Drag racing Powerglides generate higher line pressure than the OE servo-piston metal seal ring was designed to withstand. With pressures over 200 PSI, the end gap of the OE seal leaks, causing a partial-apply condition in low gear that can result in higher drag, heat and wear of the high clutch. The Sonnax No Leak Powerglide Dual O-Ring Servo Piston 28821-01K uses dual O-ring seals for superior, positive sealing. In applications with a distorted servo piston bore or case flex, O-rings will conform to the bore surface, a feature not possible with metal sealing rings. Another source of leakage is the servo pin thru bore. The Sonnax No Leak Powerglide Dual O-Ring Servo Piston 28821-01K yields a precise, slip fit with the servo pin to further improve performance.
Contact a Sonnax Parts Distributor.