Yamaha - Lower Unit Assembly Outboard Drivetrain 6L6-45300-24-8D. Overview. When a lower unit starts getting tired, you'll notice it every time you shift or get on plane. Things feel rough, maybe a little noisy, and it just doesn't run like it used to. This Yamaha assembly is what you put on to bring everything back to smooth, dependable operation. It fits right, runs clean, and gives you that solid feel you want when you're out on the water.. Key Features. Smooth Power Transfer - Delivers consistent output from engine to propeller with minimal vibration.. Corrosion-Resistant Housing - Built to handle saltwater exposure and harsh marine conditions.. Factory-Matched Design - Engineered to Yamaha specifications for proper alignment and fit.. Durable Internal Components - Heavy-duty gears and bearings support long-term reliability.. Complete Assembly Unit - Pre-assembled design helps reduce install time and get you back on the water faster.. Engine & Boat Compatibility. Designed for Yamah