Dual Mass Flywheel

[Riles]

Evening all,

I'm new to 996 ownership, last September I bought a 2003 carrera 2 manual. The last month or so i noticed a rattle or clunk when i press the clutch pedal before coming to a stop, or sometimes accelerating or decelerating. I've added Powerflex bushes to the gearbox mount, this seemed to help but may have been wishful thinking.

Anyway so after lots of searching i came to the conclusion the dual mass must be on the way out, the clutch was changed about 18 months ago and has only done around 5/6k nothing in the receipts to suggest the dual mass was changed at the same time. The car has done 73,000 miles.

Please see the video attached, i clamped the flywheel to the bench to check the backlash or movement. I've found the Porsche documentation that states the limit for that play is 15mm but it doesn't really state how much/little force needs applying to get that measurement.

My question is, do you guys think the flywheel is what could be making the noise?

I've also found plenty of jobs to while the gearbox is out..

Thanks for looking
Mark

https://youtube.com/shorts/f05UhLeyUYQ?feature=share

 

[Peter B]

DMF

Many years ago (!) my 996.1 suffered a serious DMF fail. I believe nearly all series 1's suffered the same fate.

The flywheel was heated to 150-200 degrees C and the backlash measured. In my case nearly 45mm at the circumference.

All that it caused was a deep clonk whilst pulling away, having used the engine to slow down in the last moments before the stop.

There was no rattle but as the car was only just purchased with a full OPC warranty (that was not honoured) I was £1500 out of pocket and pretty rattled.

 

[infrasilver]

This is a good video for testing your DMF

 

[Shalmaneser]

Evening all,

I'm new to 996 ownership, last September I bought a 2003 carrera 2 manual. The last month or so i noticed a rattle or clunk when i press the clutch pedal before coming to a stop, or sometimes accelerating or decelerating. I've added Powerflex bushes to the gearbox mount, this seemed to help but may have been wishful thinking.

Anyway so after lots of searching i came to the conclusion the dual mass must be on the way out, the clutch was changed about 18 months ago and has only done around 5/6k nothing in the receipts to suggest the dual mass was changed at the same time. The car has done 73,000 miles.

Please see the video attached, i clamped the flywheel to the bench to check the backlash or movement. I've found the Porsche documentation that states the limit for that play is 15mm but it doesn't really state how much/little force needs applying to get that measurement.

My question is, do you guys think the flywheel is what could be making the noise?

I've also found plenty of jobs to while the gearbox is out..

Thanks for looking
Mark

https://youtube.com/shorts/f05UhLeyUYQ?feature=share

That looks knackered to me. The 15mm is referring to the 'free play' and measured at the outer edge, that looks a lot more than that to me. Compare to a new flywheel and you will see the difference!

 

[Riles]

Thanks for the reply's and advice, i have ordered a new one now.

Ended up with several seized/sheared bolts in the removal and a failed engine mount, they look like the original mounts anyway, probably due replacement.

I also had a leak what i thought was the RMS, turns out when the previous owner had a new IMS fitted the garage managed to nip an O ring while installing the new IMS solution. :thumb: