DIABOLO PROPELLER RETAINER 93101-17054

Function and technical context

The propeller diabolo seal is a critical sealing component that seals the propeller shaft where it passes through the stern of the boat. Its main function is to prevent salt water from entering the motor cavity while allowing shaft rotation without excessive friction. This seal works in the transmission and propulsion system, specifically at the interface between the propeller shaft and the engine casing. If it degrades or fails, seawater penetrates directly into the engine crankcase, compromising the crankshaft lubrication, rusting the internal components and causing accelerated corrosion that can completely render the drive unit unusable.

When to replace this part?

Symptoms of seal deterioration include the presence of water in the engine crankcase, progressive loss of oil from the stern, or the appearance of whitish foam on the dipstick. Although there is no universal fixed time interval, it is recommended to inspect this seal annually at the beginning of the season and replace it preventively every 500-800 hours of operation, or if any sign of leakage is detected. Changing this component preventively is significantly more economical than repairing damage due to water ingress into the engine, especially in high-altitude navigation where a breakdown can be critical.

Equivalent manufacturer part numbers