2020-2025 GM 2500HD/3500HD 6.6L L5P Duramax Complete Transmissions

The factory transmission in your 2020-2025 GM 6.6L Duramax L5P can quickly become a weak point once you've stacked on high levels of horsepower and torque. Instead of upgrading individual components, a complete aftermarket transmission offers a more complete solution. Specifically designed to handle massive power, these premium transmissions are built for both durability and performance, ensuring your GM Sierra/Silverado 2500HD/3500HD can keep up with your engine modifications. GM Duramax Fitments: 2020, 2021, 2022, 2023, 2024, 2025 GM 6.6L Duramax. Submodel Fitments: WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali. Some exceptions apply, please see individual product pages for specific fitments.