Yamaha - Gear 2 - Lower Unit Gear Component - 679-45571-00-00

Overview

When you start hearing noise or feeling roughness under load, gears inside the lower unit are usually where the issue is coming from. This gear plays a role in transferring power through the gearcase, and any wear shows up fast once the engine is under stress. I’ve seen gears like this cause vibration or loss of efficiency when they start to go. When it’s in good shape, everything runs smooth and power transfers clean to the prop.

Key Features

• Power Transfer Function – Moves engine power through the lower unit to support propulsion.
• Genuine Yamaha Fitment – Designed to match factory gearcase specifications precisely.
• Smooth Gear Engagement – Helps reduce noise and ensures efficient operation.
• High Strength Construction – Built to handle torque and continuous marine use.
• Precision Machined Design – Ensures proper alignment and long-term reliability.

Engine & Boat Compatibility

Compatible with select Yamaha outboards using this gear. Verify fitment based on your specific engine model.

FAQ

Q: What are signs of a worn gear?
A: Grinding noise, vibration, or reduced performance under load.

Q: Can this affect overall boat performance?
A: Yes, it directly impacts how power is transferred to the propeller.

Q: Is this part inside the lower unit?
A: Yes, it’s part of the internal gearcase system.

Q: Is replacement difficult?
A: It can be involved and usually requires lower unit disassembly.

Q: Does gear oil maintenance affect this part?
A: Yes, clean and proper lubrication helps extend gear life.