Clutch issue

[FastCarFan]

I am having an "issue" with my clutch & I thought I would run it by the Pelican brain-trust for some insightful opinions....

I have an '88 Carrera with 57,000 miles. I bought it in 2001 with only 34,000 miles. I don't know anything about the history of the car prior to 1998, when the PO bought it. I have the repair orders from the PO & there is no mention of a clutch problem.

The car runs great...with one exception. After some time in stop & go type traffic, the clutch starts to "shudder" badly when starting from a stop. When it happens the whole car shudders badly & the shifter moves rapidly back & forth, & I feel like I can hardly get it moving.

Once I get out of the stop & go traffic it works fine after awhile. I don't drive in stop & go traffic very often. In normal driving I have no problems starting in 1st at all, nor shifting through the gears. I never feel the clutch slip.

I first experienced it a few years ago when leaving Mid-Ohio in heavy traffic after a race. I was really worried that I would not be able to make it through the traffic, but once I did, the clutch started working perfectly again.

I asked my Porsche mechanic (a great Porsche-only shop) about it a couple of years ago & he didn't know what it could be. He checked the clutch adjustment & said it was fine.

What do you think it is? I would guess it occurs when the clutch gets hot. Does that mean the clutch is shot? I would hope it would last more than 57,000 miles, although I have no idea if it was abused before I bought it. I know I have never abused it in the 8 years I have owned it. Is it just an adjustment problem? Is there anything I can do to prevent it from happening? Is it hurting the clutch when it occurs? I would guess it can't be good for it.

Thanks in advance for your help & advice.

[RoninLB]

Originally Posted by FastCarFan

I have an '88 Carrera with 57,000 miles. I bought it in 2001 with only 34,000 miles. .

wild guess is that factory rubber centered clutch disk is deteriorating.

[FastCarFan]

Originally Posted by RoninLB

wild guess is that factory rubber centered clutch disk is deteriorating.

Ronin,

Thanks for the response, but I hope you are wrong -- it sounds expensive!

To clarify, the clutch works perfectly 99% of the time. The problem occurs only after I have made multiple (10+?) starts in a short period of time (2-4 minutes?) when in stop & go traffic, which makes me think it is related to the clutch or fluid getting hot. Once I am out of the stop & go traffic & it has a chance to cool down it works well again.

Someone else suggested that it sounds like the clutch is not fully disengaging, which makes sense. That would create the shuddering. Could the fluid be heating up & not allowing the clutch to fully disengage? Could a fluid change or bleeding the line solve the problem? It sounds cheaper than Ronin's suggestion!

Other ideas?

[Tigerrat]

Sounds like the clutch is acting badly after getting heated up by frequent use. Could be the rubber but I understand the later version of the rubber centered disks held up better than the earlier ones. I'd say replacing the clutch at 57k is a bit early but not unheard of. Got any fluid or oil leaks? I might check the motor mounts. Ken

[cdrik915]

I've got the same problem of shuddering with my 86' 915 ; sometimes at the start, all the car seems to enter in vibration ; and that becomes difficult to go.

Like you FastCarFan , the shifter moves rapidly back & forth when it happens.

I think that could be the motor mounts .


What's yours opinions mates ?

[FastCarFan]

Tigerrat -- the car has never leaked anything. Ever.

cdrik915 -- the problem never occurs when I first start it. It only happens after I have made multiple starts in a very short period of time.

I am curious about the motor mounts comments. If the motor mounts are broken/shot, why wouldn't the problem occur all the time? As I said, 99% of the time the clutch works perfectly. In fact, I went out for a drive this evening & had no problems whatsoever.

I just can't see how it can be the motor mounts. Or am I missing something? Please enlighten me.

Thanks.

[Flat6pac]

The pin that holds the fork inplace needs to be updated with brass bearings as the needle bearings become worn into the cross pin.
This causes hard pedal and some shuddering but between the clutch disc and the cross pin, you ll have to bite the bullet
Recommend that you find the pin update that doesnt need to drill the boss out to install
On the 88 I did last month, I also had to change the guide tube to get the TOB to fit
Bruce

[Tigerrat]

I don't think mounts are the cause of the problem but could be a contributing factor. Or all that shuttering might damage the mounts. Anyhow just trying to think of any easy checks, short of dropping and opening the clutch. I'm afraid there is not much but maybe someone will think of others.

[robert walsh]

On pre hydrolic 911's the typical clutch problems are related to #1- the cable itself, being worn or bound inside or the bow not set in the proper direction. #2- the helper spring is worn or has breaks within. #3- the worn bushing issues relating to the pedal cluster. #4- simply out of adjustment. #5- the clutch fork is fractured and about to break. #6-the clutch is going south.