Silent blocks creak - why and how to fix it
Content
The creak of silent blocks, like any noise in the suspension, is always unpleasant, because it means the need for an early replacement. And if a creak appears after replacing the silent blocks with new ones, this is also more annoying, because such a problem should not exist by default.
If you want to know when silent blocks creak, why this happens and what to do with it, because there are several methods at once, then read the article to the end.
If the silent blocks are not new, then most often the creak indicates their wear and tear and the need for replacement. Neither lubrication nor other manipulations will get rid of the squeak for a long time. But when a creak appeared after the replacement, the reasons may be different and it will most likely be possible to remove it.
The table below summarizes briefly all the causes of silent blocks creaking and possible methods for their elimination. Moreover, these reasons are universal for all types of parts, regardless of their type and installation location. All this is described in more detail below.
| Causes | Elimination options | |
|---|---|---|
| № 1 | № 2 | |
| Wear of old silent blocks | Replacement | Give lubrication |
| Insufficient fastening force | Hold on to the mounts | × |
| Incorrect installation | Reinstall correctly | If damaged, replace |
| Lack of lubrication | Add lubricant (various types) | Use WD-40 (short-term effect) |
| Lapping new silent blocks | Pass through 200-500 kilometers | × |
| Design features | Find an analogue from another model | × |
| Poor quality | Replace with quality analogues or original | × |
How to determine that silent blocks creak
The creak in the suspension is impossible not to notice. The silent block of the rear beam creaks especially unpleasantly - usually such a sound even resembles a crunch or rattle. How the creak sounds, listen to the video:
How the silent blocks creak video (the creak is heard from 0:45)
Creaking silent block front suspension
What to do for diagnostics, in order to determine whether silent blocks or another running element are creaking? The simplest case would be if the creaking sound appeared immediately after the replacement. Yes, this is very unpleasant, but it is clearly understandable - I put in new parts, it creaked, so the problem is in them.
It is more difficult if it creaked unexpectedly or some time has already passed from the replacement. In this case, a method that can be used in a garage or on a flyover is suitable, but it is better to take an assistant to check.
Lubricate any silent block individually with a “wheel” or water, and then rock the car from side to side or press it up and down in order to simulate the operation of the suspension. Where the sound disappears during processing - and the culprit of the creak is located. If the sounds do not disappear, it is probably not silent blocks that are to blame. After all, besides them, it is common to creak and elements of the rack or ball. Silent with its squeak like that of a “cart” can most often annoy in autumn, when it is dirty or in winter, when it is cold. It was not possible to determine the source of the creak yourself - go to the service station to diagnose the chassis.
Why silent blocks creak
A squeak in the suspension can appear both in worn parts and in new ones. Even if it seems to you that the old silent blocks did not leave so much, this does not mean that they did not fail. But it happens that a new silent block creaks - then you need to figure it out. The creak is often manifested in the cold season - in autumn or winter. This may be due to the fact that more moisture begins to enter the design of silent blocks (especially floating ones), and because of the low temperature, it does not evaporate and begins its destructive effect. The creak is clearly visible when driving over bumps - for example, speed bumps.
The reason for the creaking of the rear silent block of the front lever. How to find out
Physically, this happens because the rubber part begins to move relative to the metal. And here's why this happens - there are 7 reasons.
- Wear of old silent blocks.
- Insufficient fastening torque.
- Incorrect installation of new silent blocks.
- Lack of lubrication.
- Lapping of new silent blocks.
- Design features.
- Poor quality.
Wear of old silent blocks
If the “old” silent blocks began to make sounds, then most likely they will need to be replaced. And it doesn’t matter if even they have traveled only 10 or 15 thousand kilometers - you need to check them. We raise the car or drive it into a pit and visually check for wear, delamination of the rubber part from the metal part, destruction, smacking at the attachment point, loss of elasticity (when the “rubber has hardened”).
Damage that can cause silent block squeaks
If visually the parts look serviceable, you can try to lubricate them. How exactly to lubricate silent blocks - find out below. Such a step is especially relevant when floating silent blocks creak - their work, due to the presence of a ball joint inside, is very dependent on the presence of lubrication. If lubrication does not help, then only replacement will save.
Insufficient fastening force
Silent blocks can be a concern if the fasteners were not tightened enough. Often it is for this reason that the silent blocks of the suspension arms creak. Moreover, this effect appears both in new and old parts, if the fasteners are weakened for some reason.
However, it is important not with what applied force you tightened them, but in what position of the car. Often, car owners simply put them incorrectly and attract them.
Incorrect installation
Marks on the silent block. The lever must also have at least one
After replacement, silent blocks creak if they were initially installed incorrectly. Even service station workers are not always able to do this correctly. Sometimes they can violate the integrity of the part or install it with care. This is especially likely when you need to press the silent blocks into the lever. But most often, when replacing them in the lever, they miss such a nuance as direction. There may be one or 3 marks, which should look at the ball, front silent and arrow parallel to the lever. it is also very important to clean the seat from dirt and rust.
If the part was not damaged, then you can try to fix the situation. If the silent block was damaged, you will have to change it.
also one common mistake is tightening the fasteners on a car with the wheels hung out. Remember - you need to tighten the fasteners when the levers are under load, that is, the car is on the ground! And it is better to apply an additional load.
Why is it impossible to tighten the silent blocks of levers on suspended wheels? Because in this case, under load, the levers take their working position, and the silent blocks simply scroll or even pull out. Before that happens, riding with incorrectly tightened bushings will be very harsh, because they hold back suspension travel.
Lack or lack of lubrication
Lubrication of the polyurethane silent block with lithol before installation
Initially, good silent blocks do not need lubrication, it is even recommended to press it in not for lubrication, but for soapy water. An exception may be perhaps composite polyurethane, which is sometimes put in place of the original. But, as it wears out, despite the lack of manufacturers' recommendations for lubricating silent blocks, practice proves that some silent blocks need lubrication to avoid creaking. This does not affect the operation of the part, but it removes squeaks with a high degree of probability. Most often, this problem manifests itself in silent blocks of the middle and cheap segments.
Lapping new silent blocks
Sometimes the reason why new silent blocks creak can be elementary grinding. The parts just need time to sit correctly in the seat. To be honest, this is not the most common case - so if the creak has not passed after several hundred kilometers, consider other reasons.
Design features
also one not the most common option, but which nonetheless exists. Sometimes the silent block creaks because it is a “disease” of the part on a particular car.
A vivid and common example is when the rear silent block of the front lever creaks on the Chevrolet Aveo T200, T250 and T255 (OE number - 95479763). The solution is a replacement for similar, but integral ones (OE number for Aveo - 95975940). In fact, these are silent blocks for the Ford Mondeo model from 2000. This decision has helped many car owners, so the one-piece silent block is sold by many sellers as “reinforced”.
there is also a problem with the front silent blocks of the front lever in the Audi A3, which also appears on other VAG Group cars (for example, Skoda Octavia A6, Volkswagen Golf VI) - code 1K0407182. It is solved by replacing it with reinforced counterparts that are installed on the Audi RS3 (analogue code from Lemforder, which is in the original - 2991601).
Rear silent block of the front arm Aveo
BMW x5 e53 silent block lever
In both cases described, the problem appears due to the fact that compensating slots are made in the design of the native silent block, which allegedly improve the smoothness of the ride. But judging by the reviews of car owners, they don’t feel very comfortable, but squeaks due to the fact that dirt is clogged in the slot are very noticeable.
It is impossible to say for 100% that this is a common disease of all silent blocks of a similar design, but it is obvious that they can really be prone to squeaks precisely because of the ingress of dirt into these holes. In both cases described, the problem appears due to the fact that compensating slots are made in the design of the native silent block, which allegedly improve the smoothness of the ride. But judging by the reviews of car owners, they don’t feel very comfortable, but squeaks due to the fact that dirt is clogged in the slot are very noticeable.
It is impossible to say for 100% that this is a common disease of all silent blocks of a similar design, but it is obvious that they can really be prone to squeaks precisely because of the ingress of dirt into these holes.
Poor quality
Sometimes the cause of squeaks can simply be the poor quality of the silent blocks themselves. It is low-quality rubber that leads to such a consequence. Nothing can be produced with this problem - you just have to replace the parts with other, higher quality ones.
also one controversial issue - do polyurethane silent blocks creak, especially in the cold? The material itself cannot be considered the cause of squeaks - it has nothing to do with it. On the one hand, the manufacturer is partially right, explaining the problem with incorrect installation, unremoved dirt / rust and severe wear of the seat. On the other hand, polyurethane bushings initially have a design and hardness that differ from the original products. Therefore, in the cold, the process of their wear is simply accelerated, as a result of which they begin to creak.
How to eliminate the creak of silent blocks
Some causes of unpleasant sounds are immediately the answer to the question “how to remove the creak of silent blocks”. These are cases such as poor quality parts, lapping or design features. For other cases, two universal methods are suitable - anoint and re-tighten the mount. But if they did not help you, then there is only one way out - replacement with other silent blocks.
Checking the tightening force and tightening fasteners
What to produce in order that the silent blocks would not creak? Try tightening the fasteners first. Because if, when replacing silent blocks, they were not twisted enough, this can cause unpleasant sounds.
How to reproduce it correctly? It is necessary to tighten it in a loaded state, sometimes it is even recommended to place an additional load in the passenger compartment. But first, jacking up and hanging the axle of the car on which the replacement was made, the mount should be loosened. After that, place safety stops under the levers and release the jack. the machine will sag under its own weight and in this position you need to tighten all the bolts to the stop.
This is a simple and easy to perform method, which also makes it possible to inspect the silent blocks for correct installation and possibly correct the situation.
Lubrication
In the event that one of the reasons described above could not be found, and tightening the fasteners did not help, often the problem of unpleasant sounds is solved by lubrication. And here the details of the process no longer concern how to produce it, but how to lubricate the silent blocks so that they don’t creak. Because there are a lot of options that are described by car owners in their reviews.
Lubricating the floating silent block of the control arm
Squeezing the silent block with thick grease from creaking
All of them have the right to life and have shown their effectiveness, so you can test them on your car. It will be absolutely safe, and if it does not help, then you will have to change it or put up with it. So, how to anoint silent blocks so that they don’t creak?
- Silicone lubricant spray
- Graphite grease
- Litol and other lithium greases
- Grease for hinges ShRB-4
- Engine or transmission oil
- Brake fluid
All lubrication options, except for the first one, are applied by injection, because otherwise it is very difficult to get to the silent block design. If the grease is very thick, you can warm it up or you should take thicker syringes or shorten the needle.
the underlying cause of squeaks in floating silent blocks. Is it possible to smear with glycerin and the better
In some sources you can find references to lubrication with glycerin. We do not recommend doing this. Glycerin is an alcohol and is generally not intended to lubricate rubbing parts!
you can also find reviews that someone was helped by the use of WD-40 or brake fluid. But these are isolated cases. The practice of most car owners shows that it is impossible to fix the problem forever. Using WD-40 to lubricate silent blocks from creaking helps for a short time, and in rainy and humid weather the effect disappears within a few hours.
