Main Shaft 300M Alloy w/Rolled Splines

The Coan Racing COA‑22811A “Super Shaft” Steel Alloy Main Shaft with Rolled Splines is a race-grade powerhouse crafted for extreme-duty applications in Turbo Hydramatic 400 transmissions. Made in the USA from high-strength steel alloy, this main shaft stands out with its precision-rolled spline profile, offering superior durability and a cleaner spline fit that minimizes stress concentration and enhances resistance to fatigue, making it ideal for high-torque, high-RPM environments. Designed as a direct-fitting replacement, the shaft installs seamlessly into standard TH400 cases without any need for modifications. Its robust construction ensures dependable performance during heavy-duty use, whether in bracket racing, or aggressive street-driven builds. The rolled splines guarantee a consistent and tight engagement, supporting reliable power transfer and extending drivetrain integrity under stress. The COA‑22811A “Super Shaft” delivers a thoughtful balance of strength, precision, and durability. By incorporating high-quality steel alloy and advanced spline-rolling techniques, this main shaft significantly upgrades the TH400 front-end assembly, ensuring that high-performance builds have a solid core to build upon.