Yamaha - Clutch Dog Lower Unit Shifting Component 6L5-45631-00-00. Overview. When shifting starts to feel rough or you hear that hard "clunk" going into gear, the clutch dog is usually part of the story. It's what actually engages the gears, so when it wears down, everything gets sloppy fast. I've seen plenty of lower units where this one part caused most of the shifting issues. Replacing it brings back that clean, solid engagement you want every time you drop it into gear.. Key Features. Positive Gear Engagement - Provides solid connection between gears for reliable shifting.. Hardened Metal Construction - Built to handle repeated engagement without premature wear.. Factory-Spec Machining - Ensures proper fit and alignment within the lower unit.. Restores Shift Performance - Helps eliminate slipping or grinding during gear changes.. High Wear Resistance - Designed to withstand constant contact under load.. Engine & Boat Compatibility. Designed for Yamaha outboard engines with compatib