2003 8.1 liter 2500HD Allison 1000

Meldrum88 · February 29, 2020

Looking for any one with some knowledge with my truck, I’m doing a rebuild on the Allison and may have a few questions in general. I tried searching the forum for my engine type and there was nothing popping up. Should I look more in the Duramax areas?

As well as I’m wondering after rebuilding who thinks it’s worth holding onto this beast long term as a classic one day or selling and getting a more reasonable truck. I don’t do no major towing or heavy duty work. Just I’ve always wanted this body style GMC and didn’t look into the 8.1 to much when purchasing so it’s definitely over kill for a daily driver is all.

not looking for a argument or stupid comments, just general thoughts and conversation...

davester · February 29, 2020

I suppose someone out there may want it, but I wouldn't hold on to it hoping for it to increase in value as a collectible vehicle. If you aren't towing or planning to tow/haul with it, I would suggest fixing and then selling it, as it's a total gas guzzler, and it's highest value is likely now (once the trans is fixed). Even swapping in a used transmission from a junkyard or a wrecked truck would do the job, as they are a pretty stout transmission.

As for rebuilding the transmission, yes, I would suggest checking out diesel forums, as it's much more common for the allison to be behind a duramax, and there's a lot of info about rebuilding them on those forums.

Meldrum88 · March 11, 2020

Hey thanks for the response, I appreciate it. I’m just back and forth with what to do. As far as keeping it as a classic I wasn’t thinking as in value at all , mainly just as a nice clean old truck for my self as I’ve always wanted this style or for my son one day. Looking at doing the Allison rebuild on it this weekend . If anyone is interested.