2020-2024 Silverado & Sierra 2500 & 3500 6.6L Duramax L5P Complete Transmissions

Your 2020-2024 Silverado or Sierra 2500 or 3500 and its Duramax L5P can make a whole heck of a lot of power with only a few performance modifications and tuning, but that doesn't mean your truck's Allison 10L1000 transmission is ready to hold that power reliably. Tier One's selection of built 10L1000 transmissions feature a ton of upgrades and reliability improvements that will allow you to use aggressive tuning, big turbos, fuel upgrades, and whatever else you want onto your truck without your transmission letting you down. We have 10L1000 transmissions that range from budget-friendly towing transmissions that have reliability fixes for heavy towing all the way to powerful performance transmissions that can hold upwards of 750 crankshaft horsepower. Make sure you also check out our 2020-2024 Duramax L5P Transmission Coolers, 2020-2024 Duramax L5P Tuners, or all of our 2020-2024 Duramax L5P parts & accessories!