Piston Kit
UB80E/UB80F (Bonded)

Bonded pistons are integral components in automatic transmissions, converting hydraulic pressure into precise linear motion to engage or disengage clutch packs. These pistons consist of a rigid metal core—typically steel or aluminum—over molded with a high-performance elastomer such as ethylene acrylic (AEM) or fluorocarbon (FKM).

In operation, pressurized transmission fluid is directed into a chamber behind the bonded piston. The hydraulic pressure forces the piston to move linearly, applying pressure to a clutch pack. This action engages specific gear sets, facilitating smooth gear shifts. Bonded pistons are utilized in various transmission types, including traditional torque converter-based systems and advanced electrified drivetrains.​