PIN 17-9521811

Function and technical context

This stainless steel pin is a critical fastening component on Mercury, Mariner, MerCruiser, OMC, Parsun and Tohatsu outboard motors. It acts as a structural fastening element in the engine transmission and drive system, ensuring that mechanical components remain aligned and secure during operation. Its stainless steel construction makes it especially resistant to marine corrosion and prolonged exposure to salt water, avoiding oxidation that would compromise the mechanical integrity of the powertrain.

When to replace this part?

It is a good idea to inspect this pin during each seasonal inspection, especially if you have sailed in salt water or if unusual engine vibrations have been detected. Symptoms of deterioration include excessive play between components, abnormal movements of the propeller or drive shaft, and intermittent metallic noises from the power unit. Although stainless steel pins have a long life, replacing them proactively before play is detected ensures engine reliability and prevents costly repairs at sea resulting from structural misalignment.

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers