Allison 1000

[terexgm]

Hi Allison Man, I heard that there is an upgrade for the 1000 transmission from a single overdrive to double overdrive. If so, what is it, and how is it done??
Thanks

 

[Grandview Trailer Sa]

Allison 1000

I, for one have not heard of it, but if true, would like to know more. I do know in the 2006 GM trucks there is a + - button on the gear shift. I know it has something to do with manually shifting the automatic transmission. I wonder if this is what you have heard about.