6L80 Torque Converter, question for newer models

[nomech]

I have a 2020 Tahoe that I purchased brand new and at around 140k miles the transmission went out. The garage I took the car to told me that several models/years of GM vehicles have this issue and it isn't related to lack of maintenance but a bad design/bad component. He told me to look up 6L80 Torque Converter if I was curious to learn more about this issue.

Here is my question, it isn't specifically for the 2020 Tahoe which is why I'm posting here.

Are there any mechanics on here that have history/experience working on newer models of Tahoe's that are no longer using the same transmission that were in the previous model Tahoe's?

If I were to purchase a 2024 or 2025 Tahoe, I don't want to deal with this issue on a new vehicle.

I did ask the mechanic that worked on my car and he told me that 2021-2024 Tahoe's (2025 Tahoe's were not out at the time) were still 'new' enough to still have a factory warranty and that people would take them to the dealer before they came to him, which I understand.

I am very happy with the 2020 model I have other than the transmission issue, which I'm sure everyone agrees is frustrating to deal with. I'd hate to get another Tahoe and be in the same situation that I am in now.

Thanks.

 

[Joseph Garcia]

To my knowledge, the torque converter issue was mainly for the 6 speed transmissions. If I'm wrong, folks here in the Forum will correct me.

 

[Marky Dissod]

To be precise, the problem is the way GM tuned the 6L80's torque converter clutch to behave during lockup.
Even changing the ATF every 35k miles only delays the TCC's eventual failure.
Once the TCC fails, it takes out the 6L80 with it, requiring a rebuild and a new torque converter.

Upgrade your torque converter, get your pcm tuned, and change the ATF as often as you can stand,
and your next 6L80 rebuild will last longer than this one.

 

[swathdiver]

I have a 2020 Tahoe that I purchased brand new and at around 140k miles the transmission went out. The garage I took the car to told me that several models/years of GM vehicles have this issue and it isn't related to lack of maintenance but a bad design/bad component. He told me to look up 6L80 Torque Converter if I was curious to learn more about this issue...

GM redesigned the cooling system on your generation truck. It was simplified and made higher tech, they added a thermostat to the side of your transmission on the 6L80 as part of these improvements. This kept your transmission temperature at around 195 degrees all the time which caused the material on the JMBX torque converter's clutch material to prematurely wear and break apart, wrecking the transmission as all this debris passed through it. The "fix" for several years was to "flip the pill" and then a new lower temperature thermostat was released.

Those with the previous generation truck have the same transmission and torque converter and very few have had torque converter issues. The transmissions in these trucks run much cooler.

The new T1 generation trucks almost all use the 10-speed transmission.

Install the new lower temp thermostat on the side of your transmission and change its fluid every 40-45K miles and more often if you tow and it will last you a long time.

 

[nomech]

GM redesigned the cooling system on your generation truck. It was simplified and made higher tech, they added a thermostat to the side of your transmission on the 6L80 as part of these improvements. This kept your transmission temperature at around 195 degrees all the time which caused the material on the JMBX torque converter's clutch material to prematurely wear and break apart, wrecking the transmission as all this debris passed through it. The "fix" for several years was to "flip the pill" and then a new lower temperature thermostat was released.

Those with the previous generation truck have the same transmission and torque converter and very few have had torque converter issues. The transmissions in these trucks run much cooler.

The new T1 generation trucks almost all use the 10-speed transmission.

Install the new lower temp thermostat on the side of your transmission and change its fluid every 40-45K miles and more often if you tow and it will last you a long time.

I had the mechanic I took the car to put in a non GM transmission, not sure if that includes the torque converter or not. I'm not a mechanic so I don't know much about those details. There is a warranty and I don't plan on having the car when the warranty period is over. That's one of the reasons I wanted to ask this question.

Does anyone know anything about the new 10 speed transmissions? Anything to look out for?