OIL SEAL 26-855681

Function and technical context

The oil seal is a precision sealing component that acts on the engine crankshaft, preventing lubricant from leaking to the outside and simultaneously preventing water and contaminants from entering the lubrication chamber. This seal works in the lubrication system under conditions of continuous rotary movement and variable pressure, being critical to maintain the tightness of the propeller. A failure in this component causes accelerated oil loss, moisture entering the crankcase, internal corrosion and, ultimately, crankshaft seizure with catastrophic engine failure.

When to replace this part?

Typical symptoms of seal wear include visible oil dripping in the crankshaft area, oily stains on the water surface under the boat after sailing, and a noticeable decrease in the lubricant level between servicing. Although there is no established fixed maintenance interval, it is recommended to inspect the condition of the seal during each seasonal inspection and replace it preventively if incipient leaks are observed. Changing the seal before it fails completely avoids costly repairs and the possibility of being damaged while sailing.

Compatible engines

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers