RETAINER 26-821309

Function and technical context

The 26-821309 seal is a sealing component installed on the engine crankshaft, responsible for preventing oil leaks between the rotating shaft and the cylinder block casing. It works in the lubrication system, maintaining lubricant pressure within the internal passages of the engine and preventing oil from escaping to the outside or contaminating other critical areas. Its integrity is essential to preserve the tightness of the engine, since a failure in this seal can cause progressive oil losses, deterioration of internal components due to lack of lubrication and, in severe cases, entry of seawater into the engine casing.

When to replace this part?

Crankshaft seals show progressive wear due to continuous friction and exposure to variations in temperature and salinity in the marine environment. Typical symptoms include oil stains or drips on the outside of the block, oily residue buildup around the crankshaft, and, on boats moored in salt water, accelerated corrosion around the seal area. It is recommended to check the condition of this component during each seasonal maintenance and replace it preventively every 5-8 years of regular navigation or at the first signs of leakage. Preventive change during a scheduled inspection is much more economical than repairing secondary damage caused by oil loss while sailing.

Engine Compatibility

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers