Front-wheel drive cars are loved by motorists all over the world for a reason. Most often, they use a MacPherson type suspension - a very simple and reliable design that will last for many years faithfully and does not require serious maintenance costs. Depending on the condition of the roads and the aggressiveness of the ride, however, some components will have to be changed periodically, for example, ball or bearings on the hubs. And silent blocks and levers fail much less often. This is what most car owners like - the car should drive, and not be repaired.
But there are in front-wheel drive cars and vulnerabilities, an example is the hinge of equal angular velocities, among the people it was nicknamed the "grenade" because of the visual similarity, you can also find the abbreviation - SHRUS. For their production, only high-strength alloys are used, various coatings are applied to the working surfaces, and the original lubricant should ensure the operation of the unit for a very long time. But in practice, it turns out that nothing is eternal, grenades also break, and even on brand new cars that have just left the assembly line. Therefore, if there is a suspicion of a malfunction, an early check of the CV joint is necessary.
The drive system consists of the following hinges:
- two internal ones, which are installed directly in the gearbox, drive the axle shaft (one for each side);
- two external ones - located on the hubs, serve to transmit torque to the wheels.
It may seem that they have the same lifespan. But in fact, everything is not quite so, the internal ones work longer, while the external ones fail much more often. The reason for this is too high loads that occur when the car is moving on the wheel hub, as well as the fact that the outer CV joint rotates at a much larger angle than the inner one. It can also be noted external differences– dimensions internal grenades much more than outside.
Causes of failure
Development on the holder of the CV joint
The reasons may be as follows:
- Factory defect that was not identified before installation. It is not uncommon for counterfeit products to be installed on new machines. This also includes the very low quality of the metal used to make the assembly.
- An insufficient amount graphite lubricant or its absence. The poor quality of the anthers, as a result of which it breaks and dust, dirt, sand, water and other debris get on the rubbing surfaces.
- It is also important how you drive and where. Aggressive driving coupled with poor quality road surface is rapid wear grenades and their quick replacement.
Is it possible to diagnose grenade malfunctions on your own
Since the grenade is a simple hinge, it can easily fail. The principle of its operation is very similar to the operation of the bearing - two surfaces, between which there are balls of durable metal. The difference is that grooves are cut on the surfaces, due to which it is possible to change the position of the leading semi-axis relative to the driven one. If you take a used CV joint, you can rotate the two axle shafts with your hands without much effort, see how the assembly works. On the new one, it will not work to turn them, since there are no gaps and you need to make great efforts to turn them.
Faulty CV joint
Several forces act on the hinge at once. Firstly, when driving, torque is transmitted from the gearbox to the wheel. Secondly, the relative position of the axle shafts is constantly changing, as you rotate the steering wheel or run into an uneven surface while driving. And there is always friction in the mechanism that destroys it. In some place, a development may appear, as a result of which the gap between the surfaces increases and extraneous crackling and noise become audible.
Someone with operating experience front wheel drive car, familiar with how to check the CV joint and the sounds it makes when it breaks. The first sign that grenades need to be replaced is the appearance of this kind of noise during sharp acceleration, moving over obstacles, and also when turning. But if a crunch is heard even during rectilinear movement, then this indicates that it is urgent to change the CV joints and operating the car in this state is not only undesirable, but even dangerous.
Unfortunately, many of the symptoms of grenade malfunctions are very similar, for example, with the symptoms of a broken ball or steering tip. Therefore it should once again make sure the diagnosis is correct. So, the presence of subtle jerks at the moment of starting off, clearly indicates a breakdown of the hinges. The presence of significant shaft play between the CV joints can be determined by hanging the wheel and trying to move it in different planes. If there is play, then the CV joint has become unusable and should be replaced.
How to diagnose hinge problems
Diagnostics of the external hinge is simple: you just need to unscrew the steering wheel to the extreme position and move off. At the maximum angle between the axle shafts, a characteristic crunch will appear - this is a sign of a breakdown of the external hinge.
Checking the internal CV joint is best done on a lift
But there is a peculiarity in the internal mechanisms - they can crunch during a rectilinear movement. To check, it is not necessary to have special skills, since you can check the internal CV joint by taking a trip off-road - when you get into pits and ditches, the soundtrack is amplified many times over. But the most accurate diagnosis can be made as follows:
- put the car on a lift;
- in a suspended state, engage first gear, allowing the wheels to rotate slowly;
- in this position, a faulty CV joint will emit a clearly distinguishable crunch;
- again, when trying to move the shaft by hand, a significant backlash will be felt.
If the symptoms are "obvious", then it is necessary to buy a CV joint and install it on the axle shaft. Anthers, clamps and grease are usually included in the kit.
Every motorist should know his car today. SHRUS - a constant velocity joint, or, as it is also called a "grenade", is one of the most problematic places in the modern front - and rear wheel drive car. It is noteworthy that all CV joints are made of heavy-duty materials, the wear of which, it seems, should be extremely slow. However, practice shows that even a car that has recently rolled off the assembly line can fail. And the reasons for this are completely different: from the installation of defective parts made of low-quality material and the use of lubricants Low quality, to the terrible pavement or too "dashing" driving on it. It follows from this that a CV joint malfunction is one of common problems motorists.
So how to determine the malfunction of the CV joint of our car did it yourself? First of all, it should be noted that the CV joint itself is a hinge, which means that its parts are not only in close contact with each other, but also under quite a lot of pressure. Being ball bearing, which, however, can change the angle between the axes.
The main signs of a CV joint malfunction are a characteristic "crunch" that is heard when turning or accelerating. In order to finally make sure that the CV joint is faulty, we need to pay attention to the shaft located between the CV joints. If you try to move it in different planes, and at the same time the shaft plays, then the CV joint is faulty. Also, pay attention to the "behavior" of the car during starting or changing speed: if small jerks occur, then they can also determine the malfunction of the CV joint. Also, just turn the steering wheel as much as possible and start moving - a faulty CV joint will begin to crunch.
For each driving wheel the car has two CV joints - external and internal. Since the external one is under much greater load, it fails much more often than the internal one. However, it is not uncommon for the internal CV joint to fail. So how to determine the malfunction of the internal CV joint? In this case, it must be borne in mind that the internal CV joint can grind even during rectilinear movement. If you turn on the first gear, then in the final state, the wheels of the car will begin to rotate. And, if the internal CV joint is not working, an incomparable "crunch" will immediately be released.
Finally, you can determine the malfunction of the CV joint simply by lifting the car on a lift.
Front-wheel drive cars are very loved by motorists around the world. Often in the design of such machines, suspension systems of the MacPherson type are used. It is very simple and robust design, which can work for many years without a single serious breakdown. But there are quite vulnerable nodes in cars with front-wheel drive. One of them is a joint of equal angular velocities, and if it is simpler, then just a CV joint, or a "grenade". In the production of these parts, the most modern and fairly durable alloys are used. The working part is treated with a special coating, the lubricant should ensure the parts work for a long time. But practice shows that nothing is eternal. CV joints fail, even on new cars. How to diagnose a breakdown in this node, why the CV joint crunches, what are the consequences and how to change this important detail- let's try to figure it out.
How it all works
Let's start with the fact that there are two types of such hinges.
These are internal ones that work directly in the gearbox, where they make the axle shaft move, as well as external ones - they can be found on the hubs. They transmit torque to the wheels of the car.
Sometimes it seems that both internal and external hinges can work for a very long time and fail in one day. However, it is wrong to think so. As a rule, internal nodes can work for a very long time, but external ones wear out more often. And then the car makes a popping sound from a faulty CV joint. Among the main reasons are the high loads that occur on the move. Also among the reasons is a higher angle of rotation of the external product. These details are excellent appearance- internal have much big sizes than external ones.
The design consists of a cup body with grooves inside and a semi-axis on the outside. The inner clip resembles a spherical fist with grooves. Between the cup and the clip there are 6 balls.
Why is it crunchy?
The structural element is very precise. The clip transmits force to the body and rotates it. The balls move in the grooves, and this allows you to change the angle between the semi-axes.
Over time, where the balls touch other elements, the surface is subject to wear and tear. Some balls have free play, as a result, the driver hears the characteristic sound of a faulty CV joint.
Since there are two of these nodes per wheel, it is sometimes very difficult to determine which one is worn out.
Typical causes of failure
Among the common reasons, there is a production defect that could not be identified before installation. There are very frequent cases when new cars are equipped with counterfeit spare parts made of low-quality metal.
Another one common cause- lack of lubrication.
Because of Bad quality anthers (they are torn) sand, water, dust from the road gets on the working parts.
It is also important how the driver drives the car. With an aggressive driving style domestic roads products break down very quickly. And that terrible, popping sound from a faulty CV joint appears - all car owners have heard it at least once. It's hard to confuse him with anything.
Where does this strange noise come from?
So. Each drive wheel has two such parts. The internal ones transfer rotational energy from the differential to the axle, the external ones - from the axle to the hub. With the same design, these hinges have different sizes.
To independently diagnose where this nasty popping sound from a faulty CV joint comes from, you can use one of two methods.
So, if the car is standing, you can try to pull the axle on each part in turn.
If everything is normal, you will not feel any backlash. If the CV joint rattles, then there is wear, and besides, it is quite large.
If you are in motion, it is highly advisable to listen to the sounds that the car makes.
Signs of a bad CV joint
These are the sounds when turning, sharp accelerations overcoming obstacles. However, if you hear this crunch more and more often when driving straight, then a replacement is simply necessary. It is simply dangerous to drive such a car further.
More precisely, barely noticeable jerks when starting off will tell about the malfunction. Significant play is easily determined when hanging the wheel. You gotta try to move it in different sides. Is there a backlash? SHRUS for replacement.
How to find out which CV joint is faulty?
How to determine which CV joint crunches? Unfortunately, it can be quite difficult to make the most accurate diagnosis due to the fact that breakdowns of "grenades" are very similar to malfunctions of ball joints, steering tip and others. Therefore, it is worth checking their condition again.
It is very easy to carry out diagnostic procedures with. To do this, you just need to unscrew the steering wheel to any extreme position and start moving the car. When between the axle shafts will maximum angle, you can clearly hear a popping sound from a faulty CV joint. If you hear sounds when turning right side, you need to change the right one, if it crunches when turning to the left, then, accordingly, the left one.
However, there are some peculiarities in the internal mechanism.
They sometimes crunch and when moving straight. To check their performance, you may not even have any special skills in car diagnostics. It is enough to make a short trip to where there are no roads. You will hear sounds at the entrances to the pits.
But you can find out which of the mechanisms failed even more accurately. This will require a lift. When the machine is suspended, you should engage the first gear. Let the wheels turn slowly enough. In this position, a crunch will be clearly audible. If you move the shaft, you can again feel the backlash.
If everything is as described, you have a direct road to the store for a new mechanism.
Faulty SHRUS: consequences
What can they be? In the case of an external mechanism, it can break the internal one, but it can simply fall apart somewhere. And then you have to either push or call a tow truck. Such a car will not be able to drive.
But if it happened while driving, the consequences can be completely different. Such a breakdown can cause a serious accident.
How to replace the mechanism?
You already know how to identify a faulty CV joint. But how to replace it? Some novice motorists sometimes even ask about the possibility of repairing this part. Many would like to avoid replacement, because it costs money. But, alas.
Replacement is not difficult. Anyone can handle this.
To do this, you need a set of tools and a pit or jack. If all mechanisms are being replaced, it is better to do the work in stages. First you need to do everything on one side, and only then you can move on to the other. But if you have some experience, you can change everything at once. It is worth saying that the removal of the second shaft can sometimes lead to a violation of the installation of the axle shaft gears. To solve this problem, you will have to visit the service station. Before removing the second shaft, insert the old housing of the already removed part into the gearbox.
To replace the external assembly, the wheel must be dismantled. Then unscrew hub nut, remove the brake caliper and disc, ball joint and steering tip. You can pull the part out for replacement only by knocking it out. To do this, you can use a hammer, but it is better to beat through a wooden spacer. Usually this operation does not take much time - spline connections come out fast enough.
To replace the old mechanism with a new one, put a new boot on the shaft and replace the old retaining ring. Before installing new CV joint, it is recommended to lubricate it liberally. Mounting it on the shaft is carried out using the same hammer.
We change the internal CV joint ourselves
It seems strange but internal mechanism changes much easier than the outside. All replacement is also carried out either in the pit or with the help of a lift. This node is removed only from below.
The first step is to unscrew the bolts of the product. Now the part is held in the socket only with the help of a flange. Turn the steering wheel to one of extreme provisions, you can ensure that the mechanism falls out on its own. Well, then - everything is the same as in the case of an external CV joint.
Different kits may be completed in different ways. Often, the package may have a different number of washers, retaining rings, as well as other additional elements. Don't forget to install them, even if you didn't find them in the previous bundle.
When purchasing spare parts, pay attention to the parameters.
Like most other elements of a car, this mechanism requires a certain amount of attention. After all, a car is an expensive toy. Unplanned repairs of such a plan can cause serious damage to the budget. And these are only the most minimal possible problems.
Always make sure that the car is in good condition. This will save both your life and the life of your family and friends.
So, we figured out how to identify the faulty one and replace it with our own hands. We hope the information above is helpful to you.
Most modern drivers it is desirable to know the symptoms of a malfunction inner joint. This information is useful to all owners front wheel drive cars. This will avoid unexpected breakdowns, which are very dangerous. Do not forget that problems with this element can adversely affect the handling of the car. In order not to experience safety problems, it is imperative to regularly diagnose this structural element and, if necessary, repair or replace it. This is a simple matter, and if you have certain skills, you can easily do it in the garage yourself.
Signs of a malfunction of the inner CV joint are largely determined by the features of this part. Therefore, first you need to figure out what it is.
The full name of the part is a constant velocity joint. This is the main element of the transmission. It is he who provides a full transfer of power from the box to the drive wheels. The main task of the CV joint is to ensure equalization of the speed of rotation of the wheels when cornering. Since this is a hinge, with the presence of balls in it, all signs of a malfunction are characteristic of such mechanisms.
Causes of malfunctions
In theory, the CV joint is made of durable metal, as it is supposed huge pressure to this detail. According to manufacturers, the service life of a grenade is quite long, but in practice, this is not always the case. There are several reasons for the accelerated failure of mechanics:
- Fake or defective parts;
- Bad lubrication;
- Abrasive debris entering the CV joint after damage to the anther;
- Bad roads;
- Aggressive driving style.
Problem symptoms
The failure of the CV joints can be identified by very characteristic moments in the operation of the assembly:
- Crunch when starting off;
- There is also a crunch when cornering. Here you can determine which of the CV joints began to fail. This is done on the side of the turn when a crunch is heard;
- Jerks during acceleration;
- Backlash in the hinge itself.
Diagnostics
In order to be guaranteed to avoid problems with a CV joint that popped out while driving, it is necessary to carry out diagnostic work in a timely manner. At least once a month, inspect the condition of the anther, if it is damaged, then be sure to eliminate this malfunction. Breakdown is detected as follows:
- A common way is to start with wheels turned. To carry out such a diagnosis, you will need to turn the wheels out and start abruptly from a place. The presence of a specific crunch will mean problems with the cv joints;
- Raise the wheel on a jack, ideally you should use a hoist, but these are usually not available in garages. After that, we inspect the CV joint, there should be no visible damage on it. Also try to move the wheel. The hinge must not have any backlash;
- This method is more complicated, but quite reliable. The front of the car is hanging out. The first gear is engaged, if you have an automatic, then select the mode - D. Start the engine, and listen to the operation of the wheels. They should not make even the slightest crunch.
Replacement and repair
In case of problems with the CV joint, it is necessary to repair it. The work is quite difficult, so if you are not sure of your abilities, then it is better to entrust the work to specialists. When carrying out all work, they should be done as carefully as possible, and in accordance with the instructions. Pay attention to the condition of the item. If there is a large output, then the restoration of the CV joint is impractical, it is better to replace it as an assembly. The work to bring the part in order is carried out as follows:
- The hinge is removed. Be careful. Sometimes it has to be knocked down. This should be done as carefully as possible;
- The dismantled hinge is clamped in a vice. The part is rotated until it stops, the balls are removed. To do this, they are knocked out with a screwdriver;
- The separator is installed vertically, after which it is rotated to a position where the windows intersect with the end;
- Next, a fist with a separator is removed, for this, rotate the fist until you can drown the fastening protrusion in one of the windows.
- View all items hinge. They should not have any damage, there should be no signs of wear and deformation. If there are doubts about the quality of the part, it is better to replace the CV joint. Don't skimp on your safety.
- Assembly should begin with lubrication of parts. It is important to do this work as efficiently as possible, the life of the further service of the hinge depends on it;
- The balls are placed in the CV joint in pairs, as they were located before;
- Grease is again applied over them;
- The last step is to install the boot. It should also put 50-100 grams of lubricant.
The constant velocity joint (CV joint) is an integral part of all front and four-wheel drive vehicles. It provides the transmission of torque to the axle shaft and the drive wheel.
Two hinges are installed on the axle shafts:
- internal CV joint, located on the side of the gearbox;
- external CV joint located on the side of the wheel.
The node consists of 4 parts: spherical body, inner race, separator and balls. Like any part of the machine, the hinges gradually wear out and need to be replaced.
Causes of CV joint failure
The experience of service stations shows that CV joint malfunctions occur even in new cars with low mileage. There are several reasons for failure:
- Lack of lubrication. As a result of friction, metal without lubrication begins to grind.
- Incorrect CV joint installation.
- Anther damage. Water and abrasive particles enter the mechanism through holes, which accelerate the wear of balls and grooves.
- Aggressive driving or towing heavy trailers. High load on the node resulting from fast driving By bad road, sharp acceleration and heavy load on the car accelerates the wear of the hinges.
- Low quality parts. Defective or counterfeit parts do not last long.
- Mechanical damage. As a result of an accident or a wheel falling into a deep hole, parts may be destroyed.
- Ball joint play. "Dangling" wheels increase the load on the parts.
- Natural wear.
Signs of a CV joint failure
If the problem is not detected and corrected in time, the assembly may fall apart during movement. In this case, the only way to get home is by tow truck. Therefore, it is necessary to promptly respond to the following signs of a CV joint malfunction:
- Crunch while cornering.
- Backlash in the joints of the node.
- Crunch during start-up or hard acceleration.
- Fishing during acceleration.
How to disassemble and assemble the SHRUS. Video:
These symptoms may appear with other malfunctions. Therefore, before going to the car shop, you need to check the serviceability of the constant velocity joints.
Checking the health of the CV joint
Malfunctions of the internal and external CV joints manifest themselves in different ways. To check the external hinge, you need to turn the steering wheel as much as possible and slowly drive around the site. With this position of the steering wheel, a maximum bend is formed between the axle shafts. In this case, a faulty external CV joint will emit a crunch, depending on the speed of movement.
CV joint health diagnostics. Video:
Achieve maximum curvature internal hinge more difficult. To do this, you need to do the following operations:
- hang the wheels by lifting the car with a jack or lift;
- start the engine;
- enable transmission.
In this position, the faulty inner hinge will clearly crackle.
How to check the CV joint on the VAZ 2109 and 2114
A standard “by ear” check does not always allow you to accurately determine the health of the hinges. Before buying expensive parts, make sure that the problem lies precisely in them. To do this, perform the following operations:
- install the car on the pit and hang out the wheels;
- inspect the condition of the anthers;
- check the play between the axle shafts.
On Kalina, the front wheel drive can be checked in the same way with the VAZ 2109
How to check the health of the CV joint on the Ford Focus 2
The Ford hinge test algorithm is no different from the one above.
How to check the CV joint for Renault Logan
The breakdown of parts gives out a characteristic crunch (sound) and backlash of the axle shafts.
How to replace the SHRUS with your own hands
To replace hinges, you will need the following tools, parts, and materials:
- new CV joint;
- molybdenum grease;
- new outer hinge nut;
- chisel;
- new boot;
- punch;
- hammer;
- set of wrenches;
- puller for ball and steering rods;
- balloon key;
- mount;
- jack and support.
Doing the job alone is difficult. So ask a friend to help you.
Detailed instructions for replacing the CV joint
The algorithm for replacing the CV joint looks like this:
- put the car on viewing hole and turn on the handbrake.
- loosen the front wheel mounting bolts;
- jack up the car and put it on stands;
- unscrew the bolts and remove the front wheel;
- the assistant must apply the brake to prevent the wheel from spinning;
- completely unscrew the nut holding the axle shaft;
- unscrew the nut from the ball joint pin;
- undock the ball joint by removing the pin from the steering knuckle;
- clean the drive shaft;
- loosening the clamps, slide the CV joint anthers along the shaft;
- unscrew the nut securing the tie rod joint to the steering knuckle;
- undock the rod from the steering knuckle;
- pull the wheel hub towards you so that it is removed from the splines of the axle shaft;
- remove the inner joint from the gearbox using a pry bar (in order not to tear the oil seal, do not insert it deeply);
Advice: when replacing two hinges at the same time, it is necessary to insert pieces of a rubber hose or an old CV joint into the box. Otherwise, after removing the second half shaft, the gears will shift and it will be impossible to put the splines of the new hinge into them.
- remove the retaining ring from the axle shaft;
- knock the hinge off the drive shaft with a punch.
If the CV joint is not worn out, but clogged with dirt as a result of a boot rupture, it can be restored. To do this, rinse the part with gasoline to remove dirt and grease. After that, clean splines and balls must be lubricated with molybdenum grease.
Installation of hinges is made in sequence, return to removal. When assembling the inner joint, you must not forget to put a plastic plug on the end of the shaft. The splines of the inner CV joint must be tightly inserted into the side gear of the gearbox. To do this, you need to firmly plant it with a hammer through a softening nozzle.
New circlips and axle shaft nut are installed on the machine. To prevent the latter from unscrewing, after tightening it is necessary to bend its edge with a chisel.
