This symptom occurs when the clutch is engaged at take-off, shaking the vehicle in fore- and-aft direction. The shaking stops once the clutch has been completely engaged. It occurs more often when the vehicle is carrying a heavy load, or when the clutch pedal is partially depressed for prolonged periods, as when climbing a hill in heavy traffic.
Clutch shudder resembles the vibrations made by an impact wrench such as when it is being used to tighten nuts.
Main causes
Worn clutch lining
Excessive runout of the clutch disc
Bent diaphragm fingers of the clutch pressure plate
Resonance in the drive train
Mechanism
1.When you gradually engage the clutch at take-off, the wear on the contacting surfaces of the clutch causes them to slip intermittently, creating fluctuations in the transmitted engine torque.
2.This torque fluctuation generates torsional vibration in the drive train. When the torque fluctuation and the torsional vibration resonate with each other, the torque fluctuation becomes amplified.
3.These amplified torque fluctuations are transmitted to the tire, and the vehicle shakes fore and aft.