrically activate it automatically
I would not worry about the black fluid. The main thing is to inspect everything and start with a fresh build. Make sure everything is right, and go from there. The rear band could have been adjusted wrong and was dragging or something.