I have a rebuilt 4l60e that after rebuild speed sensor doesn’t read correctly. It has a new sonnax output shaft and new reluctor ring. I don’t get any reading from sensor until I drive about 15 mph and when starts reading speed starts bouncing up and down. I don’t have a lot of confidence in the transmission shop as when I got the transmission back the first time they put the sprag in backwards. I have put a new speed sensor in and didn’t change so could they have put the reluctor on wrong.