What kind of oil should be used for electric motor transmissions?
2 Answers
Electric motor transmissions require gear oil. Transmissions and rear axles use gear oil, while the oil used in engines is called engine oil. These two types of oil have different properties and should not be confused. Additionally, gear oil for transmissions is unrelated to the engine and does not affect engine combustion. Below is a detailed introduction to gear oil: 1. Introduction: Gear oil should have excellent anti-wear and load-bearing properties, as well as suitable viscosity. It should also possess good thermal-oxidative stability, anti-foaming properties, water separation capabilities, and rust prevention. Since gear loads generally exceed 490 MPa, and hypoid gear face loads can reach up to 2942 MPa, gear oil accounts for about 6% to 8% of total lubricant usage. Gear oil is a high-performance lubricant. 2. Performance: Suitable viscosity and good viscosity-temperature characteristics are fundamental properties of gear oil. Higher viscosity results in thicker lubricating oil films and relatively greater load-bearing capacity. Extreme pressure and anti-wear properties are the most important and distinctive features of gear oil, essential for preventing wear, scuffing, and scoring of gear surfaces during operation.
I've run an auto repair shop for twenty years, and this electric vehicle transmission oil issue really needs to be clarified. There are two types of motor-driven vehicles: pure electric and hybrid. Pure electric ones like Tesla and BYD use specialized gear oil in their reduction gearboxes, which is basically maintenance-free for life - the manual says a check at 100,000 km is sufficient. For hybrids like Toyota's THS system, you must use ATF WS or THS-specific oil, changing it every 80,000 km. The worst thing is trying to save money by using random motor oil - the seals will swell and leak, ruining the reducer completely. Last time, a car owner was tricked into using GL-5 gear oil, and the copper synchronizer corroded beyond recognition, costing over 8,000 yuan to fix. Remember: consulting the manual is more reliable than asking Douyin.
