This product has been superseded by: 6D9-45300-34-8D

Yamaha - Lower Unit Assembly - Gearcase Component - F90 F100 - 6D9-45300-33-8D

Overview

The Yamaha Lower Unit Assembly | 6D9-45300-33-8D is built to keep your outboard running strong with smooth and reliable power transfer. This is the part that takes engine output and turns it into forward motion, so when it starts to fail, you’ll notice it immediately—vibration, noise, or reduced performance. Designed to Yamaha’s exact standards, this assembly restores proper function and keeps your motor operating the way it should on the water.

Key Features

• Efficient Power Transfer – Delivers smooth propulsion from engine to propeller.

• OEM Fit Precision – Engineered to Yamaha specifications for seamless installation and alignment.

• Complete Gearcase Assembly – Pre-assembled for reliable performance and easier replacement.

• Corrosion-Resistant Construction – Built to withstand harsh marine environments.

Engine & Boat Compatibility

• F90
• F100

FAQs

Q1: What are signs the lower unit is failing?
A: Grinding noise, vibration, water in gear oil, or reduced propulsion.

Q2: Can I repair instead of replacing the lower unit?
A: Minor issues can be repaired, but full replacement is often more reliable.

Q3: Does this come ready to install?
A: Yes, it’s a complete assembly designed for direct replacement.

Q4: Should I inspect other components during installation?
A: Yes, check seals, driveshaft alignment, and mounting hardware.

Q5: Is installation difficult?
A: It’s manageable with experience, but proper alignment is critical.

• Supersessions
  67F-45300-30-4D, 67F-45300-31-4D, 6D8-45300-30-4D, 6D9-45300-30-4D, 6D9-45300-31-4D, 6D9-45300-31-8D, 6D9-45300-32-8D, 6D9-45300-34-8D, 6D9-45300-35-8D, 6D9-45300-35-8D
• Engine Application
  • F90
  • F100