allison problem

[blab]

Started my GMC 3500 with duramax and allison this morning and the service engine lightcome on. When I put it in reverse the R on the dashboard started flashing and I had no reverse. I had a friend tow me out and the truck would move in drive but in a short time it went into limp mode and I had to park it. Any help you could give is appreciated.

[DmaxMaverick]

Blab

You should post this in the "2500HD/3500 HD Trucks & Drivetrain" forum. Dr. Lee will probably move it there anyway. This issue you describe comes up on ocasion, and there are simple solutions that may help you. Also, try searching that forum for your symptoms. Lots of good info on it.

[Shorty]

Hey Blab,I have the exact same problem.Mine always occurs after truck has been idle for a few days.Allison tech told me it was fixable,have to drop trans and replace springs in some valves?? He said the best solution was to start truck every day or two that has fixed mine so far. some times just shutting down and starting up ill fix it .Probably some of the pros have a better solution? hope this helps. Shorty

[madmatt]

Could just be torque converter bleed off like shorty said. If it is just let it idle for a while and it should straighten out till you let it sit next time. To correct it there are a couple of springs and pistons in the pump hsg. that would need replaced which do require the tranny to come out. if your out of warr and indeed this is what your experiencing, I'd just run it for a while every other day.