Pic. 8.1. Clutch: 1 - flywheel; 2 - clutch disc; 3 - pressure plate; 4 - clutch release bearing; 5 - fixing spring; 6 - clutch release fork; 7 - hairpin with a ball pin; 8 - protective cover
On all models, a dry single-plate clutch is installed, which consists of a driven and pressure plates of the clutch, a central diaphragm spring, a casing and a clutch release bearing (pic. 8.1).
The driven clutch disc moves freely on the splines of the input shaft of the gearbox and is clamped between the flywheel and the pressure plate by the force that the central diaphragm spring creates. Friction linings are riveted on both sides of the driven disk. The clutch disc is connected to the hub through the parts of the torsional vibration damper. The need for a torsional vibration damper is caused by the following.
With a sharp change in the speed of the car, hitting bumps in the road, abrupt engagement of the clutch, as well as due to uneven engine operation, dynamic loads occur in the vehicle transmission, causing twisting (unwinding) transmission shafts. Uneven engine torque can cause significant overloads in the transmission due to the occurrence of torsional vibrations and resonance when the frequencies of the transmitted loads coincide with the natural frequencies of the transmission. Elastic oscillations of the transmission lead not only to the appearance of noise in mechanisms and assemblies, but also to dangerous vibrations, and sometimes to breakage of parts, when the oscillation amplitude reaches a large value. An absorber is needed to absorb the energy of torsional vibrations.
Clutch release drive hydraulic. The clutch release bearing is mounted on the front side of the gearbox on the clutch release clutch. The bearing is mixed with the clutch release fork. When you press the clutch pedal, the piston in the master cylinder moves and compresses the fluid, which enters the clutch slave cylinder through the hose. Under pressure, the piston of the clutch slave cylinder, moving, actuates the clutch release fork. The clutch release fork moves the bearing, which acts on the pressure plate spring and moves the pressure plate away from the clutch disc. The clutch is automatically adjusted.
Before replacing components that are clearly defective, perform the following preliminary checks to diagnose a clutch and clutch failure:
Check the brake fluid level in the brake reservoir, which also serves as a reservoir for the hydraulic clutch.
If the level is low, add fluid and check the hydraulic system for brake fluid leaks.
With the engine idling and the shift lever in neutral, depress the clutch pedal and shift into any gear after a few seconds, no noise should be heard from the gearbox. If there is excessive noise when shifting into gear, the pressure plate and/or clutch disc may be defective.
To check that the clutch is completely disengaged, start the engine, apply the parking brake, depress the clutch pedal so that it does not reach the floor by 10–15 mm, and engage and disengage first gear several times. If the gear is difficult to engage, check the stroke of the clutch master cylinder pusher and the fluid level in the brake reservoir.
Visually inspect the clutch pedal bush located at the top of the pedal for excessive play or binding.
From underneath the vehicle, check that the clutch release fork is installed on the ball stud.