Heurofosh 18-6014A Sterndrive Trim Tab Anode for MerCruiser Alpha One — Aluminum Alloy Anode for Corrosion Protection and Trim

The Heurofosh 46399A1 is an aluminum trim tab anode designed to shield MerCruiser Alpha One and compatible outboard/sterndrive gearcases from galvanic corrosion while restoring hydrodynamic trim control.

The Heurofosh 46399A1 Trim Tab Anode replaces factory sacrificial zincs with a durable aluminum alloy that works in fresh and salt water. It mounts to sterndrives and outboards where extra clearance is needed for high-rake propellers, delivering both corrosion protection and improved steering assistance through its hydrodynamic profile. This single-piece kit is compatible with many Mercury/Mariner and MerCruiser applications and swaps directly for several OEM part numbers.

What does this trim tab anode protect and how?

The anode sacrifices aluminum instead of corroding key gearcase metals, reducing electrochemical damage to housings, prop shafts, and lower units. Its shape also generates trim lift and stabilizes steering, especially at speed.

• Protects sterndrive and outboard lower units from galvanic corrosion
• Aluminum alloy suited for both fresh and salt water environments
• Hydrodynamic profile provides trim assistance and improved handling
• Direct-replacement for common Mercury and MerCruiser part numbers

How do I know this is the right fit for my engine?

The 46399A1 is designed for applications requiring extra clearance for high-rake propellers and fits many MerCruiser Alpha One configurations as well as select Mercury/Mariner and Force outboards. Cross-reference your model and year with the listed replacement numbers before purchase.

• Fits MerCruiser Alpha One sterndrives and many Mercury/Mariner 35HP+ outboards
• Compatible with Force 90/120 (1995 & up) and most MerCruiser engines
• Replaces OEM numbers such as 46399A1, 822777 variants, and GLM 12680
• Single-piece kit includes one aluminum trim tab anode

What are the benefits of aluminum versus zinc anodes?

Aluminum anodes typically last longer than zinc in both fresh and salt water, offering extended protection and fewer replacements. They’re lighter and form-fit easily to modern sterndrive housings while providing effective sacrificial corrosion control.

• Longer service life compared with zinc in varied water types
• Lightweight and durable aluminum alloy construction
• Reduces frequency of maintenance and part swaps
• Spares are widely available and match common OEM references

How do I install and maintain the Heurofosh 46399A1?

Installation is straightforward: remove the old anode, clean the mounting surface, and fit the Heurofosh tab using the original hardware or specified fasteners. Inspect the anode periodically for wear and replace when more than 50% consumed to maintain protection.

• Remove existing trim tab anode and clean mating surface
• Install Heurofosh 46399A1 using OEM bolts or equivalent
• Check anode condition at regular service intervals; replace when heavily worn
• Keep spare anode aboard for seasonal maintenance

Who is this for: The Heurofosh 46399A1 Trim Tab Anode Kit is aimed at boat owners, mechanics, and fleet operators who run MerCruiser Alpha One or compatible Mercury/Mariner and Force outboards and need a reliable, longer-lasting aluminum sacrificial anode. It’s ideal for vessels with high-rake propellers that require extra clearance, and for anyone looking to reduce corrosion risk and improve steering stability with a direct-replacement OEM-style part.