Selection of lubricants in agriculture

What are the main tasks of lubricanting products, apart from increasing the service life of components in agricultural machinery, of course?

The tasks are related to the main purpose, i.e. the type of oil. If we are talking about engine oils, then in addition to protection against abrasive wear, they must ensure engine cleanliness, among other things. Today, it is also important that the oil is compatible with exhaust gas after-treatment systems. It should emit little sulphated ash so that particulate filters do not clog.

The situation is different with gear oils, as the most important thing is their ability to handle very high specific loads in order to protect gears, such as the sides of teeth or bearings, from seizure.

As far as hydraulic oils are concerned, their main task is to ensure the smooth operation of hydraulic systems, and an important property is that they should foam little and displace air well.

Multifunctional products are the most demanding in terms of performance, as they have to fulfil the tasks of all the previously mentioned oils.

What operating conditions need to be taken into account when selecting a lubricant for a specific agricultural machine? Loads, speed or other factors?

The most important thing is whether the lubricant in question meets the recommendations, standards of the manufacturer of the engine, gearbox or overall machine in question. It happens that machine manufacturers suggest very general requirements. So in theory many products fit but the selection can be better or worse.

For example, with high operating temperatures during the peak season, more expensive but excellent quality products are definitely preferable.

If you have a hydraulic system that requires a conventional oil rather than a universal oil, it is worth choosing a product such as AGRIFARM HYDRATEC HVI 46. Compared to cheaper counterparts, it has a higher viscosity index, which means it is stable despite temperature changes. In addition, the oil has quite a few anti-foaming additives. All these parameters ensure that the system runs smoothly and quickly, even under demanding thermal conditions in agriculture.

While we are on the subjcet of price: does it matter for agricultural oils?

As much as possible. Often, the cheapest oils do meet manufacturers’ requirements and standards, but at a minimum level. High-end oil, on the other hand, does so to excess.

It is important to be aware that there are different grades on the market. The price can depend on what additives are used. I would compare it to culinary – we all know how tomato soup is made. But it can consist of different quality ingredients, it can be prepared better and worse. This analogy fits with oils and other lubricants. Premium products such as AGRIFARM are designed to meet higher requirements. So, to use the metaphor again, we are the chefs of a top restaurant.

Better oils provide greater protection against wear and tear, smooth running of drivelines and reduce the occurrence of breakdowns, which is of great importance in the context of seasonal work, especially on smaller farms.

What is the viscosity grade of an oil?

The vast majority of oils used in the agricultural industry are described by their SAE viscosity class. Examples are 10W-40 or 15W-40. What does this mean? The number in front of the ‘W’ indicates the viscosity requirements at lower temperatures. The lower it is, the smoother the oil must be and this is then advantageous, as it results in a shorter engine start-up and less strain on the starter and battery.

On the other hand, the value after the letter “W” describes the viscosity (fluidity) requirements at high temperatures, i.e. more or less the temperatures at which a warmed-up engine operates. It depends on the engine design. So the manufacturers’ recommendations must be followed. However, we know from experience that very heavily used, worn-out engines often run better on a lubricant with a higher viscosity grade, because such an oil ‘seals’ the engine; higher lubrication pressure is achieved, which is beneficial.

So what is the NLGA consistency class?

It can be said to be the equivalent of a viscosity class, but for greases. Within it we have several consistency classes – the higher the numerical value, the harder the grease.

The most common in agriculture is NLGI class 2. This is based on how fast the lubricated components (bearings) rotate relative to each other and what the loads are. A lower class applies to fast rotations and lower loads. The selection of a grease with a specific consistency class depends primarily on the manufacturer’s recommendations.

What to look for when choosing a product for use in cold or hot condidtions? What is the best product for these operating conditions?

Let me explain using the example of engines. The correct choice of viscosity grade is crucial. Often the machine works in the field in hot weather, but after all, it also happens to work on ancillary jobs in early spring or late autumn. Some people even use the tractor in winter, using it like a snow plough. An oil designed for a wide temperature range will have a viscosity grade of, say, 10W-40, while one for a narrower range will be 15W-40.
It is also important that the oil is as resistant to oxidation as possible, because, as we all know, the higher the temperature, the greater the oxidation. And when working in the heat of summer, the engine does not have it easy. If you want to use it for a long time, the oil should therefore be resistant to this phenomenon and also contain a large amount of cleaning agents.

For extreme applications, AGRIFARM MOT X-LA SAE 10W-40 is the recommended product. It has wear protection that exceeds the latest agricultural manufacturers’ standards, as well as low evaporation, which reduces the need for top-ups. This certainly helps to reduce costs and makes the season easier.

The performance of the finished product is influenced by both base oils and additives. As a rule, a synthetic base oil is better than a mineral base oil, but this does not prejudge the application for a particular solution, as even the most advanced oil base without the right additives will not meet specific product expectations.
Therefore, from the point of view of oil selection, this particular characteristic is of little significance. What matters above all is the standard met and the sum of the parameters.

The performance of the finished product is influenced by both base oils and additives. As a rule, a synthetic base oil is better than a mineral base oil, but this does not prejudge the application for a particular solution, as even the most advanced oil base without the right additives will not meet specific product expectations.
Therefore, from the point of view of oil selection, this particular characteristic is of little significance. What matters above all is the standard met and the sum of the parameters.

This is sometimes the case with oils that meet very different standards, with different types and formulations. The additives may then interact with each other and reduce their effect. There is also the danger that such mixing will result in a sludge being released from the product, which may clog the filter or enter the lubricating node and cause abrasive wear.

There are several basic types of additives that serve to improve the base oils that are used in the blend. They all affect the properties of the product.

The basic type is viscosifiers, which increase viscosity and viscosity index. Another additive is a depressant, which lowers the fluid loss temperature. These are also antioxidants, inhibiting or slowing down the basic process that degrades oil and causes deposits in it.

Yet another example is corrosion inhibitors, which slow down or reduce the formation of rust. Then there are detergents, which are cleaning additives that wash deposits off the component. A dispersant, or cleaning additive, also plays an important role, dispersing deposits that could clump together in large groups.
Manufacturers also use emulsifiers – their job is to separate water from oils.

Within this group of ingredients, it is also worth mentioning anti-foaming additives (important in hydraulic oils) and friction modifiers used in some engine oils to reduce friction – these reduce fuel consumption.

Lubricating additives are those that form boundary layers on lubricated components. Those marked as EP protect against extreme pressures. In practice, this means that if you have a gearbox in which the gears rotate and high loads are transferred between the teeth of the wheels, there should be a lot of EP additive in the oil so that a special protective layer is formed to separate the lubricated surfaces.

AW additives, on the other hand, although also designed to protect the parts under pressure, work at much lower loads.

It is best to follow the manufacturer’s description and recommendations. For example, the API GL-5 standard specifies requirements for high EP additive content.

As far as engines used for agricultural machinery are concerned, the API standard is most commonly referred to. It could also be that ACEA standards or specific standards proposed by the manufacturers themselves will be used.

The manufacturer always states a minimum standard. There is therefore no obstacle to using a better oil that meets a higher standard. Such a product means higher performance, better protection, more cleaning additives. This is beneficial and worth paying a little extra for. Of course, you can also use multiple standards in parallel if the vehicle manufacturer accepts this.

Don’t take the risk if the manufacturer declares the need to comply with a particular standard – this must be adhered to. This is especially true for modern agricultural machines with automatic transmissions, which sometimes have very specific requirements in terms of standards to be met. The consequences of using the wrong product can be, for example, incorrect calibration of the transmission, accelerated wear and breakdowns.

Why choose multifunctional oils? Which products in this category deserves special attention?

Multifunctional oils are incredibly popular in the agricultural industry. Using them is simply convenient, because one oil serves several components of the drive train or sometimes even multiple machines at the same time. So this choice is dictated by convenience and a kind of simplification of logistics. Sometimes it is the case that modern automatic transmissions in agricultural machines even require UTTO or STOU oils.

Recommended products in this category include, for example, AGRIFARM UTTO MP, which has an incredibly wide range of applications. As far as STOU oils are concerned, on the other hand, I would recommend AGRIFARM STOU MC SAE 10W-40 in this context. Both meet a huge amount of standards and the parameters stand at a high level compared to other products on the market.

Oils labelled LOW SAPS, i.e. with reduced sulphated ash phosphorus and sulphur content, are products that are compatible with exhaust after-treatment systems and this type of system is found in the vast majority of today’s modern engines. Using this type of product ensures the proper operation of particulate filters and catalytic converters.

In the case of the former, if there is too much sulphated ash in the oil that burns, it will clog the filter. This needs to be prevented by choosing just such products, for example those meeting the API CJ-4 or API CK-4 standard, which impose certain SAPS restrictions.

Some commercial machines of various types, such as agricultural tractors – are very heavy vehicles. It turns out that if you wanted to brake them effectively with conventional disc brakes, you would quickly lose braking power or these brakes would fail after a short distance. It is therefore necessary to cool the friction discs with something.

It turned out that a good cooling medium in this case is oil. But not any oil, only one that has to comply with the standard for wet brakes and therefore be compatible with them. Among other things, the coefficient of friction must be ensured at the right level.

UTTO or STOU multifunctional oils are suitable for this. They make the braking of heavy machinery effective and, in addition, reduce phenomena such as frictional vibrations or noise from component friction. They also ensure effective braking.

However, not every product of this type is absolutely suitable for all applications, for specific wet brakes on a particular machine. This is already determined by a specific standard.
A very interesting product is AGRIFARM UTTO LN. The abbreviation ‘LN’ stands for ‘low noise’. It is suitable wherever other oils cause creaking, squeaking or other such noises. Recommended especially for heavily used agricultural machinery.

Every reputable manufacturer states what standards the product meets. These are visible in the technical information and on the labels. There are two groups of designations: viscosity standards and quality standards. The former describe the viscosity of the oil at different temperatures and this is usually defined by the SAE class, for example SAE 10W-40. The latter defines other parameters, such as oxidation resistance, cleaning ability or compatibility with exhaust gas after-treatment systems. This is, for example, the API CJ-4 standard.

In practice, for a product to be suitable for a particular application, it must meet both standards mentioned. For example, in the case of an engine, manufacturers often recommend compliance with SAE 15W-40 and API CI-4.

There are a few guidelines to follow. Certainly, the viscosity grade must be met, so for certain exemptions, SAE 85W-140 grade oils must be used and then 80W-90 oils are not suitable. It is dangerous if the manufacturer’s requirement is for a high-viscosity oil, but a low viscosity is used, as this will lead to accelerated abrasive wear and even damage.

Another issue is which additives are used. More heavily loaded gears will require oils with a high content of EP additives and this is defined by the API GL-5 standard (so there are more additives than in API GL-4).

In addition to this, it is important to be aware that in the case of agricultural machinery, we may be dealing with limited-slip differentials that contain friction discs. These types of drive bridges require a specific oil type LS (limited slip). In the FUCHS portfolio, this is AGRIFARM GEAR LS SAE 90 If conventional oil is used, this can cause the friction discs to slip and burn out.

As much as possible. Oils and lubricants should be stored in their original packaging, at temperatures above zero, in a dry room. Then we can be sure that the product will keep the right parameters for a long time. A guarantee of properly stored products is to choose a reputable manufacturer and distributor.

FUCHS runs a special support programme for its distributors. In order to obtain authorisation to sell our products, it is required to undergo a training course, during which we address, among other things, the issue of proper product storage. When choosing oils and lubricants from the FUCHS range, the customer therefore receives not only high quality from the manufacturer, but also the know-how that we give as a package to our suppliers. This is a huge added value.