Dual Mass Flywheel
Function
The dual mass flywheel is designed to reduce the noise and vibration produced by the engine, clutch, and transmission during acceleration and cruising.
Construction
The flywheel assembly is actually two flywheels in one, which raises the inertial mass on both the engine and transmission. The inner and outer flywheels are connected by high and low torsion springs. This combination effectively dampers changes in engine speed before they are transmitted to the transmission.
Since there are high and low torsion springs between the flywheels, none are used in the clutch disc, which lessens the inertial mass on the mainshaft. This reduction of the rotating inertial mass reduces the load on the synchro rings, allowing the transmission to shift smoothly. Also, the friction plate is designed to reduce the noise when the engine starts and stops.