Clutch Shudder
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Instructor
Joined: Mar 2007
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Clutch Shudder
Hey All,
90 C2. Im finding that there is a point when releasing my clutch, where if I give a certain amount of gas, I get a slight shudder through the car...
if I give a bit more gas, no shudder...
Anyone else experience this? Anyone know what it is? What causes it? Is my clutch going? Tranny?
Cheers,
Jack
90 C2. Im finding that there is a point when releasing my clutch, where if I give a certain amount of gas, I get a slight shudder through the car...
if I give a bit more gas, no shudder...
Anyone else experience this? Anyone know what it is? What causes it? Is my clutch going? Tranny?
Cheers,
Jack
Racer
Joined: Jun 2006
Posts: 377
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From: Shipley, West Yorkshire, UK
I get this when just engaging the clutch with low revs driving up a slight incline into my garage or crawling in heavy traffic. My clutch was replaced 1000 miles back and they said the dual mass flywheel was OK. I just wonder if the flywheel was borderline and should have been replaced? Would love to know what could cause this. Once driving normally from 1 to 100 mph the transmission is perfectly smooth!
IHI KING!
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Joined: Aug 2001
Posts: 13,400
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From: Nashua, New Hampshire, USA
Jack,
Shuddering is not normal. Before answering your question, can you give us some more info?
1) What is the overall condition of the car? How long has it been since the clutch was last changed?
2) How long has this been happening? What was changed just before this began?
3) Are your CVs and wheel bearings in good shape? What about the engine mounts?
4) Is there any oil drips from the bottom of the transmission bell housing or engine area?
Shuddering is not normal. Before answering your question, can you give us some more info?
1) What is the overall condition of the car? How long has it been since the clutch was last changed?
2) How long has this been happening? What was changed just before this began?
3) Are your CVs and wheel bearings in good shape? What about the engine mounts?
4) Is there any oil drips from the bottom of the transmission bell housing or engine area?
Thread Starter
Instructor
Joined: Mar 2007
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Hi Rob,
Overall condition of my car is excellent. It passed its PPI with flying colors and the clutch was changed roughly 40K miles ago. The only recent service that made a huge difference, was the replacement of the slave cyl, which fixed my 1st gear engagement issue.
No oil drips from the engine area or tranny bell housing.
I assume that the CV and engine mounts are in good shape, as the car drives great
It seems shudder mostly when cold, and now that the weather is getting cooler in the morning, Im noticing it when cold driving to work. Once heated up, it seems to go away...If I take her for a good boot, it goes away all together...
Thanks for any input Rob,
Jack
Overall condition of my car is excellent. It passed its PPI with flying colors and the clutch was changed roughly 40K miles ago. The only recent service that made a huge difference, was the replacement of the slave cyl, which fixed my 1st gear engagement issue.
No oil drips from the engine area or tranny bell housing.
I assume that the CV and engine mounts are in good shape, as the car drives great
It seems shudder mostly when cold, and now that the weather is getting cooler in the morning, Im noticing it when cold driving to work. Once heated up, it seems to go away...If I take her for a good boot, it goes away all together...
Thanks for any input Rob,
Jack
IHI KING!
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Joined: Aug 2001
Posts: 13,400
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From: Nashua, New Hampshire, USA
Jack,
The typical causes of shudder are
* oil on the clutch disk
* broken or loose engine/tranny mounts
* worn CV joints
Since you don't have any oil drips, I would rule out the first. So I would double check the engine/tranny mounts and your CVs.
The typical causes of shudder are
* oil on the clutch disk
* broken or loose engine/tranny mounts
* worn CV joints
Since you don't have any oil drips, I would rule out the first. So I would double check the engine/tranny mounts and your CVs.
Technical Guru
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Joined: May 2002
Posts: 8,138
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From: USVI
So just before the clutch is completely engaged, you are applying gas and the car feels like its shuddering? Does it feel like the rear-end is hopping?
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Joined: May 2007
Posts: 2,295
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From: Portland, Oregon
I had similar shudder issues, difficult take up, in traffic etc. I replaced the slave, bled the system, all that stuff.. no change...
One day in traffic, I was a bonehead and I slipped my clutch too much, causing it to smoke. After that, my previous shudder problems disappeared completely. I don't necessarily recommend it.. but it might be that you have something on the surface of your clutch material that needs to come off.
One day in traffic, I was a bonehead and I slipped my clutch too much, causing it to smoke. After that, my previous shudder problems disappeared completely. I don't necessarily recommend it.. but it might be that you have something on the surface of your clutch material that needs to come off.
Professor of Pending Projects
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From: Ocala, FL
I had similar shudder issues, difficult take up, in traffic etc. I replaced the slave, bled the system, all that stuff.. no change...
One day in traffic, I was a bonehead and I slipped my clutch too much, causing it to smoke. After that, my previous shudder problems disappeared completely. I don't necessarily recommend it.. but it might be that you have something on the surface of your clutch material that needs to come off.
One day in traffic, I was a bonehead and I slipped my clutch too much, causing it to smoke. After that, my previous shudder problems disappeared completely. I don't necessarily recommend it.. but it might be that you have something on the surface of your clutch material that needs to come off.
Is that the Italian approach to fixing cars?
I am game!!
5th Gear
Joined: Mar 2007
Posts: 5
Likes: 0
From: Singapore
My '89 964 C4 shudders whenever I get on and off the gas. The local Porsche specialist here thinks the cause could either be the driveshaft (= major bucks to replace) or the clutch.
I opted to replace the clutch first and with RS conversion kit. Waiting for other parts to be arrive before sending my P to the workshop.
I opted to replace the clutch first and with RS conversion kit. Waiting for other parts to be arrive before sending my P to the workshop.
Pro
Joined: Jan 2005
Posts: 701
Likes: 6
From: St. Albert, Alberta, Canada
Just got my 89 c4 back on the road after replacing the clutch and it shudders when starting from a standstill. Bled the slave and no difference.
Could it possibly be a misaligned pressure plate? I wasn't comfortable with getting the PP "prongs" to fit properly into the outer rim of the flywheel when installing but all the PP bolts were torqued appropriately.
Could it possibly be a misaligned pressure plate? I wasn't comfortable with getting the PP "prongs" to fit properly into the outer rim of the flywheel when installing but all the PP bolts were torqued appropriately.
Three Wheelin'
Joined: Jul 2007
Posts: 1,307
Likes: 0
From: Helotes, TX
I'm no expert, but I have done a feww 911 clutches.
A general answer IMHO is that juddering usually occurs when the clutch fiber disk and flywheel/pressure plate metal surfaces are not properly mated. This can occur 1) as the clutch begins to approach wear limits and there is not enough pressure on the disk, 2) when new disks are mated up with grooved used flywheels/pressure plates, or vice versa, or 3) when there is contamination of the surfaces.
I just paid the price for an experiment in relining the clutch disk. I ordered the 90-94 clutch kit recently to install with other engine repairs. (Still have it if anyone's interested.) Didn't realize the 89 is a one year only part. When I regained consciousness after seeing the $1,000 + price for the 89 kit, I decided to have the local brake and clutch shop reline the disk. I also had the flywheel turned to true the surface. This combination resulted in juddering from the beginning and clutch failure within two months.
I just replaced with new flywheel and nearly new clutch / pp from Oklahoma Foreign. Disk is nesarly new measurement and well beyond replacement limits per manual, but I hope that the issue with mating used clutch to new flywheel I mentioned earlier doesn't result in yet a third job. (As you can tell, I have more time than $.)
There are a number of openings on the bell housing on my 89 where contaminaterd rain water etc. can get in and I'll bet that kind of contamination or the clutch beginning to approach wear limits is your problem.
Good luck.
A general answer IMHO is that juddering usually occurs when the clutch fiber disk and flywheel/pressure plate metal surfaces are not properly mated. This can occur 1) as the clutch begins to approach wear limits and there is not enough pressure on the disk, 2) when new disks are mated up with grooved used flywheels/pressure plates, or vice versa, or 3) when there is contamination of the surfaces.
I just paid the price for an experiment in relining the clutch disk. I ordered the 90-94 clutch kit recently to install with other engine repairs. (Still have it if anyone's interested.) Didn't realize the 89 is a one year only part. When I regained consciousness after seeing the $1,000 + price for the 89 kit, I decided to have the local brake and clutch shop reline the disk. I also had the flywheel turned to true the surface. This combination resulted in juddering from the beginning and clutch failure within two months.
I just replaced with new flywheel and nearly new clutch / pp from Oklahoma Foreign. Disk is nesarly new measurement and well beyond replacement limits per manual, but I hope that the issue with mating used clutch to new flywheel I mentioned earlier doesn't result in yet a third job. (As you can tell, I have more time than $.)
There are a number of openings on the bell housing on my 89 where contaminaterd rain water etc. can get in and I'll bet that kind of contamination or the clutch beginning to approach wear limits is your problem.
Good luck.