New & Remanufactured Mercury & Mariner V6 Replacement Outboard Gearcases

Explore our complete selection of Mercury & Mariner 6-Cylinder outboard gearcases—available from OEM Mercury, new OBR, remanufactured OBR, and new SEI. Whether you're restoring performance or replacing a worn unit, our gearcases are compatible with a full range of 6-cylinder models across various horsepower and engine types. Backed by OBParts' decades of expertise and warranty options, you can trust you're getting a reliable, compatible, and high-quality gearcase to get you back on the water faster.