Single Mass Vs Dual Mass Flywheels

Do you need a new clutch for your TDI?  In this article we outline and compare differences between flywheel options so you can make an informed decision for your car.

Single Mass or Dual Mass?

An SMF, or single mass flywheel, is made out of a single cast piece of steel, has no moving pieces and cannot break or fail.  SMFs are also less expensive than DMFs (Dual Mass Flywheels).  So for reasons of durability and cost, many TDI owners choose to swap to a single mass flywheel and matching clutch kit to avoid problems in the future.

They are referred to as “G60″ or “VR6″ flywheel kits because the flywheel is the same size as what came on the G60 Corrado.  As an added bonus, the Sachs kit has a much higher power-rating than stock.

SMF setups did have downsides, however.  First, many owners comment on the “rattle” a SMF setup in a TDI makes at idle when in neutral with the clutch engaged.  Although this sound is not very loud (you’ll have to have a window down and all accessories off in the car to hear it clearly), some drivers don’t like it.  Experts say the noise is actually the output shaft of the transmission rattling, a vibration dampened by the stock DMF.  It does no harm.  The rattle is louder with lightened flywheels.

UPDATE: Recently the new “quiet” design has eliminated this problem.  All the performance upgrade clutches at IDParts as well as the Sachs “Quiet” clutch kit have the new design that nearly eliminates any rattling from the transmission.  With this new design there is certainly no reason not to choose a SMF for your next clutch.

Second, the stock DMF does dampen some harmonics caused by the TDI, and owners with a single-mass setup do comment that they can hear noise and vibration at different engine speeds not present with the DMF.  This is very minor, however, and not noticed by most drivers.

For these reasons some owners wish to keep the smooth engagement and feel of the dual mass over the simpler single mass design, and upgraded clutch kits for dual-mass flywheels are available.  Some Dual-Mass Flywheel kits such as the LUK kit below come fully assembled with pressure plate and flywheel screws already inserted and ready to install.

The Takeaway

  • Although dual-mass flywheels are more fragile than single-mass ones, DMFs do last a long time and offer some (admittedly minor to many) driveability advantages
  • The strongest power-handling clutch setups use single-mass flywheels.

Our Recommendation

Since the quiet clutch designs have come out we have exclusively been using them on our TDIs.  TheSachs “Quiet” Clutch Kit is perfect for any stock or chipped TDI.  If your car has high mileage, you should consider a Complete Clutch Kit that has all the other hardware associated with the clutch that should be refreshed at the same time.sDgIX20

  1. […] to offer single-mass flywheel (SMF) kits is Valeo. We review the pros and cons here – Single Mass vs Dual Mass Flywheels – but largely we recommend staying with dual mass flywheels for the new 02Q and later […]


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