2002 Chevrolet Avalanche Z66 4l60 to 6l80 swap

[Cleveland Brown]

I have lost overdrive in my 4l60 transmission. I need help to learn and know what all I have to do to put a 6l80 transmission in my Avalanche. The transmission is out of a 2007 Chevrolet tahoe 5.3 2wd police package. Please dont comment and saying rebuild mine or get another 4l60 or that is it to difficult to swap. I'm looking for all the advice before I do the swap. Thanks in advance. 

Edited October 30, 2019 by Cleveland Brown

[davester]

Start searching for a standalone 6l80 controller...

[Mikebtte]

Start reading the link below. It's a simple swap and a good swap if you plan to be doing and ruff playing around.

You can buy a harness and splice it in place and the transmission will need a modified crossmember, easy to do.

 

Swap information

[Cleveland Brown]

I am guessing this will work for the 6l80 transmission as wells as the 4l80 transmission? 

I can probably pull the harness out of the donor vehicle and tcm if needed. The cop car was rolled. 

 

Edited October 30, 2019 by Cleveland Brown

[Mikebtte]

6L80E is weaker than a reasonably built 4L80E, much more complex, heavier and bigger. Your ECM is also built to run a 4 speed and I dont know how it would handle a 6 speed.

[C/K Man]

The 6L transmissions (70/80/90) have their own internal transmission control module, which operates on a CAN/BUS network with the ECM (engine) and BCM (body) computers.  There really isn't a good way to make that swap work right without spending a lot of money.  The link in the earlier post is for replacing a 4L60 with a 4L80, both old style 4 speed automatics, and a good swap.  Maybe you could trade that 6L80 for a 4L80?   

 

There is this:

 

http://www.zerogravityperformance.com/product/tcm-2650-mechatronic-transmission-controller-6l80e-6l90e-6l50e/

 

No idea how well it works, but as you can see it is not cheap.

Edited November 5, 2019 by C/K Man

[05boostedAv]

I'm currently in the process of swapping a 4l80 into my avalanche and also making it 2wd. Does anyone know the length of the driveshaft needed or what vehicle i can snag one from? 

[davester]

If nobody knows, you might consider just measuring the distance with a tape measure and getting your current driveshaft lengthened/shortened by a driveshaft shop (and perhaps modified if necessary if there is a different yoke between a 4l60e and 4l80e

 

I did this for my truck, when I converted it from 2wd to 4wd, and it was about $300cdn and done the next day (I phoned 3 driveshaft places in my city and picked the one with the middle cost.

Edited April 25, 2020 by davester