Yep its got a 4l85E

The 4L85-E is a heavier-duty version of the 4L80-E that was purpose-built specifically for the 496 Vortec. The two rear planetary gearsets each have 5 pinions instead of 4. There are other less significant upgrades as well.

The differences are similar to the 4L60-E vs. the 4L65-E.

holy crap so you are telling me that i can buy a used tranny that already has the 5 pinions in it. i thought that was only an aftermarket part. not that i know that much but thats cool

chevy mec, you have a PM with the VIN for the avalanche. thanks for your help

Chad

got it, ill hit ya up tomorrow!

Saw previously that you posted you could look up and see from the vin if a duramax had the Allison tranny. Can you look mine up?
1GCHK23183F246454
also how would I know if it's an lb7 and the dealer says they can't tell if the injectors have been changed is there a way that I can find out?
Thank you

This thread is over 13 years old...

Next time, please start a new thread asking your specific questions. You will get better responses with a new thread Vs. a 13 year old thread with members that may no longer be active.

Use this tool for the basics
VIN Decoder - PerformanceTrucks.net Forums

In the pick up trucks, They all had Allison transmissions.

2000 - 2004 were all LB7
2004.5 -2005 were LLY
2006 - 2007 classic were LBZ. The first half of the 2006 was the new design of the LBZ but had the old head gaskets and was designated an LLY but is different from previous 2 years.

2007.5 - 2010 were LMM
2011 - 2016 were LML

2017- current LP5

There is several Deisel specific sites as well as wikipedia.org to get this info from.