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2018 5.3 6l80 and Torque Converter Stumbling

PNWSierra

By PNWSierra
in Engines & Drivetrain

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PNWSierra New Member

PNWSierra

Posted
Posted (edited)

I have a 2018 Sierra 1500, 5.3, 4wd, with 6l80, 26k miles.  I have recently been dealing with stumbling and hesitations under light acceleration at lower speeds, it feels similar to a misfire. It is not noticeable under heavy acceleration.  I do not tow much, maybe 600 of my 26k miles have been towing.  No check engine light.

 

I had identical issues with my 2015 Sierra 1500, 5.3 with 6l80.  I had these issues until the torque converter took out my transmission at 33k miles.  I took it to three different dealers and each one fed me an excuse of adaptive learning transmission or we can't recreate the issue.  The transmission finally went the next day after taking to the last dealer. That transmission was replaced under warranty and all issues were resolved under they all started to come back at 46k miles.  I traded it in at that point for my 2018.

 

I am certain the dealership will be of no help to me now without a check engine light.  My question is, is it too late to save my current transmission now that issues have started to come up?  Would an upgraded torque converter save it or has the damage likely been done by fragments/contamination?

 

My nearest dealer is 60 miles away and it is very frustrating to burn a day, explain problems, and have them reflash the transmission or tell me that they can't recreate the issue.  

 

I feel like I'm driving a ticking time bomb.

Edited by 17Sierra5.3
flyingfool Senior Enthusiast

flyingfool

Posted
Posted (edited)

this cured my clunking , engine push during stopping and hesitation.  there are many other mods to the trans file that need attention, i'm still learning but you will be very satisfied after completing this software fix.. your next problem is unlocking the encryption on 2017-2021 trucks , to access the TCM .  your not screwed but it cost over $1000 to unlock.  Next step is you get the tcm from an older truck , 2014-2016 TCM and install into your transmission. this is cheaper than the new encrypted units

 

Edited by flyingfool
CamGTP Senior Enthusiast

CamGTP

Posted
Posted

The 6L80e all the way up to 2018 can be tuned without anything else done, no unlock service required.

 

That is only for the 8L90e TCM on 2017-2018 model year trucks.

  • Like 1
flyingfool Senior Enthusiast

flyingfool

Posted
Posted
49 minutes ago, CamGTP said:

The 6L80e all the way up to 2018 can be tuned without anything else done, no unlock service required.

 

That is only for the 8L90e TCM on 2017-2018 model year trucks.

ahh thats good info, thanks for the update

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