GM Powerglides used for drag racing generate higher line pressure than the OE servo piston can withstand. At pressures over 200 psi, the OE piston can crack, resulting in transmission failure. Sonnax servo piston kit 28821-01K improves transmisison performance and durability under high-pressure conditions.

• High-strength billet aluminum piston also features a rounded profile for better stress distribution
• Dual O-ring-style piston improves sealing in worn or scuffed cases
• Easy to install, no case modifications required