2020-2024 Chevy & GMC 2500 & 3500 Duramax L5P Parts & Accessories

The L5P Duramax 2500 & 3500 trucks offer a ton of power and capability right off the showroom floor, but there's so much more potential just waiting to be unleashed by the right combination of Duramax L5P parts from Tier One. We have all the parts and accessories you need to add a massive amount of power to your Silverado or Sierra, as well as the drivetrain upgrades to hold that power and put it to the ground. Tier One has everything from our very own built 10L1000 transmissions and rebuild kits to Duramax L5P tuners, cold air intakes, and other essential driveline upgrades. Tier One is your one-stop-shop for L5P Duramax transmission performance, and we have everything you need to transform your truck right under one roof. If you don't see something you're looking for, contact Tier One or call 602-399-5484! If your factory transmission is slipping or you are pushing serious horsepower, a stock replacement just won't cut it, so take a look at our 2020-2024 Duramax L5P 10L1000 Complete Transmissions. The factory torque converter is designed for comfort, not heavy towing, so get better lock-up performance with one of our 2020-2024 Duramax L5P Torque Converters. The 10L1000 runs hot, especially when towing, so keep your fluid temps in check with our 2020-2024 Duramax L5P Transmission Coolers. The stock valve body is a known failure point subject to recalls, but you can ensure reliability with our updated 2020-2025 Duramax 10L1000 Valve Bodies. Finally, whether you need a deep transmission pan for extra fluid capacity or rebuild components, we have the parts you need in our section of 2020-2024 Duramax L5P Transmission Parts.