Re: Duramax/Allison downshift?
 

Does she have tunner or anything on the truck? How many miles are on it? I had an LB7 duramax for 10 years and didn't have much issues, just the known injector problem but that will haze like crazy out the exhaust and full the crankcase with fuel.

Re: Duramax/Allison downshift?
 

I don't think so - whatever it came with.

Seems like it was about 175K when we bought it. Injectors should have already been upgraded.

Re: Duramax/Allison downshift?
 

Ehh, there's not really up grade per say to those injectors, just the design of them the body's crack and leak fuel. Some people get 80k out of a set, some 200k. Mine were replaced at 72k when I bought my truck and we're failing at 170k when I eventually sold the truck.

The 5 speed alison is a great trans, in stock form if maintained. If there's been a tuner on it, and towed while the power was turned up that can cause issues internally. Once it limps once, it's just a matter of time until it does it again even easier.