Ade - C4 91

Hi All,

Bad news - My 91C4 original DMF has failed at 38K miles - in quite a catestrophic fashion with lots of noise and very little prior notice.

Was getting a subtle tinkling sound at idle just prior to it letting go, and the clutch was starting to judder a little, then while driving quietly along it just gave up.

JZM have just phoned and told me that the DMF has seized solid. They also told me about another one where the guy had carried on driving and destroved the gearbox housing...so beware.

It will be getting a new LUK flywheel now along with new clutch, CR bearing and forks.

Anyway - will keep you all informed.

Ade.
91 C4.

John Boggiano

This has always interested me - if the DMF fails by freezing solid - why should that cause damage? A bit of vibration maybe, but damage to the gearbox?

Ade - C4 91

Hi,

I'm my case, the DMF no longer compressed, althought it was still drivable - the noise was probably metal on metal grinding away.

With the damaged car, parts of the flywheels assembly had dislocated outwards and the centrafugal forces caused them to mash their way through the side of the bellhousing taking ot the starter motor gear and lots of metal in the process.

Ade.

Roygarth

Ade
Sorry to hear about your unexpected bill. This is the sudden double whammy bill I worry about!! Can I ask what it is going to cost at JZM inc. VAT?

Piers
1990 C4 Coupe
54K miles

Jim Michaels

Ade.

I'm sorry to hear of your bad fortune. Did you read the 6/19/02 post by Hampton on the 964 forum? His DMF went at 40k miles as he was on the grid at a DE. Like yours, his made lots of ugly noises, like rocks being shaken in a big can. He just rolled it back on the trailer. My '93 RSA is at 46k miles now, and I'm considering replacing the DMF and the clutch over the winter as a precaution. I just had the distributor belt replaced to prevent its sudden failure. Good LUK.

Bill Wagner

Jim:

If your car is a '93, it should already have the LUK installed in it. I can't guarantee that, but supposedly the LUK became a standard install in May of 1992.

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Ade - C4 91

Hi,

The sound of bolts rattling in a can is a very good description of what I heard. Althought it happened so suddenly, without any real warning, that's what's so surprising. Hopefully the "tinkling" sound ive been hearing at idle will have gone now.

Replacing the DMF, Clutch, bearings, Fork + labour looks to be around the 1500 GBP + VAT mark.

Replacing some bits of tin work around the engine as well, as they have corroded. I've been told this is a common fault - and no doubt this has been identified by porsche and the replacements at 140 GBP will never ever corrode again. Or is that too optimistic.


Ade

Jim Michaels

Thanks for the note, Bill, but if you read the rather lengthy thread started by Hampton that I mentioned above, you'll read that apparently my RSA has a completion date (May 12 1992) one day before the first 964s rolled off with the LUK units (May 13, 1992). As I recall, my engine number is 17 units before the first LUK unit was installed. Some mystery remains, however, as another RSA owner from Virginia reported on that same thread that he found his Feburary '92 built RSA to have a LUK, and his engine number was way before mine. I wish I knew for sure, but I've long assumed that my car had the Freudenburg DMF.