Yamaha Lower Unit Assembly - 6J8-45300-04-8DYamaha Lower Unit Assembly Complete Drivetrain 6J8 45300 04 8D Overview The Yamaha Lower Unit Assembly 6J8 45300 04 8D is what actually puts your engines power into the water, and when its right, everything just feels smooth and solid. When a lower unit starts going bad, youll hear it, feel it, and sometimes lose confidence running at speed. Instead of chasing gears, seals, and bearings one by one, dropping in a complete unit like this gets you back