Shudder when pressing clutch
 

Every now and then when I depress the clutch pedal I will get a shudder from the rear of the car. Sometimes it happens a couple of times a day, or I can go a week without it happening at all. It happens across all gears. Any ideas?

What's the Year and type (S or not)?

When you hit the clutch pedal are you doing it quickly or slowly?

2000S. It has happens when depressing both slow and fast. I thought it might be the synchros, but was told that then it would consistently occur in the same gear. Mine is inconsistant and across gears.

What about RPMs? Have you checked to see what RPM you're at when it happens and/or if it's in a specific range?

It has happened at both ends of the RPM scale also. On the highway, 5000 or so in 3rd, press clutch to go to 4th - shudder. Just crawling out of a parking garage in 1st, 2000 or so, press clutch at exit gate - shudder. Other times, exact same scenario, nothing. I would say that the shudder happens less than 5% of the time. As it is my daily driver, I'll probably wait to have it checked at my 45K maintenance, which is coming up soon. But I just wondered if anyone else had experienced this or recognized it as a really serious problem, in which case it would go in tomorrow.

It could be minor or serious. It sounds to me like there are two things that could be causing it, the flywheel or the clutch itself. The bad thing is the only way to really tell is to take it apart and check out the parts.

If your 45K is soon (say within 5K miles), then I would have them check out the clutch and flywheel. They should check the clutch for wear on the release and pilot bearings and the intermediate shaft and also check the flywheel for uneven wear. If it happens only when you release the clutch (engage the clutch pedal) then it sounds more like a worn bearing to me than other things. They all work together, so an uneven flywheel can put undue pressure on bearings and start wearing them out prematurely. You can have less than 1/2mm of wear on a bearing and start to feel a shudder.

If the clutch has to be replaced, it's expensive, especially if the flywheel is gone too. I'd take it to an independent shop and see if there are aftermarket options to the flywheel. The dual-mass flywheel that comes in the 2000 is troublesome and cannot be machined flat. The part is over $700 itself. Clutch installed I've seen on here up to the $4K range. :eek:

Synchros and flywheel were my 2 biggest fears. Cha-ching! Although the numbers for the complete clutch/flywheel rebuild were a bit less then the $4K that you mentioned. Actually, I seem to remember someone (actually, I think it was you) posting on here about replacing the stock flywheel with a low-weight one.

Yeah, but I don't know if a dealer will put in an aftermarket part. I am definitely replacing my flywheel with a low weight one that has inserts in the next 10K miles. That way the wear area is the insert so that's all that has to be replaced in the future when the clutch disc has to be replaced. I think the replacement inserts are about $200. The low weight flywheel with the first insert is ~$450 IIRC. You get a little more RWHP too since the engine has a lot less weight to turn.

The biggest thing is I keep hearing time after time, with the Boxster and other German cars, that the dual-mass flywheel causes this vibration problem so I don't want to have to do this several times with the same results. :rolleyes:

If it's in all of the gears I don't think it would be normally the synchros.