6L80E (2014 Sierra) TCC shudder

Mar 2, 2004
I have a buddy that owns a 2014 GMC Sierra SLE w/ around 165K (5.3L w/ 6L80E) that is experiencing pretty bad shudder at lower RPM under load when the torque converter clutch is engaged / locked. No codes at all are being thrown for the powertrain.

He took it to a transmission shop that did zero diagnosis, simply stated the transmission needs rebuilt to the tune of $4500. I believe he's been driving it this way for quite some time and has resorted to tow/haul mode nearly 100% of the time as it tends to keep the TCC out of lock-up longer.

Can someone explain this failure in detail, what causes it, etc? Is there anything he can do at this point to save the transmission and perhaps replace just the torque converter, or is it too far gone at this point? I'm not sure exactly how a TCC clutch works, or what fails in this unit, and why it affects the torque converter itself, so feel free to educate me on the fine details and what the best approach would be at this point. I haven't ridden in it, but he tells me it's pretty severe to the point he avoids the TCC lockup (at lower engine speeds) whenever possible.

I discovered this thread (https://bobistheoilguy.com/forums/threads/6l80e-discussion.344669/page-2) which covered the issue somewhat, enough to know it's a common problem, but didn't want to revive it. Any help would be much appreciated.
Dec 19, 2013
Fort Worth, Texas
The pan needs to be dropped & inspected for metallic debris.

This is such a common issue that trans shop don't need to do any diagnostic. 165,000 miles on a stock 6L80E Converter Clutch & Calibration is a pretty good run in my opinion.

The TC Clutch Lining wears because it is constantly slipped during AFM operation.....Once it wears to a certain point the TCC piston & front cover make metal to metal contact which at first causes symptoms like TCC shudder.