Allison @2100 Question

[artpe54]

I just purchased a Winnebago Forza 34T with the 2100 transmission. As I was driving it home I've noticed that it never goes above 5th gear. In checking the manual it says in D it will be 1-6, 1-5 with 3 asterisks stating calibration dependent. I'm confused, should it shift to a 6th gear or not?

[terry735001]

even knowing you have a 6ed speed the OS in your TCM well never tell it to go to 6th

your GVWR is to high

you mostly find a working 6th in LT trucks

you can reflast the TCM from a C4500 and you well find posts out there on how to do that but in doing so ... some have to swop back as the HP/RPM vs GVWR well now stop it from going in to 5th and then 2 gears are lost

the allison 4th GEN TCMs are really funny how they are setup to shift from 5 to 6

[BFlinn181]

I think you'll need to take it to a shop that can program your transmission. You didn't say what engine you have, perhaps it's the limiting factor. If it's still under warranty, I'd take it in and see what's up.