Mercury - Hydro Surge Kit - 856627T3. Restore your propeller system's efficiency with the Mercury Hydro Surge Kit - 856627T3. This OEM replacement kit includes all necessary components to replace the worn or damaged inner hub system in select Mercury propellers. Designed to absorb shock and reduce gearcase stress during sudden impacts, the hydro surge design helps protect your drivetrain while maintaining performance and handling.. Key Features. Genuine OEM Quality - Manufactured to Mercury's st