Yamaha - Gear 2 - Lower Unit Drivetrain Component - 6J9-45571-02-00

Overview

When gears start wearing down, you’ll usually hear it first—noise, rough engagement, or that uneasy feeling when shifting. This gear plays a key role in how power gets transferred through the lower unit, so it needs to be solid. I’ve worked on units where replacing a worn gear made everything feel tighter and quieter right away. It’s one of those internal parts that keeps the whole drivetrain working the way it should.

Key Features

• Precision Gear Engagement – Designed for smooth interaction with mating gears inside the lower unit.
• High-Strength Construction – Built to handle constant load and rotational stress.
• Reduced Mechanical Noise – Helps maintain quiet and efficient operation when properly installed.
• Factory-Spec Fitment – Ensures correct alignment within Yamaha drivetrain assemblies.
• Wear-Resistant Design – Engineered for long-term durability under marine conditions.

Engine & Boat Compatibility

Designed for Yamaha outboard engines with compatible lower unit drivetrain systems. Commonly used across small to mid-range outboards on fishing boats, skiffs, and utility vessels. Always confirm part number compatibility before installation.

FAQ

Q: What are signs this gear is worn out?
A: Grinding noise, rough shifting, or vibration during operation are common indicators.

Q: Can this cause shifting problems?
A: Yes, worn gears can prevent smooth engagement and lead to inconsistent shifting.

Q: Is replacing this gear a simple job?
A: It usually requires lower unit disassembly, so it’s best done during a full service.

Q: Should I replace other gears at the same time?
A: It’s recommended to inspect all related components to avoid uneven wear.

Q: What causes premature gear wear?
A: Lack of lubrication, water intrusion, or heavy use can all shorten gear life.

• Supersessions
  6J9-45571-01-00, 6J9-45571-00-00