Genuine Makita 318158-4 Gear Housing for selected Makita angle grinders and concrete planers. This replacement housing encloses and supports components within the tool's gear mechanism and is suitable for replacing a worn, cracked or damaged original housing. Manufactured to Makita specifications for the correct fit and alignment of the internal components. Makita documentation confirms 318158-4 as a gear housing, including use on the PC5000C, while parts listings confirm additional GA and PC applications.