I was wondering if my '02 has theautoAllison transmission. I have the 'HD with the 6.0 gas engine. A friend has a 2004 HD and he says he has the Allison. I'm guessing that I have the 4L80-E, the 4-speed auto. Is there a reference. I'd like to know the rear-end ratio as well. Thanks

 

Alisons are behind the diesels only.
Rear end - provide VIN or last 3 digits from # in glovebox.

 

the allison only comes with the duramax or if you have a 8.1L so no u dont have it and your rea end is most likly 4.10s

 

give me your vin if you want,and i'll give ya the build sheet

 

My HD '04 has the 6.0 and I took it in to the dealer once cuz it was making a whistling noise from the tranny. When i got it back they told me it was a regular noise for those allison trannys. Maybe they told me some wrong info. As for the rear i have 4.10 gears front and rear.

 

the allison is not available with a 6.0 liter