41100-ZY6-715ZD Gear Nh565 Case - Overview. The 41100-ZY6-715ZD gear nh565 case is an essential component in Honda marine engine systems, specifically serving as a gear case in the lower unit assembly. It plays a critical role in protecting the gears and ensuring smooth mechanical operation, supporting reliable propulsion and performance on the water. Engineered to fit perfectly with factory parts, it ensures seamless integration with existing parts, maintaining optimal performance and durabilit