Yamaha - Lower Unit Assembly Gearcase Component 6EE-G5300-00-8D. Overview. The Yamaha Lower Unit Assembly 6EE-G5300-00-8D is what keeps your small outboard putting power into the water the way it should. On F4 and F6 motors, even a small issue in the lower unit shows up fast-rough rotation, noise, or weak push. This assembly handles everything from gear transfer to prop output, so it needs to stay tight and aligned. If your motor isn't running as smooth as it used to, this is often the fix that brings it back.. Key Features. • Efficient Power Transfer - Delivers engine output smoothly to the propeller for consistent performance.. • OEM Fit Precision - Built to Yamaha specifications for proper alignment and easy installation.. • Complete Gearcase Assembly - Pre-assembled unit for straightforward replacement and dependable operation.. • Corrosion-Resistant Construction - Designed to withstand freshwater and saltwater environments.. Engine & Boat Compatibility. • F4 2016-2018• F6 2016-201