Caterpillar 8S-9004 Piston Clutch

Caterpillar 8S-9004 Piston Clutch is a genuine Cat replacement part for Cat transmissions, identified by part number 8S-9004 and described in Cat catalogs as a Transmission Planetary Clutch Piston. This hydraulic piston component actuates the planetary gear set within the clutch assembly, delivering the stroke and pressure required to engage and disengage gears in compatible Cat powertrain transmissions. The 8S-9004 designation signals its use with Cat transmissions that employ planetary clutch configurations in the 8S-series family. As a factory Cat part, it is built to Caterpillar's specifications for heavy equipment service. Use this piston clutch when the planetary clutch piston specified by Cat service data is 8S-9004, ensuring proper fit within the clutch housing and compatibility with the hydraulic actuation system during repair or replacement.