Toyota Corolla

1992-1998 of release

Repair and operation of the car

Toyota Corolla
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 4. Cooling systems, heating
+ 5. Fuel, exhaust systems
+ 6. System of decrease in toxicity
+ 7. Transmissions
- 8. Coupling and half shafts
   8.1. Specifications
   - 8.2. Coupling
      8.2.1. Coupling elements
      8.2.2. Release bearing and fork of switching off of coupling
      8.2.3. Main cylinder of the drive of switching off of coupling
      8.2.4. Working cylinder of the drive of switching off of coupling
      8.2.5. Hydraulic system of the drive of switching off of coupling
      8.2.6. The switch blocking start of the engine
   + 8.3. Half shaft
+ 9. Brake system
+ 10. Suspension bracket and steering
+ 11. Body
+ 12. Electric equipment


8.2. Coupling


Coupling elements

1. Flywheel
2. The conducted clutch plate
3. Coupling casing
4. The release bearing with the plug
5. Coupling switching off fork
6. Cover

On all cars with the mechanical transmission dry, disk coupling with the central spring of diaphragm type is established. The conducted clutch plate has the plug with vents on an internal surface that allows it to slide along shlits of an entrance shaft of the transmission. Conducted and press clutch plates are kept together by pressure of plates of the diaphragm spring established in a press clutch plate.

On cars the hydraulic drive of switching off of coupling is used. It consists of a pedal of coupling, the main cylinder and a tank with hydraulic liquid, hydraulic tubes, the working cylinder which sets a fork of switching off of coupling and the release bearing in motion.

By pressing a coupling pedal for coupling switching off, hydraulic pressure is transferred to the external end of a fork of switching off of coupling. At turn the fork puts pressure upon the release bearing. That, in turn, puts pressure upon plates of a diaphragm spring that coupling releases.

At the description of elements of coupling the used terminology can cause problems as in certain cases the old names used by the producer changed. For example, the conducted disk often is called the conducted clutch plate or just a clutch plate, press the disk sometimes is called a coupling casing, the coupling switching off bearing sometimes is called the release bearing, and the coupling switching off cylinder sometimes is called the working cylinder.

Besides replacement of elements of coupling which have obvious damages it is necessary to carry out diagnostics of the reasons of emergence of malfunction.


1. First of all, it is necessary to check the level of hydraulic liquid in a tank of the main cylinder (see subsection 8.2.5). If the level of liquid is lowered, add liquid and check hydraulic system for tightness. If the tank of the main cylinder was empty, it is necessary to pump over hydraulic system (see subsection 8.2.5) and to check operation of the drive of switching off of coupling.
2. For check of time necessary in order that the released clutch plate ceased to rotate, start the engine and leave it to work in the idling mode by the included neutral transfer (the pedal of coupling is released - coupling is included). Switch off coupling (squeeze out a coupling pedal), wait several seconds and include transfer of a backing. You should not hear a friction sound. If there is a friction sound, it testifies to possible problems in a press clutch plate or the conducted disk.
3. To check whether coupling is up to the end released, start the engine (having put it on the emergency brake) and squeeze out a coupling pedal so that it did not reach about 12,7 mm a floor. Switch the first transfer and transfer of a backing several times. If transfers switch hard, coupling means it is faulty. Check the size of the course of a rod of the working cylinder. At completely squeezed out coupling pedal the rod of the working cylinder has to act considerably from the cylinder. If does not act, check the level of hydraulic liquid in a tank of the main cylinder.
4. Examine the coupling pedal plug from above of a pedal and check that she did not jam and was not too worn-out and free.
5. Under the car check that the fork of switching off of coupling was reliably established on an axis with a spherical tip.