Another rattling flywheel and slipping clutch fixed. If your manual car or ute has developed a rattle at idle, a judder when you take off or a clutch that’s starting to slip, a worn dual mass flywheel could be part of the problem. Dual mass flywheel replacement is a common clutch-related job, especially on diesels.
The job at a glance
- Vehicle: Manual vehicle with a dual mass flywheel
- Problem: Rattling flywheel and a slipping clutch
- Fix: Flywheel and clutch problems sorted together
The worn dual mass flywheel from this job, showing heat discolouration on the clutch face.
What is a dual mass flywheel?
A conventional flywheel is a single, solid disc bolted to the back of the engine. A dual mass flywheel, or DMF, is made of two separate masses joined by heavy springs and dampers. Those springs absorb the vibrations and shudder from the engine before they reach the gearbox and the rest of the driveline.
DMFs are common in diesel utes, 4WDs and plenty of modern petrol cars, because they make the car smoother and quieter. The trade-off is that the springs and internal bearings wear over time, and once they do, the flywheel has to be replaced.
Signs of a worn dual mass flywheel
- A rattle or knocking noise at idle, which often changes or goes away when you press the clutch pedal
- Vibration through the floor or pedals, particularly at low revs
- Judder when moving off from a standstill
- A clunk when you engage or release the clutch
- Clutch slip, especially when the clutch and flywheel are worn together
A rattle on its own can be easy to ignore. But a failing DMF can do further damage to the clutch, and in bad cases it can break up.
Why a slipping clutch and a worn DMF often go together
The clutch friction plate presses against the face of the flywheel. When a clutch slips, it generates a lot of heat, and that heat goes straight into the flywheel. You can see the blue and dark heat marks on the clutch face of this one.
Heat damage, combined with worn springs inside the flywheel, is why the flywheel should always be inspected when a clutch is replaced. Fitting a new clutch against a worn or heat-damaged flywheel can lead to judder, noise and a shorter life for the new clutch.
Can a dual mass flywheel be machined?
A solid flywheel can usually be machined to give the new clutch a fresh, flat surface. A dual mass flywheel generally can’t, because of how it’s built, so a worn DMF is replaced rather than resurfaced.
Some vehicles have a single mass conversion kit available, which swaps the DMF for a solid flywheel and a sprung clutch plate. These can suit some owners, but they usually bring more vibration and noise into the cabin, so we’ll talk through the pros and cons for your vehicle before going down that path.
Dual mass flywheel replacement on the Gold Coast
If your manual car or ute is rattling at idle, juddering or slipping, have it looked at before it gets worse. Our repairs and diagnostics service covers clutch and flywheel problems, and our workshop is in Mudgeeraba. Call 0478 499 369 or contact us for a quote.
Need a mobile mechanic on the Gold Coast?
Certified Automotive offers professional Repairs & Diagnostics across the Gold Coast, with mobile mechanics who come to you 7 days a week and a workshop in Mudgeeraba.
We service Mudgeeraba, Robina, Nerang and all Gold Coast suburbs. Call 0478 499 369 for a free quote.
