Iv got a 7060 Allis charmers I have a question on. It’s our main loader tractor so we depend on it. It has 5 main gears, and also a high and a low gear. For whatever reason you can only go into high gear. Low gear and park are neutral right now. You can put it in low gear and put the other stick in any of the 5 gears and it won’t move. Any clue at all what we have going on??