40106-ZV5-000 Case (Lower) Grom - Overview. The 40106-ZV5-000 Case (Lower) Grom is a specialized component within Honda marine engine systems designed to provide a secure and waterproof seal for the lower casing of the engine. This part functions as a durable rubber grommet that prevents water ingress and protects internal components from damage caused by vibration or external elements. Crafted to meet factory specifications, it ensures seamless integration with existing parts, maintaining optim