41100-ZY3-C23ZD Case Gear Nh565 - Overview. The 41100-ZY3-C23ZD Case Gear Nh565 is a crucial component designed for Honda marine engine systems. This gear case assembly plays an essential role in protecting and housing the gear mechanism that transmits mechanical power within the lower unit of the outboard motor. Crafted to factory specifications, this genuine part supports reliable operation and durability of your marine engine by ensuring seamless integration with existing parts and maintainin