The General Motors 6L80 (MYC) 6-speed automatic transmission was produced from 2005 to 2021, was installed in popular SUVs and pickups such as the Chevrolet Tahoe, Silverado, and GMC Yukon. This transmission was also installed in a number of performance models, such as the Cadillac STS-V, and Corvette C6.
Specifications
| Type | automatic transmission |
| Number of gears | 6 |
| Type of drive | rear / all wheel |
| Engine volume, l | up to 6.2 |
| Torque output, Nm | up to 595 |
| Recommended oil | Dexron VI |
| Oil capacity, liter | 11.9 |
| Partial replacement, liter | 6.0 |
| Maintenance | every 60 000 km |
| Gearbox lifespan, km | ~250 000 km |
| Weight, kg | 104 |
Gear ratios GM 6L80
Using the example of a 2010 Chevrolet Tahoe with a 5.3-liter engine:
| Main | 3.08 |
| 1st | 4.027 |
| 2nd | 2.364 |
| 3rd | 1.522 |
| 4th | 1.152 |
| 5th | 0.852 |
| 6th | 0.667 |
| Reverse | 3.064 |
Using
The transmission was installed on:
- Cadillac Escalade 3 (GMT926) in 2006 – 2014;
- Cadillac Escalade 4 (GMTK2XL) in 2014 – 2015;
- Cadillac STS I (GMX295) in 2005 – 2009;
- Cadillac XLR I (GMX215) in 2005 – 2009;
- Chevrolet Avalanche 2 (GMT941) in 2008 – 2013;
- Chevrolet Camaro 5 (GMX521) in 2009 – 2015;
- Chevrolet Corvette C6 (GMX245) in 2005 – 2013;
- Chevrolet Silverado 2 (GMT901) in 2008 – 2013;
- Chevrolet Silverado 3 (GMTK2RC) in 2013 – 2019;
- Chevrolet Silverado 4 (GMT1RC) in 2018 – 2021;
- Chevrolet Suburban 10 (GMT931) in 2008 – 2013;
- Chevrolet Suburban 11 (GMTK2YC) in 2013 – 2019;
- Chevrolet Tahoe 3 (GMT921) in 2006 – 2014;
- Chevrolet Tahoe 4 (GMTK2UC) in 2014 – 2019;
- GMC Yukon 3 (GMT922) in 2006 – 2014;
- GMC Yukon 4 (GMTK2UG) in 2014 – 2019;
- GMC Yukon XL 3 (GMT932) in 2008 – 2013;
- GMC Yukon XL 4 (GMTK2YG) in 2013 – 2019;
- GMC Sierra 3 (GMT902) in 2008 – 2013;
- GMC Sierra 4 (GMTK2RG) in 2013 – 2019;
- GMC Sierra 5 (GMT1RG) in 2018 – 2021;
- Hummer H2 (GMT820) in 2007 – 2009;
- Pontiac G8 1 (GMX557) in 2007 – 2009.
Disadvantages of the GM 6L80 gearbox
- The weak point of this transmission is the torque converter, especially its hub;
- Also, active owners wear out its locking clutch very quickly;
- This dirt then clogs the solenoids, causing a drop in lubrication pressure in the system;
- Then the clutch packs begin to burn out, and often even their drums burst;
- Like the 4L60 automatic transmission, the petal-type oil pump does not tolerate high-speed driving;
- Control unit failures due to transmission overheating are quite common;
- In the early years, there were many cases of the pump cover O-rings turning.
