Dual mass flywheels

What is a dual mass flywheel? Do I have one? Well, most modern vehicles are fitted with a dual mass flywheel now, so if your car is reasonably new the chances are yes, you do have one.

What does it do though? Well, it is designed to dampen engine vibrations, delivering a quieter and smoother ride. So that’s good – they clearly provide a good service then.

So what’s the problem? Well, as with any of the drive train components, they can and do wear out.

How would I know? You will notice increased engine noise – particularly when you start the engine from idle. Also you will notice the ride gets a little rougher, so basically you will notice the dual mass flywheel isn’t working properly when you notice the things it is designed to stop/reduce.

Typically the dual mass flywheels will need changing at the same time as the clutch in most, if not all, diesels. This isn’t always the case with petrol engines, but due to the labour required in getting to the dual mass flywheel in the first place it might be prudent to get it changed if it is not in tip top condition.

Of course, the luxury feel of the quieter and smoother ride come at a price – replacing the dual mass flywheel is more expensive than a conventional single mass flywheel, but conversion kits are available and can be fitted – so the choice is yours when the time comes that it needs to be changed.

As well as the increased noise and vibration, the conventional single mass flywheel will also increase the wear and tear on the gearbox syncromesh as it would have to cope with the increased weight of the sprung clutch plate – so it is a choice with more than a few simple considerations.

Another would be fuel consumption – our earlier post looked at how you can increase your MPG through adopting various tactics, however we did not touch on the use of a dual mass flywheel. When replacing a dual mass flywheel with a conventional single mass one, be prepared for some alarming fuel consumption stats! The difference in price at the point of purchase will more than be matched by the saving in the first year of motoring when you replace the dual mass flywheel with a like-for-like replacement. Controlled tests showed a 21% reduction in fuel economy where a single mass flywheel replaced a dual mass flywheel on a vehicle where it was designed to take the dual originally.

Our recommendation would be to replace like for like and benefit in the long run from a smoother, quieter ride and the knowledge that it is not speeding up the wear of other engine components.

So if yours is on the way out give us a call and we can recommend the best course of action for you and your car.