What are the phenomena of double-mass flywheel failure?

The failure of dual-mass flywheel will produce abnormal sound at the joint between automobile engine and gearbox housing, similar to metal knocking sound. Methods: Turn the driven flywheel with both hands and observe the angle between the driven flywheel and the driving flywheel. If the angle is obviously greater than 12, the dual-mass flywheel has a problem and needs to be replaced.

The main characteristics of dual-mass flywheel performance: 1. Torsional vibration isolation: the dual-mass flywheel can almost completely isolate the torsional vibration of the engine crankshaft from the gearbox, especially completely filter out the imbalance in the low-speed region of the engine. This can reduce the idle speed and make the engine mainly run in the low speed area, thus improving fuel economy and reducing vehicle noise. 2. Load reduction of the gearbox, because the dual-mass flywheel reduces the imbalance of the input shaft, the load and stress generated by the gearbox are also reduced. The dual-mass flywheel almost completely eliminates the additional torque of high-frequency transmission in traditional systems. Because the gearbox reduces the extra load, it can transmit higher static torque. This is especially true for diesel engines with dual-mass flywheels. 3. Crankshaft load reduction: Because the primary mass of the dual-mass flywheel is much smaller than that of the traditional transmission system, the inertia moment of the flywheel is very small, and the bending load of the crankshaft caused by the secondary mass can be ignored, so the dynamic load exerted by the inertia moment of the flywheel on the crankshaft is reduced. 4. The shifting performance is improved. Because the dual-mass flywheel can effectively isolate the vibration of the engine, lubricating oil with lower viscosity can be used in cold weather to obtain better gear shifting effect. In addition, canceling the shock absorber of the clutch also reduces the force on the synchronizer, making the shifting force smaller.