Anyone play with their tranny tune?

[Justin9212]

I have a 2007.5 LMM Allison, I want the shifts to be a little quicker and more firm. Anyone have a good starting point on what I should do?

[GeneralTJI]

There isn't much you can do through tuning for this....

DON'T mess with the shift timing tables. You can probably get a way with some very minor adjustment without grenading the trans, but you probably won't notice it anyway.

The Allison is not like a normal trans. It works off of clutch to clutch handoff. This process takes time (mechanically, and hydraulically), you can't speed it up or you will get a tie up (2 gears at once). Built transmissions can shift quicker, but they still work off the same principle and will only shift so fast (unlike a "normal" trans with over running clutches etc.)

You also can't raise line pressure via tuning

Put a trans go jr. shift kit in your allison. This can be done by dropping the pan and pulling the valve body. It's not real hard to do... it will give the trans a bit of extra holding capacity. Thats the best (easy) thing you can do.

You can play with your shift points and TC lockup points... Beyond on that you don't want to mess with too much.

[TwoFast4Lv]

See my post