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Fidanza Flywheel
- Thread starter LucasHigh
- Start date
Has anyone figured out the cause/failure mode?
A quick search is suggesting that the failure is occurring with all lighter-than-stock flywheels (both dual mass and single mass), but is not a common failure with OEM (or stock weight single mass flywheels?) Maybe also in the case of single mass + unsprung clutch?
Resulting chatter is killing reverse (or occasionally other gears). Failure is either shift fork or synchros. Does that sound correct?
A quick search is suggesting that the failure is occurring with all lighter-than-stock flywheels (both dual mass and single mass), but is not a common failure with OEM (or stock weight single mass flywheels?) Maybe also in the case of single mass + unsprung clutch?
Resulting chatter is killing reverse (or occasionally other gears). Failure is either shift fork or synchros. Does that sound correct?
Some VW's needs to be recalibrated for SMF due to increased vibration in the engine causing false knock and eventually throwing a code. Talked to my cousin, he's a mechanic, and it needed to be adjusted with VW specific tester. He was doing an OE DMF to SMF on a Polo when I asked.
As @Dialcaliper mentioned, the issue might come right down to vibration/chatter. Going unsprung SMF and unsprung clutch is likely a recipe for disaster in these gearboxes. I know SPEC and RTS have sprung clutches for the IB6. Might leviate some issues with chatter/vibration and lightweight SMF.
As @Dialcaliper mentioned, the issue might come right down to vibration/chatter. Going unsprung SMF and unsprung clutch is likely a recipe for disaster in these gearboxes. I know SPEC and RTS have sprung clutches for the IB6. Might leviate some issues with chatter/vibration and lightweight SMF.
It’s worth noting that trying to put a sprung clutch disc on a dual mass flywheel (if it even fits) is *also* bad. Maybe not as bad for the transmission as no springs at all, but with both in series you can set up all kinds of crazy resonances..
Basically you need one spring in the driveline - either the one inside the dual mass, or a spring clutch. At least one, not both 🤷
Ironically it’s more actually more important on small boosted engines with smaller class gearboxes. With less mass in the rotating assembly (crank/pistons/rods) and higher power levels, there’s just not enough inertia in the engine itself to damp out the combustion pulses and crank vibrations from transferring into the driveline - hence the rather hefty OEM dual mass flywheel - it’s not there just to make the car smoother or even just to make engaging the clutch easier. Without the clutch spring, the only compliance left in the systems between the engine and the relatively rigid ground is transmission, driveshaft, tires.
Basically you need one spring in the driveline - either the one inside the dual mass, or a spring clutch. At least one, not both 🤷
Ironically it’s more actually more important on small boosted engines with smaller class gearboxes. With less mass in the rotating assembly (crank/pistons/rods) and higher power levels, there’s just not enough inertia in the engine itself to damp out the combustion pulses and crank vibrations from transferring into the driveline - hence the rather hefty OEM dual mass flywheel - it’s not there just to make the car smoother or even just to make engaging the clutch easier. Without the clutch spring, the only compliance left in the systems between the engine and the relatively rigid ground is transmission, driveshaft, tires.
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