MERCURY TRANSOM ANODE 821631

Function and technical context

The transom anode is a cathodic protection component that is installed in the aft area of ​​the outboard motor, specifically in the transom structure. Its function is to absorb the galvanic corrosion that occurs naturally when different metals come into contact with salt water, thus protecting critical components such as the engine block, transmission and cooling systems. By preferentially oxidizing before the vital metal parts of the engine, the anode acts as a sacrificial barrier that significantly extends the useful life of the entire propulsion unit. Without this component, corrosion would advance rapidly on the transom and adjacent structures, compromising the tightness and mechanical integrity of the assembly.

When to replace this part?

Transom anodes wear progressively throughout the boating season, especially in saltwater where galvanic corrosion is more aggressive. It is recommended to inspect the condition of the anode at least once a season and replace it when it is 50% worn or shows signs of significant erosion, or preferably preventively at the beginning of each intensive navigation season. Carrying out this replacement preventively avoids surprises on the high seas and guarantees maximum protection of the engine throughout the entire fishing or recreational campaign.

Equivalent manufacturer part numbers