WASHER SUPPLEMENT 12-78910 REC12-78910

Function and technical context

The shim washer is a precision component that acts as a load distribution element in Mercury, Mariner and MerCruiser engine mounting systems. It is used in critical fastening assemblies where uniform pressure and proper force transfer between mating surfaces is required. Its main function is to prevent the specific concentration of stresses, thus avoiding damage to the threads, deformations in the mounting surfaces and the progressive loosening of the fastening elements. This component works in coordination with screws and nuts in areas where structural integrity and tightness are essential for engine operation.

When to replace this part?

Shim washers should be inspected regularly during seasonal maintenance, especially after exposure to salt water or prolonged vibration that may compromise their load distribution function. If deformation, corrosion, pitting or loss of thickness is observed, immediate replacement is mandatory to restore contact pressure and prevent leaks or loosening of critical elements. It is recommended to preventively replace these washers when working on the engine fastening systems, since their cost is very low compared to the damage that poor fastening could cause at sea.

Compatible Mercury Mariner Engines

Equivalent manufacturer part numbers