What is the difference between GL4 and GL5 gear oil?
2 Answers
The differences between GL4 and GL5 gear oil are as follows: 1. GL-5 grade gear oil contains more sulfur compared to GL-4 grade oil. 2. GL-4 grade is a medium-duty gear oil, suitable for differential gears, transmission gears, and steering gears. 3. GL-5 is a heavy-duty gear oil, suitable for differential gears and rear axle gears operating under extremely harsh conditions. Here is more information about gear oil: 1. Gear oil mainly refers to the lubricating oil used in transmissions and rear axles. It differs from engine oil in terms of usage conditions, composition, and performance. 2. Gear oil primarily functions to lubricate gears and bearings, prevent wear and rust, and assist in heat dissipation for gears. 3. Automotive gear oil is used in gear transmission mechanisms such as steering systems, transmissions, and drive axles. Due to the high surface pressure during gear transmission, gear oil plays a crucial role in lubrication, anti-wear, cooling, heat dissipation, anti-corrosion, rust prevention, cleaning, and reducing gear surface impact and noise.
When I first bought a car, I was also confused about the difference between GL-4 and GL-5 gear oils. They both seem like lubricants, but their actual applications in vehicles differ significantly. GL-4 is typically used in manual transmissions, especially in models with synchronizers, because its chemical composition is gentler and won’t corrode the copper components, ensuring smooth gear shifts. On the other hand, GL-5 is more robust and is used in high-pressure environments like differentials or rear axles, with stronger additives to protect gears from wear. However, be careful not to mix them up—using GL-5 in a transmission can damage the synchronizers, leading to rough shifting or even premature failure. I once made that mistake and ended up paying extra for repairs. Always check the vehicle manual or consult a professional shop before making a switch; using the wrong oil can cause hidden risks. In short, choosing the right oil based on the part and load will save you trouble and money.
