my name is Alex, i'm not from the USA and so i'd like to apologise for my bad englisch at first.
I've got installed a new clutch in my Porsche 944 S2 from 1989.
The clutchkit is a Spec Stage II with light weight option.
The flywheel is a modified stock part, freshly resurfaced, lightened and balanced (1kg off).
Both hydraulic cylinders (master/ slave) and the flexible clutchtube are new.
All screws, bolts and seals are new.
Clutchfork, clutch release shaft and bearings are new.
The central tube has been redone, the engine mounts and the mounts of the rear axle are new also.
The problem is a massive chattering if i shift down in 3'rd and 2'nd gear. The whole drive train starts vibrating so massive the gear bounces to neutral.
I've driven now for 400 miles with the new clutch but no improvement so far.
(The first 100 miles everything worked fine)
Is there still hope for improvement or have you any suggestions for what could be wrong?
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Alex, no need to apologize for your english.
Regarding your clutch vibration, check out Tom Pultz's web site www.944s2.com if you follow the link for "engine" you can scroll down to his information about the 944s2 clutch. I suspect your new unit may have the short hub or the unbalanced flywheel that is causing the vibration similar to what Tom experienced.
Best of Luck
Last edited by RDL; 02-21-2009 at 01:58 PM.
Reason: additional info
I've read Tom Pultz's article with interest, but he talks of transmission noise... and a vibration in the gear shift lever between 3200-3400 rpm which vanished the moment he newly balanced the flywheel.
The difference in hub design seems to have no influence on that if I understand this text right.
In my case there are no vibrations in the gear shift lever or heavy noise in the transmission at any rpm.
The vibrations and the noise only starts if I let out the clutch when the difference of crankschaft- and transmission- rpm is too big.
Leaving the autobahn. shifting down on slow-down lane from 5'th to 4'th gear while breaking down the car.
Everything works fine.
Shifting down to 3'd gear while breaking or just not pedaling the throttle ends up in massive chattering.
The friction disc of the Spec Stage II is a spring center disc with short hub layout like the sport disc used by Sachs. The friction material is Kevlar.
The aluminium pressure plate is made by Sachs.
The kit can hold 350 ft lbs tq.
So again my questin if there is still hope of improvement.
Hasn't anybody a Spec Stage II in his 944!?
Same over here.