Tranmission won't shift into gear
Hi, my name is Hank, and I own a 1999 Blue Bird school bus. 8.3 liter, 12 valve Cummins engine, and the transmission is an Allison md-3060. The problem I'm having is the transmission will NOT shift into gear. What I think I've learned so far is that I have a shift inhibit problem. My transmission has a push button shift selector keypad which blinks D and R respectively, but will not shift into gear. When I push the up and down arrows simultaneously to read the codes it does not give me any, which the Allison dealer told me over the phone that means the transmission is not going into gear for some other reason. I'm not sure what is causing this shift inhibit. Apparently it could be a number of things, one of which is engine speed or transmission output shaft speed but those things seem to be fine. Can anyone help me figure this out?