Clutches can fail for a variety of reasons...

How do you know when it's time to replace your clutch?
I own a 2004 Boxster 550 SE with 60K miles, with all my service intervals completed.
After watching Pedro's very interesting DOF video, I would like to protect my engine, but
I would like to wait until my clutch needs service. The clutch feels fine with no difference from the last 25 k miles of driving.
I just fell out of my class action warranty period this month, however, I am of the school to not worry about the ims and just drive the car.
My car does sit in the garage for weeks at a time and that does concern me a little based on the new information from the video.

Thanks for any input on the "feel" of my clutch. The service intervals make no mention of a time to replace..

Jack G

I've got 110+ miles on mine. You replace it when it goes out. I had an Acura Integra that went 130k before it needed a clutch.

About all one can do is be aware of the behavior/symptoms of a failing clutch and then take action.

Any squealing/grumbling or abnormal noise when you depress the clutch pedal is always a bad sign. While the clutch may grip ok still the release bearing can be failing or something else mechanical can be going wrong.

There is of course the failure for the clutch to disengage when the pedal is depressed. This can be a hydraulic or mechanical failure.

There is extreme/severe shudder/judder/grabbing when letting the clutch pedal out when moving the car from a stop. This can be due to a disc that has come apart for some reason, a clutch that has been overheated, or simply a worn disc -- in one case the shudder/judder was the disc rivets contacting the flywheel -- or believe it or not from a clutch hydraulic fluid problem. In the case of my Boxster a few months back the fluid problem was just due to an overdue clutch fluid flush/bleed.

Then there is the good old slipping symptom when the clutch slips under high torque situations: Hard acceleration in a higher gear.

Provided the clutch is used properly the clutch can last a long time. Greg posts he's got 110K miles on his car's clutch and I can add that I have 281K miles on my Boxster's original clutch and a 123K miles on the original clutch in the 996. I had this car in back a few months ago for an RMS leak and with the transmission out of the car the tech and I got to examine the clutch hardware. Everything looked just fine and in fact the disc looked almost new. I measured the wear and there as none. The new disc friction material thickness is 1.7mm and that is what I measured.

Oh, I have to stress do not skimp or postpone that clutch (and brake) fluid flush and bleed. A few months back my Boxster was becoming hard to move from a stop without the clutch shuddering and shifts felt like I was not pushing the clutch all the way down when shifting. Of course I concentrated on trying to get the car off the line smoothly and when shifting to be sure I was depressing the clutch all the way and not trying to shift too soon or too late but with little improvement. I learned the car's last brake/clutch fluid flush/bleed was over 2.5 years prior so I booked the car in for this service. Afterwards, while the brakes felt ok -- they were ok to begin with -- the difficulty moving the car from a stop was gone as was the shifting issue. Do that brake/clutch fluid flush/bleed every 2 years. It is important.

Thanks for the great feedback Marc.

Clutches, more than anything else, wear based on style of use.

When the clutch is engaged, it does not rub, and wear is nearly zero. So they can easily go some large number of miles (200k? 300k?) on the hgihway.

if you match revs and shift smoothly, wear is minimal.

An inexperienced driver or drag race sadist can ruin a clutch in one day

Grant

Grant

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