Allison 1000 problem


New Member
Allison man,
I have the Duramax/Allison combination and I currently have it in the shop for my Allison Tranny. It has been giving me a "Range Shift Inhibit" on the DIC from time to time and to cure it you just put it into park and then back into the gear. But when you put it into drive there is a slight delay, then a loud thud in the transmission and you only have 4th gear. That's what I limped it to the dealer with. They replaced that park/ gear sensor on the side of the tranny and it seemed all was well again. I drove it 20 miles back to Boise and it shifted perfect, until I shut off the truck and restarted. Then Thud and 4th again. The SES light was on and I had to take it back to the dealer again in the same day. The SES code said something like Transmission shift control problem.....DUH!!! My truck has 36,300 miles on it. Yes 300 miles over warranty on my transmission. This sucks........Can you please shed some light on what you might think it is. I think it's definitely electronic related (possible solenoid or something).......Thanks