Alison 1000

[Destroyer]

I have an Alison 6 speed that is mated to a 6.6L Duramax turbo. Does anyone know if this Alison is the one(Alison 1000) that is programable for bigger tires? Or like what to look for to find the Alison model? It has the manual touch shift option.

[Destroyer]

Oh I Guess I should have said I read this and it lead me to the question.

In addition, GM's C4500/5500 medium-duty trucks equipped with the Duramax 6600 and Allison 1000 can be dealer programmed for different tire sizes and even differential gear changes. Why not the 2500HD? Hey, even the new for 2006 mid-size H3 Hummer gets 33's...

I have the 2500HD with the Alison XXXX not sure yet

[ISEEDIT]

You have the 1000 ally. The truck can be programed for some select tire sizes. You dealer should be able to do it for nothing, takes a second. I have 285x18's Nitto's on my '06 and they are pretty much the same size (tall) as 265's x 16, so dealer programed for the 265 size and the DIC comes out pretty darn close.

[STPETEBLUE]

As I understand it, 265s are as high as it can be programmed.

[DmaxMaverick]

As I understand it, 265s are as high as it can be programmed.

Unless GM changed their policy and software since last week, there is NO reprogramming to correct the speedo. They can calibrate it for the ABS, but not the speedo. You will need an aftermarket programmer or buffer to do that. The dealer can only program for tire sizes that can be had as factory options, according to the VIN. In this case, 245/75/16 for 2500HD, and 265/75/16 for 3500SRW.

The case of the 4500/5500's, that is a different world altogether. There are several options available OEM for gears and tires.

We don't have to like it, but that is the way it is.

[STPETEBLUE]

Since the 3500 SRWs come with 265s, GM CAN adjust all functions to correctly operate with 265s.

Your post would seem to indicate that GM is selling 2500s and 3500s with speedometer errors.:confused:

[DmaxMaverick]

Since the 3500 SRWs come with 265s, GM CAN adjust all functions to correctly operate with 265s.

Your post would seem to indicate that GM is selling 2500s and 3500s with speedometer errors.:confused:

Programming options are available according to the VIN. Even the dealers that have said, "if it's possible, we'll do it", couldn't do it. You could probably get away with it if you installed a 3500SRW PCM into your 2500HD, and had a dealer that would work with you. Many dealers were happy to program the tire size for ABS function, but couldn't help with the speedo. We've been down this road many times since the onset, and the result has been the same. So far, no one has been able to get it done. A few folks came back saying their dealer did make the change, but later discover, no change to speedo. GM will have to change its position on the tire size before dealers will be able to do more. GM hasn't indicated any interest to change, and we still don't have to like it.