Yamaha - Gear - 69W-45560-00-00Yamaha Gear Lower Unit Drivetrain Component 69W 45560 00 00 Overview Gears inside a lower unit take a constant beating, especially when youre shifting under load or running long distances. When everythings in good shape, you get smooth, quiet operation and solid power transfer to the prop. But once a gear starts wearing down, it shows up fast with noise or rough engagement. This is one of those parts you replace to keep the drivetrain tight and