A little background:
When I bought my 09 C2 997.2 it had 80k miles and since then I've put 7k on it. My clutch was starting to slip in 2nd and 3rd gear and the pedal was also heavy, so I figured it was time. I DIY'd the work and now the clutch pedal is much lighter and I'm getting better bite and engagement.

200 miles ago I replaced the following parts:

1. Sachs OE clutch kit (pressure plate, clutch disk, release bearing)
2. Flywheel 9G1-114-012-02
3. Release fork 997-116-712-0
4. Function First transmission mounts - orange

Issue:
When I press my clutch pedal I can feel vibrations that increase with engine RPM. The vibration is unnoticeable from 0-2k RPM and increases in severity from 3-7k. The vibration was not present before replacing the clutch. Pressing the clutch at idle feels perfectly smooth and produced no noise.

Shifting at 3-7k RPM (both relaxed or quick), the clutch pedal initially has a lot of vibration and then it tapers off as the RPMs drop. As I engage the clutch again to shift into the next gear, the vibration is not very noticeable. Full engagement produces the most vibration during normal driving. However, If I sit in neutral and hold my RPMs at 3k+ RPM and slowly engage the clutch pedal I can feel constant vibration that gets worse the further I depress the pedal. I can almost distinctly feel when the slave first moves the fork, when the fork moves the release bearing, and when the bearing presses into the pressure plate. The vibration will stop if I reduce RPM while the clutch is engaged.

I initially thought the the new transmission mounts might be to blame. They introduced a lot of gear noise and additional NHV. I posted in the Function First thread (https://rennlist.com/forums/997-foru...l#post18070920) and others mentioned that the transmission mounts shouldn't introduce clutch pedal vibration since they didn't feel a difference when adding the mounts. I still might take them off just to rule them out.

What next?
I've been doing some searching and it appears there are a few parts that I didn't replace that I should have, and maybe these are causing my issue? I plan to pull the transmission again and also replace the following parts:

1. Guide tube 9P1-141-181 (mine was slightly worn, but didn't look that bad)
2. Fork clip and rubber washer (I reused the originals)
3. Pivot pin (again, reused original)

Additionally, I read that the fork I purchased is an updated version from the original, and may require a different/updated pivot pin than what was original. So, I'm not sure which pivot pin to buy, and If I have the wrong fork/pin combo, could that cause the vibration? I unfortunately don't have the parts I pulled off my car as I already disposed of them, so I cannot verify if the fork/other parts were different in any way. Next time I'll hold onto original parts until I know everything is gravy.

From what I understand, the vibration I'm feeling would normally be caused by a bad release bearing. The new one felt very smooth, so I'll inspect that when I get everything taken apart. Could my issue be coming from the pressure plate/flywheel being out of balance?

Am I missing anything? Any advice on the parts to buy, things to test, possible cause of the vibration would be very helpful.

 

Was it a new Porsche flywheel and Porsche factory clutch kit?

 

Hello!

I did exactly the same procedure as you did last summer when I replaced my clutch and flywheel and didn’t replace everything around the clutch and flywheel.

in my case the clutch shattered, vibrated when it was released and it ruined the nice feeling of a new clutch.

So the only thing to do was to remove gearbox and replace everything else inside.

My guide tube also had small scoring and believe my problem was the guide tube since the release bearing slides over it and a new release bearing doesn’t like being forced into the old grooves as it seems?!

After the second assembly everything feels and work perfect.

 

Sounds to me like it's out of balance (may not have come balanced right) or wasn't perfectly aligned on installation.

 

I did not buy the Porsche branded flywheel and clutch kit, but they are the OE parts from my understanding.

Very interesting! Your commented about the clutch shattering is scaring me so I'm going to optimistically assume that you meant chattered, right? My guide tube did have some small grooves in it that matched up with the grooves from the release bearing. Both the original and new bearing had these grooves, so I didn't think much of it at the time. I'm hopeful a new guide tube will help. Which pivot pin did you end up buying?


What else could I look for in terms of symptoms if the flywheel or pressure plate are not balanced? I originally thought about an alignment issue, but honestly everything fits so tightly together that I don't know how it they could be installed misaligned and still function at all. I'm going to take it all down again when I replaced the additional parts just to be sure, though.

 

I do a lot of clutch jobs. Probably 4 or 5 a year for Porsches and Ferraris. I always, always, always pay for factory original parts. And I refuse to change only the clutch plate. The job will always be: clutch plate(s), pressure plate, throw out bearing, pilot bearing, sometimes a slave cylinder, and sometimes a flywheel. Those parts will always be factory original or I don't do it. What happens to you is exactly why I don't touch non Factory parts. The factory, especially Porsche, will demand much stricter quality control measures that don't get put in place for run of the mill after market sales.

My motto is "when it is deep in the belly of the beast, buy factory, period"

 

Sachs and *** were stamped all over the parts I pulled out and I replaced them with the same, so I'll be pretty bummed if this comes down to a QC issue.

 

Sorry for my poor English but it’s not my primary language as I live in Sweden.

I bought Sachs clutch kit (same as original), and all other parts from The Porsche Dealer.

My grooves where quit severe on one side, the throwout bearing seems to lean towards one side of the guide tube.

No other wear was found on the other parts.

I hope you find your solution.

 

do you do Dodson clutch plates

 

Update:
I ordered new parts for the guide tube, pivot pin, retainer clip and washer, but haven't been able to install them yet. I am planning to pull the transmission inserts this weekend to go back to the stock baseline NHV. I did get a few minutes recently to do some more data gathering and wanted to share what I found.

While cleaning the transmission during the initial clutch job, I noticed an open hole on the passenger side, opposite to the slave. Remembering this now, I decided to use a bore camera and take a look inside. Take a look at these two videos I took from inside the transmission bell housing, is my flywheel or pressure plate misaligned/out of balance? Could this be the source of my pedal vibration?

https://photos.app.goo.gl/nFgctCDwJSUcCTCJA

• Car is started at 7 seconds and you can see the clutch disk free floating
  • Initially I thought letting go of the clutch may have changed the perceived wobble in the pressure plate, but I went back and recorded more footage while leaving the clutch pressed and the wobble is still there.
• What looks like visible wobble on the pressure plate can be seen during idle from 7-19 seconds. Is it actually wobbling? I don't know. Camera illusion? Also, I don't know, but something looks off to me.
• At 20 seconds I increase RPM to about 2k and the wobble isn't captured by the video camera anymore (I believe this is more a frame rate situation rather than actual wobble reduction since the vibration increases in the pedal with RPM)
• At 28 seconds I return to idle RPM and again it looks like there is wobble present

https://photos.app.goo.gl/hrjWQ7RPuJd3cr4c8

• I repositioned the camera to see if I could get a shot of the flywheel itself. This was not an easy feat but was able to get a clear shot.
• Car starts at 2 seconds and idles until the end
• Wobble looks similar to the first video
• I am unable to tell if the flywheel itself is also wobbling

I repositioned the camera multiple times to look at the throw out bearing etc, but everything looked to be stable/normal. Based on the videos, I'd be curious what you guys think.

 

I think that is your pressure plate wobbling. I have seen plenty of pressure plate - clutch plates spinning while they are running and they have zero wobble. They are supposed to be balanced such that they have zero wobble. Any wobble on the PP makes the release bearing move in-out which pushes the hydraulic pressure in the line to the master cylinder and finally to the clutch pedal.

 

If this is the case, would a new clutch kit be the only solution?

 

A new clutch kit from Porsche would be your only solution.

 

Ugh, redoing your work is painful! So sorry. Been there before brotha. If you were closer to me I'd come help you out. Can I ask where you sourced your Sachs kit? I have personally done three 911 clutches and probably another 4-5 VW/Audi's over the years. All were Sachs kits and had zero issues with any of them. I'm certain Sachs makes the Clutch kits for Porsche Factory/Luk for the Flywheels. I can share I did have some wobbling issues on a 993-more at idle though. Ended up the DMF was worn-it had 100K on it. When I took it out it was out of spec (springs had excess side to side play). Replaced that as well and it felt brand new. Has the DMF been done. 80K is getting up there from original. Was there any wobbling before you changed the clutch? Although your description does sound more PP related
Think of how fast you'll be the second round-and how much you are getting to know your car!

 

Thanks jib - I appreciate the consideration

I got my clutch kit from rockauto. The kit was a little cheaper than other shops and I've had good luck with them in the past. I just did a warranty return and they shipped a new clutch kit to me today, so I'm bummed the initial unit was bad, but glad they are making it right.

The DMF was also replaced with the initial work. I used the Luk OE part and based on all my findings so far I don't suspect it's part of the issue, but will investigate once I get it all taken out again.