I bought a used AOD trans that the linkage went up ( from a column shift car) and I switched it to being down for my Mustang but now it won't shift from 1st gear, it works in reverse and 1st only, I pulled the trans back out and put my old one back in and used it for a while but it has finally gone out and I need the used one I bought to work, any ideas what is causing it to not shift out of 1st gear?