What are the chemical components of automotive gear oil?
2 Answers
Automotive gear oil is an important lubricating oil primarily composed of petroleum-based lubricating base oil or synthetic lubricating oil, with the addition of extreme pressure anti-wear agents and oiliness agents. It is used in various gear transmission devices to prevent tooth surface wear, scratches, sintering, etc., thereby extending their service life and improving transmission efficiency. Gear oil mainly refers to the lubricating oil for the transmission and rear axle. It differs from engine oil in terms of usage conditions, composition, and performance characteristics. Applications of gear oil: Automotive gear oil is used in gear transmission mechanisms such as steering gears, transmissions, and drive axles. Functions of gear oil: Lubricates the transmission system, reduces wear on gears and other moving parts, ensures normal operation of the transmission system, and extends service life; reduces friction and transmission losses in gear transmissions, improving mechanical efficiency; cools transmission components. During gear transmission, a large amount of heat is generated due to tooth surface contact friction. If not dissipated in time, it can cause localized high temperatures on the tooth surface, and in severe cases, lead to burning and adhesion. Gear oil continuously carries away heat during the circulation lubrication process, dissipating it through the air and the transmission housing, ensuring proper operation of the transmission components.
After all these years of repairing cars, I've found that gear oil is primarily composed of base oils and various additives. The base oil is typically mineral oil refined from crude oil, or synthetic oils like polyalphaolefins, which are responsible for lubricating gears and reducing friction. The additive part is quite diverse, including extreme pressure additives containing sulfur and phosphorus, which prevent wear on metal contact surfaces under high speed and high temperature conditions; there are also anti-corrosion agents like zinc-containing compounds that protect metals from rusting; additionally, there are anti-foaming agents to prevent the oil from foaming. I've also encountered cases where a car owner's transmission was making strange noises, and upon inspection, it turned out the additives in the oil had degraded, leading to increased metal friction. A reminder to everyone: regular oil changes are crucial, generally every two to three years or 60,000 kilometers, to extend the lifespan of the transmission.
