The Speedmaster 1-215-001-05 is a complete Ford 9-inch third member assembly built around a helical gear limited-slip differential, delivering smooth, automatic torque transfer without the harsh engagement associated with clutch-style units. The lightweight aluminum carrier housing helps reduce unsprung weight while maintaining the structural integrity needed for performance street and track applications. With a 3.89:1 ring-and-pinion ratio and 28-spline axle compatibility, this assembly is engineered for builds demanding strong acceleration and reliable traction.
Designed as a drop-in third member for Ford 9-inch rear axle housings, this assembly simplifies installation and allows for quick ratio changes without pulling the entire axle. The helical LSD design requires no special friction-modifier additives and provides consistent, predictable limited-slip performance over the long term. Whether you are upgrading a classic muscle car, hot rod, or performance build running a Ford 9-inch rearend, the Speedmaster 1-215-001-05 offers a purpose-built solution that combines durability, efficiency, and improved traction in one ready-to-install unit.
