However, progress does not stand still, and recently analogues of classic rubber silent blocks have begun to gain popularity - polyurethane silent blocks, which, like everything new, have been received ambiguously, as a result, motorists have been divided into two “camps” of those who are “for” polyurethane and those who are not. who is “against” polyurethane silent blocks.
In this article I will talk about the “pros and cons” of polyurethane silent blocks so that you, dear Question Auto readers, can decide for yourself which is better - rubber or polyurethane silent blocks.
A few words about where these polyurethane analogues came from. In my opinion, installing polyurethane instead of rubber “silents” was invented in Russia, because “here” ordinary rubber cannot withstand such loads and becomes unusable twice as fast as it should be. The price of original silent blocks is quite high, and when it comes to foreign cars, sometimes even exorbitant... While the polyurethane silent block is more durable and capable of withstanding increased loads, therefore, it will last longer, which ultimately results in real savings.
But why then does the question arise: “Which is better: polyurethane silent blocks or rubber?”, if at first glance everything is obvious and polyurethane looks more attractive from a financial point of view? The fact is that you have to pay for the durability and endurance of polyurethane with comfort; this, by the way, is one of the main reasons why many motorists do not like polyurethane silent blocks. Polyurethane “silents” make the suspension more rigid, and if your car was already “crazy” before, then after installing polyurethane bushings you will truly feel all the “charm” of Russian off-road. In short, the “fifth” point will suffer constantly, there will be no comfort. Things are better with “soft” comfortable “business class” cars, which have a soft suspension. On these cars, polyurethane silent blocks will not be felt so clearly.
Topical: Which is better: air suspension, hydraulic or conventional? Let's find out!
Difficult bushings
So, as mentioned above, silent blocks are a bushing consisting of two metal cylindrical elements connected by a rubber or polyurethane insert.
Thanks to its design, the bushing perfectly dampens vibrations, which extends the service life of the suspension, and also has a beneficial effect on our comfort and vehicle controllability.
Without them, the car would turn into a rumbling incarnation of hell, and trips would become painful and tiring events.
Experienced motorists know that if suddenly unusual sounds begin to come from the suspension, and the car itself becomes a little unruly during maneuvers, the first thing you need to do is check the silent blocks.
Although silent blocks themselves are quite durable, domestic roads, due to their quality, do not spare them. Rubber inserts are especially affected - they become deformed and tear.
Having calculated that the time of rubber-metal bushings has come to an end, the car owner goes to the store. And then he is faced with a choice: what to buy, rubber or polyurethane silent blocks. Well, let us help you decide.
What are silent blocks?
Polyurethane suspension silent blocks
Silent block is the main component of a car suspension, providing less noise and soft movements. This is the connecting part of the other components of the chassis. Thanks to it, vibrations become softer, and less shock load is transferred to the car body.
Outwardly, it resembles a lightweight structure. Two metal bushings hold an elastic rubber insert. It is this rubber that softens impacts.
Due to constant shocks, the chassis of the car requires special control from an experienced motorist.
Modern technologies do not stand still. And the production of polyurethane silent blocks is proof of this. Should I install polyurethane blocks, or give preference to classic rubber ones?
Classic rubber or polyurethane silent blocks?
Which silent blocks are better, rubber or polyurethane? Almost all car owners who are faced with the need to replace these spare parts ask themselves this question.
It must be said that you should not immediately buy polyurethane parts in the hope that they will make your car better. In fact, the result of an ill-considered purchase can be completely unexpected.
This is a multicomponent polymer material, the main advantage of which is that during production it is possible to set certain properties for it
For example, polyurethane silent blocks can be made the same in rigidity as rubber ones; they can be made harder and softer than rubber.
This, by the way, is what auto parts manufacturers use. Polyurethane silent blocks are produced with varying degrees of hardness, and you can find out which is which by simply looking at their color: orange is the softest, green is a harder type, blue is even harder.
Therefore, do not grab the first-time polyurethane bushings, but understand their rigidity.
Polyurethane is not afraid of aggressive environments, sudden changes in temperature and other nuances that ordinary rubber is not friendly with.
At first glance, the choice is obvious, you need to take the newfangled bushings, but don’t rush, because we haven’t yet fully figured out which silent blocks are better, rubber or polyurethane.
But if there are pros, there will definitely be cons. Perhaps, having familiarized yourself with the latter, you will make a choice in favor of classic rubber silent blocks.
TOP 10 Lithuanian automotive sites for searching cars and spare parts
Buying cars in Europe is much more profitable than on the domestic Russian market, even taking into account all the fabulous fees and taxes. For comparison, a BMW 5 Series produced in 2004-2006 can be purchased in Lithuania for 6-8 thousand euros. In Russia, such a copy will cost 23-25 thousand, and even the condition of the Russian car will be much worse.
Bad roads, low-quality fuel, savings on maintenance – there are many factors that lead cars in Russia to a ruined state. Therefore, many are looking towards the Baltic states in order to purchase a higher quality and reliable car, while spending much less money.
The most popular Lithuanian sites for searching cars
Almost all Lithuanian car websites have versions in Russian, which makes it much easier to search for cars and compare different options. We present to your attention the TOP 10 most popular and extensive Lithuanian portals with the ability to search for cars:
- Autobonus.lt is a large portal with an extensive database of used vehicles. Allows you to use convenient filters to search for the desired car, and also lists all prices in euros and litas.
- Autogidas.lt is one of the largest portals in Lithuania. Here you can not only buy a used car, but also communicate with Lithuanian entrepreneurs who, for a reasonable fee, will transport the car to Russia and help with the documents. The portal has a large forum where you can ask all your questions.
- Auto.plius.lt is the largest and most popular portal about cars, which contains advertisements from all over the Baltics. You can look at prices for new vehicles, as well as buy used cars from their owners.
- Autotaurage.lt – the portal is aimed at Russian buyers who want to buy a car in Latvia and Lithuania. There is information on how to get to the desired city, where to inexpensively spend the night and have lunch. Large database of advertisements, since the portal is completely free.
- Skelbiu.lt is one of the young, but very interesting Internet projects that offers users a convenient search through a database of used cars in Lithuania. There is also a lot of other interesting information about the features of purchasing transport in the Baltics.
- Alio.lt is a Lithuanian bulletin board where you can search not only for cars, but also related products, components and body parts. There is a convenient form for searching for spare parts for any equipment.
- Autoaiksteles.lt is a portal for those who want to travel to Lithuania on their own and choose a car on the car market. Here is a map of automobile markets with all the necessary information for visitors.
- Egzotika.lt is a professional website for searching car tires and wheels. Much more attractive prices for tires than in Russia. There is a convenient search form for tire manufacturers, sizes and properties.
- Autozebra.lt is a new used car search site. Few advertisements, but quite detailed information about each vehicle. Lots of photos and other useful data.
- Balsana.lt is another specialized portal for tires and wheels. A large selection of manufacturers, types and sizes of tires, as well as original wheels for almost any European car.
Polyurethane silent blocks pros and cons
pros
- long service life;
- do not wear out under the influence of aggressive environments;
- withstand high mechanical and temperature loads .
Minuses
- high price;
- As a rule, the rigidity of such bushings is higher than that of rubber bushings, which is why the suspension becomes not as soft and comfortable as before. Increased chassis rigidity affects not only our level of comfort, but also negatively affects the parts of the car, especially if the manufacturer has included softer settings;
- do not tolerate torsion well . And this is the main disadvantage. Whatever one may say, rubber in this regard does not yet have an alternative.
As you can see, you should think a few times before switching to polyurethane bushings. Is he ready for a more aggressive suspension, will this affect the durability of other components and assemblies?
I hope, colleagues, after reading the article you will seriously think about what to install on your car. The choice is, of course, up to you - rubber or polyurethane silent blocks,
Conclusions and recommendations
Although polyurethane silent blocks are positioned by manufacturers as new and high-tech products, there are several caveats to their use. At the same time, rubber hinges can be used in any conditions and on machines of various classes without restrictions. If you are in doubt whether it is better to choose traditional rubber or polyurethane, use the following recommendations:
- Silent blocks with PU elastomer will serve well on passenger cars with short suspension travel, operated within the city and on smooth road surfaces.
- Residents of northern regions, where bitter frosts are not uncommon, are better off buying rubber-metal products, although they will have to be replaced more often.
- You should not install polyurethane hinges on cars with large suspension travel - crossovers and SUVs, especially when driving on bad roads. The elasticity of the material may not be enough to turn the levers; the insert will rotate on the bushing and begin to creak.
When buying silent blocks, do not forget about counterfeits, which are often found in the retail chain . Do not try to save on spare parts, so as not to get low-quality products that will “live” 3-5 thousand km. The recommendation applies equally to rubber-metal and polyurethane hinges.
Why do you need a silent block?
A silent block is considered to be a metal hinge, structurally consisting of two metal bushings and a rubber or polyurethane spacer between them. These extremely necessary parts serve to connect all the moving parts of the vehicle suspension to each other. A hard rubber or polyurethane insert allows you to dampen all vibrations that form between the system components.
These elements can be located in the front and rear suspension, used to attach various arms (including where the front arm is located), to attach the anti-roll bar, bar and torque rods.
A rubber or polyurethane silent block is capable of damping the following types of loads: axial and radial forces, impacts, angular breaks, loads that cause torsional vibrations in some suspension elements. It bears heavy loads, so its service life is initially very high. Due to the fact that there is no friction between the bushings, thanks to the filler, the silent block lasts a very long time. Under normal conditions, this safety element can serve you for at least fifty years or up to one hundred thousand kilometers.
Polyurethane silent blocks are a fulcrum, reliable connection and safe operation of many vehicle components.
What is a silent block and how does it work?
For a comparative assessment of rubber and PU, it is important to understand the principle of operation of the element. The silent block used in car suspension is a “dry” hinge consisting of 3 parts:
- internal steel sleeve with thick walls;
- outer metal shell;
- the space between them is filled with elastic material (elastomer).
Note: The joint is called dry because it functions without the use of lubricant.
The front and sometimes the rear wheels of the car are attached to the body using a strut-lever system. To absorb vibrations from unevenness, the latter must rotate on its axis, which is what silent blocks provide. Their outer shell is pressed into the body of the lever, and the inner bushing is put on the axle and clamped on both sides with nuts. That is, the metal parts of the hinge are tightly fixed and do not rotate while the car is moving.
Thanks to this method of fastening, the part performs 2 tasks:
- The main thing is to ensure the movement of the lever on the axis without friction and any lubrication. This is the principle of operation of the silent block - the outer and inner bushings are able to rotate relative to each other only due to the elasticity of the material inserted between them.
- Secondary - to soften and reflect small impacts on the suspension so that they are not transmitted to the steering wheel. Here, too, the properties of the elastomer play a major role.
At the moment, polyurethane or rubber made from synthetic rubber is used to make the middle part of the hinge. The latter is reliably welded to the metal parts of the element using vulcanization. The elastomer, made of PU, is pressed and pinched between steel shells, which prevents it from turning on the bushing.
Differences between polyurethane and rubber
As I mentioned above, depending on the filler, the silent block can be rubber or polyurethane. Let's look at what is better, polyurethane for silent blocks or rubber. What is the difference between polyurethane?
- Polyurethane is much harder than rubber. Thanks to this quality, this material provides a stiffer suspension to the vehicle. But at the same time, the driving comfort of such a car decreases; passengers will feel the particularly stiff suspension. Therefore, to say that polyurethane is better than rubber (regarding comfort) will be controversial.
- The service life of polyurethane silent blocks is much longer than rubber ones. On average (depending on the quality of polyurethane and rubber, as well as their thickness), the service life exceeds ten years. But this figure is impressive only by ear. If you look in more detail, you can understand one simple thing: a silent block on a rubber layer will play once, but its opponent can play two or even three times. Hence the conclusion - the service life of a polyurethane set is not that much higher than its rubber counterpart.
- High resistance to extreme temperature loads. This material easily tolerates sudden changes in temperature and does not crack or dry out like rubber.
Why isn't polyurethane put on a conveyor belt?
If polyurethane is so good, why is it not installed on production cars, a car enthusiast will ask and he will be absolutely right. For a car plant, this material is simply unprofitable. Raw materials for the production of polyurethane cost 10 times more than raw materials for rubber, and the service life of a polyurethane part is tens of times higher than that of a rubber part. At the same time, the price of a new car with such a suspension would increase significantly, but there are no enterprises ready to produce polyurethane analogues of rubber suspension parts in huge quantities. No, for the reason that the production cycle from raw materials to the finished part is 85 times higher than rubber.
In addition, in the process of customizing the suspension, you can select polyurethane not only by hardness, but also by design. For example, many manufacturers sell silent blocks of various hardnesses, both with and without an outer metal sleeve, both with a welded inner sleeve and with a pressed one. Hardly anyone thought about the difference between them, right? But there is a difference. Due to the fact that the material practically does not wear out, it has become possible to eliminate the external bushing from the silent block design, which greatly facilitates installation and replacement with your own hands, and also eliminates possible squeaks.
By choosing the right polyurethane silent blocks, you can forget about suspension repairs for a long time, but you need to choose them very carefully. Silent suspension and smooth roads to everyone!
Reviews
It’s not for nothing that there is a proverb: “How many people, so many opinions.” Drivers do not adhere to any specific opinion. Positive feedback about polyurethane can only be given by those drivers who have personally experienced this type for their car. But you can also find negative reviews on car forums.
The fact is that many manufacturers equip cars with rubber parts. Considering this fact, many drivers do not even worry about replacement, as they are of the opinion that the car is more familiar with the elements and components with which the car was equipped during assembly.
Before changing silent blocks, you need to decide how much you need them. The decision must be considered. Good luck.
Characteristics of polyurethane products
Currently, buying a set of polyurethane-based silents is not a problem. They are even produced by domestic companies, such as Tochka Opory. Reviews about them are pretty good, to be honest.
Polyurethane itself is a colorless material. But the parts are painted, which is done to indicate the degree of their hardness.
In the case of the automotive industry, polyurethane with hardness values in the range of 65-70 units is used.
It is worth highlighting the floating variety of silents. But domestic craftsmen agree that they are not suitable for use in cities such as Irkutsk, St. Petersburg, Samara and many others. Such parts are not intended for our roads, and wear out too quickly.
How to drive through potholes correctly
Nothing special. An ordinary rubber-metal bushing, but how much depends on it. A standard silent block of good quality can last up to hundreds of thousands of kilometers if it is chosen correctly and the driver takes its features into account when driving. Proper handling of uneven surfaces greatly extends the life of suspension elements.
When the suspension is relaxed and completely absorbs irregularities, then the load on its elements is minimal. And to do this, we need to accustom ourselves, even if we missed a hole, not to put the car down, but just before the bump, release the brake pedal, thereby helping to work out the terrain without damaging the suspension and body. If you become accustomed to braking directly on uneven surfaces, the rubber suspension elements are the first to fail.
What kind of material is polyurethane?
Many experts say with great confidence that polyurethane is a material with a great future. It can work successfully not only in normal conditions, it is not at all afraid of extreme conditions.
A few words about the properties of this material
Polyurethane is based on two different types of raw materials. For its production, synthetic materials are used: polyol and isocyanate. It belongs to the group of polyether polyols, which means that its technical characteristics depend entirely on its molecular structure. Polyurethane is endowed with high elasticity, which allows it to return to its original state when stretched, bent, or other types of deformation. Various additives helped him obtain such properties. The material may be in different states:
- Viscous liquid.
- Soft rubber.
- Hard plastic.
The elasticity of a material can also range from very low to high. Polyurethane does not change its state when exposed to low or high temperatures. He is not afraid of mechanical influences. The material is not afraid of exposure to chemical solutions, technical fluids, motor oil, and ultraviolet radiation. It is used in the manufacture of aircraft, the construction of various facilities, and the manufacture of hydraulic systems.
Technical indicators
The excellent technical data of this material have made it acceptable for use in many industries, where the characteristics of the product used must be resistant to wear, have good resistance, the ability to work in an aggressive environment, resistance when working in conditions of low or high temperatures in the area of use or aggressive environment.
- the density of the material is in the range of 30–300 kg/m3;
- hardness indicators (Schor scale A, D) are 50–98 units. The material can be used for components with high mechanical loads;
- The operating temperature range is in the range from -600C to +800C. In some cases, during short-term use, the temperature can be up to 1400C;
- tensile strength can reach a limit of 50 MPa;
- good dielectric;
- the low density of the material makes its mass significantly lower compared to analogues from other materials;
- high resistance to ozone;
- It is possible to program the friction coefficient.
It is impossible to note the presence of some shortcomings. These include:
- It does not allow air to pass through, which excludes its use for the shoe industry.
- Foam parts shrink, making it difficult to apply a high-definition pattern.
- When exposed to low temperatures for a long time, it becomes brittle and too hard.
- Poor resistance to twisting.
- It is almost impossible to recycle polyurethane products.
How to choose silent blocks for a car?
The suspension design of modern car models includes rubber-metal joints called silent blocks and located on both the rear and front wheel arms, subframe mounts, torque rods and stabilizers.
All listed VAZ auto parts are consumables and require regular replacement depending on the mileage of the car. If a classic silent block is used on domestic roads, it can last at least 100,000 kilometers, but it is advisable to carry out technical inspection and diagnostics every 30 thousand. You can determine whether the hinges require replacement by the following signs:
- Upon visual inspection, deformation of the elastic insert is noticeable.
- The car squeaks when rocked in different directions.
- While driving, a knocking sound from the suspension is heard in the cabin.
- Rubber wears unevenly.
If any of the above symptoms appear and a full diagnosis is carried out, the silent blocks are changed, if required. This can be done either independently or in a car service center, where there is the necessary equipment and a lift or inspection pit. When changing it yourself, you may encounter certain difficulties, especially if you do not have the appropriate tools and do not have the skills to press the silent block.
In the automotive parts markets you can find Nissan polyurethane silent blocks from different manufacturers. Despite the fact that most of the parts are original, you may encounter a low-quality fake, the installation of which will lead to its replacement after some time.
As already mentioned, polyurethane silent blocks, reviews of which are mostly positive, were able to gain popularity among car owners. Such products are characterized by increased strength and are less subject to wear, although the pros and cons certainly need to be taken into account.
Products made from polyurethane
The technology for producing automobile parts from rubber and polyurethane is significantly different. For this reason, spare parts made of polymer can be of different shapes. Special processing of the material improves the strength of the connection with metal parts, which improves the performance characteristics of the finished parts. Products made from polyurethane are widely used in the automotive industry.
The cost of such products is several times higher than their rubber counterparts, which is explained by the complexity and resource-intensive production technology. For this reason, polymer parts cannot replace rubber parts everywhere; despite this, polyurethane is quite widely used in areas where the quality of materials is required.
Professional tuning of car suspension requires the use of parts that are reliable, high quality and wear-resistant. Of course, changing the suspension of racing cars or SUVs requires only spare parts of increased strength and reliability, but polyurethane products can also be used in the suspension of a regular car.
Conditions for long-term use of silent blocks
Parts made of polyurethane will last a long time, provided that certain requirements are met:
- Purchasing high quality products only from reliable manufacturers.
- Carrying out a major overhaul of the suspension simultaneously with the replacement of silent blocks.
- Installation of new parts using special equipment.
- The polyurethane support is treated with silicone grease or lithol.
- Regular check of the suspension and its parts.
- Operate the car at an ambient temperature of at least -20 degrees.
