40105-ZW9-020 Grommet A, Oil Case - Overview. The 40105-ZW9-020 Grommet A, Oil Case is an essential component within the Honda marine engine systems. This oil case grommet is specifically designed to provide a secure seal around the oil case assembly, ensuring no oil leaks or contamination occur. Serving as an integral part of the engine's sealing system, it helps maintain the engine's reliability and efficient performance. Characterized by precise OEM manufacturing standards, it ensures seamles