Most automotive lubricant manufacturers have online services that allow you to select oil by car make or vehicle identification number (VIN). In addition to the make and model of the car, it is also advisable to know the type of engine and transmission.
Transmission oil is a special type of oil formulated for use in power steering, transfer cases, gearboxes, axles, manual and automatic transmissions. The main requirement for transmission oil is the ability to create and retain an oil film on the surface of transmission parts, which will withstand high loads created during the operation of equipment.
Gearboxes, steering gears, gearboxes and other elements of the automotive transmission require high-quality lubrication for normal operation. It not only reduces the wear of rubbing parts, but also reduces vibration, noise, and removes excess heat. The additives in the transmission oil have anticorrosive properties, reduce foaming, and ensure the safety of rubber gaskets.
Transmission oil serves for a long time, but it gradually loses its properties and requires replacement, the frequency of which depends on the modification of the transmission and the mode of operation of the vehicle.
The wrong choice of lubricant can lead to damage to the gearbox and other transmission parts. When choosing, you must first take into account the type of transmission in which it will be used.
Performance classification
The API grease classification developed by the American Petroleum Institute is universally accepted, although not the only one. It divides gear lubricants for manual transmissions into several groups, depending on the performance, quantity and quality of additives:
- GL-1 – transmission oil without additives;
- GL-2 – used in worm gears, mainly in agricultural machinery;
- GL-3 – for manual transmissions and truck axles, not suitable for hypoid gears;
- GL-4 – has anti-seize, antiwear and other additives, used for manual transmissions and steering mechanisms;
- GL-5 – intended primarily for hypoid gears, but it can be used for other types of mechanical transmissions if provided by the automaker.
The use of gear grease of a lower grade than prescribed by the manufacturer for the given vehicle model is not permitted. The use of a higher grade oil is usually not profitable due to the significant price difference.
Most modern synchronized manual transmissions should use GL-4 grease. This is true for both rear-wheel drive and front-wheel drive vehicles.
Oil manufacturers also produce universal greases for use both in gearboxes with synchronizers and in gearboxes with hypoid gears. Their labelling has a corresponding indication – GL-4 / GL-5.
There are various automatic transmissions – hydromechanical, CVT, robotic. The oil for them must be selected taking into account the design features. In them, it not only plays the role of a lubricant but also serves as a kind of hydraulic fluid connecting the gearbox elements to each other.
For lubricating fluids used in automatic transmissions, API standards are not applicable. Their performance is regulated by the ATF standards of the transmission manufacturers.
Oils of this group can be brightly coloured in order not to be confused with conventional gear lubricants.
Applicability of transmission oil
The use of one or another type of oil directly depends on the requirements of the manufacturer of special equipment. Therefore, we urge you to adhere to the requirements specified in the instructions for the technique and not to use oil with a lower API level. Let's take a look at the general principles of using gear oil in relation to the "GL" rating.
In most cases, GL-3 oil is required for the transmission of trucks (without hypoid gears), but in some cases, GL-5 oil is used for gearboxes and axles of some vehicles.
In cars and trucks with gearboxes with a hypoid gear coupling method, GL 5 oil is used. This is due to the fact that it is this oil that will help to avoid the appearance of scoring on the gear teeth.
In the transmission of passenger cars, it is customary to use GL 4 oil for manual transmissions and GL 5 oil for lubricating drive axles.
Classification by viscosity parameter
When choosing a transmission lubricant for a car, its viscosity must also be taken into account. In this case, one should focus on the climatic conditions in which the machine is operated.
At high temperatures, the lubricant should maintain normal viscosity and the ability to close gaps, and in cold weather, it should not become too thick and not complicate the operation of the gearbox.
The internationally recognized SAE standard, which distinguishes winter, summer and all-season lubricants. Winter ones are marked with the letter "W" (winter – winter). The lower the number in front of it, the lower the temperature the oil will withstand without becoming too thick.
- 70W – ensures the normal operation of the transmission at temperatures down to -55 ° С (-67 °F)
- 75W – up to -40 ° С (-40 °F)
- 80W – up to -26 ° С (-14.8 °F)
- 85W – up to -12C (10.4 °F)
Oils marked 80, 85, 90, 140, 250 without the letter "W" are summer oils and vary in viscosity. Classes 140 and 250 are used in hot climates. For middle latitudes, the summer class 90 is most relevant.
The service life of grease for an auto transmission is usually much more than six months, therefore, unless there are some special reasons to use seasonal oil, it is easier to use a multigrade oil and change it as needed. The most universal brand of gear oil for Ukraine is 80W-90.
Choosing a transmission fluid by car make
The correct selection of lubricant for the transmission must be carried out with the obligatory consideration of the requirements of the automaker. Therefore, the first step is to look at the operating instructions for your machine. If you do not have it, you can try to find the documentation on the Internet.
You can find a great transmission fluids list here at https://engineswork.com/best-transmission-fluid.
Most automotive lubricant manufacturers have online services that allow you to select oil by car make or vehicle identification number (VIN). In addition to the make and model of the car, it is also advisable to know the type of engine and transmission.
This is a good way to familiarize yourself with the range of products, but the information in these services is not always comprehensive. Therefore, before purchasing a product, it will not be superfluous to additionally consult an authorized dealer or check the manual if the selected oil complies with the recommendations of the automaker.
