4L60E to 4L80E conversion in a GMT900

I've done some digging...looks like the 2008 trucks came with t-cases RPO code "NQH" for Gas Engine Transmissions and "NQF" for Allison Transmissions if my research is correct.

NQH = MP3023/3024
NQF = MP 1625/1626

Both of these units feature electronic shift controls.

http://www.gmpartsgiant.com/componen...mn8k20743.html

I'll try and decipher what the MP part numbers stand for as far as input spline count, etc.

I may be wayyy off here, someone please chim in so we can learn haha.


Well I've found an article that shows a 2008 2500 suburban with a 6.0L engine, 6L80e tranny (should have 32 spline output) that uses the MP 3024 tranfer case with the dial selector on the dash: Motor Trend Article Page 4

I also found this magazine article that lists specific DTCs of the MP 3023/3024 tranfer cases: Transmission Digest Article Page 18

ill have to do this swap soon...about how much am i looking at total?and what year of 4l80e am i looking for?its going on my 08'2wd

I had almost all the parts already so I have no idea on cost. Get as new of an 80e as you can find/afford. I've run a 97 model until it burned up and then got a 2002 model, they were in my OBS truck until I bought the GMT900. My only expense was the tune since I had all the parts already.

Has enyone figured enything out on swaping to a 4x4 with the t case issue

The one 4wd truck we've done, 4wd still don't work. THat's after doing the 80e conversion, and using an 80e tcase.

gonna figure it out next week.

thanks I realy need a 4l80e because Im going to boost I have the mp3023 tcase please post it ones U figure it out THANKS

we bought every part and tried everything we would think of with the stock 60e tcase, no parts we bought were interchangeable.
we tried to install the larger shaft to accommodate the larger output shaft of the 80e.

We ended up putting an 80e tcase in the truck, of course went right in, but now the controls don't work.

the 80e case has a different connector setup and missing one solenoid, if i remember correctly.

we'll get back on it in a couple weeks, customer dropping off for a whole for us to ts.

nice I will b waiting for the results

I wonder if U could use the mp3024 tcase from wat I read its a 32 spline

I'd be curious to see if the 3024 case would work also...