Mercury – Quicksilver Trim Tab Anode | Corrosion Protection & Steering Aid | Cast Aluminum | 31640Q4

Overview

Protecting your outboard or sterndrive from corrosion is just as important as keeping it running strong. The Mercury Marine 31640Q4 Quicksilver Aluminum Trim Tab Anode does both — it shields your lower unit from galvanic corrosion and provides subtle steering assistance through its hydrodynamic design. Built for Mercury and Mariner 30–200HP outboards and MerCruiser sterndrives (except Bravo), this anode is made from mil-spec cast aluminum that lasts longer than traditional zinc. It’s easy to install, simple to inspect, and crucial for keeping your drive protected season after season.

Key Features

• Purpose: Guards your gearcase housing and drive system from galvanic corrosion.
• Design: Dual-purpose trim tab anode adds steering balance while protecting critical components.
• Material: Made from cast aluminum, meeting or exceeding MIL-A-24779(SH) military standards.
• Performance: Provides more effective corrosion protection than zinc and works in fresh or saltwater.
• Installation: Simple to replace using basic tools; check prop clearance after installation.
• Compatibility: Fits Mercury and Mariner 30–200HP outboards and all MerCruiser drives except Bravo models.

Engine & Boat Compatibility

• Designed for Mercury and Mariner outboards from 30–200 horsepower.
• Also fits all MerCruiser sterndrives except Bravo drives.
• Commonly used on bass boats, cruisers, pontoons, and runabouts.
• Suitable for both freshwater and saltwater operation.

Performance & Practical Benefits

The 31640Q4 anode does more than just protect metal — it keeps your boat running true. The hydrodynamic shape helps balance steering torque, while the aluminum alloy sacrifices itself to corrosion before your gearcase or drive components can be damaged.

Compared to zinc, this aluminum anode lasts longer, reacts faster, and performs in a wider range of waters, including brackish or mixed conditions. Once installed, it quietly goes to work, guarding your engine’s most exposed parts from electrolysis and corrosion. Inspecting it once or twice a season ensures your system stays protected year-round.

Why Buy OEM

Mercury’s Quicksilver 31640Q4 is a genuine factory part, engineered for the exact metallurgy and balance your drive system needs. Aftermarket anodes can use impure or inconsistent alloys that wear unevenly or provide poor electrical contact.

With Mercury OEM, you get a part that’s been tested for fit, corrosion performance, and hydrodynamic stability. It installs easily, fits perfectly, and lasts longer — a simple, low-cost investment that protects the rest of your drive from costly damage.

FAQ

Q1: Which engines and drives does this anode fit?
It fits Mercury and Mariner 30–200HP outboards and MerCruiser sterndrives (except Bravo).

Q2: What’s it made from?
It’s made from cast aluminum, built to MIL-A-24779(SH) military standards for marine corrosion protection.

Q3: Can I use it in both fresh and saltwater?
Yes — aluminum anodes perform in both environments and last longer than zinc.

Q4: How often should it be replaced?
Inspect it regularly and replace when pitting or heavy corrosion appears — usually once per season.

Q5: Why use an OEM Mercury anode?
OEM parts ensure proper alloy mix, correct fit, and balanced performance — all essential for real corrosion protection.