What is a clutch release bearing. How to understand that the clutch is out of order. Bearing replacement tools

The release bearing, which is a component of the clutch system, plays an important role in the operation of the car. Thanks to it, the clutch is engaged and disengaged. The process starts because the pedal is connected to the clutch release bearing located in the middle of the disc, which exerts pressure on the petals of the basket.

In modern car mechanisms, 2 types of bearings are used: roller and hydraulic ball bearings. The first - the usual one, is a mechanical device that transmits force due to a rigid connection of traction. Hydraulic operates through the force generated by the hydraulic system, which does not require the application of pressure on the pedal. The function of the clutch is to smoothly disconnect the transmission from the engine when changing gear. I cannot single out for myself which of the two mechanisms is better. They both have a long life if used carefully and correctly.

The device of this mechanism is as follows: by means of pressure, the pressure plate presses the driven disc against the flywheel. The flywheel hub is connected to the input shaft and moves along it. Damper springs inside the shaft reduce vibrations. Thanks to this, the inclusion is smooth. And in order to create the desired force, the diaphragm spring acts on the pressure plate. The inner diameter of the spring, made in the form of metal petals, is affected by the clutch release bearing. It is on the axis of rotation. It is entrusted with the functions of a transmission device between the clutch and the drive.

I often meet the erroneous opinion that the rotation of the release bearing occurs exclusively when the machine is moving. But in reality, when the clutch is depressed, a torque drive is applied to the clip. If you hold the clutch for a long time in gear, an uneven load is placed on the bearing. For this reason, parts wear out quickly. After all, when the vehicle is moving, it remains at rest, it starts working when shifting gears. Any breakdown leads to the impossibility of further control vehicle.

Symptoms

The release bearing is very important for the operation of the entire mechanism of the car. Therefore, if any deviations appear, you should not postpone them for a long time. I know from experience that the sooner a problem is fixed, the better.

The main sign of wear is a knock when the engine is running, which sounds when the clutch is depressed. Although there is one caveat. This characteristic sound is amplified at low temperatures - so it can be ignored in winter time of the year. But, when the whistle near the clutch pedal increases, the part needs to be replaced. In the summer, a similar sound almost always guarantees the appearance of problems.

The clutch release bearing has the advantage of high strength. So sometimes when a knock appears, it is possible to observe the further development of events. The sound may not be amplified. But I still recommend starting a repair or replacement. The reason why it fails is most often the human factor. Many drivers keep their foot on the clutch while the gear is out. For this reason, in most cases, the clutch release bearing breaks.

In my case, things were even simpler. Starting the engine, I shifted into reverse to drive out of the garage. At the moment of pressing the clutch pedal, a sharp crunch was heard - evidence of a failed pressure or driven disc. Due to the impossibility of continuing to move without the presence of a reverse gear, it was necessary to urgently eliminate the problem that had arisen. And I wondered how to change the release bearing?

Replacement and repair

Replacing a release bearing that has failed can be done independently. I, having little experience in car repair, carried out this procedure quite quickly. First of all, I remove the gearbox, disengage the spring retainer. I remove the bearing from the guide bush. With the help of tools, I squeeze the “legs” of the spring holder and take out the part. Before putting in a new one, I check it with great care. It’s better to look at everything carefully and feel it than to redo the work twice. It is not permissible for the bearing to seize, its rotation must be easy, without play.

When installing a new part on the coupling, I carefully make sure that the part of the inner ring that protrudes looks to the side. It is easy to fix it with the holder. I apply grease to the guide bushing and only after that I replace it with another one. It is fixed with a clutch using a spring retainer. I put the checkpoint in place.

The new spare part will work properly up to 150 thousand km. run. But it is often necessary to replace the release bearing every 50 thousand km. due to driver errors and poor road surface.

Video “Replacing the release bearing”

The recording shows how you can replace the release bearing and lubricate the worker.

An important component of the clutch is the release bearing. It is located on the input shaft of the gearbox, with the help of a pressure clutch, it exerts pressure on the inner ends of the levers. These levers make a direct connection or disconnection of the clutch release and clutch disc. It is important to remember that the standard clutch position is on. But when you press the clutch pedal, the clutch discs disengage.

It must be realized that all these elements are involved in the transmission of tremendous power. The release bearing is subjected to high mechanical loads, which affect its wear. It is also commonly referred to as a "thrust bearing". Some vehicles use a thrust bearing. It is also called a heel. There are models in which this element is absent altogether. For example, VAZ-2108.

Ball bearing is a well-known element of any car. The principle of operation of any bearing and the device is familiar even to a schoolboy: a cage, an outer and an inner ring, balls, a raceway.

Signs of malfunctions, breakdowns

It, like other spare parts, is subject to severe mechanical wear. The release bearing is only affected at the moment of gear change. The more often and longer this is done, the faster the wear. Its signs of wear lead to malfunction and complete failure of the entire clutch mechanism. Incomplete disengagement of the clutch is often associated with a malfunction. In the language of drivers, this is called "clutch leads." A clear example of severe wear on the release bearing can be loud noise when disengaging the clutch.

A good sign of a bearing failure is an incomplete disengagement of the clutch, its slipping. What else can indicate possible wear or malfunction:

An auxiliary sign may be the smell of burning, engine overheating, increased consumption combustible material. Ignoring such symptoms is fraught. The wear of any bearing is affected by its operating time, the conditions in which it worked, the ingress of dust, dirt and foreign bodies. A lot is determined by the mechanical load on its body, vibration and heating. Obvious signs of a breakdown should prompt only one thing: hurry to the service station.

Repair only

The problem is solved only by replacing the bearing, it cannot be repaired. It is impossible to replace without removing the gearbox. This is a difficult, laborious task. It can only be done in a professional workshop, with the help of a partner. A job like changing a bearing requires skills, equipment, and conditions. When replacing, it is not recommended to select a cheaper analogue. This is dangerous with a new quick breakdown. It is even more efficient to change the clutch completely.

Replacement and issue price

Any driver in our difficult time will ask the question: “How much does it cost to replace a bearing, what is the best thing to do: buy a bearing in a trade, or entrust it to the service station masters?” Many decent establishments try to have their own reliable suppliers of spare parts, not to wind up an additional margin when replacing parts. In this case, the benefit of the car owner is obvious: the workshop is responsible for both the work and the spare part.

The release bearing for an average foreign car costs from 9 to 22 dollars. If it's an expensive car (BMW), then the price is a bit higher: $25. Different companies are engaged in the release of these parts, the price may vary. The replacement work itself costs as much as the bearing itself. A lot depends on pricing policy enterprise, the "greed" of the owner, the availability of shares and additional services.

Every vehicle needs to replace the release bearing from time to time. Not only comfort, but also the safety of movement by car depends on its condition. After reading the article, you will learn how the bearing works, what functions it performs, what signs will indicate its malfunction and how to replace it.

The role of the release bearing

Clear gear shifting on the mechanics is possible only when the input shaft of the gearbox (gearbox) is disconnected from the engine. This principle is true for any car with a manual transmission. The clutch disc is in constant contact with the flywheel due to the fact that the basket presses the disc against its surface. To disconnect the gearbox input shaft from the engine, it is necessary to press the release fork on the basket, forcing it to squeeze the petals and release the disk. For this, a release bearing (VP) is needed, which transmits the force from the fork to the rotating clutch basket. When you press the clutch pedal, a cable or hydraulic actuator activates the gearbox fork. In turn, the fork, with the help of a bearing, presses on the basket and disconnects the transmission from the engine. Such a device is used on those clutches where there is one disc. Clutch, where more than one disc is installed, the basket works a little differently. The basket releases the first disc, then the springs take the second disc away from the flywheel surface. On all vehicles with manual transmission it stands in the bell (case) of the clutch, at the end of the fork that connects the basket and the clutch drive.

How to Determine the Status of a VI

The main symptoms of a part failure are - extraneous sounds(bearing makes noise or whistles) with the clutch pedal fully depressed and the engine running. To check the bearing, depress the clutch at different speeds. It is advisable to perform this operation together, if the part is noisy, it is better heard not from the cab, but from the hood side. If it only makes noise in a small rev range, then most likely the problem is in some poorly tightened nut. If the part makes noise at any engine speed, then this indicates a bearing malfunction, therefore it must be replaced. If you hear these signs while driving on the highway, do not be alarmed. From malfunction to jamming, it will work for at least 10 thousand kilometers. After all, the bearing makes noise due to the wear of the rollers and the vibration caused by this, and the principle of its operation is such that it is very far from noise to destruction.

Bearing replacement tools

For work you will need:

• pit, overpass, lift or jack, two props and wheel chocks;
• a set of cap and open-end wrenches;
• stand to support the box.

If you are repairing a front-wheel drive car, then you will need:

• wrench for hub nut;
• new hub nut;
• chisel;
• a hammer.

VP replacement

Roll the car onto a flyover, pit or lift. If this is not possible, then jack up the front left side and support it. Then lift the front right side and place the prop.

Do not work under a vehicle without a partner. If something goes wrong, he will be able to lift the car and get you out, or at least call for help. Be sure to remove the terminal from the battery.

If you are repairing a front wheel drive car, first loosen the nuts on the front wheels and hubs.

Raise the car and remove the gearbox. On rear-wheel drive vehicles, for this it is necessary to unscrew 4-6 nuts and bolts that connect the flanges cardan shaft and gearbox output shaft. After that, move the shaft to the side so that it does not interfere with the dismantling of the box. Remember, the box weighs 10 or more kilograms, and complete with transfer case its weight can reach up to 50 kilograms. If you have a bridge SUV, then before removing the gearbox, unscrew the bolts and nuts that connect the transfer case flange and the front shaft. If you have an SUV with independent front suspension, then first disconnect the rear shaft, then proceed in the same way as with front-wheel drive vehicles.

If you have a front-wheel drive car, then the release bearing should be replaced as follows. Remove the front wheels, unscrew the hub nuts, remove thick metal washers from the CV joint shaft. Then unscrew the steering pin nut and ball joint nuts/bolts. Using a puller, pull the steering pin out of the rack. Press the hub down, remove the rack from the CV joint shaft and take it aside.

After that, on front - and rear-wheel drive vehicles, substitute a support under the checkpoint. On powerful SUVs, if possible, it is necessary to maintain a checkpoint from the passenger compartment. Disconnect the hydraulic or cable clutch and unscrew all the nuts that attach the bell to the engine. Pull the box to pull the input shaft out of the engine. Put the box on the table.

Press the VP retainer and remove it from the input shaft. The installation of a new VP must be carried out in the reverse order. Do not forget to lubricate the input shaft splines with grease (Litol or its analogues). On the front wheel drive vehicles install new hub nuts and, after tightening to the required torque, tighten them with a chisel and hammer. After installing the shafts, be sure to check whether you have tightened all the nuts, whether you have put lock washers everywhere.

Do-it-yourself repair is not difficult

Now you know the main signs of a malfunction of this node and the principle of its operation, you understand what to do if it makes noise and you can replace it yourself. This will help you keep your car in good condition. The repair technology is applicable to all machines where a cable or hydraulic clutch is installed.

It is useful for the driver to know all the signs of a clutch release bearing failure. After all, problems with this element begin, as a rule, unexpectedly. And continued operation of the car with such a malfunction can lead to a complete failure of the clutch. Clutch failure on the road is an unpleasant problem that you simply cannot solve.

The car has to be towed to the garage, which is a rather laborious process. The tow truck is expensive. It is much easier to monitor the condition of the bearing and other parts of the clutch in advance. This will save you from possible problems on my way.

Device

Signs of malfunction of the clutch release bearing directly stem from the structure of this part. At the moment, two types of such bearings are used in automotive clutch systems:

• Roller (mechanical);
• hydraulic;

The mechanical bearing consists of two elements. The main part is the bearing race itself. A plastic casing is located on top of it, and the drive lever is attached to it. The hydraulic bearing differs in the structure of the outer casing. It is able to move relative to the cage when pressure is applied from the hydraulic drive system.

Bearing danger

Another hazard, often leading to breakdowns, is an external factor. Many drivers drive through mud, puddles, snow. Some are forced to do this because of the poor quality of roads, others go fishing and hunting. In any case, water and dirt get under the box bell. Because of this, the grease contained in the release bearing loses its properties. This leads to increased wear, and, accordingly, the failure of the part.

The average bearing life is about 150,000 kilometers. In case of careless use or bad roads, this period is reduced by 3 times.

Symptoms

The release bearing is quite reliable, but still it sometimes breaks. To avoid a complete failure, it is necessary to diagnose the breakdown in a timely manner. Timely replacement will save you from unnecessary hassle in case of an unexpected failure.

The first sign is a knock that appears when the clutch is depressed (engine is running). This indicates the beginning of the destruction of this structural element. But there is one caveat. If the knock is observed only in frosty weather, and disappears after the engine warms up, then there is no breakdown. It's all in the plastic case. In the cold, it shrinks somewhat and the clip begins to knock. After warming up the engine and gearbox, everything returns to normal.

If you hear a whistle from the pedal side while depressing the clutch, then most likely the clutch has run out of lubrication. or replace with a new one. Also, in very rare cases, a sign of a malfunction may be the inability to engage the gear. This occurs when the bearing is completely destroyed. What happens extremely rarely, the part is made of high-strength steel.

Repair and service

Like any spare part in the car, the release bearing requires attention. At the first sign of a malfunction, it should be replaced with a new one. During operation, it is desirable to lubricate it periodically, this should be done every 70,000 kilometers. If the machine is operated in difficult road conditions, then it is better to reduce this distance.

Even if there is a knock and whistle, you should finally make sure that the problem is in the bearing. To do this, you have to remove the box. The only way to determine the condition of a part is to hold it in your hands. Replacements require bearings that are damaged - cracks, chips. Check how freely it spins. Even the slightest wedging is unacceptable. If no signs of malfunction are found, then you can lubricate it and install it back. Most likely, the problem will disappear.

To change gear in the gearbox, you need a short break in the transmission of rotation from the engine to the transmission. The clutch, consisting of a number of parts, is responsible for this, among them is the release bearing.

Operating principle

The classic "dry" clutch scheme used on cars, is permanently closed. The design of such a unit includes a basket with a drive disk, which is bolted to the flywheel. A driven disk is installed between them, planted on the splines of the gearbox input shaft. Due to the powerful diaphragm spring, the driven disk constantly presses the leading disk to the flywheel, which is why this circuit is called closed.

The task of the release bearing is to open the flow. The driver, depressing the clutch pedal, by means of the drive shifts the bearing along the guide sleeve mounted on the input shaft towards the basket. Due to the effort of the driver's foot, this bearing presses on the diaphragm, resulting in the movement of the drive disk along the guides inside the basket. It moves away and releases the driven disk - the transmission of rotation is interrupted. After releasing the pedal, the bearing moves towards the gearbox, and the spring returns the drive disk to its place - the flow resumes.

Types and design features

Two types of release bearings are used in the clutch design of a car:

1. Mechanical.
2. Hydraulic.

The main elements of release bearings are ball or roller bearings of a closed type. They are used on both mechanical and hydraulic types of products. Their design also includes a body.

In mechanical elements, this housing is designed to interconnect with the clutch fork. Such nodes can have a very different design (the body is presented in the form of a sleeve inserted into the inner cage, or it is installed on the outer ring), but all cases have special protrusions that are affected by the fork. In general, in mechanical bearings, housings are only designed for this.

Clutch diagram of a VAZ - 2107 car
1 - flywheel; 2 - driven clutch disc; 3 - clutch basket; 4 - release bearing with clutch; 5 - clutch hydraulic reservoir; 6 - hose; 7 - the main cylinder of the clutch release hydraulic drive; 8 - clutch pedal servo spring; 9 - return spring of the clutch pedal; 10 - limiting screw of the clutch pedal travel; 11 - clutch pedal; 12 - hydraulic clutch release pipeline; 13 - spherical bearing forks; 14 - clutch release fork; 15 - release spring for the clutch release fork; 16 - hose; 17 - working cylinder of the clutch release hydraulic drive; 18 - clutch bleeder

In hydraulic release bearings, the housing design is more complicated, since it acts as a hydraulic cylinder. The essence of his work is this - the driver, pressing the pedal, creates fluid pressure in the clutch drive. This fluid enters the housing and squeezes out the hydraulic cylinder piston with the bearing fixed to it. The housing itself in this design does not move along with the thrust element, which makes it possible to rigidly fix it with bolts to the clutch housing.

The bearing in the design of the unit is used to create pressure with minimal friction. When in contact with the diaphragm spring, it rotates at the same speed as the clutch elements, due to which there is no friction between the contact surfaces. There is friction in the bearing itself, but it is negligible.

The release bearing drive is mechanical, hydraulic and combined. In the first case, the force from the pedal is transmitted by a linkage system or a drive cable. This drive is used with mechanical bearing assemblies.

The hydraulic drive is accordingly used on the second type of bearings, since the liquid is its main working element (the hydraulic cylinder is triggered by its pressure).
The peculiarity of the combined drive is that the fluid does not act on the bearing, but on the fork, and that in turn moves the mechanical bearing.

Something else useful for you:

Video: Car clutch

Signs of worn release bearing

Release bearing units are reliable products and can last a long time. It usually fails due to natural wear of the bearing itself. But its resource can be significantly reduced by incorrect clutch adjustment and frequent long clutch releases.
With regard to adjustment, the wear rate increases when the assembly is brought very close to the spring, due to which they are in contact with each other. As a result, the bearing is constantly running, which reduces its life.

Hydraulic bearings are less reliable due to the housing. The design of the hydraulic cylinder necessarily contains rubber seals, which eventually begin to let fluid through. Because of this, the actuator may become airy and stop working.

Signs of a failed release bearing are:

• increased noise when squeezing the clutch (rustling, hum)
• crunch and knocks;
• wedging of the pedal;
• ease of pedal failure and clutch “leading”;

Increased noise appears when the bearing is worn. Due to the backlash, its components may shift and warp somewhat, which is accompanied by the indicated sounds. The operation of the car is possible, but it is better not to delay the replacement of the assembly, since it can crumble at any time.

The crunch and knocks appear as a result of the destruction of the node. Usually, the bearing cage breaks, and its particles fall into the zone of movement of the rolling elements, which causes crunches.
The wedging of the pedal is not due to the bearing, but to the sleeve along which it moves. Corrosion and dirt on the surface makes movement difficult.

In hydraulic bearings, the engagement of the clutch, the ease of lowering the pedal, and the constantly decreasing fluid level in the reservoir signal a loss of tightness. And if there are no visible smudges on the drive, then the node itself should be checked.

Release bearings are non-repairable parts and should be replaced if they show signs of wear. The difficulty in carrying out replacement work lies in the fact that in order to remove the assembly, it is necessary to dismantle the gearbox.