We decided to discuss such a non-standard topic as mixing gear oils. Not many motorists know the rules for mixing lubricating oils in the gearbox and gearbox, and many mechanics generally recommend never doing this. In fact, there is nothing wrong with this, if everything is done correctly.

Features of the compositions

Any modern automotive transmission oil consists of a base, which is the basis for creating a certain type of lubricant:

• synthetics;
• mineral water;
• semi-synthetics.

It is known that some different manufacturers use the same base, but besides it there are also additives and additives that each company has its own. It is on them that the quality and performance characteristics of the lubricating fluid depend.

Formulas for creating additives and additives are a trade secret that is kept in strict confidence. As with motor oils, transmission fluids have different parameters:

• tolerances;
• temperature conditions;
• additives;
• additives.

Thus, in order to unambiguously say whether it is possible to mix gear oil from different manufacturers, it is necessary to study all the technical characteristics and additional parameters.

What happens when mixed?

The gearbox or gearbox does not get as hot as an engine, so many people decide that mixing gear oils will not cause problems. In fact, this opinion is erroneous, since when mixing incompatible liquids, sometimes a precipitate forms - whitish flakes.

The resulting flakes clog the insides of the mechanism, which is especially dangerous for CVT and automatic. After clogging the filters, the unit quickly fails, and this leads to serious and expensive repairs.

Of course, the described precipitate in the form of flakes does not always occur, but it is better not to risk it.

Popular misconceptions

Gear oil, like engine oil, is divided into three categories:

• mineral water;
• synthetics;
• semi-synthetics.

Even experienced motorists sometimes think that adding mineral fluid to synthetic fluid results in semi-synthetics. This is a mistake and every auto mechanic can tell you about it. What will happen if you mix gear oils of different types, we will now tell you.

First of all, foam is formed, and after a few hundred kilometers a whitish precipitate will fall, which has already been mentioned above. After 1000 kilometers, the grease will thicken and clog all the holes and oil channels in the unit. Often, seals are squeezed out because of this. If a problem is detected in time, all oil must be drained and the system thoroughly flushed. After that, normal oil recommended by the automaker is poured.

Dangerous consequences of mixing oils

The thoughtless mixing of gear oils has a variety of consequences, and we have already managed to consider some of them. Some motorists, when they detect a drop in the fluid level in the transmission or gearbox, in order to save money, buy and add less expensive oil.

As you understand, in gearboxes and gearboxes, lubricating fluids operate at lower temperatures than in the engine, but these oils differ from different brands in chemical composition, especially additives. For this reason, an unpredictable chemical reaction can start during stirring, causing precipitation.

This sediment clogs the insides of the system, especially in automatic transmissions or CVTs. The design provides for a filter element that will quickly become clogged with sediment and the box will fail over time, as its internal elements will collapse due to the lack of normal lubrication.

Many motorists are wondering if it is possible to mix gear oils of the same manufacturer, but of different types. In no case should this be done, otherwise the lubricating fluid will soon foam and a sediment that is detrimental to the unit will form again.

What to do if you make a mistake?

If for one reason or another you mixed different transmission fluids and noticed uncharacteristic signs in the operation of the gearbox, as soon as possible you need to come to the service and do a hardware replacement of the lubricant using professional flushing compounds.

The procedure must be done in specialized service centers, where real professionals work and use specialized equipment. You will not be able to perform a full flush on your own - it is simply technically impossible.

Summing up

Given all of the above, it should be noted that mixing gear oils that differ in any characteristics is not recommended. These experiments may cost you too much, and you will later regret your negligence.

In many ways, the problem is due to the presence of high-precision mechanics and electronics in automatic transmissions, which can be easily spoiled by topping up with the wrong lubricant.

You can mix different lubricants only in an emergency, if there is no oil in the system, and you need to somehow get to the service station. After a short trip, the oil must be immediately drained, the unit flushed and filled with new lubricant.

It is no secret that in the process of using a personal car, many owners resort to mixing several technical fluids designed to simplify the operation of one of the vehicle's structural mechanisms. There are many reasons for such actions. However, the most common is the desire of the car owner to save money. Therefore, it happens that grease from a new package and residues from the old one are added to the system. Very often, the car owner even mixes liquids under different brands. So is it possible to mix gear oils from different manufacturers will be discussed further.

Can engine and transmission oil be mixed?

There are many common components in the composition of engine oils and transmission lubricants. However, this does not apply precisely to the identical composition of both liquids. It's just that each of these oils cannot be called a unified product. In other words, according to existing rules and recommendations, even without taking into account very similar characteristics, the answer to the question of whether engine and transmission oil can be mixed is negative. In the most extreme cases, this action is allowed. But as soon as the “native” liquid is found, the gearbox system will need to be cleaned of the mixture.

Danger of mixing lubricants

Careless mixing of several types of gearbox oils can cause very serious consequences. But the main ones will be related to the design features of the box.

The work of lubrication in gearboxes and gearboxes occurs at low temperatures, relative to the operating conditions of engine oil. However, liquids under different brands can have many differences in chemical composition, and certainly in terms of additives. This circumstance can have an impact on the appearance of an unpredictable reaction during the mixing process, causing the appearance of sediment, which will simply create a blockage in the system. This is true for variators and automatic machines. The fact is that the design of the gearbox provides for the presence of a filter. This part is very quickly clogged with reaction products, and the box itself breaks because its internal elements are poorly lubricated. Things are a little different with the manual transmission. However, the consequences of mixing the oil will not be any easier.

Even experienced motorists sometimes believe that by mixing synthetics and mineral oil, you can get a liquid that resembles semi-synthetics in composition. And this is a very big misconception. First of all, when these liquids are mixed, foam will form, and after a couple of days of driving, sediment will appear. It was talked about before. After the car has traveled thousands of kilometers, the oil in the gearbox will become thick and clog oil channels and other openings. Further, the extrusion of the seals may occur.

Conclusion

Whatever information sounds from different sources, it is important to remember that when mixing gear oils from several manufacturers, you can get extremely negative consequences for the operation of the box, up to its complete failure.

But, after all, there is no high operating temperature in the box, which is when the motor is running. But the gearbox is stuffed with high-precision electronics (especially on the machine) and such a mixture of different oils will easily disable it. The only option when you can mix several lubricants under different names is in an emergency on the road. And even if such a case occurs, it is imperative to fill in liquids with the same marking. And, as soon as the car successfully arrives at its destination, you will have to drain the mixed lubricants, flush the box, and fill in a new fluid recommended for use by the vehicle manufacturer.

What happens if you mix different gear oils? This question worries many motorists, and in our article we will talk in detail about the properties and features of gear oils, as well as the likely consequences of mixing lubricants from different manufacturers.

1 Classification of gear oils - what are they?

As with motor oils, gear oils are based on a synthetic, semi-synthetic or mineral base. Therefore, they are usually distinguished by the viscosity coefficient and by the number of additives in the composition. To date, there are two generally accepted classifications of gear lubricants - API and SAE.

SAE-classification divides oils according to the degree of viscosity. Distinguish:

• winter oils, viscosity index from 70 to 85 W;
• summer oils, viscosity index from 80 to 250 W;
• all-weather, 80-150 W according to the SAE index.

The second indicator by which all gear lubricants are classified is the API index, which divides them into 7 possible subgroups, based on the maximum allowable load factor. Symbols GL 1 to 6 or MT-1. Other characteristics of the oil, the amount of additives, additional properties, as a rule, are indicated on the packaging with the product, while each manufacturer tries to draw the attention of the buyer to the features of his lubricant to the maximum.

Synthetic, semi-synthetic or mineral oils of the same subgroup with practically similar indices, for example 5W30 and 5w40, differ significantly from each other in the package of additional additives. That is, the amount of chemical impurities in synthetics is much higher than that of mineral water, respectively, mixing these two materials will lead to unknown and unverified chemical reactions, which can provoke various consequences for transmission parts.

2 Is it possible to mix formulations from different manufacturers?

As you know, the transmission of a car does not carry as much load as the engine does. Based on this, some motorists conclude that it is possible to mix gear oils with different components and from different manufacturers, since the requirements for the performance of this oil are much lower and more loyal than for motor lubricants. However, this opinion is wrong!

In case of an urgent and urgent need to add oil to the box to the recommended level (for example, to get to a car service), you can do this without any special consequences for the car.

The absence of a normal oil level in the box is much more detrimental to its parts than the temporary mixing of lubricating fluids of different composition, therefore, in emergency cases, it is possible to fill in instead of one another. But over a longer distance, as practice shows, when using such a mixture, serious problems can arise in the system.

The most dangerous factor in mixing different oils for gearbox assemblies is a negative chemical reaction, as a result of which a white precipitate forms and falls. Over time, it clogs the most vulnerable transmission nodes, especially when it comes to CVT boxes. In addition, the oil filter becomes clogged very quickly, which also slows down the normal operation of the gearbox.

It is also impossible to mix oil with different characteristics from the same manufacturer. For example, some car owners save money by adding some synthetics to the mineral, thereby wanting to get a mixed semi-synthetic material. But due to the difference in additives and the different requirements for the operation of the two types of oil, a gradual thickening occurs, it turns into a “slurry”, with the same dangerous white precipitate falling out. As a result, the rubbing parts of the box wear out and the oil seals and filter fail, which leads to inevitable repairs.

3 What if I had to mix different oils?

In the event of an emergency, such as a sharp drop in the oil level on the road, did you still have to top up the box with what is available? Or was there an unsuccessful experiment to create homemade semi-synthetics? We recommend that you perform a comprehensive hardware cleaning of the system as soon as possible. You can do this at any car service that has specialists in automatic transmissions.

It is possible to flush the systems yourself with the help of special cleaners, it all depends on the type and access to the gearbox, but this still does not guarantee complete washing out of the previous lubricant, the remnants of which can subsequently spoil the freshly filled composition. There are special devices at the services that wash even the most hard-to-reach parts of the system several times, thereby completely washing out the remnants of the old material.

In this case, we do not recommend using special additives that “harden” or improve the operation of parts in the system, as in the case of engine flushing. It is better to fill in high-quality gear oil from a trusted manufacturer immediately after flushing. Additives in detergents are chemicals, some of which remains on the rubbing parts of the box and creates an additional protective film. However, this film does not last long, and chemical elements enter and mix with the new product without improving its properties.

Use only oils recommended by the car manufacturer, or high-quality, universal options from trusted and well-known companies. You should not save on transmission lubricants, remember that its repair is a very expensive task that not everyone can afford.

Is it possible to mix transmission oils, and what happens if the car owner, through an oversight or intentionally, combines different brands or types of transmission oil fluids? To answer this question, you should first of all be aware that transmission lubricants, as well as motor oils, by the way, are not fully considered unified products.

Lubricants for transmission are different and experts do not recommend mixing them.

Despite the fact that gear lubricants may have similar characteristics and properties, they still differ significantly in their basis, in the component composition of additive packages and process impurities, as well as in their response to weather conditions, loads and temperature conditions. Experts do not recommend mixing gear lubricants, no matter how similar they are in terms of technical characteristics.

Characteristics, classifications and differences of gear oils

It is important to note that the basic basis of modern gear oils is a synthetic, semi-synthetic or mineral component. They differ in the degree of viscosity and in the degree of load. These oils are commonly referred to by two abbreviations - API and SAE.

The SAE classification provides for the division of gear lubricants according to the degree of viscosity and is divided into 3 subgroups:

• for winter use with indices from 70 to 85W;
• for summer use with indices from 80 to 250W;
• all-weather with indices 75-90W and 80-140W.

The API classification divides these oils into 7 subgroups and characterizes the degree of permissible load on the gear lubricant. Such subgroups are designated by indices from GL -1 to GL - 6, as well as by the index МТ -1.

More specific information about the base of the oil and its viscosity is always indicated in the instructions provided by the manufacturer.

The main difference between synthetic oil and mineral oil is the level of stability of properties and characteristics at various temperatures and duration of operation.

Despite the fact that, regardless of the oil manufacturer, synthetic (semi-synthetic) and mineral lubricants have approximately similar viscosity indexes (it can often be that “synthetics” and “mineral water” are set in the same range, say 80 - 140W), there is a serious difference according to the chemical impurities (additives) added to their composition.

It is the additives of the manufacturers of these lubricants that make a significant difference in the composition of the gear oil and do not allow mixing gear lubricants in the car gearbox without possible consequences. At the same time, as mentioned above, if different grades of oils are the same in viscosity, then they always differ in additive components. After all, each company that produces oily fluids develops them independently and treats this as its trade secret.

So the car owner, who, on his own initiative, was going to mix gear oil in the car's gearbox, must clearly know and take this into account.

At the same time, in exceptional situations, it is still possible to allow the mixing of transmission oils (this may be an emergency loss of the volume of oil in the vehicle's gearbox).

Naturally, a severe lack of oil in the transmission is much worse than its possible mixing. Thus, in the absence and inability to purchase the type of gear oil currently used, it is allowed to replenish it with any other lubricant. Of course, this measure is temporary, and at the first opportunity it is necessary to remove the resulting lubricant mixture from the transmission.

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Possible consequences when mixing gear oils

Due to the difference in the composition of the oils, it becomes possible for chemical reactions to occur in the box.

Many car owners, when for various reasons they face the question of the need to replenish the volume of transmission fluid in the gearbox, make a trivial conclusion - the gearbox is not exposed to the aggressive conditions that occur in the car engine as a result of fuel combustion, and therefore, special requirements for restoration the amount of gear lubricant is not assumed.

Therefore, an inexperienced motorist believes that there is no reason to worry about the possible consequences when mixing transmission fluid in a box. After all, sometimes it looks attractive, since oil producers exhibit their products in different price ranges.

In this regard, when it becomes necessary for the car owner to normalize the level of lubricant in the box, some are tempted to save money by purchasing less expensive gear oil. Indeed, in theory, it will be of the same composition and with the same characteristics as the oil fluid currently in the gearbox. In this case, he may make a mistake, which will eventually lead to serious damage to the transmission and entail higher costs for the necessary repairs.

Indeed, in the nodes and parts of the transmission there are no such aggressive temperature conditions as in the engine itself. However, as mentioned above, oil transmission fluids from different manufacturers have additives that are different in their chemical composition. In this regard, when they are mixed, a negative chemical reaction is possible, which leads to the appearance of a precipitate (whitish flakes).

Mixing oils of even the same brand can lead to malfunctions in the car.

As a result of the formation of sediment due to the incompatibility of different types of oils, clogging of the entire transmission system can occur (especially for automatic transmissions and CVTs). In addition, we must remember that automatic transmissions provide for the presence of a special filter in their design. When it is clogged with sediment, the entire operation of the transmission system is disrupted. As a result, the gearbox can completely go out of working condition with significant damage to the components and parts of the transmission.

It should be especially noted that car service specialists sometimes noted cases when mixing transmission fluid, even from the same manufacturer, led to serious malfunctions in the gearbox. This happened if the car owner wanted to get a semi-synthetic lubricating mixture by mixing synthetic and mineral oils from the same manufacturer.

Despite the fact that both oils were of the same production grade, as a result of the indicated mixing of oils, after a certain time (400-600 kilometers of run), foaming and precipitation of the same whitish precipitate very often formed. If the car owner did not notice any malfunctions in the transmission in time and did not take any action, then subsequently such an oil mixture, together with foam and sediment, began to thicken, which led to rapid wear of the gearbox components rubbing together, as well as to excessive pressure on the oil seals (as a result, they just squeezed out).

Quite often in the process of repairing a gearbox, a problem arises. It is necessary to fill in a certain brand of oil that was previously filled in, but it is not available. As a result, a logical question arises - is it possible to mix gear oils, how compatible they are, and what will happen after mixing.

To correctly solve the problem, you need to know that transmission oils do not belong to the group of unified products. Of course, they have the same characteristics, their properties are sometimes very similar. However, there are some major differences:

• Completely different package of additives;
• Response to temperature value,
• Various technological impurities;
• Responding to changing weather.

Based on the above data, professionals recommend not mixing gear oils, even if they have very similar specifications.

Mix or not

As a rule, the gearbox operates in a quieter mode when compared to the engine of the car. Therefore, at first glance, it is not worth making special requirements for gear oil, and the volume can be supplemented with any brand that is close in parameters. Such an opinion can be called a serious mistake.

Do not think that if you mix gear oil in the gearbox, then nothing serious will happen. Sometimes when choosing a composition, the main role begins to play its cost. This is what causes the purchase of a different brand of transmission fluid. Like, it’s still cheaper, and the characteristics are almost the same with the already filled composition. However, such a decision can lead to the failure of the gearbox and its further repair, which will cost much more than you can save on the purchase.

Of course, when the gearbox is running, it does not experience huge thermal loads, in comparison with the engine. But it must be remembered that gear lubricants are produced by different manufacturers. They add additives that differ chemically from other brands. If you start mixing such products, a chemical reaction may begin that adversely affects the operation of the gearbox.

What are the consequences of mixing

The incompatibility of oils leads to the appearance of sediment, which will begin to clog the entire transmission assembly. The automatic transmission fails immediately. The fact is that they are equipped with a special filter. The sediment quickly clogs it, the transmission stops working normally. Its parts are destroyed.

I must say that professionals talk about cases when a mixture of transmission products from the same manufacturer caused serious damage to the gearbox. The reason was a mixture of synthetics with mineral water. The oil began to foam after 500-700 km of run and precipitated white.

If such a phenomenon is not noticed in time, the mixture, together with the sediment, begins to thicken. As a result, the friction force between the moving parts increases, the seals begin to experience increased pressure, they are simply squeezed out.

What to do when mixing gear oil

If, after mixing the TM, the gearbox began to work unstably, extraneous sounds appeared, it became difficult to shift gears, it is urgent to replace the lubricant, after washing the box with a special flushing fluid.

To carry out such an operation at home is quite difficult. It must be performed by specialists who can perform a complete replacement. Only after flushing, it will be possible to fill in new gear oil, taking into account the recommendations of the car manufacturer.