Allison 6sp: Won't pull in drive or reverse.

[Bosox89]

Looking at a high mileage lbz with a few problems. They said the transmission would engage but would not pull the truck in drive or reverse. What possible problems could it be? Transmission will be built if I buy it, would is fix it?

 

[Cougar281]

Any codes? If the transmission actually does engage, but the truck doesn't move, it could also be the transfer case.

 

[Bosox89]

Not sure if it's throwing any codes, and they aren't in today for me to ask. It's quite little drive away from me so I wanted to go down there with a fair idea of what to expect with it. I kinda suspected the tranfer case but I didn't know if there could be anything else that might cause a similar problem.

 

[Mike L.]

If the trans is totaly wasted you will be looking at a 2,000.00 core. Be carefull. Hrd parts are expensive.