Gearbox grease Bosch angle grinder

Do-it-yourself angle grinder grease for gearbox

Although the listed lubricants of domestic production are affordable, they are not always at hand.

Is it possible to make a lubricant for the gearbox of an angle grinder with your own hands?

And there is an affirmative answer to this question.

gearbox, grease, bosch, angle, grinder

Since the main technical characteristics of lubricants for gearboxes of an angle grinder are presented above, they can be taken as the basis for drawing up a lubricant of the desired characteristics with your own hands.

Homemade gear grease should be based on a highly adhesive grease. It must adhere firmly to the touching parts.


Grease for CV joints has increased adhesion. SHRUS is a joint in a front-wheel drive vehicle that works in conditions of increased dirtiness, shock loads, temperature fluctuations and humidity.

Taking grease for CV joints as a basis, it is necessary to add liquid grease (MS-20) to give the mass the desired consistency. Oil MC-20 must be served dropwise, thoroughly kneading the mass using a homemade mixer.

Good results are obtained by a mixture of a mixture of Tsiatim-221 and TAD-17 lubricants, where Tsiatim is the basis.

Correct grease filling process in angle grinders

Packing grease into the units of an angle grinder has its own rules. You need to know not only the order of its application, but also how much, and where to lay it.

Bearing Grease Angle Grinder

Three bearings are installed in the design of the angle grinder. Two bearings are mounted on the rotor of the tool, one bearing is mounted on the shaft of the driven helical gear of a larger diameter.

The angle grinder uses bearings already filled with grease. But from improper operation, overheating of the tool, grease flows out.

How to Choose the Right Bearing Grease Angle Grinder?

Bearing grease must meet the following requirements:

  • increase sliding;
  • reduce friction between component parts of parts;
  • evenly distribute heat and act as a coolant;
  • prevent the occurrence of corrosion;
  • protect from dirt and dust getting inside;
  • work in the required temperature range up to 150C;

The operating conditions of the electric motor bearings differ from the operating conditions of the gearbox bearing, not only because of the temperature requirements, but also because of the operating modes, load modes, frequency and speed of rotation.

The grease for the bearings of the electric motor must have protective properties that prevent the ingress of dirt, dust and moisture on the bearing parts.

The Russian market offers a wide range of foreign greases designed for bearings operating in different conditions. But their cost makes us look for cheaper, not inferior in quality, domestic lubricants.

Among domestic lubricants, we recommend paying attention to the Tsiatim-221, VNIINP-246 (GOST 18852-73), VNIINP-235 lubricants.

Well proven lithium greases.

Possessing high water-repellent properties, they have a wide temperature range. The role of the thickener in them is played by organic and inorganic substances. For sealed bearings, it is best to use CIATIM-203, VNIINP-242 greases.

Among pigment greases for electric motor bearings, blue grease VNIIMP-246 and dark purple ointment VNIINP-235 have become widespread. The first grease is less common than the second one due to its high price.

In today’s Russian market, domestic manufacturers of lubricants are represented in a wide range of products.

Main Features of Lubricant for Angle Grinder

In angle grinders, the main unit that is subjected to the greatest loads during operation is a gearbox consisting of helical gears.

The torque generated by the angle grinder rotor is transmitted from the rotor to the working tool through the small helical gear to the large helical gear. Correctly selected gear lubricant significantly reduces frictional force and heating temperature.

The grinder uses bearings that also require periodic lubrication. This is especially true for the spindle bearing of the large helical gear.

A lubricant is suitable that meets not only the listed requirements, but also environmentally friendly.

Lubricants for an angle grinder must have certain characteristics and must be of the required consistency in terms of properties.

The lubricant for the gearbox of the angle grinder must have:

  • viscosity no more than 800 Pa s;
  • dropping point not less than 120 ° С;
  • ultimate strength not less than 120 Pa.

Lubricant for an angle grinder should not have mechanical impurities, be resistant to corrosion, adhere firmly to lubricated parts, not melt at high temperatures, prevent the formation of scoring at the contact points of parts and, of course, have water-repellent properties.

In an angle grinder of any company, two types of plain bearings are used: bearings for an electric motor and support bearings for a gearbox.

The selection of grease for the bearings of an electric motor is different from the selection of grease for the gearbox bearing. It’s all about different working conditions.

Gearbox grease angle grinder

The grease for the gearbox of the angle grinder differs from the grease for the bearings in the main feature. increased adhesion. It should firmly adhere to the gearbox teeth when it rotates a lot.

In general, the lubrication process of the gearbox in angle grinders occurs due to the fine spray of the lubricant and its suspensions. The gearbox operates as if in oil mist. Therefore, the lubrication requirements for gearboxes are slightly different.

In addition to increased adhesion, gear lubricants must be highly heat resistant and not melt at elevated temperatures.

Lubricants of domestic manufacturers for bearings and gearboxes angle grinder

With the rise in for foreign lubricants, the lubricants of domestic manufacturers are especially in demand.

Russian lubricant manufacturers have learned to produce high-quality lubricants suitable for any tool.

Lubricants have been developed for gearboxes of grinders, perforators, drills.

The most popular products are Nanotech Metal Plak Electra. The range of lubricants produced by this company allows you to select the lubricant required for each unit

How much grease should be used when replacing the gearbox angle grinder

If the amount of grease in the bearings is controlled by flowing out from the back, then a certain amount of grease is packed into the gearbox of the angle grinder. Excess grease will leak out during operation. And a small amount of it will not ensure high-quality operation of the gearbox.

Leave as much lubricant in the gearbox as needed to cover the gear teeth.

Apply enough grease as a guide so that it occupies slightly less than half the volume of the gearbox cavity.

The procedure for applying grease to the gearbox angle grinder

The new grease is thoroughly mixed before application and applied in a thin layer. The bearings are lubricated by packing. If the grease is in a plastic tube, then the neck of the tube is pressed against the side bearing cage and squeezed out until it flows out of the back.

Gearbox grease Bosch angle grinder

Concern “Robert Bosch GmbH” is a recognized world leader in the production of power tools and accessories for them, as well as innovative solutions to design problems, the production of other high-quality products and the provision of services. Through the use of modern technology in all stages of design and development, the quality of Bosch power tools serves as a reference worldwide for both users and some power tool manufacturers. An example of this is the fact that a number of the largest tool manufacturers have acquired licenses from Bosch for a range of electrical tools. Bosch engineers do more than just design tools. they design and make their dreams come true.

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Manufacturer’s products

Hitachi G12SA Angle Grinder, Gear Lube

Correct grease filling process in angle grinders

After the choice of lubricant for the angle grinder is made, proceed directly to the maintenance of the tool. The correct maintenance process for an angle grinder consists of several steps. First you need to open the gearbox, then remove the old lubricant, apply a new one, check the correct application. Removing the old grease is necessary for the reason that mixing with new grease will not allow it to work correctly and the entire maintenance procedure will not bring any result.

Correct packing of grease into the angle grinder

How to properly remove old grease in an angle grinder

The disassembled angle grinder gearbox must be well cleaned of old lubricant. It no longer fulfills its functions, plus solid particles have already accumulated in it, resulting from wear of moving parts. Mixing with new, old lubricant also significantly degrades its performance. Therefore, the gearbox and gears must be thoroughly cleaned.

Removing old grease from the gearbox

Remove old grease with a rag, paper towel, or just a rag. The removed parts can also be washed in gasoline or thinner. The washed parts must be thoroughly dried before assembly. Residual solvent or gasoline will mix with the new grease and change its consistency, which again will worsen its performance.

Gearbox grease angle grinder

The guarantee of a long life of any hand tool consists in correct periodic maintenance. Of course, you can give it to special service centers for maintenance and diagnostics, but, as they say, “If you want to do well, do it yourself.” Therefore, it is worth figuring out how to independently service such a popular tool among home craftsmen as an angle grinder or an angle grinder, in common people.

The movable parts of the angle grinder are most susceptible to wear. These are the bearings of the armature, gears, as well as the gears themselves, which are in the gearbox. The lubricant (or lubricant) put in by the manufacturer ages over time, its properties are lost, all this leads to greater wear of the gears in the gearbox and, as a consequence, to increased vibration and the appearance of extraneous noise during operation. Periodic maintenance and replacement of the lubricant in the gearbox of the angle grinder must be carried out at least once a year.

Overview of lubricants for angle grinders

Earlier it was said that there are many types of lubricants from both a foreign manufacturer and a domestic one. A good lubricant for power tool gearboxes is available from Bosh. It is called “Lubricant for gearboxes” and is packaged in tubes of 65 grams. One such tube is enough for several servicing angle grinder.

Grease for gearbox angle grinder of various brands

Of the lubricants intended for the gearbox of the angle grinder, produced by a domestic manufacturer, we can recommend the products of the Nanotech company. It is called “Nanotech MetalPlak Electra” and is intended for tools that work with intense load. And also from domestic lubricants, SHRUS or Tsiatim-221 are widely used, however, they require preliminary preparation and, in fact, are a homemade lubricant.

The procedure for applying grease to the gearbox angle grinder

Before applying a new lubricant, it must be thoroughly mixed and made sure that there are no lumps or foreign objects in it. Apply a thin layer of lubricant to the gears, making sure that it completely covers the teeth. It is more convenient to fill the grease inside the bearings with a syringe. Then the grease intended for the angle grinder is hammered into the gear housing. This is necessary for the reason that during operation it can fly off the gears and with a small amount of it, the gears will run “dry”.

When to change the lubricant in an angle grinder

The frequency of changing the lubricant depends on how often and under what load the tool is used. Typically, this interval is about a year. In the case of intensive use with frequent overheating, the replacement frequency is reduced to six months, sometimes more often.

To carry out maintenance, you will need to disassemble the angle grinder gearbox by unscrewing 4 screws on its cover.

After removing the cover, you can see two bevel helical gears: a large and a small gear. The small gear is anchored and drives the large gear. The large one, in turn, is seated on a secondary shaft, to which a cutting or grinding disc is attached.

Checking the correct lubrication of the gearbox angle grinder

The last step in servicing your angle grinder is to check that the lubricant is correctly applied and distributed inside the gearbox. To do this, after the gear unit is assembled, the power tool is turned on without load for a few minutes, while ensuring that there are no extraneous sounds, odors and other things. If they occur, you must immediately disconnect the angle grinder from the mains. The heating of the gear unit is also checked. The lubricant must distribute heat evenly and the temperature of the gear unit must not be too high.

After a short work, unscrew 4 screws, then remove the cover from the gearbox. Visually inspect the helical gears for lubrication. If it is absent, then too little lubricant has been loaded and should be reported. If in the process of work it squeezes out of the cracks, then it was laid too much and the excess should be removed. After making any changes, check the operation of the angle grinder again without load.

Gearbox lubrication angle grinder

Surely you will not compare the word “angle grinder” with a citizen of the solar angle grinder, but immediately remember about the angle grinder. which forever secured this name. It is understandable, because this term came into our use back in the 70s, when such a tool was produced exclusively on the territory of an angle grinder.

Since then, the angle grinder has not only not lost its importance, but, on the contrary, has become even more efficient, safer and more durable. Due to its enormous functionality and ability to work with different types of material (metal, concrete, stone, brick, tile, etc.), it has become an integral part of any major overhaul or construction.

However, given the high workload of the tool, in the process of use, inaccuracies in its operation may occur, which can lead to quite unforeseen and unpleasant consequences. Therefore, if you want the device to serve you for a long time to the maximum of its capabilities, you need to approach its maintenance more than seriously.

Of course, the right decision would be to take the equipment to a service center, where it will be diagnosed and repaired by experienced specialists. But this option will be relevant if the warranty period has not yet expired, and if you are not limited in time. For the rest, you have to learn the device and make repairs yourself.

There is a lot of information on the Internet (including a video), where the process of disassembling, cleaning and lubricating the main structural elements of an angle grinder is described in stages. For example, to get to the gearbox, it is not necessary to completely disassemble it; it is enough to unscrew a few screws. And even though this process is relatively simple, it requires strict adherence to instructions, as well as accuracy, precision and care.

Before starting to dismantle the tool, it is necessary to study in detail its internal components.

Angle grinder device consists of:

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Main body made of shockproof plastic.
Side handle for comfortable holding of equipment during operation.
Start buttons.
Spindle lock buttons for quick disc changes.
An electric motor, which includes a rotor and a stator.
Reliable gearbox.
Speed ​​control wheels (not for all models).
Super-Joint-System (not available on all models).
Nuts for fixing the working element.
Wide protective cover.
Power cable or battery pack.

Disassembly of the gearbox angle grinder

The angle grinder gearbox is responsible for transmitting the rotary motion from the rotor of the electric motor to the working element. With the optimal rotation speed and the correct selection of the wheel diameter, you get a tool that is tuned for the most productive and efficient work.

The design of the gearbox consists of a bearing, a large and a driven gear. As for the body, in most cases it is made of high-quality aluminum alloy, on the base of which there are several threaded connections for fixing the side handle.

To remove the gear mechanism, one Phillips screwdriver will be enough.

The first thing to do. remove the working disc and the protective cover from the spindle.
Then unscrew the bolts that secure the angle grinder body and the gear mechanism. Typically, it is held to the body by four screws.
Take out the gearbox and assess its internal state.

How to determine if a lubricant change is necessary in a gearbox angle grinder?

Check teeth and gears for damage or wear. If you notice excess grease, which, under the influence of centrifugal force, completely settled on the walls of the housing, then with its normal quality, you can reapply a thick layer to the gear teeth. If the oil is outdated, then it should be completely replaced. To do this, thoroughly flush the gearbox with kerosene or another volatile solvent.

It is also worth considering the fact that in the process of intensive work, the lubricant can overheat, which will lead to its increased evaporation and, consequently, deterioration of the equipment operation. For example, if you notice an increased noise emanating from the device, then surely there is not enough oil in the gearbox and it is necessary to relubricate.

How much grease to use

The amount of lubricant can be easily determined by eye. It should be slightly less than half of the total volume of the gearbox. After you have squeezed out the necessary part of the composition, spread it over all rubbing surfaces of the parts.

What is the best lubricant to use

According to experts, it is best to use a lubricant of the same brand as the tool. For example, if you use TM Makita equipment in your work, then the lubricant should also be from this manufacturer, since its production takes into account the characteristics of your equipment. Thus, you can protect the device from premature failure, maximizing its service life.

However, there is a significant disadvantage in this. the price of branded formulations is quite high, which is why many people refrain from buying, preferring cheaper materials.

In addition, a large number of craftsmen use inexpensive Chinese equipment in their work, for which lubrication is not provided. However, it, like all electrical equipment, requires periodic maintenance.

What we would strongly advise you not to use is lithol or solidol. Since they are not designed to work in conditions of strong friction and high temperatures. The use of such materials leads to premature wear of the equipment and, consequently, to its breakdown.

How often to lubricate

If the tool is used intensively, then its prevention is recommended to be done every year. Since the gearbox is a rather complex mechanism that has to withstand regular heavy loads, dust can form in its internal component. With timely and correct lubrication, you will provide your device with guaranteed stable operation and a long service life.

Preparing for a grease change

Having studied the options, how to anoint the gearbox of the angle grinder. it is necessary to understand the process of applying a new composition to the elements of the mechanism. Follow the manufacturer’s power tool maintenance plan for this procedure. This must also be done when replacing gearbox parts or rotor bearings.

The processing will have a dirty color. This is due to the ingress of metal and dust particles into it. Before lubricating the gearbox, it is necessary to remove the old oil from the surfaces of the mechanisms. The working off is removed completely.

Automotive cleaning products are suitable for this procedure. You can also use kerosene or gasoline. With the help of these means, traces of old grease are completely removed from the surfaces of all parts. After processing, the gearbox must be thoroughly dried. Only then can you start refueling.

The role of lubricant

The manufacturers of the presented power tools in the manufacture of the tool mechanism provide moving, rubbing parts with a special lubricant. The composition of these products may vary. Therefore, if you are interested in how to lubricate the gearbox of an angle grinder (it is “DeWalt” or another brand), you need to look at the instructions. The manufacturer can clearly define the formulation options that are allowed to be used when servicing equipment.

Under heavy loads in which the equipment has to operate, as well as at high heating temperatures, lubricants prevent premature wear of metal parts.

Special components allow the excess heat to be removed from the rubbing steam. Also, many manufacturers provide for such an important function of their products as anti-corrosion effect. The complexity of the action allows you to ensure the full operation of the tool, extend its operation for many years.

Gearbox maintenance

Having chosen how to lubricate the gearbox of the angle grinder, as well as having prepared the mechanism for this process, you can start servicing the tool. The product must be mixed thoroughly. It is applied in a thin layer to the gearbox parts. The mass is applied to the bearings using the packing method.

If the product is packaged in a tube, its neck is placed on the side of the bearing cage. The composition is poured inside until it flows out from the other side. The gearbox is filled with enough grease to cover the gear teeth. Excess will flow out during operation of the angle grinder. Lack of lubrication leads to increased heating and friction inside the mechanism.

Experts recommend putting in such an amount of substance that it takes up almost half of the space in the gearbox housing. In this case, the operation of the tool will be correct. The manufacturer may indicate in the operating instructions some of the nuances of this process. They should also be considered when servicing the angle grinder.

Specialist recommendations

Experienced experts give recommendations on the best way to lubricate the angle grinder gearbox. They argue that if it is impossible to service the tool with branded lubricant, you can choose a different composition. The second most popular grease for CV joints is recognized in our country. It is most often used for domestic-made tools. Some masters choose grease for CV joints and for foreign angle grinders. However, the quality of the original formulations will be much higher.

It is worse if the master gave preference to such compositions as lithol or solid oil. These are universal remedies. They are not able to properly service the angle grinder gear system. When using them, the work of the tool will not be able to be complete. At the beginning of operation, the difference will be imperceptible. But over time, serious problems may appear in the operation of the unit.

Therefore, experienced craftsmen do not recommend saving on lubricant for the gearbox. The costs of purchasing original or other high-quality products are paid off by the long service life of the equipment.

Domestic lubricants

Considering how to smear a domestically produced angle grinder gearbox, it is necessary to pay attention to locally made compositions. Today Russian companies offer a wide range of such products. They are affordable.

Modern domestic materials for lubrication of the gearbox of the angle grinder are characterized by high quality. They meet high foreign standards. They are used not only in angle grinders, but also in other types of power tools.

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The products of the Nanotech Metal Plak Electra company are especially popular. However, there are other types of service compositions for any unit of the angle grinder, including the gearbox.

Signs of grease aging

Wondering how to properly lubricate the gearbox in an angle grinder. the signs of grease aging should be considered. If the technician disconnects the gearbox from the angle grinder and looks inside, he may see clear signs of the need to change the composition.

During operation of the unit, lubricant splashes and settles in a dense layer on the inner walls of the housing. Over time, the substance dries up. This creates lumps. This indicates the need to change the lubricant.

As the temperature rises, the lubricant becomes more fluid. It can spread out leaving the gear mechanism. To prevent friction, the amount must be controlled. If there is no thick layer of grease on the gears, then it’s time to change it. Otherwise, the tool will quickly fail.

Foreign lubricants

To determine how you can lubricate the angle grinder gearbox. a number of expert recommendations need to be considered. They argue that you should choose the oil that is produced by the manufacturer of the equipment. Such formulations are not cheap. However, they have a balanced set of additives to ensure long-term performance of your angle grinder. If the user of the equipment purchases other lubricants to service the power tool, the equipment may not even be covered by the warranty.

However, if you wish, you can replace the formulations recommended by the manufacturer with similar products. For foreign models, an angle grinder is quite suitable for products that contain additives identical to those used by the manufacturer of the angle grinder.

If molybdenum was present in the lubricant, it is necessary to purchase a composition labeled MoS2. For angle grinders, which are serviced by consumables of the second viscosity class, the composition NLGI2 is suitable. The ISO standard corresponds to greases marked ISOL-XBCHB 2. If the product was manufactured according to the German quality standards DIN, the new oil must be labeled with the indication DIN 51825-KPF 2 K-20.


To have an idea of ​​how to lubricate the gearbox of an angle grinder (this is Interskol or products of other manufacturers), it is necessary to consider the features of this tool. They affect the technical characteristics that a lubricant must have.

The main and most loaded unit of the angle grinder is the gearbox. It consists of gears of a certain configuration. Correct lubrication can reduce frictional force and heating of moving parts. For this, the consumable must have a viscosity of not more than 800 Pas. Its dropping point must be at least 120 ° C. The ultimate strength is recommended at 120 Pa. This allows the product to form a strong film on the surfaces of the parts.

The lubricant must be composed of naturally soluble components. It should not harm the environment and human health. Means of trusted well-known manufacturers have the appropriate quality certificates, so it is they that are recommended to be used for tool maintenance.

What, how and when to lubricate the angle grinder

Lubricant for the gearbox angle grinder: service life, the main stages of replacement. Application technology, recommended amount. Selection criteria and options, self-made lubricant.

In angle grinders (angle grinder), commonly called angle grinders, the main load falls on the gear reducer that changes the axis of rotation.

Care is required throughout the entire period of operation, since the mechanism needs to reduce friction between its interacting parts, timely maintenance.

The use of lubricant for the gearbox of the angle grinder allows not only to minimize the destructive frictional effect, but also helps to cool the tool.

How to properly lubricate an angle grinder

Bearing grease phase

Old grease removal phase

Removing used grease is the first step in gearbox maintenance. It is necessary to remove the old layer for several reasons:

  • the spent lubricant is not able to perform its functions;
  • it contains small particles formed during the wear of the rubbing elements;
  • old grease will mix with new grease, because of this, the unit will not work correctly, replacement will not bring any results.

Removal of waste is carried out using disposable paper towels, rags or a piece of tissue at hand. The removed parts of the gearbox should be thoroughly washed in thinner or gasoline, and dried before installation.

Residues from cleaning materials can also mix with the new grease and change its consistency, resulting in performance degradation.

What kind of lubricant to choose

  • the use of expensive special lubricants for gearboxes from well-known brands;
  • the use of universal compounds suitable for any power tool;
  • lubrication of the gearbox with lithol or grease;
  • using a self-made lubricant.

Application of special materials is the optimal solution. When choosing a lubricant for a gearbox, it is recommended to give preference to compounds produced under the same brand as the angle grinder itself. For example, if the machine is of the AEG brand, then the lubricant must be bought of the same brand.

When using specialized products, the service life of the angle grinder is significantly increased, since the manufacturer takes into account all the features and nuances of operating its own equipment. The disadvantage of using branded materials is their high cost, which can affect the family budget.

Most craftsmen use budget angle grinders or tools made in China. For such machines, specialized lubricants have not been developed by the manufacturer and are unlikely to ever appear. However, this technique also requires maintenance. How to proceed in this case?

Specialists and service technicians recommend purchasing any budget non-branded composition designed specifically for gearboxes. You can also use the grease used for CV joints. the hinge of front-wheel drive vehicles operated under significant loads.

The most unfavorable solution is the use of lithol or solid oil, since both of these materials are not designed for lubrication of friction units heated to high temperatures.

Some owners of an angle grinder use only these compounds, which is why their machines cannot last for the lifetime declared by the manufacturer. In an effort to benefit from the here and now, they do not factor in future spending on a new tool or replacement of expensive parts.

How much grease is required to replace

Therefore, it is better to first put in a little more material than required, and make sure that the lubricant is evenly distributed after the gears of the reducer are activated. The generally accepted norm is filling with lubricant about 40% of the volume of the gearbox.

Gearbox lubrication stage

The gearbox must be filled with such a volume of grease that it completely covers the gears.

The sufficiency of lubrication for the angle grinder gearbox is checked by switching on the angle grinder for a short time. If, within 3-5 minutes of operation, the node temperature has increased and lubricant is leaking out, part of its volume must be removed. To do this, the gearbox is disassembled again, the excess is removed with a rag or rag.

When checking, the opposite situation can be observed, when a noise appears when the angle grinder is turned on. This means that there is not enough lubricant and needs to be added.

When using an angle grinder, a periodic check of the adequacy of lubrication of the gearbox elements, the quality of the available lubricant is required.

To carry out routine inspections, it is necessary to unscrew the bolts tightening the cover and visually inspect every detail. If slightly dry or completely dry areas are observed, a complete replacement of the lubricant is recommended.