The vehicle is a rather complex device, the design of which includes a mass of various mechanisms and elements. In the course of work, all its components interact with each other, which is why friction appears. The duration of this process, over time, is able to cause damage to the component of the same node, therefore, in order to avoid such a scenario, various lubricants are used in mechanical nodes. These compositions include transmission oil, mainly used to lubricate the elements of the transmission of the car and steering mechanisms. About this further in the article.

Transmission oils, application, which requirements are imposed on transmission oils

Transmission oils are used in the following vehicle nodes:

1. Transfer case.
2. Transmission.
3. Leading and intermediate bridges.
4. Racred and worm gears of steering.

Transmission oils are designed to perform the following functions:

1. Toping heat from friction surfaces.
2. Prevent depreciation of friction surfaces and reduce friction loss.
3. Reduced shock loads on gears, noise and vibrations.
4. Protection against corrosion and removal of wear products from friction areas.

The following requirements are presented to transmission oils:

1. Deficiency.
2. Low fire hazard.
   
3. Optimal antipaic properties.
4. Stability when applying and stored.
5. Good lubricating properties that do not destroy rubber products and do not cause corrosion.
6. Low frosted temperature.
7. Good temperature and viscous characteristics.

What is the main criterion for selecting transmission oil

Transmission oils, first of all, classified by viscosity level (SAE). In addition, the level of compliance with the conditions under which the vehicle is operated (by APL) has great importance.

SAE transmission oils are divided into three categories:

1. All-season transmission oil (80W-140, 75W-90).
2. Summer transmission oil (250w, 140w, 90w, 85w, 80w).
3. Winter transmission oil (85W, 80W, 75W, 70W).

According to APL, transmission oils are divided into seven groups, but the most common are the following:

1. GL-4 - is well suited if the transmission is operated under conditions of small loads.
2. GL-5 - is intended only for rigid operating conditions of transmission.

Mineral transmission oil, dignity and disadvantages

Advantages of mineral transmission oils:

1. Efficiency.
2. High solubility.
3. Low cost.
4. Protection against the appearance of lacquer products.

The lack of mineral transmission oils is thick at low temperatures.

Synthetic transmission oil, dignity and disadvantages

Benefits of synthetic transmission oils:

1. Hydrolytic stability.
2. The optimal range of operating temperatures.
3. Saving fluidity at low temperatures.
4. High viscosity index.
5. Hydrolytic stability.

Disadvantages of synthetic transmission oils:

1. Next to the appearance of side lacquer products.
2. Low solubility of additives.
3. Relatively high cost.

The viscosity of the transmission oil, the role of the viscosity of the oil at different temperature modes

The optimal viscosity of the transmission oil affects its ability to continuously and uninterruptedly lubricate the surface of the mechanisms, as well as the locations of the elements of each other. It is these technical characteristics of a transmission, as the load on the teeth and the slip speed determine whether the fluid of viscosity should be applied. Indeed, in conditions of an increase in viscosity, lubricating oil properties may worsen. Also viscosity affects the service life of elements - the oil with the required viscosity significantly extends their lives.

The oil with the required viscosity characteristics provides the possibility of a vehicle to touch from the place at low air temperature, can reduce hydraulic losses, reduce fuel consumption and increase the transmission efficiency. If the viscosity of the oil is not suitable, then breakdowns of the details of the clutch and gearbox are possible.

Frozen temperature of transmission oils

The temperature of the simplicity of transmission oils is the temperature, in which the oil actually completely loses the mobility (fluidity). As a rule, summer transmission oil is frozen at temperatures -5 degrees Celsius, and winter - at 20 degrees.

Classes of transmission oils

To date, there are a number of transmission oil classifications abroad. The most famous of them are API and SAE. In our country, for separation of operational groups and viscosity classes, as well as to establish standard designations, GOST-17479.2-85 is used. Under this standard, transmission oils depend on the value of viscosity under a temperature of 100 degrees Celsius are divided into 4 classes - 9, 12, 18, 34, and according to possible areas of use and level of operational properties - by 5 groups: 1, 2, 3, 4 , 5.

What a transmission oil on the API marking is suitable for most cars

The advanced marking APIs are the following classes - GL4 and GL5. These presented strict requirements for anti-wear and antisaded properties. For modern cars, it is necessary to fill a transmission fluid with a marking of at least GL4, and for the newest foreign cars - GL5.

Transmission oil for automatic transmission, whether it is suitable for manual transmission

Oils for automatic transmissions are very different from oils for "mechanics", since they are presented with special requirements for foaming and viscosity. The most important thing is foaming. Oils for "automata", in contrast to "mechanics," do not have complex international standards. Leading automotive manufacturers have developed their own requirements and classifications. In addition, ATF (oils for automatic transmission) have one feature. To accidentally not apply them on the "mechanics", for which they are in principle are not intended, they are specifically coloring with a noticeable color, as a rule, red.

Tips Prof.

To give preference to one or another transmission oil follows from technical documents to the car. It is worth noting that on many cars the period for replacing the oil in the gearbox is equal to the life of the most power unit itself. But, it is desirable to change the transmission oil at least once every 5-6 years.