This product has been superseded by: 68U-45300-12-8D

Yamaha - Lower Unit Assembly - Gearcase Component - 68U-45300-12-4D

Overview

The lower unit assembly is one of the most critical components of your Yamaha outboard, responsible for transferring engine power to the propeller. This assembly ensures smooth and efficient propulsion by housing the gears, driveshaft, and internal mechanisms needed for forward, neutral, and reverse operation. Built with high-quality materials, it is designed to withstand harsh marine conditions while delivering reliable performance. Replacing a worn or damaged lower unit helps restore proper handling, smooth shifting, and overall engine efficiency.

Key Features

• Complete Gearcase Assembly – Transfers engine power to the propeller for propulsion.
• Smooth Shifting Performance – Supports forward, neutral, and reverse operation.
• Durable Marine Construction – Built to resist corrosion and wear in harsh environments.
• OEM Yamaha Fitment – Engineered to factory specifications for proper alignment and reliability.

Engine & Boat Compatibility

Compatible with Yamaha outboards using this lower unit assembly within the drive system.

FAQ

Q: What does a lower unit assembly do?
A: It transfers engine power to the propeller and houses the gears for shifting and propulsion.

Q: What are signs the lower unit needs replacement?
A: Grinding noise, vibration, shifting issues, or water contamination in gear oil.

Q: Will replacing the lower unit improve performance?
A: Yes, especially if the existing unit is worn or damaged.

Q: Is this a complete assembly?
A: Yes, it is a full gearcase assembly designed for replacement.

Q: Is installation difficult?
A: It’s a more advanced repair and is typically handled by experienced technicians.

• Supersessions
  68U-45300-12-8D, 68U-45300-12-8D, 68U-45300-12-8D