The machined overdrive piston is a performance upgrade part for the Ford 5R110W (TorqShift) transmission (used in 2003–2010 Super Duty trucks with 6.0L/6.4L Powerstroke diesels).
- Stock version: The factory overdrive clutch piston is a molded rubber-bonded design, typically supporting only 3 clutches and 3 steels in the overdrive pack.
- Machined upgrade: This is a modified (precision-machined) piston—often starting from an OEM piston—that’s thinned or reshaped to create extra clearance. This allows fitting more clutches and steels (commonly a “5-pack”: 5 frictions, 4-5 steels, and additional pressure plates) without altering other tolerances.
- Purpose: Increases clutch surface area for better heat dissipation and torque holding capacity (essential for tuned/high-HP trucks, towing, or racing). It enables the overdrive pack to handle 500–1000+ HP builds while maintaining reliable apply pressure and OEM-like clearances.


