10L1000 Rebuilt Automatic Transmission

The Tier One Stage 3 Allison 10L1000 transmission is a robust solution for Duramax owners pushing the limits of their stock transmissions. Built to handle over 800 horsepower, this transmission is ideal for trucks with aggressive tuning, turbo upgrades, and other bolt-on modifications. It directly addresses common 10L1000 weaknesses, including "E" drum deflection and "F" clutch failure, ensuring reliable operation under heavy loads and high power. Key upgrades include a High Capacity "E" Clutch Drum with a Billet 6061 aluminum apply piston and 4140 steel dowels, increasing clutch capacity by 29% over OEM. The "F" clutch pack is enhanced with an extra clutch (5 total) and utilizes Raybestos Powertrain GPZ frictions. The valve body and pump assembly are modified for increased main line pressure (up to 60psi) and a 250% increase in lube circuit pressure, ensuring proper cooling and clamping force. A Deep Cast Aluminum Pan is included, providing an additional 4 quarts of fluid capacity and enhanced cooling. This transmission is specifically designed for the 2020 and newer Chevrolet Silverado and GMC Sierra 2500HD/3500HD models equipped with the 6.6L Duramax engine. Custom tuning is recommended to fully utilize the performance enhancements, including quicker shift timing and optimized lock-up characteristics. A 2-year, unlimited mileage warranty backs this transmission, with a mandatory 300-mile break-in and relearn process required to maintain warranty coverage. Additional core charges and freight shipping apply. The product also requires consideration of potential liftgate fees for residential deliveries.