Mercury – Quicksilver 809666A03 Aluminum Prop Nut Anode | MerCruiser Bravo Three Drives | Corrosion Protection | 809666A03

Overview

Corrosion doesn’t make noise, but over time it can do real damage below the surface. The Quicksilver 809666A03 Aluminum Prop Nut Anode is built to stop that silent wear before it starts. Designed for MerCruiser Bravo Three drives (serial No. 0M179451 and below), this anode protects your propeller shaft and gearcase from galvanic corrosion — the kind that slowly eats away at metal parts when your boat’s in the water.

It’s one of those simple parts that does a big job. Easy to install, easy to check, and made from marine-grade material that’s built to sacrifice itself before your expensive components do.

Key Features

• Purpose: Shields the prop shaft and lower unit of your Bravo Three drive from galvanic corrosion.
• Fitment: Designed for MerCruiser Bravo Three drives (serial No. 0M179451 and below).
• Construction: High-quality aluminum anode for strong protection in both freshwater and saltwater.
• Kit Contents: Includes prop nut, anode, and fastener for quick, straightforward installation.
• Design Detail: Meets Mercury Marine OEM standards for fit, conductivity, and long-term performance.

Engine & Boat Compatibility

• MerCruiser Bravo Three sterndrives (serial No. 0M179451 and below)
• Common on twin-prop inboard/outboard cruisers, sport boats, and runabouts

Performance & Practical Benefits

The 809666A03 anode takes the hit so your drive doesn’t. By absorbing the electrolysis that happens naturally in water, it protects your gearcase, prop nut, and propeller from corrosion. This anode kit installs quickly — just swap it in place of the old one using standard hand tools.

Because it’s aluminum, it lasts longer than zinc in both fresh and saltwater, offering balanced protection without forming hard oxides that block conductivity. Whether your boat stays in the water full-time or only during the season, this anode helps prevent costly repairs and keeps your Bravo Three running clean and efficient.

Why Buy OEM

When it comes to corrosion protection, the alloy composition matters. Mercury’s OEM anodes are precisely formulated to provide the right level of electrical activity, ensuring predictable erosion and full-system coverage. Aftermarket options can look similar but may use mixed or impure metals that corrode unevenly — leaving key areas exposed.

An OEM Quicksilver anode is tested, certified, and proven in real-world marine environments. It’s engineered to erode at the correct rate, protecting the parts that matter most — your drive, your prop, and your investment.

FAQ

Q1: Which drives does the Quicksilver 809666A03 fit?
A: It’s built for MerCruiser Bravo Three drives (serial No. 0M179451 and below).

Q2: What’s included in the package?
A: The kit includes one prop nut, one aluminum anode, and one fastener.

Q3: Can this anode be used in saltwater?
A: Yes. It performs well in both freshwater and saltwater environments.

Q4: How often should I inspect or replace the anode?
A: Check it regularly — at least every few months — and replace it once more than half of the material has eroded.

Q5: Why choose aluminum instead of zinc or magnesium?
A: Aluminum lasts longer than zinc and works across a wider range of water types. Magnesium is for freshwater only, while aluminum performs in both.