Magazine PROAVTO №4 (04) November-December 2013
Six months ago, when the need arose to replace the collapsed front suspension silent blocks on my RAV4, I became interested in polyurethane in the car’s suspension and began to study the existing proposals on the Internet. In the end, I settled on the products of the Polyurethan company, visited their office in Novosibirsk, held their products in my hands and even arranged an interview with a technologist and a visit to production workshops. There I was shown the production process of making polyurethane products.
The specialists of Polyurethane LLC managed to convince me of the quality of their products, and I installed polyurethane suspension parts.
How has the suspension been performing over the past few months? Well, for starters, I’ll say that the knock that was already familiar has disappeared. Of course, the car’s handling has become tougher, but this did not affect the driving performance in any way.
Having sent the car for diagnostics, I made sure that the suspension parts remained intact, without losing their functionality.
I was offered a choice of two options for the same product: one silent block, in addition to color, outwardly differs little from a rubber analogue, but the second looked somewhat unusual. So I even doubted that these parts were really interchangeable. An employee of Polyurethan LLC called the first option “welded”, the second – “composite”.
On the official website of Polyurethan LLC, the following is written about composite silent blocks:
“In silent blocks of this design, initially there is no connection between the material and the inner sleeve – therefore, its separation from the inner reinforcement is impossible, and from the outer one is practically excluded due to a significant reduction in load. Such a silent block has large softness zones comparable to those of the original part. The problem of dust and dirt ingress was solved by the additional installation of two anthers that protect the silent block. Anthers also prevent vertical displacement of the silentblock. “
The answers to the questions were given by the engineer of LLC “Polyurethane” Alexander Sazonov:
– What is the difference between the so-called “welded” and “composite” silencers?
Welded silent blocks differ little from rubber counterparts. It’s just that in their production we use a different material, so they surpass the originals in physical properties: they are resistant to [abrasive] abrasion, the effects of lubricants and solvents, low temperatures …Composite silent blocks have a fundamentally different design, and first of all we resort to such a design to solve the problems inherent in “swinging” silent blocks. Especially at low temperatures.
– Why “composite” silent blocks are better than the original ones?
Due to the design features, they do not tear – the [inner] sleeve is not glued to the metal and simply has nothing to come off of. Anthers protect the silent from dust and dirt, which means that it will not creak either. Due to the same anthers, by the way, the silent is fixed and will not move.
– Why do you recommend me exactly “composite” silent blocks?
The composite version is suitable for your situation – it is specially designed for this [vertical] unit. Of course, you can always put on “regular” silencers, if you are afraid to experiment. The main thing is to keep in mind that composite silent blocks are more resistant to low temperatures, which is always important in Siberian conditions.
– Do the “composite” silent blocks have any installation features?
The product is installed in the lever in parts: first, the silent block itself is pressed. Then all places of contact of polyurethane with metal are filled with grease (for example, lithol). Then the sleeve is manually pressed in and the anthers are put on.
– Why don’t OE manufacturers use this design?
Well, firstly, a rubber silent block of this design will not last long – the abrasion resistance of rubber is much lower, and the rotation of the inner sleeve will quickly render the spare part unusable.
Why manufacturers do not use polyurethane in suspension parts has already been written and said more than once. In short, the raw materials are several times more expensive, and the production process is more laborious, which is not suitable for mass serial production of spare parts.
– Is this the final stage of the silent block “development”?
(smiles) Our technical idea does not stand still! Of course, it is difficult to create something radically new, but we listen to the wishes of customers, again, we conduct constant experiments. Something is constantly changing, and we should not think that we will stop at one, “successful” option.
– Thanks for the conversation, Alexander. Do you have any advice for our readers?
Take care of your car – then there will be fewer problems with repairs!
Having listened to the recommendation of the developer-technologist, I installed composite silent blocks to my car, and do not regret a bit.
