Clutch Vibration - Please Help!!!!

rctools · 05:33 PM

I just replaced the clutch in my 85.5 944, but now am experiencing a lot of vibration on the pedal when letting out or downshifting. Doesn't do it when the pedal is all the way down, or all the way up, just in the first 1/3 of the pedal movement. Can at times make the whole back end shimmy. Any hints on what I could have done wrong, or if there is anything I could have missed. I replaced the clutch with a 3 piece kit (spring centered). Not the rubber hub. Could this be the reason? It showed when ordering that both were replacement parts. Also on the old clutch there was some sort of a round housing attached, that was not similar to the new clutch, but figured this was just old style vs new style. Please help if you can!!

Thanks!

Mark
rctools@attbi.com

ae1969 · 12-29-2001, 08:40 PM

Did you machine the flywheel face? This would allow for a nice flat surface for the new disc to mate to.

The surface of the old flywheel and the new clutch disc can cause this......

T86951 · 12-29-2001, 09:21 PM

Does sound like a warped flywheel and surfacing the flywheel is always nice to do but if it wasn't warped and vibrating before it wouldn't just warp all of a sudden cause you have a new clutch. I have changed mine and not resurfaced the flywheel with no problem as have a millions of others. I would think more like the transaxle bolts/mounts may have been left loose or the torque tube bots loose or axle bolts loose or something like that loose. I just don't undersatnd if it wasn't warped before why it is warped now. Check all your bolts first. Also maybe a tranaxle mount broke on the removal and reinstallation. Other thing would be a warped clutch disc but a new one should be ok. good luck , maybe someone else has had the exact same thing happen and will be about to tell you the problem but I would check all my bolts before I took it back apart.

rctools · 07:51 AM

Was sure hoping it was not the flywheel, lots of hours to get back to. I had heard that it was a good idea to resurface, but not necessary, and the clutch was running perfectly prior to change. If in fact it is the flywheel, is there any damage in going back in and having it resurfaced now, to mate up to the new clutch? I have only had it driving for about 1 week now.
Also, could it be the lineup of the transaxle spline? If they did not get matched up exactly as before, could it cause vibration? Wasn't quite sure if it was all balanced.
Thanks for the help!

Bob's944 · Bob's944's Garage

rc... sounds to me like you just answered your own question

rctools · 12-30-2001, 12:19 PM

If I answered my own question, why am I just as unsure as before??

Is it the transaxle or the flywheel? If the flywheel is not resurfaced, will the clutch eventually wear to the form of the flywheel? Or should I put more time into the Transaxle?

Sorry if this is not as clear for me, this is the first time for me working on this.

Thanks for any help you can provide!

OlGoat · 12-30-2001, 01:23 PM

I resurface every flywheel if I'm attaching a new pressure plate. If I reuse a pressure plate I mark the parts before dissassembly. Used pressure plates will be wear matched to the flywheel(vibration free). In short the area of the pressure plate with the strongest springs will force the cluch plate to make contact same point with the flywheel first,removng more material from the flywheel at this point. While the amount of varance is only in thousands of an inch, if placed in a different orentation (flywheel to pressure plate) you can doubble the mismating effect. (VIBRATION)

T86951 · 12-30-2001, 07:24 PM

I really think a warped flywhell would have been doing the same thing before. Check all your transaxle mounts. Last thing would be to take it all apart again. Now the spring ones are a little rougher on engagement as my 951 is but doesn't cause a bad vibration. Maybe the new disc and pressure plate needs a lillte time to sorta wear in but I have never had that problem. Anyone out there actually had this same problem? Our friend here needs some solid help and I haven't had this problem with either of my cars on clutch changes and I have never resurfaced my flywheel after 2 clutches and 207,000 miles on my NA 944 that I drive every day. See why I don't think its a warped flywheel . 2 clutches and 207,000 miles and mine isn't warped. But I guess its possibe. Maybe someone has run across the same problem and will read this post. good luck!

rctools · 12-30-2001, 09:46 PM

Thanks! I appreciate the help, and the input. I will check the rear end closely, before diving back in.

Let's hope it doesn't come down to that!! Although, I can put money on the fact that I will be able to do it much quicker the second time around!!

slevy951 · 05:42 AM

Hmmm.....May not be the flywheel. I had a serious vibration in the pedal directly after replacing my clutch this past summer. It turned out to be the release bearing. Sachs made a change in the bearing. See this link to a thread on Rob's 944 board.

Clutch Pedal Vibration

Good luck......

Walker944 · 01-20-2002, 04:10 AM

RC,

Did you ever get your vibration problem resolved? If so, what was the culprit? I found this thread searching on "clutch vibrations". I recently had the rubber-centered clutch replaced with a spring-centered one on my wife's early '85 944. Immediately after doing the job, there was a very noticable vibration, but only when downshifting. I thought the mechanic I hired to do the job had screwed it up, so I took the car in to the dealership for evaluation a couple of days ago. The very trusted dealer mechanic asked if I had a spring clutch put in. He then pointed out that the spring clutches on the earlier 944s tend to result to 'new' vibration issues. He said the rubber-centered clutches have a tendency to damping the vibrations, but the spring clutches, while a longer lasting clutch, tend to amplify any existing vibration areas such as worn motor mounts, worn CV joints, etc.

Although your issue is somewhat different in that your symptom is in the pedal, there may be a similar cause... the rubber-centered clutch may have been masking other vibration causing problems not known until the clutch was replaced with a spring-centered one.

By the way, the mechanics parting words were that there isn't much I can do to fix the problem other than replacing the clutch again (which ISN'T going to happen) or replace the other worn parts, which should provide minimum relief from the vibration.

Don't know if this helps, but if had to do it over again, I think I would stick to the rubber centered clutch. Might be useful info for anyone contemplating a clutch job and trying to decide on which style to go with.

--Mike

rctools · 01-20-2002, 07:19 PM

Thanks for the info. I have not yet gone back in to tear it apart. Not really lloking forward to it!! But I will contact the technical advisors at Pelican Parts to see if they can shed more light on your info. If this is the case, it may be worth it to change the clutch out again. I will post a response when I am done. Thanks again!

Mark

ae1969 · 01-20-2002, 07:39 PM

Uhmmm now you have me wondering if I should replace my clutch with the spring centered or the rubber?????

CAn we get a quick poll of who has had any vibration problems with the spring centered................and who has gone with the rubber centered one instead?????

Thanks