That Darn Flywheel!
06-27-2001, 04:29 PM
#1
Racer
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That Darn Flywheel!
So I’m getting closer each day to owning that ‘90-’92 C2 Coupe. A few more $ and I’ll be there. (YES!)
However, I’m getting a bit nervous about the dual-mass flywheel.
If I buy a car that still has the original dual-mass flywheel, how likely is it that I will have a problem?
Is the failure of the dual-mass flywheel more related to mileage, time, or driver habits?
What are the symptoms I should look/listen/feel for during a test drive?
I have this horrible vision of driving away in a clean, lo-miles coupe only to have the flywheel take a dump six miles outside of Nowhere Junction. Should this happen, what is a typical cost to get the improved (I understand it’s call a “LUK”
flywheel installed? Is the engine dropped to do this, or can you just drop the transmission or what?
However, I’m getting a bit nervous about the dual-mass flywheel.
If I buy a car that still has the original dual-mass flywheel, how likely is it that I will have a problem?
Is the failure of the dual-mass flywheel more related to mileage, time, or driver habits?
What are the symptoms I should look/listen/feel for during a test drive?
I have this horrible vision of driving away in a clean, lo-miles coupe only to have the flywheel take a dump six miles outside of Nowhere Junction. Should this happen, what is a typical cost to get the improved (I understand it’s call a “LUK”
flywheel installed? Is the engine dropped to do this, or can you just drop the transmission or what?
06-27-2001, 05:02 PM
#2
Burning Brakes
Robert, the "Luk" flywheel is the upgraded dual mass flywheel that was installed in the middle of the 92 model year. To determine whether a '92 has the Luk, check the engine number stamped in the engine compartment. The owners manual tells exactly where it is. If the engine number is past a certain number (which I'll look up tonight and post for you), then the car should have the upgraded Luk flywheel.
I'm not sure about the symptoms of a failed flywheel, but I remember someone once saying that you'll hear a clunk when the engine is turned off. If the flywheel has to be replaced, I'm pretty certain the engine has to be dropped. Including a complete clutch job, I believe this would cost at least $2000.
From what I've heard, the Luk flywheel is reliable. Ideally, any 964 you purchase either already has the Luk flywheel or has been upgraded to the Luk flywheel.
Drew
92 C2 coupe
I'm not sure about the symptoms of a failed flywheel, but I remember someone once saying that you'll hear a clunk when the engine is turned off. If the flywheel has to be replaced, I'm pretty certain the engine has to be dropped. Including a complete clutch job, I believe this would cost at least $2000.
From what I've heard, the Luk flywheel is reliable. Ideally, any 964 you purchase either already has the Luk flywheel or has been upgraded to the Luk flywheel.
Drew
92 C2 coupe
06-27-2001, 05:17 PM
#3
Skippy
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Robert,
Marv has a good description on his site about the problems which are likely to occur on a 964. Freudenberg flywheel is one of them. Even cars with very low mileage can get it and sooner or later any Freudenberg will have to be replaced by a LUK (or RS) flywheel.
URL to Marv's site http://www.gemair.com/~debequem/Four.html
Marv has a good description on his site about the problems which are likely to occur on a 964. Freudenberg flywheel is one of them. Even cars with very low mileage can get it and sooner or later any Freudenberg will have to be replaced by a LUK (or RS) flywheel.
URL to Marv's site http://www.gemair.com/~debequem/Four.html
06-27-2001, 05:48 PM
#4
I have a different question along similar lines. Is the flywheel the kind of thing that fails within a certain number of miles? In other words, if someone buys a 964 with, say,100k miles, will the flywheel have already had to have gone bad and been replaced (because they all fail within approximately x miles)?
06-27-2001, 07:12 PM
#5
Robert / John
I had the same questions when I bought my '90 C2.
My mechanic stated that you may be able to tell during a test drive that the Freudenberg dual mass is failing by performing the following: Downshift from one gear to the next lower gear at decent revs and you should feel a shutter or clunking. He recommended shifting down from 2nd into 1st and observing what happens. I have never driven a 964 with a failing Dual Mass, so maybe someone else can confirm my mechanic's test procedure.
He also stated that you'll know when the Dual Mass is failing and you'll have some advanced notice as to the problem. It may not leave you stranded in Nowwhere Junction, but should be fixed very soon after the symptoms show up. Hopefully others that have experienced their DMF failing can help.
I've read and heard that mileage and driver habits all contribute to the failure of the Freudenberg DMF. Some cars that spend their life babied on the freeway may have a DMF that lasts a long time. My mechanic stated that a car that is driven hard will sometimes tend to have the DMF fail sooner.
My mechanic also stated that the C2 models only need a tranny drop to replace the DMF. He needed to drop both the motor and tranny on C4's to get to the clutch and flywheel assemblies due to the added complexity of the AWD.
I believe Kris is correct in the post above. My C2 has 28,000 miles and the original DM flywheel. I'm positive that it will fail at some point, but I've got the $2k in the bank waiting for that repair to come along in the future.
Don't let the DMF problem keep you from buying a nice, early 964. If there is no documentation that the flywheel has been upgraded, bargin the sales price down to allow for this repair, keep the extra cash ready and enjoy the car until it does fail.
Hope this helps,
Jay
90 964
I had the same questions when I bought my '90 C2.
My mechanic stated that you may be able to tell during a test drive that the Freudenberg dual mass is failing by performing the following: Downshift from one gear to the next lower gear at decent revs and you should feel a shutter or clunking. He recommended shifting down from 2nd into 1st and observing what happens. I have never driven a 964 with a failing Dual Mass, so maybe someone else can confirm my mechanic's test procedure.
He also stated that you'll know when the Dual Mass is failing and you'll have some advanced notice as to the problem. It may not leave you stranded in Nowwhere Junction, but should be fixed very soon after the symptoms show up. Hopefully others that have experienced their DMF failing can help.
I've read and heard that mileage and driver habits all contribute to the failure of the Freudenberg DMF. Some cars that spend their life babied on the freeway may have a DMF that lasts a long time. My mechanic stated that a car that is driven hard will sometimes tend to have the DMF fail sooner.
My mechanic also stated that the C2 models only need a tranny drop to replace the DMF. He needed to drop both the motor and tranny on C4's to get to the clutch and flywheel assemblies due to the added complexity of the AWD.
I believe Kris is correct in the post above. My C2 has 28,000 miles and the original DM flywheel. I'm positive that it will fail at some point, but I've got the $2k in the bank waiting for that repair to come along in the future.
Don't let the DMF problem keep you from buying a nice, early 964. If there is no documentation that the flywheel has been upgraded, bargin the sales price down to allow for this repair, keep the extra cash ready and enjoy the car until it does fail.
Hope this helps,
Jay
90 964
06-27-2001, 10:25 PM
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I was getting a 30k service on my car and saw another 94 C4 WB and the engine and trans was out. Come to find out it had the old style flywheel. Hearing this did not make my day!!!
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06-28-2001, 03:46 AM
#8
Skippy
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I can confirm what RDSII says about late models having the Freudenberg DMF. Apparantly, according to my dealer, they just grabbed the DMF that was lying around in the factory. Having a 93 or 92 with the Freudenberg DMF is possible. Although the vast majority should be LUK.
06-28-2001, 04:38 AM
#9
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The average fail time of the original dual mass flywheels installed in the 1990 thru 1991 models and maybe into the 1992 model year as well is between 50 and 80,000 of your miles. 80,000klms and up.
The LUK dual mass flywheel is approved for use on both the C2 and C4.
Now everyone correctly focuses on the flywheel but do not forget the clutch. If you drive hard you are going to use up clutches as well. They simply wear out. If you have a high time flywheel and it needs replacing I would recommend you do the clutch as well. For 1989 C4 owners, all you have to worry about is the clutch. Hard driving and you should get 50,000 miles or 80,000 klms out of the clutch.
Mine failed at 88,000klms and was replaced. You will know the symptoms of a failed clutch. You do not go anywhere,
Ciao,
Adrian
911C4
PS: That burning smell you get inside sometimes after putting the foot down and dumping the clutch. A few less miles on the clutch.
The LUK dual mass flywheel is approved for use on both the C2 and C4.
Now everyone correctly focuses on the flywheel but do not forget the clutch. If you drive hard you are going to use up clutches as well. They simply wear out. If you have a high time flywheel and it needs replacing I would recommend you do the clutch as well. For 1989 C4 owners, all you have to worry about is the clutch. Hard driving and you should get 50,000 miles or 80,000 klms out of the clutch.
Mine failed at 88,000klms and was replaced. You will know the symptoms of a failed clutch. You do not go anywhere,
Ciao,
Adrian
911C4
PS: That burning smell you get inside sometimes after putting the foot down and dumping the clutch. A few less miles on the clutch.
06-28-2001, 10:45 AM
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The flywheel in my car gave out at just over 30k miles. Nothing catastrophic. The only symptom was drive-line vibration while lugging the engine. For example, being in too high a gear while climbing a steep grade.
The dealer didn't give me the impression that I had to have the DMF replaced NOW, and I drove the car a few thousand miles before I got around to having it replaced.
On the other hand ... someone posted recently that their DMF failed catastrophically--exploded is the word I think he used.
The LUK flywheel in my car now has 58k miles, no problems. Also, the LUK is what's used in the 993, and you never hear of 993's with failed DMF's. So, the LUK seems to be quite durable indeed.
[ 06-28-2001: Message edited by: Randall Granaas ]
[ 06-28-2001: Message edited by: Randall Granaas ]
The dealer didn't give me the impression that I had to have the DMF replaced NOW, and I drove the car a few thousand miles before I got around to having it replaced.
On the other hand ... someone posted recently that their DMF failed catastrophically--exploded is the word I think he used.
The LUK flywheel in my car now has 58k miles, no problems. Also, the LUK is what's used in the 993, and you never hear of 993's with failed DMF's. So, the LUK seems to be quite durable indeed.
[ 06-28-2001: Message edited by: Randall Granaas ]
[ 06-28-2001: Message edited by: Randall Granaas ]
07-01-2001, 10:40 PM
#11
Racer
Hello folks,
I have a '91 C2, since new, and around 25000 miles, the clutch pedal started creeking when applied,at 29000, the fly wheel failed. I heard cluncks when the pedal was pushed about 2 weeks before the failure( i knew it was coming).It was grinding after that. I replaced it w/ a piece from Andial,a carrera cup flywheel w/ 7 extra pounds added to it,w/spring center.The guys at Andial explained that the 7 pounds added will take care of the idle issues on street cars. It works fabulous! it waas more money but it was worth it. my car picks up a lot quicker now and i dont have to worry about it breaking either.
call em and see, Geo
I have a '91 C2, since new, and around 25000 miles, the clutch pedal started creeking when applied,at 29000, the fly wheel failed. I heard cluncks when the pedal was pushed about 2 weeks before the failure( i knew it was coming).It was grinding after that. I replaced it w/ a piece from Andial,a carrera cup flywheel w/ 7 extra pounds added to it,w/spring center.The guys at Andial explained that the 7 pounds added will take care of the idle issues on street cars. It works fabulous! it waas more money but it was worth it. my car picks up a lot quicker now and i dont have to worry about it breaking either.
call em and see, Geo
07-06-2001, 09:16 AM
#13
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No the tips have a slightly different system installed,
Ciao,
Adrian
911C4
PS: MInd you tips have their own problems. You try finding someone who really knows how they work.
Ciao,
Adrian
911C4
PS: MInd you tips have their own problems. You try finding someone who really knows how they work.
07-06-2001, 01:05 PM
#14
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Oh well, fingers crossed I guess. I have a tiptronic because it suits my wife much better. Better than no Porsche at all!
Actually I quite like it, even if it's not the purist option. The only real frustration is when it doesn't want to kick down if you've been maintaining a steady speed on a motorway for example. It's easy enough to override when you're aware of the problem, but still a bit irritating. I should prtoably try resetting it which I believe you can do by disconnecting the battery and holding the accelerator down for 15 seconds?
Daniel
Actually I quite like it, even if it's not the purist option. The only real frustration is when it doesn't want to kick down if you've been maintaining a steady speed on a motorway for example. It's easy enough to override when you're aware of the problem, but still a bit irritating. I should prtoably try resetting it which I believe you can do by disconnecting the battery and holding the accelerator down for 15 seconds?
Daniel
07-08-2001, 05:56 AM
#15
Prior to getting a 964 I looked into the dual mass flywheel problem with a fair amount of detail. FWIW, here's what I've found out:
1. Failures are erratic. Some people still have the original Freudenburgs installed with well over 100K miles on the car, but this is an exception, not the rule.
2. Most of the early Freudenbergs tended to fail somewhere between as low as 15K miles up to about 50K miles...with somewhere in the 30K range seeming to be very common.
3. The later Freudenbergs seem to last longer (those installed in late '90s and beyond) because Porsche forced them to do a better QA job on them...it probably doesn't mean they're exempt from failure...I don't know.
4. The LUK appears to be much better, but it can still fail (what doesn't?).
5. One sure way to kill a Freudenberg it is to race with it.
If you have a Freudenberg and you're worried about this, I would suggest you learn the art of "rev matching". This is just a theory of mine, but I think that by rev matching you can elimate a lot of strain on not only the flywheel, but the clutch as well...hopefully this will work for me.
Although a replacement of a Freudenberg SOUNDS expensive, look at some of the prices of other high performance cars. A C-5 Corvette job will likely approach $2000. A clutch job on my old Stealth ran $1500..and the entire driveline is unreliable to boot. High performance cars COST MONEY to run.
The symptoms of a failing DMF are usually a rattling sound at idle coming from the engine compartment, high pedal effort, or klunks and other types of "odd" noises. Rattling seems to be the most common, but make sure it's coming from the engine compartment before hyper-ventilating. I recently ran across a rotted piece of rubber (damper) that was causing a rattling noise and it turned out to be trivial.
If you're buying an older 964, check the owners records as the DMF may very well already be replaced. If it's a mid-92 or later model, odds are it already has the LUK installed on it.
Hope this helped,
Bill Wagner
1. Failures are erratic. Some people still have the original Freudenburgs installed with well over 100K miles on the car, but this is an exception, not the rule.
2. Most of the early Freudenbergs tended to fail somewhere between as low as 15K miles up to about 50K miles...with somewhere in the 30K range seeming to be very common.
3. The later Freudenbergs seem to last longer (those installed in late '90s and beyond) because Porsche forced them to do a better QA job on them...it probably doesn't mean they're exempt from failure...I don't know.
4. The LUK appears to be much better, but it can still fail (what doesn't?).
5. One sure way to kill a Freudenberg it is to race with it.
If you have a Freudenberg and you're worried about this, I would suggest you learn the art of "rev matching". This is just a theory of mine, but I think that by rev matching you can elimate a lot of strain on not only the flywheel, but the clutch as well...hopefully this will work for me.
Although a replacement of a Freudenberg SOUNDS expensive, look at some of the prices of other high performance cars. A C-5 Corvette job will likely approach $2000. A clutch job on my old Stealth ran $1500..and the entire driveline is unreliable to boot. High performance cars COST MONEY to run.
The symptoms of a failing DMF are usually a rattling sound at idle coming from the engine compartment, high pedal effort, or klunks and other types of "odd" noises. Rattling seems to be the most common, but make sure it's coming from the engine compartment before hyper-ventilating. I recently ran across a rotted piece of rubber (damper) that was causing a rattling noise and it turned out to be trivial.
If you're buying an older 964, check the owners records as the DMF may very well already be replaced. If it's a mid-92 or later model, odds are it already has the LUK installed on it.
Hope this helped,
Bill Wagner
