Changing The Lubricant In The Gearbox Angle Grinder

21st July 2020

Gearbox grease angle grinder Gearbox grease angle grinder prevents wear of gears, protects against vibrations and abnormal noise during operation.

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

The amount of lubricant put into the gearbox must be such that the oblique teeth of the gears are completely covered by it. An excess will cause it to be squeezed out from under the cover, and an insufficient amount will not ensure proper operation of the gearbox.

In this regard, it is better to put a little more and check the correct distribution of the lubricant after turning on the angle grinder. In general, the amount of lubricant is usually around 30-50% of the full capacity of the gearbox.

changing the lubricant in the gearbox angle grinder

The procedure for applying grease to the gearbox angle grinder

Before applying new grease, 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 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.

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, in turn, is planted on the secondary shaft, to which the cutting or grinding disc is attached.

Characteristics and features of greases for grinders

When servicing any hand tool with moving parts, a lubricant is used that has the following characteristics and features:

It should not contain solid particles that can cause chipping of the moving parts of the mechanism.
The temperature at which the lubricant becomes liquid must be over 120 degrees.
The oil should not absorb moisture, it should form a strong film that protects the parts from corrosion.
And also, most importantly, the oil should be of such a viscosity that it was able to hold onto moving parts.

The consistency or viscosity of greases is classified according to the NLGI (National Lubricating Grease Institute), and in certain cases it is necessary to use an oil of a certain thickness. The viscosity of the oil is selected depending on the speed of the gearbox, the higher it is, the more liquid the oil should be. So, depending on the tool, the viscosity is selected:

Drills, hammer drills, jigsaws, where the gearbox has a low rotation speed. Nlgi-2 grease which is soft.
Lightweight rotary hammers and impact drills. Nlgi-1 grade, very soft in consistency.
Angle grinder, circular saws, lawn mowers. Nlgi-0 grade, semi-liquid in consistency.
Heavy hammer drills, jackhammers. Nlgi-00 class, liquid in consistency.

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 several 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 grease. 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 is too much laid and the excess should be removed. After making any changes, check the operation of the angle grinder again without load.

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

In this regard, it is better to put a little more and check the correct distribution of the lubricant after turning on the angle grinder. In general, the amount of lubricant is usually around 30-50% of the full capacity of the gearbox.

Gearbox lubrication angle grinder

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

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. Thanks 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), where the process of disassembling, cleaning and lubricating the main structural elements of the 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 you start dismantling the tool, you need to study its internal components in detail.

Angle grinder device consists of:

The main body is made of shockproof plastic.
Side handle for comfortable holding of equipment during operation.
Start buttons.
Spindle lock buttons for quick disc replacement.
An electric motor, which includes a rotor and 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 rotational 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 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.

One Phillips screwdriver will be enough to remove the gear mechanism.

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 in place by four screws.
Take out the gearbox and assess its internal state.

How to determine when a relubrication is required in the angle grinder gearbox?

Check teeth and gears for damage or wear. If you notice an excess of grease, which, under the influence of centrifugal force, has 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 out of date, 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. For example, if you notice an increased noise coming 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.

Which lubricant is best 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 save 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 discourage you from using is lithol or solidol. Since they are not designed to work under conditions of strong friction and high temperatures. The use of such materials leads to premature wear of the equipment and, therefore, 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.

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 changing the rotation axis. Care for it 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

Which 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;
Gear lubrication 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 formulations 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 purchased from 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.

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 grinders use only these formulations, 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.

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