C4 26 Spline Input Shaft

The C4 26 Spline Input Shaft from TCI is a heavy-duty billet steel transmission component engineered for C4 automatic transmissions requiring OEM-specification or upgraded input shaft replacement. Manufactured to precise spline geometry, this input shaft delivers the strength and durability demanded in both stock restoration and high-performance transmission builds where torque capacity and longevity are non-negotiable.

Constructed from billet steel, this component resists the fatigue and shock loads that occur during aggressive acceleration, towing, and sustained high-RPM operation. The 26-spline design matches OEM C4 transmission specifications, ensuring proper engagement with the torque converter and internal transmission gearing. At 1.7 lbs, the input shaft integrates seamlessly into existing C4 assemblies without modification. The compact 1.5 x 1.5 x 18.8-inch envelope maintains compatibility with standard C4 housings and mounting locations across a wide range of Ford vehicles equipped with this transmission family.

This shaft serves builders and restorers undertaking C4 transmission rebuilds, performance upgrades, or OEM-spec repairs on classic Fords, muscle cars, and street machines. Whether replacing a worn factory shaft or building a fresh transmission assembly, the precision billet construction provides the reliability required for daily driving, weekend cruising, and competitive use. Technicians and experienced builders trust TCI components for their adherence to transmission engineering standards and consistent fit across multiple vehicle platforms.

The C4 transmission remains one of the most proven and versatile three-speed automatics ever produced, favored for its strength and adaptability to both stock and modified powerplants. Quality input shaft replacement ensures optimal power transfer from the engine to the transmission and maintains the integrity of the entire drivetrain during operation.