What type of oil is used to coat all internal components of the planetary final drive?

The use of 90-weight oil for coating the internal components of the planetary final drive is rooted in its properties, which are particularly suited for lubrication and protection under heavy loads and varying temperatures. This type of oil has a higher viscosity, which means it can maintain a thicker film between moving parts, reducing wear and tear in a system that experiences significant stress and potential temperature fluctuations.

In the context of a planetary final drive, where gears and components are subject to high pressure and must operate smoothly, the thicker 90-weight oil ensures that all parts are properly lubricated, minimizing friction and enhancing the overall efficiency and lifespan of the drive mechanism. The oil also assists in dissipating heat generated during operation, contributing to a stable performance.

Choosing a lower viscosity oil, like 30 or 10-weight, would not provide the necessary protection and lubrication required in high-load conditions, while 50-weight oil, though thicker than the lower options, may still fall short in delivering the level of film strength needed for the ultimate lubrication of a planetary gear system.