Dual mass flywheel – symptoms of failure and when should it be replaced?

The Dual Mass Flywheel (DMF) is one of the most expensive consumable parts found in modern cars. When the dual mass flywheel it breaks down, it is often necessary to replace other components as well (such as the clutch or gearbox oil). In addition, the replacement service is also not cheap (due to its labor- and time-consuming nature). 

Symptoms of DMF failure

How to recognize if the dual mass flywheel needs to be replaced? Here are typical symptoms of DMF failure:

• Reduced driving comfort – clearly perceptible vibrations in the cabin of the car;
• Vibration in the cabin, noticeable when the engine is idling (previously not present);
• Knocks when the engine is turned off – beware, in diesel engines they can be the result of throttle failure (not closing fully);
• Knocks when starting the engine;
• Knocks during acceleration;
• Rattling at idle.

Repair of the dual mass flywheel

What are the options available to a driver whose car has experienced a failure of the DMF?

• The use of a new dual-mass flywheel – along with a clutch. As we mentioned earlier, it is most cost-effective to buy a medium-quality replacement. What is obvious, it is worth considering what is causing the failure – and eliminate it. (Change the driving style, repair the engine, etc.).
• Using a factory conversion kit that uses a clutch with larger torsional vibration dampers instead of the DMF. Such kits are only available for certain engines. They are usually low-powered units.
• Removing the dual mass and using a standard flywheel instead (this is the worst possible solution). The absence of a dual mas will cause vibrations to be transmitted to driveline components (gearbox and drive half-shafts) causing accelerated wear. You may be able to save money on replacing the dual mass, but the cost of repairing the transmission will be higher. On top of that, there will be poor driving comfort – the absence of the dual-mass flywheel will cause vibrations of the cabin.