Gear Oil is dark in color and smells heavy. Is it normal?
Engine gear oil is a high-viscosity lubricating oil, which is specially used to protect transmission power parts. It can form a continuous and tough oil film on the contact surface between the teeth, that is, it has high oiliness, so that the transmission parts Maintain a tough boundary oil layer to ensure that the transmission parts are less worn and prevent their abrasions.
We know that the composition of lubricating oil is basically Base Oil and additives, and vehicle gear oil is no exception, so what kind of base oil and additives used determines the color and smell of vehicle gear oil.
For heavy-duty gear oils commonly used in large vehicles, due to the requirements of heavy loads and extreme pressures, under normal circumstances, a considerable part of the base oils with higher viscosity and better bearing capacity are used. The color of the base oil varies from transparent to dark brown-red due to different origins and production processes, and the odor is also different (the color and odor of the base oil cannot characterize the quality of the base oil).
Currently on the market, the color of gear oil for large vehicles is mainly divided into two categories, dark yellow or dark brown red. This is not only related to the base oil, but also has a lot to do with the selection of additives. There are several well-known compounds on the market. The additive system of the chemical company has its own characteristics, and even if it is the same compounding company, the compounding agent of gear oil will be subdivided into several categories. This has also led to more diversified colors and odors of vehicle gear oils on the market.
Some repair shop masters like to judge the quality of gear oil based on the color and smell. They say that the quality of the gear oil with a big smell is not good because it may use recycled pickling oil or inferior oil. This statement is wrong, and the smell is big. It is part of the characteristics of the first-class base oil. At the same time, the mainstream of the existing gear oil additives adopts the extreme pressure sulfur-phosphorus compound system, which also causes the odor of vehicle gear oil to have a part of the irritating odor of sulfur. Conclusion: So smell and color cannot be used to directly judge the quality of gear oil.
