"Super Shaft" Steel Alloy Torsional Main Shaft w/ Rolled Splines

SUPERSHAFT STEEL ALLOY "TORSIONAL" MAIN SHAFT W/ROLLED SPLINES

The Coan Racing COA‑22811C “Super Shaft” Steel Alloy “Torsional” Main Shaft with Rolled Splines is a race-focused drivetrain upgrade engineered for extreme-duty applications in the Turbo Hydramatic 400 transmissions. Machined in the USA from premium steel alloy, this high-performance main shaft features precision-rolled splines and torsional reinforcement to dramatically reduce stress concentrations and fatigue under brutal load cycles. The torsional design adds rigidity to the shaft, helping resist twisting and flexing during repeated high-RPM launches, heavy-hitter starts, or bracket-style drag encounters, ensuring consistent power delivery and shift recovery.

The COA‑22811C installs directly into standard TH400 transmission cases without modification. Its clean, rolled spline profile provides superior spline engagement by enhancing load distribution across the spline surface. This precision engineering translates into crisper gear shifts, sturdier output under torque spike scenarios, and an overall drivetrain foundation that's built to break typical limitations.

In short, the COA‑22811C is a purpose-built main shaft for racers and heavy-duty builders seeking increased structural integrity, fatigue resistance, and drivetrain efficiency. By incorporating torsional reinforcement and refined spline technology into a drop-in package, it gives high-performance TH400 applications the reliability and resilience they require at the strip, the track, or in serious performance street builds.