Ok, to start with it is a 1994 F-250 4x4 with the 7.3 turbo diesel. We have just replaced all the internals in the trans and now we can't get the thing to shift down automatically. It will shift down if you put it inlow, then shift up accordingly. everything was done right right down to the tolerances and fluid. Was able to shift down before and had no problems with it, besides what made it fail (overdrive on while towing a trailer over a mountain pass, NOT GOOD). Need it to work...its an auto not a manual for dag's sakes! any help would be greatly appreciated!