hi, so I'm working on a Oshkosh front discharge mixer and its having a shifting issue. it has a cat c13 twin turbo motor, and a Allison hd4560 trans with the pad shifter. for some reason when trying to put the truck in gear the left side of the screen just flashes 6 and the right side just says on N. it does the exact same thing in reverse just instead of 6 popping up r pops up and just flashes. iv tried a new shift pad and a whole new tcm and the issue still exists. I'm really stumped here. my jaltest and my Allison scanner does see any codes in the unit either. and help or ideas would be great. thanks
Is there an Allison transmission dealer in your area? Might not hurt to give them a call. I had a similar problem with a 1000 series which I believe is very similar. It was a broken trim spring causing the problem. Turned out there was a service bulletin on the spring failure.
did you happen to have any codes. that is the part that is really throwing me off, because it seems like everything is working right other then the truck going into gear.
No there were no codes. Its was a mechanical problem not electrical. The left side the number would flash and the right side was blank.
got ya, my right side just stays on n like its inhibited