What Is The Grade Of Gear Oil?
The basic grade of gear oil shows its basic performance and is determined by the GL values are :
GL-1 to GL-3: The base oils and obsolete oils for manual transmissions and axles lack special additives to cope with extreme pressure, friction and heat.
GL-4: The most common base oil grade in the world, the oil contains a large number of extreme pressure additives.
GL-5: GL-5s contains more additives than GL-4 oil, and can be used to make gear oils with extremely high load resistance to protect systems such as hypoid gears.
On top of this, the engine oil grade is a conventional gear oil grading system.
What Are Gear Oil Grades?
When buying gear oil, you will encounter conventional gear oil grades. Two of the most common are SAE and ISO grades, where SAE is used in automobiles and ISO is used in industrial applications.
SAE Grade Gear Oils :
SAE grades are used to mark various lubricants, but for gear oils, only SAE numbers of 60 or above are used.
Like SAE grades of monograde motor oil, SAE monograde gear oil grades use a single number, with cold season gear oils using the identifier “W” and oils for hotter summer conditions using only a number. The higher the number, the more viscous the oil will be.
SAE multigrade gearbox oil grades include two numbers separated by a “W” (75W140, for example), with the starting number before the “W” indicating performance at 0 ° C and the number after displaying. the performance of the lubricant at 100 ° C. As with monograde oils, the higher the number, the higher its viscosity.
ISO Grade Gear Oils
ISO grades are used with industrial gear oils. A single number, the higher the number, the higher the viscosity, and the grade number corresponds closely to the midpoint viscosity value (in centistokes (cSt))-for example, ISO 3 is equal to 3.2 cSt and ISO 220 is equal to 220 cSt.
Which Viscosity Is Higher Or Lower?
Lower and higher viscosity oils are suitable for different applications. Lower viscosity gear oils better cover fast-moving parts due to their improved cooling capacity and thinner film, thereby providing better protection and lubrication for high-speed gearboxes with relatively low loads.
High-viscosity gear oil can provide thick film, better wear resistance and corrosion resistance, making it suitable for slow gearboxes operating under higher pressure and load. They can also seal the components better, providing longer replacement intervals.