If it does that with the side cover off and you can SEE the sliders are centered, then there is a problem IE the input pinion is stuck/ welded to the output shaft. Maybe someone ran it low/ without oil and the needle rollers in the drive pinion are AFU
Could be. I really don't have a clue. Just try to get a possible idea where to look. If I were to pull the front retainer, should the input shaft slide out "freely"?
