41100-ZY3-C13ZD Gear NH565 Case - Overview. The 41100-ZY3-C13ZD Gear NH565 Case is a vital component in Honda marine engine systems, specifically designed to house and protect the gears that transmit power from the engine to the propeller. This gear case supports the lower unit system of compatible Honda marine outboard models, ensuring reliable and efficient operation. Built to meet exact OEM specifications, it guarantees seamless integration with existing parts, maintaining optimal performance