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Automotive Clutch Parts and Functions

Dec. 15, 2021

What is a clutch? A clutch is a mechanism that connects and disconnects engine power to the drive wheels depending on road and load conditions. In a car, the clutch is located between the engine and the transmission (transfer case). This allows torque to be transferred from the engine to the transmission when needed.

However, in addition to connecting and disconnecting the engine power to the transmission, the clutch has several functions, such as

✴ It makes gear changes easier

✴ It stops the car while the engine is still running without changing gears to neutral.

✴ It allows the car to move smoothly during the first movement

✴Releasing the car movement without engine braking

In clutch cars, there are many different kinds of clutches. It depends on the type of vehicle and its usage, such as dry clutch, wet clutch, single clutch, double clutch, etc. However, the most common type of clutch used in manual transmission cars is the single dry clutch.

This article will provide you with information about the main clutch components of a car and their functions. The following are the automotive clutch components and their functions.



1. Flywheel

The first automotive clutch component is the flywheel. The clutch flywheel is connected to the rear engine crankshaft and will rotate at the same speed as the engine. The flywheel is very similar in appearance to a brake rotor. It is a large metal disk that stores and releases the energy pulses from the crankshaft.

The flywheel also actuates the clutch by providing the friction surface for the clutch disc. In addition, the flywheel provides a mounting surface for the clutch cover that also dissipates heat.

The flywheel has three main functions, such as

✴ Providing one of the driving friction surfaces for the clutch (friction) disc.

✴ Maintains rotating mass (inertia) during operation to aid engine rotation.

✴ provides a ring gear for the starter motor to engage.


2. Pilot bearing

The second automotive clutch component is the pilot bearing. Pilot bearings are not found in all clutch assemblies, but are most common in rear wheel drive engine configurations. The pilot bearing supports the engine side of the input shaft from the gearbox.

The bearing is located at the center rear of the crankshaft or in the flywheel and locates the input shaft. The pilot bearing uses ball bearings and only turns when the clutch is disengaged.

Positioning the input shaft at the rear of the crankshaft is important for proper clutch life and operation. Without a pilot bearing, excessive wear will occur on the hubs of the splines and clutch discs, resulting in clutch disengagement problems.


3. Clutch (friction) disc

The third automotive clutch component is the clutch (friction) disc. The clutch disc is the link between the engine and the transmission. It is the component that is used to connect or disconnect the engine rotation from the transmission input shaft.

The clutch disc is always connected to the input shaft of the transmission and is sandwiched between the flywheel and the pressure plate. It provides a large surface area made of friction material on both sides. The clutch disc transmits engine rotation to the transmission as it is pressed down by the flywheel and pressure plate.

To ensure that the flow energy from the engine to the transmission is transferred well and comfortably, the clutch disc consists of several components, such as

✴ The clutch hub, which is the hub that connects the input shaft to the clutch disc. Therefore, when the clutch disc rotates, it also rotates the input shaft.

✴ The clutch face is the friction material riveted to the pad on both sides, which directly contacts the flywheel and pressure plate surfaces.

✴ Torsional damper, the torsional damper absorbs the shock of clutch engagement, acceleration, deceleration and power pulses from the engine.

Cushion plate. The cushion plate has a wavy design that compresses the face when the pressure plate engages. It provides a smooth engagement of the engine and transmission.

Automotive Clutch Parts and Functions


4. Clutch cover assembly

The fourth automotive clutch component is the clutch cover assembly. The clutch cover is bolted to the flywheel. It provides the pressure needed to secure the clutch disc to the flywheel for proper power transmission.

The clutch cover assembly functions to engage and disengage the power from the engine to the transmission via the clutch disc. If the clutch disc is always connected to the transmission via the input shaft, the clutch cover assembly is always connected to the engine via the flywheel.

The clutch cover assembly consists of three main components that connect or disconnect power from the engine to the transmission

✴ Pressure plate. The pressure plate clamps the clutch disc together with the flywheel face to flow to the input shaft.

✴Diaphragm spring. The diaphragm spring is used to press the pressure plate, so the pressure plate has the power to hold the clutch disc. When the diaphragm spring is pressed down by the release bearing, the pressure plate loses pressure and the clutch disengages the power.

✴Cover. This cover is used as the body of the clutch cover assembly and is bolted to the flywheel. Therefore, the rotation of the clutch cover assembly is the same as the rotation of the engine.


5. Clutch release bearing

The fifth automotive clutch component is the clutch release bearing. The function of the clutch release bearing is to transfer the movement of the clutch release fork to the rotating diaphragm spring on the clutch cover to disengage the clutch plate.

The clutch release bearing is mounted on the clutch release fork. When the clutch release fork is near the diaphragm spring, the clutch release bearing will contact the rotating diaphragm spring. It causes the outer ring of the bearing to start rotating.

At the same time, the release bearing will compress the diaphragm spring and lift off the pressure plate. When the pressure plate is lifted up, the clutch disc disconnects the power.


6. Clutch release fork

The last automotive clutch part is the clutch release fork. The clutch release fork is used to move the clutch release bearing (attached to the end of the fork) in and out of the diaphragm spring. On the other side, the clutch release fork is connected to the clutch slave cylinder.

The release fork pivots on a ball stud inside the gearbox bell housing. The clutch slave cylinder operates the fork movement. So, when the clutch slave cylinder rod pushes the fork, the fork pushes the release bearing and disengages the pressure plate from the clutch disc. 

Shindary Automotive Parts Co., Ltd.

  • Add.: Rm.11-12, 4th Tower, Daya Jinkai Int'l Plaza, No.1230, Jinkai Ave., New North Zone, Chongqing, China.
  • Tel.: +86 23 6305 1623
  • Fax: +86 23 6320 5611
  • E-mail: overseas@shindary.com
  • Skype: sararoman521
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