Clutch kit - time to replace?
Content
Every self-respecting owner should take the time to properly care for his car. Regular and adequate operation of each part of the car is important, because even the slightest damage can lead to expensive repairs.
Everyone knows: if you do not even pay attention to a seemingly insignificant problem, it can develop into a more serious one. When all the parts work synchronously, the risk of possible traffic accidents is accordingly reduced.
Every part of the design of the car, including the clutch, is important. This is an element from a long list of automotive parts necessary for the correct and uninterrupted operation of the vehicle.
What is the role of adhesion and why is it necessary?
The clutch is a mechanical drive device that serves to effectively connect the shafts and various elements of the machine, such as drums, gears and others. In cars, the clutch provides a kinematic and power connection between the gearbox and the engine. In other words, its task is to transmit torque from the flywheel of the crankshaft of the engine to the drive shaft of the mechanical gearbox, as well as to other drive elements.
In addition to transmitting power from the engine, the clutch has another function - to briefly interrupt the transmission of torque, as a result of which the connection between the gearbox and the engine is interrupted, and then a smooth connection is established again. This is necessary so that the driver can safely shift gears for the motor to ensure smooth movement of the car.
In passenger cars, lightweight single-plate clutches are most common, while in trucks and buses, single-plate or double-plate clutches are most common. The most important element of the clutch is the drive disc, which transmits rotational motion from the knee disc. The transmission is used to transmit torque from the engine to the drive wheels and to change the amount of torque and its direction (forward or reverse).
Clutch mechanism
The clutch consists of a metal disk and friction linings located on its front and rear. Thin linings are attached to it with rivets. Elements are made of asbestos and brass chips, which are bonded with plastic resins. The friction disk is pressed against the flywheel with great force by the pressure disk.
Six or eight large springs or one central spring create a compressive force. Different cars have different types of clutches. The clutch consists of a drive and a transmission mechanism. The drive parts are located in the clutch housing.
Clutch drive
Clutch with external springs consists of:
- flywheel;
- pressure disk;
- adjusting nut;
- disconnecting ring;
- clutch shaft;
- rings with graphite insert;
- clutch compression springs;
- clutch covers;
- release bearing;
- friction disc with wear-resistant pads;
- pressure plate;
- master drive;
- a casing (or basket);
- disconnector
- gearbox shaft (its task is to transmit rotational movements from the engine to the transmission with the clutch engaged).
The whole mechanism is connected to the gearbox. It allows you to change traction and wheel speed with an unchanged engine power. This is done by connecting different pairs of gears in the gearbox.
The most common causes of clutch wear
To search for the cause of a node malfunction, it is necessary to carry out its visual inspection. This can be done while it is still installed or after disassembly. This will help to more accurately diagnose the problem and repair damaged items.
Sometimes the problem may not be related to the mechanism itself, but to the details located near it. Some problems can be solved by very simple methods without the need to dismantle the clutch.
There are several common problems that definitely indicate clutch wear. One of them is, for example, softening the pedal. This effect is the result of a decrease in the properties of the compression spring, which can lead to insufficient disconnection of the drive shaft of the box, which will eventually lead to damage. Often this problem is accompanied by a crunch of gears in the gearbox when a particular gear is engaged.
Weak coupling of the friction disc to the flywheel surface. It can be caused by wear on the asbestos pads, which can cause poor adhesion and, consequently, loss of power transmission from the engine to the gearbox.
Other signs of wear occur when the clutch makes a loud noise, vibrates, loosens badly, slips and when the clutch pedal is hard to press. Loosening and damaging the engine mountings can displace the mechanism. It can also cause vibration in the gearbox.
What clutch elements fail?
Flywheel
When the car has a high mileage, we can notice signs of wear on the friction disc that works with the flywheel’s working surface. If we see scratches and dents, it means that the flywheel has been overheated.
Such damage must be repaired, but when grinding, the permissible limits established by the manufacturer must be observed. For this reason, it is imperative that such a repair be performed by a professional.
Disconnect plug
It is recommended to replace the release yoke with the clutch. When it is worn, this can lead to clutch opening mainly in 1st and reverse gears.
A damaged release fork also separates the release bearing from the pressure plate. If it rotates due to very strong vibrations, this rotation can create contact between the diaphragm spring and the compression disc cover. In this case, replace the clutch kit with a new one.
Another cause of damage to the clutch is wear on the contact pins of the yoke. This process is gradual. When worn, the surface of the contact fingers becomes flat, and they cease to have a spherical shape. This leads to the inclusion of the friction disk, which leads to the opening of the clutch when starting the car. It is important to note that the dual-mass flywheel dampens clutch vibrations.
Broken, bent and worn forks prevent the clutch from releasing. Loosening the clutch shaft bushings slows down the release bearing.
Release bearing
If the release bearing is locked, the clutch may not disengage. Damaged thrust bearings cause noise and angular displacement, resulting in damage to the friction disc. This part should slide freely along the guide sleeve without tilting. A worn out working surface of the release bearing leads to noisy operation.
Thrust bearing guide bushings
Worn guide sleeves do not allow the sliding bearing to move freely. This causes vibrations and slippage of the clutch. They should be centered and parallel to the input shafts of the transmissions.
Here are the forks
Worn axle bearings cause a tilt that locks the clutch and causes it to shake at startup. The shaft of the disconnecting plug must be disassembled before checking for damage.
Clutch cable
The cable must not pass through sharp corners or bend. It must be replaced when replacing the clutch.
In the process of threading, it is necessary to ensure that the casing does not pass near the movable elements and is not pressed by them. A torn cable core will not allow you to squeeze the clutch and engage the gear.
How to determine that the clutch needs to be replaced?
One of the steps you need to take is to check the clearance between the yoke shaft and the disconnecting yoke and worn axle bushings. Check the condition of the guide tube well.
- Visual Inspection of the Release Fork - In this type of inspection, it is important to know that the areas of contact with the release bearing are located on the side of the transmission. This makes them difficult to access. In such cases, you can use a mirror or resort to removing the disconnecting plug from the gearbox.
- It is recommended that the condition of the crankshaft damping washer be checked.
- Check the toothed ring of the starter.
What will help to avoid damage to the mechanism?
Avoid abruptly depressing the accelerator pedal, as this may cause vibrations and slippage of the friction disc.
Worn parts of the dual-mass flywheel must not be reused, as this may damage the bearing. Since the flywheel is located between the gearbox and the engine, when removing the gearbox together with the flywheel, we must replace the clutch with the corresponding parts: friction and pressure plate, clutch bearing. This is most economical when we buy parts in a kit.
To lubricate the splines of the release bearings, a heat-resistant material without suspended particles should be used. Nickel plated hubs must not be lubricated. We need to check the clutch alignment with the flywheel.
And last but not least, when repairing, it is recommended that you always follow the established specifications of the original manufacturer of your car, since clutch repair of different brands is different. In case of doubt and questions, it is better to consult an authorized service center where they can identify your problem and help in buying suitable spare parts.
