Team-BHP - How does a clutch burn?

well, here goes the sunday school version...

imagine 2 circular metal plates in contact with each other. when one is rotated by some external force, the second plate that is in contact with the first one will rotate along with it. but if some sort of opposite force is applied to the second plate, then there will be friction between the two plates due to the difference in speed between them, causing heat and energy, as the first plate will try to move the second plate, but in vain. the clutch works something like this - the flywheel of the engine is the first plate, and the clutch is the second plate, which is attached to the gearbox, which is attached to the wheels via driveshafts. when you press the clutch pedal, the clutch, is rotating at the same speed as the gear (which is connected to the wheels), and is free from contact with the flywheel. when you release the clutch pedal, the clutch is slowly coming in contact with the flywheel, and the flywheel is trying to rotate the clutch. so, when you are on an incline, (or under any sort of load) and trying to move the vehicle by pushing the accelerator and slipping the clutch, the flywheel and the clutch are rotating at different speeds, while in contact, thus creating excessive friction and heat. this, causes the clutch to wear, which is called burning/ frying.

you can tell when the clutch is burnt by this simple method; if you notice that you have to accelerate more than you have to, to maintain a constant speed, then the reason could be a burnt clutch; or, if you notice that the engine is revving more without any significant increase in speed, then it is the clutch's fault. but under both these circumstances, it could also be due to a faulty pressure plate, which causes the clutch to disengage/engage while pressing /releasing the clutch pedal....the pressure plate is what keeps the clutch in contact with the flywheel (it pushes the clutch onto the flywheel), with a certain amount of force......