6L80 question 2011 tahoe

[buds56]

I bought an 11 Tahoe 5.3 with a bad trans at 160k on it.

My plan is to get a used trans hopefully with 100k or less on it from a yard.

My question is, will the used trans work without the need for a reprogram of the computer?

Hope to get it running again rather than parting it out.

Thanks

[Bigdav160]

I've never tried to swap one, only overhaul. These transmissions have a weak spot at the pump gasket and small 4-5-6 clutches (like most other 6-speeds). I wouldn't trust a used one.

[Richard]

The TCM will need to be flashed or swapped out to allow communication with the ECM. TCM is in the valve body.

[LS short box]

I would think as long as you got another 2011 trans you would not need any reprogramming.

[Richard]

Originally Posted by LS short box

I would think as long as you got another 2011 trans you would not need any reprogramming.

Would be nice but that is not the case in the 6L. Besides the "tune settings" which must be right for the application, the vin is stored in the programming. FWIU if the vin does not match in the ECM and TCM they will not communicate. In my simple mind I understand that if either module does not recognize the other no communication will happen. One of the reasons aftermarket integration and stand alone control has been difficult on the newer 6+ speed transmissions. Also why I got my engine and transmission from the same vehicle for my swap.

[buds56]

Thanks for the replies.
I bought it sight unseen, the guy was going to send it to the junkyard.

I figured I would have a 5.3 for a future swap but it turned out in better shape than expected when it came here.

So now I'm going to fix it. It still moves so I'll tear it down and see what it takes to fix it, I have some transmission experience but that was 40 years ago.

It seems that parts are pretty expensive for these, that's why I was thinking used initially.
Thanks again.

[Richard]

Lucked out with the output splines on my 6L90. Do not have to tear down. So will run the 55k trans for now. FWIU there is a monster C-clip in the middle which can be a bear to get out without the proper pliers, which I now have. Parts are expensive. Sonnax has some upgrades available to address the weaknesses. You should be able to read the TCM in the old trans and rewrite to another if you have HP tuners. The knowledge to do that is something you pay a programmer for or learn.