New Clutch Chatters/shruds?
 

Just got my stock clutch replaced today along with new seals.
On the way back home, I noticed the car/gearbox would shrudders/chatter/vibrate (can't find the exact word to explain it) from stop position.

So let say I'm stopping at the red light. When the light turns green, I engage the clutch, put 1st gear , gives it some gas and slowly disengage the clutch. Now that's when it happens. It feels liks I'm not giving enough gas but when I do it still chatters even when i press the clutch full down again.

And when I rev it too high (about 1800rpm) i feel like the tyre is slipping. I'm not sure of this because it has been raining today and I've been driving with my windows shut.

Is this normal? Maybe because it's new and the plate isn't gripping well? Or there's something wrong with me/the clutch?

Apart from that, the clutch is supoib,especially after I got the gear handle/knob fixed. It feels really firm and when i munch the gas then shifting from 2nd to 3rd, it doesnt slip as it used to anymore.

Your advice would be greatly appreciated.


Yans

Who did the work? If the flywheel required resurfacing and that wasn't done it can cause these problems.

A local rotary workshop did it for me. And yes, the flywheel was machined. I told him about the clutch fork and he said it didnt need to be replaced.

Do you think it's probably the new clutch needs to adapt with the old gearbox n flywheel?

Sorry if I sound stupid. I'm a noob afterall ;)

Could be. The clutch disc takes a little while to break in too. If it persists after more than a week or so of driving I'd get concerned.

1. Did you replace the pressure plate, too, or just the disk? Pressure plates (as well as flywheels) can develop hard/high spots that can cause shuddering.

2. Sometimes, the presence of grease or other contaminants on the clutch surfaces can cause shuddering.

3. As a side note, on my '79 1st-gen RX7, I had clutch shuddering/chattering that was not cured by any normal stuff (new clutch components, new engine mounts, etc.), but WAS cured by the addition of an engine damper that I made out of a VW steering damper.

Yep, I did change the pressure plate too. Could it be that it's because my clutch is a ceramic type?

Just as an extra info, the brand is Xtreme Ceramic Cushion Buttoned Clutch. It's an Australian brand (pretty much like ACT in the US).

I have the same problem as yours and I just changed the clutch and pressure plate too with an Exedy Ceramic Cushion Buttoned Clutch and a midum pressure plate. I told my Specialist on it and he said it is normal for these kind of clutches. I also checked at Exedy's website and found all info I could on the clutch. In fact it states that these results are expected from these kind of clutches.

This is the quote form the website.:
As with any cerametallic clutch system, some compromise of startup drivability should be expected as compared to a stock clutch (i.e. chatter on light throttle, low rpm startup). This characteristic is considered generally acceptable in modified performance cars.

This is the website: http://www.coximport.com/exedy/cerametallic.html

I also believe that the problem will reduce by time but I only have the chance to drive my 7 for 2 day a week so I cannot tell how much it will take.

..did you get a light weight flywheel or disc? Is your disc made from some special compound? ...if so then this could be your problem...

That's brilliant! I've asked around and yes....we're not alone. It seems to happen to those ppl with ceramic clutch and the quotation you gave me seem to clear everything up. I found a way to reduce the chatter in low rpms that I accidently findout on the way from work justnow. I'll go and give it a try again later tonight if it's not raining.


Yeh, I'm in your position too. I dont drive my FD much. Maybe during the weekend or when I think no cops are out doing traffic blitz.

On another note, I find out that the chatter in reverse is crazy :| It chattered as if the gear box is going to fall down. I'm not sure about this. Maybe because I'm too sleepy to do a proper parking manouver (been working from 5 PM- 7 AM the next day).


Once again, thanks for the brilliant input.

Yans

Nop. I still use my stock flywheel as I was quoted 700 for one...That's way too much to spend while I got some other important things to do on my FD list.

I'm leaning towards the idea that Ceramic button clutch does this kind of chatter.

if someone is charging u 700$ for a flywheel, i think u have other problems that should be addressed....

$700 Australian.

My apology, yep..it's A$700. So probably about $500.00 USD.

I have the same problem with my stock clutch. its really noticeable in reverse since I have to back up my driveway. it only started hapening after I replaced the motor in the car. not quite sure what my problem could be. I thought at first it was the diff mounts or the rear bushings. Replacing those did not help. Then I read this thread and the symptoms are very similar.

Help anyone?

Would this happen if a new clutch was mated with a used "not-resurfaced" flywheel. This is what I am dealing with now, using an new Exedy Racing Stage 2 Thin Pad Cerametallic Clutch Kit part 10900 and my reused lightweight flywheel. Flywheel was allegedly resurfaced by Racing Beat, but it came back looking used with surface imperfections. I didn't see it when it was sent out to RB, only when it came back.

Does anyone think that bedding in the clutch to flywheel (similar to new brake pads) would work to fix shudder?

The one time I replaced a clutch without resurfacing and properly cleaning the flywheel surface it shuddered. 40k later it still shuddered, there was no bedding in at all.

David

That sucks. I can't deal with this living in NYC constantly clutching out from a stop.

It sounds like grinding marbles in my diff. (note: I have RP race diff bushings)

Drain the diff oil, filter out the marbles, and put the oil back in. Problem solved. :)

Your mention of bushings does have a point: there is a chance that your shudder issue is partly related to the stiffness of the drivetrain and lack of damping. Rigid bushings will pass on the vibration energy due to the lack of damping.

David