6L80 TC Shudder

orange150

orange150

Well-Known Member
Joined
Mar 20, 2005
Location
Fairfax City, VA
I think we're starting to experience this on our 2012 Suburban. It intermittently shudders cruising on the highway, then RPMs fluctuate by about 200. It's also been kind of clunky feeling.

Do I just need to be prepared to replace the transmission when it finally lets go? Can we get by with just a TC replacement? Is it just a ticking time bomb?
 
Is this something where I just replace the torque converter or is the whole thing boned?
From reading around it looks like when they TC starts dying it starts shredding itself, which in turn gets metal errwhere
 
orange150 said:
Is this something where I just replace the torque converter or is the whole thing boned?
From reading around it looks like when they TC starts dying it starts shredding itself, which in turn gets metal errwhere
Click to expand...

There are a few threads about it. @Ron and myself seem to both have had the same experience with them. They're fine, until they're not. Once they're not they are toast. Last one I had that fried had metal everywhere according to the tech.
 
We went down the internet rabbit hole. There is a belief that the issue is caused by the internal of the TC delaminating and killing the trans. Problem is you buy a new TC and the junk is still in the trans. GM has a new and resolved TC supposedly. So we went nuclear. New Gm trans, new improved TC, new (external) cooler and replaced every line in the system...no more worries for us, right?
Well 90k miles on new everything and guess what’s shuddering again.
paid a tuning buddy to turn pressure up and it working. For now.
I want to dump the pos and buy something different but it’s my sons and he’s done all sort of stuff to it to make it cool.
 
If you are super lucky you could just put a new torque converter on. I would not drive it again until you do it. Mine started with this and within a few hundred miles it was completely toast.

I tried to save a few dollars and do some work myself. It has been a steep learning curve.

If you get it early enough you might could flush it and get away with a new toque converter but once the torque converter completely lets go you will need a rebuild.

I just went through this with my 2011 Sierra with 145,000 miles on it.

There is nothing but metal shavings in the bottom of my transmission. Everywhere you looked there was little bits of metal. The fluid that came out was just black.

I got quotes from 2800(rebuild mine with warranty), to 3800 (rebuilt with warranty), to 5000 something at dealer.

I did add an external filter, a drain plug, and a larger cooler. All have already come in handy.

Hindsight being what it is I would have gone with the 2800 which is an old local guy you can't get the number for.
 
Called two shops up here. Both were right at 5k. Ugh.

One shop does enough of them that they stock 6l80s on the shelf. That shop has a 3 year / 36k mile warranty.

The other shop has a 4 - 8 day turnaround but a 3 year / 150k mile warranty
 
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How's the fluid look? I might would chance jist throwing a converter in it. Something other than stock, personally. Stock specs, just a different brand.
 
The 6L80E torque converter in my 2014 started letting go after ~146k, about 2k after the 3rd fluid change. Dealership never would change the filter so the first time it acted funny it actually sounded like a hydraulic pump starving for fluid. Turned out the media filter was pretty clogged with metal particulate. I drove it enough to get to the parts store, get a filter and a gallon of fluid, went home and changed the filter out and topped it up. It drove fairly well with some shudder here and there. When I used Tow/Haul mode it would leave the lockup clutch open most of the time so it would not shudder at all. I limped it another 10k before it was turned in at the end of the summer (company lease vehicle). I had to drive it slightly slower than I usually did on the highway and it would not shudder.

After reading all about this problem and how widespread it is I was surprised I had not read about it before it happened to mine.
 
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