What tranny do I have?

04-silver · April 27, 2004

Somewhere on this forum I had figured out what which one I had, since winter has now left us, so have my brain cells.

Naturally I can't find that info anymore.

I have an 04 2500 Silverado LS E/C 4x4, not an HD and has the auto trac, 2 HI, 4 HI, 4 LO buttons.

Also has the tow/haul button at the end gear shift, which is D,3,2,1.

Came with the trailer package and was built/assembled in Ft. Wayne.

Edit: 6.0 engine-4.10 RAR-locking rear diff-

Bought this truck in Canada.

How'd they get this truck up here with only 36 Klms on it??

Thanks in advance

John

piratebaseball · April 27, 2004

I don't think they make the 4L-80 anymore in the trucks...if I remember correctly, wiht the 6.0 liter i believe you have an 4L-60HD (heavy duty). Anybody feel free to correct me. Its been 3 years since I worked at the chevy dealership so my memory is a little fuzzy

Butch 02 Denali · April 27, 2004

I hear you on the memory thing!!! Actually the 4L80 and the Allison are the only 2 trannys available with the 6.0 engine, except for the SS's, Denali's and Escalades, and H2's, they all use the 4L65E, which is another and newer name for the 4L60HD.

Butch 02 Sierra Denali

coyotekid · April 27, 2004

Is the Allison actually available with a 6.0 gas? If it is, this must be a special order deal?

The only standard auto in all the 6.0 HD trucks is the 4L80E to my understanding.

Also, you can still get a five-speed manual in the 6.0 HD's, correct?

Thanks!

Butch 02 Denali · April 27, 2004

My mistake! The Allison is only available with the 8.1 and Duramax!

04-silver · April 28, 2004

Thanks guys

John

piratebaseball · April 28, 2004

I thought when the 6.0 liter first came out they were mated to the 4l60 heavy duty trans? Maybe that was just when they first came out and since they have changed. I tried looking up a couple of sites to see which one it was and every site just says four speed auto trans. Even the official chevrolet site didn't help out any...grrrr... Proves I need to go back to studying for this final tomorrow instead of roaming the truck forum

04-silver · April 30, 2004

I never did find anything definite/concrete on the web either, this is why I asked

My truck is a 2500 only, not a 2500HD. I assume there is a difference other then not having those little HD letters glued on my truck........lol

John

citydriver · April 30, 2004

You can always check your RPO codes against the list on this sight in the FEATURES section on the top left of this page

04-silver · May 5, 2004

I found "MT1" in the glove box, appears I have the 4L80-E

Found these maybe be helpfull:

Hydra-Matic 4L80-E/4L85-E Transmission (MT1/MN8)

Hydra-Matic 4L60-E/4L65-E Transmission (M30/M32)

Thanks again

John

coyotekid · May 18, 2004

Yep, if you have the MT1 RPO code, then I'm almost certain that means you have a 4L-80E. However, this Auto Trac thing kinda confuses me. It's my understanding that GM doesn't offer Auto Trac in any of the 2500HD or 3500 trucks, only the 1500 series. For this reason, I'm thinking you have the same tranny as the heavy duty trucks but the transfer case and four wheel drive setup from a 1500?

Someone please enlighten me.

04-silver · May 19, 2004

My truck is just a 2500 not a 2500HD, minor weight/suspension difference I guess.

John

robsawatsky · May 19, 2004

The 2004 2500 (not 2500HD) was available with the following combinations:

6.0 and 4L80E

6.0 and 5-speed manual (MW3)

The 4L85E was only with the 6.0 on the SS or GMC versions with the HO 6.0.

Autotrac is available in 2004 with the 2500.

In 2003 they actually had a 6.0 with 4L60E, or it least it was published as an option, maybe it was required for AutoTrac in 2003?

snoman · May 28, 2004

I don't think they make the 4L-80 anymore in the trucks...if I remember correctly, wiht the 6.0 liter i believe you have an 4L-60HD (heavy duty). Anybody feel free to correct me. Its been 3 years since I worked at the chevy dealership so my memory is a little fuzzy

It could be a 4L-65E or a 4L-80 or 85E. The 65 came out before the 85 and they are just tweaked versions of their predecessors. Nice thing about the 60/65E is like its parent the 700R4, it has a deeper first and second gear than the 80/85E and a slightly taller OD as well.