2019-2021 Chevy & GMC Silverado & Sierra 1500 5.3L Parts & Accessories

Your 2019-2021 Silverado or Sierra 5.3L V8 is a workhorse, but the factory 8-speed (8L90) and 10-speed (10L80) transmissions often hold it back with clunky shifting, high temperatures, and reliability issues. Tier One carries the essential drivetrain upgrades you need to fix these common faults. We have everything from high-performance valve bodies and billet torque converters to deep transmission pans and thermal bypass valves. Whether you use your 5.3L for daily driving, towing, or off-roading, Tier One has the parts to keep your transmission shifting firmly and running cool. We are your one-stop-shop for Silverado & Sierra transmission performance. If you don't see what you're looking for, contact Tier One or call 602-399-5484! If your stock transmission has failed or is slipping, reliable replacements are available, so check out our 2019-2021 Silverado & Sierra 1500 5.3L Complete Transmissions. The factory torque converter is known for shuddering and flexing, so get better power transfer with one of our billet 2019-2021 Silverado & Sierra 1500 5.3L Torque Converters. These transmissions run hot by design, which kills fluid life, so keep your temps in check with our 2019-2021 Silverado & Sierra 1500 5.3L Transmission Coolers. Erratic shifting and flares can be fixed with our updated 2019-2021 Silverado & Sierra 1500 5.3L Valve Bodies. Finally, whether you need a deep pan for extra capacity or a thermal bypass valve, find it in our section of 2019-2021 Silverado & Sierra 1500 5.3L Transmission Parts.