I have a 1988 700R4 out of a 1500 I just rebuilt. I put if back in and it worked fine for a couple of days, then it wouldn't shift out of first until it got warm.
I put a transgo shift kit in it hoping that would fix it. It didn't. So now I took it back out and all the way apart. I don't see anything wrong.
Does anyone know what is making it do this?