What is the right way to lubricate the gearbox of an angle grinder? Useful tips and expert advice
Angle grinder (angle grinder) is called in a simple way angle grinder. Masters perform many operations with this tool. It is just like any other piece of equipment, it requires proper maintenance. Moving parts require lubrication. Special tools are used for this purpose.
There are several options than to lubricate the gearbox of an angle grinder. Advice from experienced craftsmen will help you choose the best way. the angle grinder will work long and efficiently.
Thick grease for the gearbox of a power drill
All the time we see on forums sighs and ahs of “specialists”, who immediately after the purchase open the gear reducer of the power drill for some reason and then begin to write nonsense about a small amount of grease in the gear box, misleading other people by their illiteracy. But none of these figures have not yet written a post about the wrong type of lubrication in the power drill. This is probably because the “experts” in quantity are not interested in the quality.
Nevertheless, the grease in any of our mechanical drills, is enough to start work immediately after the purchase and continue it at least for a year, and then you should think about checking the oil. We have already told you how to change the grease, but in this article we will tell you about the grease in detail.
And it will not be the liquid oil that “experts” regularly try to pump through the grease nipple inside the gearbox. Coaxial gears require a thick lubricant, sometimes called NLGI (National Lubricating Grease Institute, USA) acronym. This is not the brand name of the lubricant, it is the name of the certification body that developed approvals for the use of this lubricant. The blue color is just one of the colors of the lubricant.
Most of the major oil companies produce the grease of NLGI type, and each has its own trade name, Mobil grease of NGLI 2 category has the trade name GADUS, Shell has a grease called NAUTILUS. Our native and well treated domestic grease Litol-24 was not tested according to the requirements of National Lubricating Grease Institute, but its properties are very similar to the NGLI 2, which is stuffed into gears at the factory of power drills.
Why is NGLI 2 and not 3 or 4? ? The reason is that this grease is divided into its classes, which are intended for different uses in mechanisms. For a coaxial motor drill it uses a class 2 grease that has a penetration number of 265-295. But that’s not what some people think ). Using the National Lubricating Grease Institute’s “working penetration” laboratory method, the density of grease is measured. Penetration is Latin for “penetration. This is measured using a penetrometer with a cone, which is dipped for five seconds in the grease at 25°C. The measuring method is similar to our domestic GOST 5346-78 for greases, according to which Lithol-24 is made. The depth of penetration of the cone is measured and expressed in tenths of a millimeter. Normally the penetration ability is determined with both stirred and unstirred grease. The difference of these indicators characterizes the stability of the grease and the ability to withstand mechanical stresses. Also, the higher the number of penetrations, the gentler the grease.
NGLI 2 lubricant is used in all mechanical coaxial gearboxes of power hammers. the grease may be dyed blue, red, gray or natural yellowish. And for replacement after the gearbox washing you can safely use Lithol-24. These greases work perfectly well within the ambient temperature range from.40 to 120 degrees Celsius. At temperatures below zero the grease becomes thick, but after 30-40 seconds after starting the engine and running the gearbox, the grease heats up and becomes less thick and gets the right viscosity for penetration between the gears and into the working cavities of the bearings. That is why it seems that there is little lubricant in the gearbox, chatterboxes from the forums do not even realize that the friction heats up the grease becomes more fluid.
The amount of 100-120 ml of grease is factory set in the gearbox and this amount is enough for painless work, despite the angry Комментарии и мнения владельцев of “experts. Therefore, there is no need to open the gearbox and add grease. The grease is not changed often, if the trimmer is used daily, it is necessary to change the grease before the second year of use.
Manufacturers of lubricants for gears
Manufacturers of lubricants for power tools can be divided into two types. This is primarily directly from tool manufacturers. They are also engaged in developing lubricant formulations specifically for their products. This includes Makita angle grinder gear lubricant index 181490-7. This is a composition designed specifically for angle grinders made in Japan, but, of course, it can also be used for grinders of other brands.
But the basis of the segment is formed by products of specialized manufacturers of lubricants. Users praise Castrol grease. A well-known company produces a special composition for power tools in green color, which can also be used for the bearing group. A similar grease for the gearbox of an angle grinder is presented in the “Mobil” line. This product is already blue XHP 222, which comes in boxes with a syringe shape for oil delivery. For the budget, many praise the grease “Nanotech”. The composition is suitable as a periodic means of maintenance of angle grinder, used in home works.
What, how and when to lubricate the angle grinder
In angular grinders (angle grinder), known as bolgarkami, the main load is on the changing axes of rotation of the gear reducer.
It requires care throughout the entire period of operation, because the mechanism needs to reduce friction between its interacting parts, timely maintenance.
The use of the grease for the gearbox of the angle grinder allows not only to minimize the destructive frictional effects, but also contributes to the cooling of the tool.
When to change the grease in the angle grinder
The period of the next grease change depends on the loads and intensity of use of the angle grinder. It usually equals 12 months. In everyday use of the angle grinder with frequent overheating, the frequency of replacement is significantly reduced, at least up to half a year.
To confirm that new grease is needed, the gearbox must be disassembled by removing the screws from the gearbox cover. Inside are a pair of helical gears. The small one is located on the armature and is used to drive the big one located on the secondary shaft. A grinding or cut-off disc is attached to this shaft.
During operation, the grease spreads along the walls of the housing, eventually drying out and forming large clods. Material used for a long time overheats, becomes liquid and flows out of the housing. Therefore, its volume in the gearbox decreases. If there is only a thin layer of lubricant on the gears, it needs to be added.
The grease for the angle grinder must be changed if there are dry lumps on the inner walls of the gearboxes or if the amount of grease is insufficient.
How much grease to change
The required amount of grease for the angle grinder is assigned based on full coverage of the bevel gears. Too much material will squeeze out of the housing, and too little will not ensure proper functioning of the gearbox.
It is recommended that the amount of lubricant included at the factory should be used as a guide. Note that during long-term storage in the warehouse or store, some amount of lubricant may dry out and shrink in volume.
For this reason it is better to add a little more grease at first and be sure that the grease is evenly spread after setting the gear wheels in motion. It is customary to fill about 40% of the Geareducer volume with lubricant.
How to properly lubricate an angle grinder
Lubricating the gearbox of an angle grinder requires several steps.
Stage of removal of old grease
Removing the Expired Lubricant is the First Step in Gearbox Maintenance. Removing the old layer is necessary for several reasons:
- used lubricant is not capable of performing its function;
- there are small particles in it from wear and tear of the rubbing elements;
- the old grease will mix with the new one, because of this the unit will not work properly, replacement will not bring any results.
Use disposable paper towels, a rag, or a rag handy to remove the used lubricant. Parts that have been removed should be thoroughly cleaned in solvent or gasoline and allowed to dry before reassembly. The remains of the materials used for cleaning can also mix with the new grease and change its consistency, resulting in poor performance.
The step of applying grease to the bearing
Gear bearings should be lubricated by plugging all available loose spots. The lubricant is squeezed out of the tube until the excess flows out the back. this is an indication of the desired filling level.
Lubrication stage of a gearbox
The Geareducer should be filled with as much lubricant as is necessary to completely cover the gears.
Check that the gearbox of the angle grinder is adequately lubricated by turning on the angle grinder for a short period of time. If after 3 to 5 minutes of operation, the temperature of the assembly has increased and some lubricant is observed leaking out, remove some of the lubricant. To do this, disassemble the gearbox again and remove the excess with a cloth or rag.
When checking the opposite situation can be observed, when the angular grinder turned on there was noise. It means that the grease is not enough and must be added.
When using the angle grinder, periodic check of lubrication sufficiency of the gearbox components, quality of available grease.
For preventive inspections, it is necessary to unscrew the bolts tightening the cover and visually inspect each part. If areas appear to be slightly dry or completely dry, it is advisable to completely replace the lubricant.
Which lubricant to choose
There are several ways to reduce the frictional effects on the interacting gear elements of the angle grinder. Choosing what to lubricate the friction nodes, is carried out of these options:
- The use of expensive special greases for gearboxes of famous brands;
- use of universal compositions suitable for any power tool
- Greasing the gearbox with lithol or solidol;
- use of a self-made lubricant.
Application of special materials is the optimal solution. When selecting a lubricant for the gearbox, it is recommended to give preference to compositions produced under the same brand as the angle grinder itself. For example, if the machine brand AEG, then the lubricant should buy the same brand.
When using specialized products, the service life of the angle grinder increases significantly, as the manufacturer takes into account all the features and nuances of operating its own equipment. The disadvantage of using brand materials is their high cost, which can affect the family budget.
Lubricant for the gearbox of angle grinder
The guarantee of a long life of any hand tool is in its proper periodic maintenance.
Of course, you can give for maintenance and diagnosis in special service centers, but as they say, “If you want to do well. do it yourself.
Therefore, it is worth to understand how to independently serve such a popular by home masters tool, as an angle grinder or angle grinder, in common parlance.
The most exposed to wear and tear moving parts of the angle grinder. These are armature and gear bearings, as well as the gears themselves, which are in the gearbox.
Lubricant (or lubricant), laid down by the manufacturer, over time, it gets old, its properties are lost, all of this leads to greater wear of gears in the gearbox and, as a consequence, to increased vibration and the appearance of extraneous noise during operation. Periodic maintenance and lubricant replacement in the gearbox of an angle grinder should be performed at least once a year.
Characteristics and peculiarities of lubricants for angle grinders
When servicing any hand tool that has moving parts, a lubricant with the following characteristics and features is used:
- It should not contain solid particles, which can cause breakage of moving parts of the mechanism.
- Temperature at which the lubricant becomes liquid, should be above 120 degrees.
- Oil should not absorb moisture, should form a strong film that protects parts from corrosion.
- Also, most importantly, the oil should be of such viscosity that it has the ability to retain on the moving parts.
Lubricant MakitaLubricant BoschLubricant Mobil
The consistency or viscosity of the grease is determined by NLGI (National Lubricating Grease Institute), whereby in certain cases it is necessary to use an oil of a certain thickness. Oil viscosity depends on gearbox speed; the higher the speed, the more fluid the oil must be. So, depending on the tool, the viscosity is chosen:
- Drills, peorators, and jigsaws, where the reducer has a low speed. NLGI-2 rated grease, which is soft.
- Lightweight peorators and impact drills. Class NLGI-1, consistency very soft.
- angle grinder, circular saws, brushcutters. Class NLGI-0, consistency semi-liquid.
- Heavy rotary and demolition hammers. NLGI-00, which is liquid in consistency.
Gear lubricant for the angle grinder
Virtually all of the world’s major tool manufacturers require their recommended lubricants for their brands. This is correct in principle.
Bosch angle grinder Greasing
The lubricant to be applied to the gearbox of an angle grinder is tested in the factory and guarantees long term and correct functioning of the angle grinder.
However, there are disadvantages, which are the high price of lubricant from these brands.
In addition to original oils, there are many lubricants on the market, manufactured by third-party manufacturers, so the question of what exactly to lubricate the gear reducer of angle grinder, is not acute.
Products from Haskey, Castrol, Liqui Moly and others showed themselves well for adding to the gearbox of angle grinder.
Russian manufacturers also do not lag behind foreign ones and offer their products. Thus, a very popular lubricant for the bevel gear of an angle grinder from the company “Nanotech”. Of course, such grease for the gear is not original and recommended by the manufacturer, so if you use it, the subsequent warranty repair can simply refuse.
The correct process of filling grease in angle grinders
Once you have selected the right lubricant for your angle grinder, proceed to maintenance. The proper 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.
The old grease has to be removed because mixing with the new grease prevents it from working properly and the whole maintenance procedure is useless.
When to change the grease in an angle grinder
The frequency of lubricant replacement depends on how often and under what stress the tool is used. As a rule, this interval is about a year. In the case of heavy use with frequent overheating, the frequency of lubricant replacement may be reduced to half a year, sometimes more frequently.
To perform maintenance, it is necessary to disassemble the angle grinder gearbox by removing the 4 screws on the cover of the angle grinder.
After removing the cover you will see two helical bevel gears: one large and one small. The small gear is on the armature and drives the large gear. The large, in turn, is seated on the secondary shaft, to which the cutting or grinding disc is attached.
Harbor Fright angle grinder. gear lubrication
The disassembled gearbox of the angle grinder must be thoroughly cleaned of old lubricant. It no longer performs its functions, plus it has already accumulated solid particles resulting from wear of moving parts. Mixed with new, old lubricant also significantly impairs its performance. Therefore, the gearbox and gears must be thoroughly cleaned.
Remove old grease with a rag, paper towel, or simple cloth. Removed parts can also be washed in gasoline or solvent. Washed parts must be dried thoroughly before reassembly. Residues of solvent or gasoline will mix with the new grease and change its consistency, again reducing its performance.
How to Grease a Gearbox Angle grinder Makita, Bosch, Interskol and more
Lubricate with what? Most manufacturers insist on the use of lubricants produced under their brand. The list of recommended greases is usually found in the owner’s manual. Listen to the opinion of the author, buy in advance a tube or can of the original material.
If the manufacturer is so democratic that in the instruction was limited to indicating the use of “for this purpose” compositions, the decision “than lubricate” takes the owner of the angle grinder. And buy. as a counterpart. universal grease of another manufacturer. Or, having recollected a clips watched at YouTube they say to themselves: “Somewhere in my garage there is a similar can, I will lubricate it if I have to”. It is up to you to decide if you want the original or an analogue. Or take your dealer’s advice. Or use someone else’s experience. Options “make grease yourself or use a surrogate”. do not recommend.
Amount of grease needed. Getting a new power tool, it is desirable to know how much grease should be put in his gearbox for maintenance, the need for which will arise sooner or later.
Remove the cover of your new angle grinder and look inside the gear housing. A conscientious assembler should put in such an amount of grease that it covers the gear case and pinion with a thin film, fills the teeth of the idler gear completely, and fills the cover volume under the idler gear. Take this amount as a benchmark and follow it steadily.
Reference. Authorized Makita dealers state that lubrication should not take up more than 50% of the gearbox volume.
Therefore, it is very useful to buy an angle grinder, buy a tube of grease at the same time. Original or similar.
Some sources say that you should lubricate the gearbox of an angle grinder once a year, others say “as needed”.
Lubrication intervals depend on tool grade. A professional angle grinder that works “without interruption, for a long time with full load” simply will not survive until one year of age without lubrication. Try to determine for yourself whether you have to lubricate the gearbox using simple diagnostic methods.
If in doubt, open the gearbox for inspection. It is easier to add fresh lubricant in five minutes than to have the power tool “brought in for repair” all weekend. You can see the proper procedure for changing the lubricant on YouTube:
Important. On some models the gear cover is secured with Torx 3.5 or Torx 4.0 socket head screws. Store such a bit in advance.
Watch the video to see how and in what order you can change the grease. Do not listen to recommendations like “eternal grease for angle grinder gearbox”. Perpetual grease is intended for use only in perpetual motors.
After opening, carefully inspect the grease in the gearbox housing and cover. If it is translucent, the original yellowish or blue-green (depending on the brand), has no inclusions of dirt and wear products. the grease is not worth replacing. It’s enough to refill it.
Old grease is greasy enough. remove it with a soft cloth (rag). If it has turned into clumps of dirt (low-temperature sludge), flush and dry the gearbox after removing it.
Be careful with the rear spindle bearing when cleaning and flushing the gear housing. If it is needle bearing, do not flush or grease it. Needles can fall out of a worn cage (or outer ring, if so designed) and you may run into a lot of trouble, up to and including bearing replacement.
When the spindle is installed in plain bearings, do not flush them too hard. The porous bronze-graphite material of the bushings is soaked with grease and there is no need to “degrease” it.
When flushing the gear housing, hold the angle grinder with the motor up so dirty solution does not flow over the rotor shaft into its bearing and electrical guts.
To flush, use clean gasoline or mineral spirits and a stiff bristle brush.
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How much grease to replace
The quantity is limited by the volume of the gearbox. If too much new lubricant is put in, it will leak through the housing connector. The angle grinder must be kept dry, otherwise it can be damaged.
Amount is estimated to be sufficient to cover the gear teeth from the motor. In total this will be up to 50% of the volume. When reassembling a gearbox, the inserted part will distribute grease and take up some more volume. When the motor is turned on and started, the grease will distribute to the walls, shafts, and teeth.
Depending on the brand and characteristics of the grease, it can dry out over time. Therefore, it is necessary to follow the instructions of the angle grinder and use the stated amount of grease.
How to lubricate the gearbox
Every tool that has moving parts requires periodic lubrication. Especially if you use it extensively. The consistency and composition of lubricant for angle grinders must meet certain requirements.
Solid or, worse still, abrasive substances will cause abrasion on the work surface and in parts. Cheap lubricant simply evaporates when it reaches the temperature threshold of 100-120⁰C. Therefore, you should pay special attention to the maximum allowable values of the lubricant, otherwise the tool in the heat of work will be left without lubrication.
A good composition protects the surface from moisture, as well as from subsequent corrosion, which means it must have water-repellent properties. Adjusted consistency allows to keep grease on the surface: too thick lubricant will hamper operation of the mechanism, and liquid one will simply flow down into the gearbox.
The viscosity of power tool lubricants is graded according to NLGI (National Lubricants and Grease Institute abbreviation). The choice of consistency depends on the specific angle grinder model, namely the speed of the gearbox. the higher the value, the less thick the grease needs to be.
Viscosity Classification for power tools:
- NLGI 00. Lowest consistency, used in heavy equipment: demolition hammers, professional rotary hammers, etc.п.
- NLGI 0. It is a semi-liquid compound, which is precisely what is used for angle grinders, as well as circular saws and petrol power hammers.
- NLGI 1. Sufficiently viscous consistency for use in construction and medium power impact drills.
- NLGI 2. Soft type of grease. Used in power jigsaws, light scroll saws and drills.
The required lubricant grade must be indicated in the instruction manual of the equipment. If there are no documents with the angle grinder, then all the parameters of the model should be listed on the official website of the manufacturer of the equipment.
Situations where there is an urgent need to lubricate the elements of an angle grinder are not uncommon. And at the same time, as bad luck would have it, there is no way to get a suitable lubricant for this purpose. Then the owner can try to make a remedy with his own hands from available materials.
To achieve the required level of adhesion the following automotive CV joint grease is used as a basis. In addition to its excellent penetrating properties, it is acceptable for use in conditions:
- significant loads;
- high humidity;
- temperature fluctuations in a wide range;
- considerable heat;
- exposure to solid contaminant particles.
To liquefy the material and obtain the desired consistency for the reducer, it is recommended to add MS-20 oil. Liquid is added to the base gradually, preferably in drops, while constantly mixing the resulting composition with a mixer.
No less effective is the use of homemade material based on “Citiam-221” with the addition of TAD-17.
What kind of gear lubricant do you use?? Have you ever made your own lubricant?? Please share your experiences with us.