Yanmar Rear Retaining Cover Gasket 105225-02040

Function and technical context

This rear seal cover gasket is part of the engine block sealing assembly on Yanmar 2GM series marine diesel engines. Its function is to guarantee sealing between the rear seal cover and the block, preventing oil leaks through the rear area of ​​the crankshaft. As it belongs to the main metal section of the part (callout 5), it works directly in the engine lubrication system: any deterioration of this joint compromises the oil pressure and can cause contamination of the engine compartment or progressive damage to the internal components of the propeller. Its correct installation is essential to maintain the integrity of the lubrication circuit and avoid unacceptable oil losses in a boat in use.

When to replace this part?

The most common symptoms that indicate the failure of this gasket are the appearance of stains or traces of oil in the rear area of the engine, the smell of burnt oil in the compartment or a progressive drop in the oil level without apparent cause. It is recommended to inspect this element during each seasonal maintenance or whenever the rear seal cover is removed to replace the crankshaft seal. Replacing this gasket preventively every time you intervene in that area of ​​the engine avoids repeating the operation and rules out leaks that could lead to major breakdowns far from the port.