Gear Oil

Question: Where is gear oil used? 

MITASU OIL Expert Help: Gear oil is used for greasing transmission elements. In the international classification it is named as Gear Oil (literally — “oil for gears”). These oils are used for greasing enclosed gears, as a rule, in manual gearboxes, transfer gear cases, including in power take-off devices, inter-axial and inter-wheel differentials and axles. The oil type named ATF (Automatic Transmission Fluid) and CVT Fluid (Continuously Variable Transmission) is used in automatic gearboxes and variable-speed gears.  

Question: How does gear oil work? 

MITASU OIL Expert Help: Gear oil forms a hard film on friction surfaces of gear elements, thus preventing from their tear and wear. In addition, oil film reduces the impact loads on gears, reduces vibrations and transmission noises, as well as draws of heat from friction surface, preventing from their corrosion. 

Question: How can one select gear oil? 

MITASU OIL Expert Help: First, oil selected by you should correspond to the requirements of the car producer or exceed them. For example, the majority of Japan cars' producers use oils with the class not lower than API GL-5 for mechanical gearboxes, you can use oils of higher class API GL-5, which have better characteristics in comparison with API GL-4. 

Second, the oil viscosity should correspond to the temperature range, in which your car will be operated. For example, MITASU GEAR OIL 75W-90 Limited Slip 100% Synthetic universal gear oil of API GL-5 class can be used all-the-year-round (from -30 °С to +40°С );it has a set of special Limited Slip additives and due to its synthetic basis an increased life without any significant decrease of anti-scoring, anti-acid, and anti-foaming properties.  

And finally the third that one should take into account when buying gear oil is the basis (synthetic, semi-synthetic or mineral), on which oil is produced. Synthetic oils have the higher viscosity index and their physical properties are less exposed to any changes depending on the temperature. If your cars' transmission lines require oils with Limited Slip additives, your choice is limited by synthetic gear oils having an additional LS index. 

Question: What is the peculiarity of the Limited Slip system? 

MITASU OIL Expert Help: Gear oil with Limited Slip system can be used both in the most spread differentials of open type and self-blocking differential (LSD). In other words, if a differential with limited sliding is installed in your car you should use only special gear oil with the set of Limited Slip additives. Otherwise, there is a risk of the transmission line elements' failure. 

Question: How often should gear oil be changed? 

MITASU OIL Expert Help: It is recommended to check the gear oil level every year. If it is necessary to refill one should use only that gear oil, which is used in the system. When passing to a new type or grade of gear oil one should change completely the oil in the system. For determination of the gear oil change interval one should be guided by the car producer's recommendations and its operation conditions. The general rules are the following: gear oil is subject to change each 40 - 60 thous. km (or once per two-three years).