Choosing gear oil
An article about how to choose the right gear oil and what are the fundamental differences between different types of fluids. At the end of the article there is a video about which gear oil is better. An article on how to choose the right one gear oil , what are the fundamental differences between different types of liquids from each other.
Contents of the article:
practice shows that all drivers know about transmission oil, but do not distinguish between its types and functional properties, as well as its use in various components of the car. Some people choose oil by trial and error, some rely on the advice of a friend, others completely trust their car to a maintenance specialist. Even worse, not everyone understands the letter and number designation of the label. Including the purpose of this oil.
However, it is not necessary to oil every transmission-related part of your car. For front-wheel drive vehicles, car manufacturers recommend using motor oil rather than transmission oil. In addition, none of these oils are suitable for automatic transmissions. For automatic transmissions, it is recommended to buy ATF – a special low-viscosity fluid.
Types of oils
- Synthetic, synthesized from chemicals, has the best price. Typically used in mechanical boxes and main axles, suitable for cold climates and heavy loads.
Marking
The abbreviation SAE on the label indicates the viscosity of the oil, which is one of the main characteristics of this fluid. A correctly selected viscosity index promotes uninterrupted lubrication of mechanisms and components, prolongs operation, increases transmission efficiency, movement even in severe frosts and reduces fuel consumption. Excessive viscosity robs the lubricant of some of its fluid.
The presence of the letter w in the name indicates the possibility of using the oil in the off-season. Therefore, the SAE 75W90 marking describes the properties of this type of oil as follows:
- Number 75 – degree of fluidity at sub-zero temperatures.
If there is an intolerable indicator after the “w”, this indicates that the liquid is intended for use in the winter season. If this letter is not in the labeling, then the oil should be used only in summer.
The degree of viscosity is also an important criterion in the process of neglecting it when purchasing gear oil. For example, synthetic liquids with the above markings, when the temperature drops, have such a viscosity index that the maximum frost in mineral water i s-12 degrees.
In the northern regions, such differences have a very serious impact on the performance of the car: when using one oil, its speed instantly changes after applying a certain force.
In accordance with the climatic characteristics of our region, oil can be divided according to geography.
- With an SAE score of over 140, they are best suited for southern regions.
Oil intended for transmission components is selected based on the following parameters:
- Load on the mechanism.
Based on these criteria, an oil of the required viscosity, supplemented with appropriate additives, is selected for each car.
Drivers should not be concerned about the presence of sulfur compounds, which are present in many additives. The chemical effect they have on the metal is insignificant compared to the level of wear reduction on the parts they come into contact with.
Cars are traditionally filled with the two most common types of oil: GL-4 and GL-5 – ACCORDING TO IMPORTED classification. According to Russian markings, they are classified as TM-4 and TM-5. There are universal GL-4/5 oil classes suitable for various types of transmissions.
Class GL-5 is divided into types depending on viscosity.
- The 85W-90-SUCH marking refers to thick mineral oils, such as Lukoil TM-5-18.
Differences between GL4 and GL-5:
GL4 is used for bevel gears and some hypoid gearboxes, components and main axles.
GL5 – already works with hypoid, but with high-speed transmissions forced to experience high loads and temperatures.
A variety of factors influence the health of a car. The main ones are the condition of the transmission, engine and body. The car owner bears full responsibility for the operation of these mechanisms. These mechanisms depend on the actions and choices his car makes.
One of the most important tasks of a car owner is to choose the right gear oil and replace it in a timely manner.
Semi-synthetic fluids have an ideal balance between price and quality and absorb the best from mineral and synthetic oils. They regularly serve their purpose.
- It guarantees transmission stability at low temperatures.
Based on these data, the most rational choice is 75W90 oil with a protection level of GL-5, even at high loads and pressures exceeding GL-4.
Additives
Gray phosphorus additives protect transmission parts by creating a special protective coating. At the same time, however, the consistency of this coating is such that it exceeds the density of the copper surface and other soft parts. This leads to the fact that over time the protective layer itself wears out, and the parts are made of softer metals.
Therefore, transmission oil manufacturers draw the attention of motorists to the fact that some fluids are not recommended for synchronous gearboxes. Their use will not decrease, but will contribute to increased wear on synchronizers made of copper.
Possibility of replacing one oil with another
All of the above applies to GL-4 boxes, which operate at moderate speeds and loads, and GL-5, which operate at high speeds and loads.
However, this is not a fundamental difference: the additive in GL-5 has very high displacement properties, which are not combined with gearbox synchronization; the use of GL-5 causes an unpleasant grinding noise in the gearbox mechanism, and further use of this fluid completely removes the mechanism from working condition and is removed.
The GL-4 and GL-5 variants, while presented as versatile, actually serve their purpose far less well than their cleaner counterparts.
However, if the car owner changes the transmission oil himself, then the service center employee, in addition to the gearbox, can also pour fluid into the main axle.
What are the consequences? The owner hears an unwanted noise and discovers the presence of an oil seal in the car. This is due to the small amount of fluid entering the pump and the small number of containers in the container that act on the bearings or cause the seals to leak. Therefore, it is very important to pay attention to the filled oil; GL-4 should be intended exclusively for the gearbox, and GL-5 – for the units and components of the main axle.
As a result of the analysis of various transmission oils and methods of working with them, the following conclusions were made:
- In the category of the most optimal all-season fluid, SAE 75W90 took first place.
Therefore, car owners should not be deceived by the statement that all transmission oils are the same. A flooded tool will either extend the life of the vehicle or render it non-functional.
