Rather than find the numerous parts individually, several parts can be purchased as a single package deal.
Motorcycles, cars, agricultural and industrial equipment, trucks, transit coaches and even some diesel locomotives utilize clutches. This broad array of uses necessitates a tremendous variety in clutch design, operation and production. For that reason there is an expansive market for clutch sets. Some kits are designed for the specific model and year of a vehicle while others offer more general applications.
While the manufacturers provide the initial clutch, consumers are responsible for clutch replacement. In addition to replacement kits, performance enhancing clutch sets are also available and widely used, especially in competitive cars. These kits are designed to improve the speed of shifting as well as the vehicles capacity to handle increased horsepower and torque. Torque rating, power, rotational speed and maximum pressure allowances are important considerations when selecting the proper clutch for a given application.
In general, the compression of a clutch pedal or lever causes several springs connected to a pressure plate to compress as well. This pulls the plate, and connected clutch disc, away from the flywheel which is bolted to the engines crankshaft. The disconnection stops the rotation of the clutch disc which intern disconnects the central hub of the disc from the input shaft. The driver may then shift gears or coast. After shifting, the pedal is released and the clutch disc reengages the flywheel. The clutch system works to ensure consistent clutch engagement and disengagement. As the friction from this process generates a great deal of heat and pressure, materials for each clutch component are carefully chosen.
Metallic and ceramic composites are among the most common selections for those parts which incur the greatest wear, while steel and other durable metals are used where friction materials are less essential. When selecting a clutch set it is important to consider the materials used to produce each component. It is also important to be clear as to what constitutes a kit as some are more inclusive than others. Some sets provide the clutch, or lever, and pressure plate while others include pilot bearings, throw-out bearings, discs, and alignment tools as well.