Transmission oil: which is better, choice, characteristics

To reduce the wear of rubbing parts, protect the surface at high temperatures and protect against corrosion, the transmission oil is used . Which is better and what is their difference? What are the classifications of lubricating fluids? Let's talk about this in this article.

general characteristics

Due to the use of lubricating fluid in the gearbox, the mechanical parts are protected against seizing, premature wear and other damage. This is due to the formation of a dense film. In addition, it reduces the load on the gears and, as a result, the noise during the operation of the mechanism. Another feature of the lubricating fluid is the function of removing heat from contacting surfaces. Thus, the energy loss due to friction is significantly reduced. Oils for the gearbox, as well as for motors, have different classifications.

Classification according to GOST

There is a domestic GOST for transmission lubricating fluids. Depending on the viscosity and performance, they are divided into five groups. Each of them has its own designation. For example, TM4-10 means:

• TM - gear oil;

• 4 - operation group;

• 10 - viscosity class.

Let us consider them in more detail.

1. TM-1 is a group to which nigrols are classified as summer and winter. It is a question of the crude residues which were formed at distillation of oil.

2. TM-2 is a group for steering oils and gearbox. They are characterized by low quality and therefore are used only on old domestic cars.

3. ТМ-3 are such lubricants, for example, Tсп-10, Тсп-15К. They are used for heavy-duty trucks of cylindrical, conical and spiral-conical types.

4. TM-4 is made up of oils: Tcp-14rn, Tscnp and TSZ-9rn. The latter type is used in the northern areas for trucks, where the temperature can reach up to fifty degrees below zero. The first type is used for temperate zones and in hot climates.

5. TM-5 are oils TM5-12rk and TAD-17i. The first type is used for trucks in cold climates as an all-weather, and the second - for hot and temperate climates.

Other Classifications

In Europe, the United States and in our country there are two classifications: SAE and API. They are convenient and complementary. One of them determines the viscosity, and the other is different, depending on the additives contained in it.
This classification exists not only for transmission, but also for motor oils, although it differs from it. We consider both types in more detail.

SAE

This classification was developed by the American Society of Engineers. On it, the lubricating fluid is divided into types depending on the viscosity. This classification is known to everyone, and it is used because most car manufacturers recommend, with this viscosity index , the gear oil .

Which is better, is solved based on the temperature at which the vehicle will be operated. Therefore, there are types for high and low temperatures.

Viscosity at low temperature is checked by measuring the exponent at which one hundred and fifty thousand cP is achieved by Brookfield. Then the temperature is fixed. If this value is exceeded, the bearings will begin to break down. Of course, the process depends on the structure of the bridges. But the fact that the negative impact on them will begin is an established fact. That is why it is so important to follow the recommendations for a low-temperature indicator.

If the temperature often reaches thirty degrees of frost, then synthetic oils with a marking of 75W-XX and a viscosity limit of 5,000 cP are suitable for MKPP.

The high-temperature maximum is determined at one hundred degrees. Therefore, the transmission elements will not start to break down, even if they work for twenty hours at a high temperature.

API

This classification is the most universal, which determines the required transmission oil. Which is better, is selected by marking GL. The most common are GL-4 and GL-5.

For the mechanics, in principle, gear oils GL-1 and GL-2 are also purchased. They are suitable for gentle and medium-duty operation, and the second option even contains additives. But they found more use for agricultural machinery.

GL-4 and GL-5 are universal for various conditions, have a sufficient set of additives. The last view for a mechanical transmission is no longer suitable.

ZF

There is one more classification according to the products of the manufacturer Zahnadfabrik Friedichshafen. If you have purchased such a transmission oil, which is better, the question will not be faced to you, since this lubricant is the highest quality mark. The marking can be from ZF TE-ML 01 to ZF TE-ML 15. Today such a quality indicator is becoming very popular.

1. ZT TE-ML 01 means that the oil is for non-synchronized gearboxes.
2. ZT TE-ML 02 is suitable for trucks and buses.
3. ZT TE-ML 03 - for torque converters;
4. ZT TE-ML 04 - for ships.
5. ZT TE-ML 05 - for the leading bridges of off-road vehicles.
6. ZT TE-ML 06 - for tractors.
7. ZT TE-ML 07 - for cranes, electric drive systems.
8. ZT TE-ML 08, 09 - for steering systems.
9. ZT TE-ML 10 - for cars.
10. ZT TE-ML 11 - for mechanical and automatic transmissions.
11. ZT TE-ML 12 - for bridges of commercial vehicles and buses.
12. ZT TE-ML 13 - for transport vehicles of NATO.
13. ZT TE-ML 14 - for automatic transmissions of commercial auto.
14. ZT TE-ML 15 - for brake systems of special NATO vehicles.

Each class includes lubricants on a different oil base: mineral, semi-synthetic and synthetic. Also, different degrees of viscosity and type of lubricating fluid are meant.

Application Features

And the mineral, semisynthetic, and synthetic gear oil has a long service life: from twenty to one hundred thousand kilometers. The distance depends on the quality of the lubricant, as well as on the operating conditions and design of the mechanism. Oil change is carried out only in case of essential change of its indicators.

Stable operation is provided due to the fact that there is a reliable protection against penetration of road dust, which becomes the main reason for the quality decrease. Also the functionality falls when the moisture gets into the mechanism. Therefore, if the unit is provided with excellent sealing of all components and connections, then the performance properties will remain at a high level for a long time.

Transmission oil 75W90

This lubricating fluid belongs to the all-season class. Oils are thickened and ungreened. The first have special additives and are designated by two figures, and the second ones do not contain thickeners in their composition and are denoted by one digit.

Transmission oil 75W90 refers to the thickened species. Its peculiarity lies in the fact that the viscosity is the same at operating temperature, and at low lubrication becomes lighter.

For the 75W90 transmission oil the price is traditionally high, as it has excellent characteristics, providing the mechanism with a long-lasting good operation under different operating conditions.

Grease adequately withstands a low temperature to forty degrees of frost. High temperatures are transferred by them, as well as by other species, very easily.

Transmission oil 80W90

This variant has in the title the letter W, which means winter, and in translation from English "winter". Transmission oil 80W90 refers to winter species. It is the same as the 85W90, it is perfect for a cold climate. This oil, like the previous one, refers to the thickened species. 80W90 is fully capable of transferring the temperature to twenty-six degrees of frost.

ZIC

Consider, for example, the gear oil ZIC 75W90. It is characterized by one of the best fluidity at low temperatures.

1. According to the API, oil is characterized by GL-4/5.

2. The flash point is 230 degrees.

3. The pour point is 45 degrees below zero.

Thus, it can be concluded that this transmission oil is 75W90 (the price of which is more than one and a half thousand rubles, that is, it is quite expensive), will ensure excellent performance of the unit, and the transmissions will switch gently and smoothly. High synchronization characteristics at the same time protect the transmissions from premature wear and guarantee excellent performance for a long period of time.

However, do not forget that in order to choose the right transmission oil ZIC or another model, you must first pay attention to the manual. After all, there are cars for which the oil change during the whole period of operation is not provided at all.