Grease for splines. Spline Grease Cardan Spline Grease

12.10.2019

There are quite a lot of nodes in the car, where for separation rubbing surfaces thick, ointment-like products are used, called greases. They will be discussed.

Greases are used to reduce friction and wear of units in which forced oil circulation is impractical or impossible. For example, wheel and pivot bearings, steering and suspension joints, universal joints and splines, etc. Previously, this list was quite extensive, but today we see that the share of greases among other operating materials in a car is decreasing. The reason for this is the use of maintenance-free units based on innovative structural materials (for example, the replacement of a bushing-pin friction pair with a high-molecular rubber hinge). However, where there is no alternative to the use of ointment-like products, today the most stringent requirements are imposed on them, including environmental ones. It often happens that for each specific unit, whether it is a fifth wheel coupling or cab suspension joints, only a certain brand of operating material is recommended. How to choose the right product? This is what we have to figure out.

Both solid and liquid

Greases are intermediate in consistency between liquid oils and solid lubricants (graphites, for example). At a low temperature and no load, the lubricant retains the shape given to it earlier, and when heated and under load, it begins to flow weakly - so weakly that it does not leave the friction zone and does not seep through the seals.

The main functions of greases do not differ from those assigned to liquid oils. Everything is the same: wear reduction, scuffing prevention, corrosion protection. Specificity only in the field of application: suitability for lubrication of heavily worn friction pairs; the possibility of using in non-sealed and even in open nodes, where there is forced contact with moisture, dust or aggressive media; the ability to adhere firmly to lubricated surfaces. A very important property of greases is their long service life. Some modern products practically do not change their quality indicators for the entire period of work in the friction unit and therefore can be laid one-time, during assembly.

If we talk about the general disadvantages of ointment-like substances, then first of all you should pay attention to the lack of cooling (heat removal) and the removal of wear products from the friction zone. By the way, this is probably why some automakers, when developing such components as, for example, wheel hubs, often prefer gear oils.

The simplest grease consists of two components: an oil base (mineral or synthetic) and a thickener, under the influence of which the oil becomes inactive. The thickener is the skeleton of the lubricant. Simplistically, it can be compared with foam rubber holding liquid with its cells. Most often, calcium, lithium or sodium soaps (salts of higher fatty acids) are used as a thickener, the content of which can be from 5 to 30% by weight of the product. The cheapest are calcium greases obtained by thickening industrial mineral oils with calcium soaps - greases. Once they were so common that the word "grease" has become a common designation for grease in general, although this is not entirely correct. Greases do not dissolve in water and have very high antiwear effects, however, they function normally only in units with an operating temperature of up to 50–65 ° C, which greatly limits their use in modern cars. And the most versatile lithols are lubricants obtained by thickening petroleum and synthetic oils with lithium soaps. They have a very high dropping point (about +200°C), are exceptionally moisture resistant and work in almost any load and thermal conditions, which allows them to be used almost everywhere where grease is required.

Also, hydrocarbons (paraffin, ceresin, petrolatum) or inorganic compounds (clays, silica gels) can be used as a thickener. Clay thickener, unlike soap, does not soften at high temperatures, so it can often be found in refractory lubricants. But hydrocarbon thickeners are used mainly for the production of conservation materials, since their melting point does not exceed 65°C.

In addition to the base and thickener, the composition of the lubricant includes additives, fillers and structure modifiers. Additives are practically the same as those used in commercial oils (engine and transmission), they are oil-soluble surfactants and make up 0.1-5% by weight of the lubricant. A special place in the additive package is occupied by adhesive, that is, sticky components - they enhance the action of the thickener and increase the ability of the lubricant to stick to the metal. To insure the operation of the lubricant in the limiting thermal and load conditions, sometimes solid and oil-insoluble fillers are introduced into it - as a rule, molybdenum disulfite and graphite. These additives usually give the grease a specific color, such as silver black (molybdenum disulphite), blue (copper phthalocyanide), black (carbon-graphite).

Properties and standards

The scope of the lubricant is determined by a large set of indicators, including shear strength, mechanical stability, dropping point, thermal stability, water resistance, etc. But the role of the most important characteristics is assigned to the dropping point and the level of penetration. In fact, it is this pair that is the output parameter for evaluating lubrication.

The dropping point indicates to what extent the lubricant can be heated so that it does not turn into a liquid and, therefore, does not lose its properties. It is measured very simply: a piece of lubricant of a certain mass is heated evenly from all sides, gradually increasing the temperature until the first drop falls from it. The drip line of the lubricant should be 10-20 degrees above the maximum heating temperature of the assembly in which it is used.

The term "penetration" (penetration) owes its appearance to the measurement method - the density index of semi-liquid bodies is determined in a device called a penetrometer. To assess the consistency, a metal cone of standard size and shape under its own weight is immersed for 5 seconds in a lubricant heated to a temperature of 25°C. The softer the lubricant, the deeper the cone will go into it and the higher its penetration, and vice versa, harder lubricants are characterized by a lower penetration number. By the way, such tests are used not only in the production of lubricants, but also in the paint and varnish business.

Now about the standards. According to the generally accepted classification of lubricants, it is customary to distinguish them by scope and density. Lubricants are divided into four groups according to the scope of application: anti-friction, conservation, sealing and rope. The first group is divided into subgroups: general purpose lubricants, multi-purpose lubricants, heat-resistant, low-temperature, chemically resistant, instrumental, automotive, aviation lubricants. In relation to the transport sector, anti-friction lubricants are most widely used: multi-purpose (Litol-24, Fiol-2U, Zimol, Lita) and special automotive (LSTs-15, Fiol-2U, SHRUS-4).

To distinguish products by consistency, the American classification NLGI (National lubricating Grease Institute) is used all over the world, which divides lubricants into 9 classes. The division criterion is the level of penetration. The higher the grade, the thicker the product. Greases used in automobiles are more often classified in the second, less often in the first class. Semi-fluid products recommended for use in central lubrication systems are divided into two separate classes. They are designated by codes 00 and 000.

Previously, in our country, the name of lubricants was set arbitrarily. As a result, some lubricants received a verbal name (Solidol-S), others - a numbered one (No. 158), and others - the designation of the institution that created them (CIATIM-201, VNIINP-242). In 1979, GOST 23258-78 was introduced, according to which the name of the lubricant should consist of one word and an alphanumeric index (for various modifications). Domestic petrochemists adhere to this rule today. As for imported products, there is currently no single classification for all manufacturers in terms of performance indicators abroad. Most European manufacturers are guided by the German standard DIN-51 502, which establishes the designation of greases, which displays several characteristics at once: purpose, base oil type, additive package, NLGI class and operating temperature range. For example, the designation K PHC 2 N-40 indicates that this grease is designed for lubrication of plain and rolling bearings (letter K), contains antiwear and extreme pressure additives (P), is based on synthetic oil (HC) and refers to the second class of consistency according to NLGI (number 2). The maximum application temperature of this product is +140°C (N), and the lower operating limit is limited to -40°C.

Some of the world's manufacturers use their own designation structures. Let's say Shell's grease naming system has the following structure: brand - "suffix 1" - "suffix 2" -
NLGI class. For example, Shell Retinax HDX2 stands for Very High Performance Extremely Heavy Duty (HD) lubricant containing molybdenum disulphite (X) and an NLGI consistency grade 2.

Often on the labels of foreign products there are two designations at once: own marking and a code according to the DIN standard. By analogy with liquid oils, the most complete requirements for operating materials are reflected in the specifications of car manufacturers or component manufacturers (Willy Vogel, British Timken, SKF). The numbers of the corresponding tolerances are also applied to the lubricant label next to the designation of its operational properties, but the basic information on recommended products for use and the timing of their replacement is contained in the vehicle maintenance manual.

Lubricants from different manufacturers (even for the same purpose) cannot be mixed, as they may contain additives and other components of different chemical composition. Also, do not mix products with different thickeners. For example, when mixing cast grease (Litol-24) with calcium grease (solid oil), the mixture receives the worst performance properties. Of the automotive greases offered on the market, it is most advisable to choose those recommended by the car manufacturer.

02.06.2017

Hello, friends!

Today we will talk about lubricants for splines. To do this, we analyze the features of the work of this type of joints and the nature of friction in them.

So, a spline connection is a connection between a shaft (male surface) and a hole (female surface) using splines (grooves) and teeth (protrusions) located radially on the surfaces of the shaft and hole. Provides the possibility of axial movement of parts along the axis.

Rice. 1 Spline connections

Of course, a spline joint is a movable joint that allows the shaft that transmits rotation to lengthen and shorten during operation. The power transmission of rotation is characterized by a torque that causes appropriate contact pressures between the side surfaces of the splines.

Thus, a spline-tooth friction pair is a kind of linear plain bearing in terms of the nature of friction. Features of splined connections as part of cardan shafts and drive spindles are low sliding speed and high specific pressures. This creates an unstable elastohydrodynamic friction mode, which turns into boundary friction.

Fig.2 Spline connection of cardan shaft

Lubricants for the protection of units in the boundary friction mode must necessarily contain solid lubricant additives designed to enhance the effect of extreme pressure additives, which are so ineffective at low sliding speeds. Usually it is graphite or molybdenum disulfide. While graphite is preferred for high temperature applications, molybdenum disulfide is tribologically more efficient.

Tribology is the science of friction and the phenomena that accompany friction. The tribological properties of a lubricant are a combination of anti-wear and extreme pressure properties.

As an example of a lubricant based on molybdenum disulfide for splines, I will give a popular lubricant from a Russian company ARGO. Here are its characteristics:

Characteristic	Method
Thickener


Lubricant classification
Grease color	Visually	Dark grey
NLGI consistency class
Penetration 0.1 mm
Base oil viscosity at 40ºС, mm2/s
Dropping point, ºС

Welding load of 3920 Newtons is a fairly high indicator of extreme pressure properties, which allows it to be used in the most heavily loaded spline joints. In low- and medium-loaded splines, for example, in passenger cars, it is not necessary to use such a “powerful” lubricant. Universal automotive lubricants are quite effective here. Here is another example of lubricant from ARGO for universal automotive applications – :

Characteristic	Method
Thickener
Operating temperature range, ºС
Lubricant classification

Greases are widely used where the operating conditions of the machine preclude the use of conventional oils. Recently, the role of special lubricants has significantly increased, which make it possible to ensure high-performance operation of modern and expensive equipment. There are two main ways to increase the effectiveness of lubricating greases to reduce friction and wear. The first way is to use chemically active additives that increase the ability of the lubricant to withstand heavy loads. The second way is the use of greases containing in their composition fine particles of a special substance or compound (in the form of the thinnest lamellar inclusions) - molybdenum disulfide, graphite or ceramics. Liqui Moly has successfully applied both of these methods to develop advanced high performance lubricants. At relatively low pressure, grease behaves like a solid body. But as soon as the pressure increases, the product begins to resemble a liquid in its properties. This is where its main difference from conventional oils lies.

Wide range of greases

Liqui Moly manufactures various types of lubricants with different viscosities that can be used:

in cars and trucks;
in agricultural vehicles;
in equipment used in the paper, food, clothing, textile industries;
in devices used in the household.

A wide range is a guarantee that you will definitely find a tool that will help you effectively solve your problems. Detailed information about all lubricants of our production can be found on the website. Liqui Moly greases are available in both mineral and synthetic bases. They are offered to customers in convenient packaging. In our catalog you will find lubricants that are suitable for individual use in a personal car, in your own household, and can also be used by various service departments. An important advantage of such products is the ability to use them where conventional lubricating oils cannot be applied. The composition of each product is carefully thought out, which allows for a long time to maintain the operation of units and mechanisms at the required level. The developers used various additives to give them anti-corrosion, antioxidant and other properties. Liqui Moly lubricants can be used over a wide temperature range; they are not washed out with cold and hot water, withstand significant pressure, effectively prevent jerks and vibrations, and reduce wear when parts rub against each other. Do you have questions about Liqui Moly lubricants? Contact the specialists of our company. They will tell you about the properties of the product, the features of its application, and also help you make the right choice.

The cardan drive of any car is subjected to a specific load, which mainly falls on the needle bearings of the articulated mechanism. For its maintenance, not only a special lubricant for the crosses is required, but also a certain tool. The further operation of the car depends on this and a number of other factors.

The term "cardan shaft" began to be used from the time Gerolamo Cardano became interested in this knot. Since then, the unit has been called that and nothing else.

Cardan drive device and its role

The main task of the driveshaft is to transmit torque from the engine to the wheels. It provides a connection between the output shaft of the gearbox and the drive shaft of the rear or front axle. This is in cases with rear or front wheel drive. In all-wheel drive models, the front and rear axle shafts are connected to the transfer case shafts.

The main node of this connection is a hinge, in which, in turn, there is an equally important detail - a cross. And as you can understand from the name, it is made in the form of a cross. Each end has a cup with a needle bearing, which is separated from the body by a rubber or plastic o-ring. In the absence of lubrication for universal joints and bearings, they quickly fail. The size of the crosspiece is different for each car.

Diagnostics

Carrying out any repairs is impossible without a preliminary diagnosis of the car. And since the cross is the central link in the driveline, it is worth taking a more responsible approach to its inspection.

The error usually appears:

noise
whistling;
buzz;
strong vibration;
clicks;
metallic screeching or crackling.

This can be especially felt when starting off, or while the vehicle is moving, or when changing gears. In some cases, a malfunction can be hidden, so it is extremely important to detect a breakdown in a timely manner.

Currently, in many car services, diagnostics of car parts, including the hodovka, is carried out using modern equipment. This allows you to quickly and with maximum accuracy detect a breakdown and determine whether there is grease for the crosses or not at all. Depending on this, one or another method of elimination is selected.

Consequences of ignoring the fault

It is worth noting that if any detected breakdown is not eliminated, then the consequences may be different. And since we are talking about a driveline in this case, ignoring a breakdown can threaten the life and safety of the driver and passengers. And in some cases, the consequences are irreversible.

You need to be responsible to yourself, as not only the driver himself is at risk, but also the surrounding road users. And if a car enthusiast is used to neglecting himself and the car, then everyone else should not suffer because of this.

Simple procedure

It is most convenient to inspect the cardan shaft in a pit or drive the car onto a lift. Next, you need to set the box lever to the neutral position and you can go directly to the visual inspection.

Particular attention should be shown when evaluating the technical condition of the seals and the hinge. Then, holding the cross with your hand, try to scroll the cardan. If play is detected, which is very easy to notice, the part needs to be replaced. If noises and squeaks are heard during the rotation of the cardan, most likely the crosspiece itself is in order and the grease for the crosspieces needs to be changed.

It is worth noting that there are two cruciform parts and it is necessary to inspect each. And since the maximum loads are applied to the rear cardan, this crosspiece suffers most often. In addition, during the movement of the car, moisture and dirt get into the rear cardan.

As you can see, the whole procedure for inspecting the cardan is simple. It is possible to do it yourself. But in any case, it is better to contact a specialist if possible, as he can give useful recommendations.

List of major faults

Usually, the crosspiece in the driveline serves for a long time, and its resource is calculated for about 500 thousand kilometers. However, in reality, everything is not so and the cross after 50-100 thousand km already needs to be replaced. And this is influenced by a number of factors:

terms of Use;
manufacturer;
the quality of the materials used.

Frequent movements in the countryside also contribute. Dirt and potholes - all this significantly reduces the already short period of operation of the hinge. Here, lubrication alone for the propeller shaft crosses will not be enough.

The list of the most common frog failures includes the usual inattention during a scheduled inspection. In some cases, the lack of lubrication is not given due importance. And subsequently the crosspiece will make itself felt accordingly.

Other common faults include the following:

there is a noticeable play of the cross;
the needle bearing wears out;
wear of the cross itself occurs;
leaked lubricant or its complete absence;
destruction of sealing rings;
while the car is moving, you can hear a metallic ringing;
crackling is heard in the area of \u200b\u200bthe cardan joint.

No matter how reliable the crosspiece is, sooner or later it fails. In this regard, the best option for the prevention of this part is to inspect it every 10-15 thousand kilometers. It also does not hurt to make sure that there is lubrication for the crosspieces.

And for those motorists, in particular, who own jeeps, who like to take mud baths, it is worth checking the condition of the driveline after each such trip.

Needle bearing features

In addition to the cross, the cardan drive also includes another necessary element - a needle bearing, which is a type of roller product. Its main distinguishing feature is the size of the bearing, which allows, if necessary, to do without the inner ring. This is achieved due to the ability to withstand a large axial load.

The use of a needle bearing implies some restrictions on the use of lubricants. When deciding which cross lubrication is better, it is not allowed to use products with solid additives that have a crystalline structure. It's all about graphite or molybdenum disulfide, which are usually added to some lubricant formulations. These components can lead to wedging of the needles, which leads to increased wear of the part.

Cardan maintenance

High-quality service of cardan transmission consists in timely lubrication of parts. Usually, for lubrication, many masters at the service station use a special oiler with a convenient spout for access to hard-to-reach parts. As an alternative to this tool, a conventional syringe is used. The lubricant itself must be of high quality and only from a well-known manufacturer.

Lubricant manufacturers endow their products with high performance properties, including versatility. For example, the Liqui Moly product for lubricating crosses and bearings. For older cars, there were strict requirements regarding the types of lubricants. Now the situation has become much simpler. However, it is better to purchase products whose characteristics are best suited for lubricating driveshaft parts.

Features of the cardan lubrication process

As a rule, cardan lubrication is carried out right on the spot, that is, without removing it from the car. Theoretically, there is nothing complicated here, but in reality, difficulties inevitably arise during the process. First of all, when using a syringe, a dangerous illusion can be created. The fact is that a minimal view gives rise to a false feeling that the lubricant has got where it is needed, although in reality it is not. The seals should literally bathe in grease.

Also, do not use a product that, due to inaccuracy, accidentally spilled onto the floor. As a result, with contact with another surface, Liqui Moly (or any other) grease for crosses loses sterility, which is unacceptable.

In most cases, the process is delayed for an indefinite period of time. Often in the following days, the work is completely forgotten. Therefore, it is desirable to completely dismantle the connection. This will make it possible to make a better visual diagnosis of the cardan and lubricate its parts well. After that, it remains to install everything in its place.

One of the best

One of the best lubrication products for gimbal crosses is Liqui Moly brand grease. As the manufacturer himself assures, lithium soap-based grease is ideal for servicing propeller shaft crosses. It is also suitable for the lubrication of plain and rolling bearings that operate under normal conditions and at medium and high temperatures.

Lithium grease for propeller shaft crosspieces contains special components and additives, which increases its resource. The versatility of the product allows it to provide good sealing. In addition, there are other benefits:

increased stability in conditions of high humidity and dust;
resistance to hot or cold water;
reduced friction of lubricated parts;
the tool has a good ability to absorb compression.

You can also highlight the resistance to aging and corrosion. As for the operating temperature range, it ranges from -30 to +125°C.

Blue remedy number 158

In the days of the USSR, blue grease for crosspieces "158" based on a lithium-potassium complex was in great demand. At present, greases using a lithium thickener have begun to be produced. This made it possible to significantly increase the upper operating temperature range, which is now +165°C or more.

A characteristic distinguishing feature, as it can be understood, is the shade of grease at number 158. However, this does not say anything specifically about the properties. For a number of manufacturers, this step is justified in order to identify products and give them an attractive presentation.

In European countries, pigments are used for this, which color the lubricant not blue, but green or red. The color version may also differ if, for example, the same grease for Liqui Moly gimbal crosses is ordered by different suppliers.

Successful advertising

Thanks to the efforts of many marketers, blue grease is now a sign of versatility and high quality. For the first time, a blue-tinted lubricant was released by ExxonMobil and Chevron in the west. The product unexpectedly showed its best side under normal operating conditions of almost any equipment.

Now blue lubricants are already the standard of quality. They are especially popular in the Russian Federation. They are widely used in servicing not only various types of transport (automobile, railway, water, tractor, special equipment), but also various industrial equipment. And the question of what kind of lubricant to inject the crosses is solved by itself.