What is GL-5 gear oil?
1 Answers
GL-5 represents heavy-duty, and 85W/90 indicates that the viscosity of the gear oil is 90, and it is a multi-grade gear oil. Currently, the viscosity classification of vehicle gear oils in China adopts the SAE viscosity classification, which is divided into six viscosity grades: 75W, 80W90, 85W90, 85W140, 90, and 140. Among them, those with W are winter gear oils, and those without the suffix W are for use at normal and high temperatures. If two viscosity grades are connected together, it indicates multi-grade oil, and its performance must meet the requirements of both viscosity grades. For example, 80W90 oil means that the low-temperature viscosity meets the 80W requirements, and the high-temperature viscosity meets the 90 requirements. GL-5 is the quality evaluation standard for vehicle gear oils by the American Petroleum Institute (API), and it is currently a relatively high grade. Taking the lubrication of closed gearbox gears as an example, if the mechanical factors are not considered, the reasons for excessively high temperature may be: 1. The new gear mechanism has not been properly run-in, resulting in abrasive wear, which causes the gear surface temperature to rise. At this time, filtration should be strengthened, and the oil should be changed after run-in. 2. The load is too heavy, the oil film breaks, and wear or other failure tendencies occur, causing the gear surface temperature to rise.
