Mitchy260

What determines the rating of a clutch? The pressure plate or the friction plate? (I assume the pressure plate )

Today i had a new clutch fitted, its a 4 puk sachs paddle clutch with a 430lbft spec 3+ pressure plate.

Probably a silly question, but if i dont ask ill never know

How does the clutch work? Is the pressure plate clamped against the friction plate, or is it the other way around?
How is it clamped, hydraulic or spring? Will the pressure plate clamp with more force to the friction plate or is it just the fact that when the 2 meet,anything upto the rated torque level will transfer?
If there is more torque than rated, the pressure plate will not be able to hold the friction plate and that is when the clutch slips? Is that correct

Also what are the benefits of using a 4 puk paddle clutch against say a conventional clutch

Many thanks

911

The clutch works as an assembly of compatable parts.

The driven disc (or paddles in your case) are clamped between the cover and the flywheel surfaces by a diaphram spring in the cover plate. This spring provides the clamping pressure to the assembly.

The spring pressure is released by the hydraulic action of the clutch pedal assembly through the 'thrust bearing' acting on the cover plate assembly.

The clutch is torque rated under set repeatable conditions.
The rating is a function of size/surface area/surface finish and materials designed into the clutch (and the quality of all the materials/assembly.)

Heat and contamination will change a clutches ability to transmit torque without slip.

Slip is where all the above designed features are over-whelmed by the torque of the engine and the resistance to the car moving (it's weight/inertia) and prevailing conditions. Also caused by changes to all the above due to wear!

There are many designs of clutches.

The clutch in my 1963 Lambretta is steel with cork inserts running in a deep oil bath!(all you need for 12 bhp)

Good question to ask.

Hope my description helps.

Graham