ts80

I just got my new ACT clutch kit and flywheel installed today. The throw-out bearing and release bearing was also replaced. It feels pretty good, no issues getting used to it. Haven't stalled it yet.

Anyway, I am getting a "shudder" when starting from a dead stop. It feels like the clutch is engaging then slipping rapidly. Feels like it slips then grabs about 4-6 times very quickly before totally engaging.

Since I'm breaking it in I haven't pushed it yet. I've been babying it but it has me a little worried.

The shop was recommended by several s2ki members in the mid-atlantic region and has done numerous S2000 clutches. So I don't think it was a bad installation, but then again, this is my first aftermarket clutch in the S2000.

Is this just normal during break-in? Or was it a bad install?

Thanks in advance.

InterHat

I unfortunately had this happen during one of my supra's clutch installs and it never got better, it just got worse You were able to smooth it out if you slipped it at like 2.5-3k but after it heated up it was just nasty. The whole car shook when taking off.

We never figured out what it was, but there was a ton of scoring on the clutch and flywheel after we got it out and had it replaced again (at our cost). It may have just been bad parts, but I suspected some grease or something got on the clutch disk or flywheel during the initial install.

I don't mean to be the bearer of bad news, this was just my experience. NO ONE had heard of anything like this ever happening and all of the mechanics were completely stumped by it. I was constantly blamed for "destroying" the clutch. I'm extremely easy on my cars' drivetrains and I almost never launch them (3-4 times max with my supra on all seasons, NEVER with my mazda 6, and never with my S). I broke it in easy, and I don't ride the clutch.

ahrmike

It took a while for my clutch on the camaro to wear in. It got a lot better, it used to chatter until it was broken in. This was the 2nd time around though, when I did the clutch change by myself. The first time, when I took it to a shop, they got grease on the clutch/flywheel and like interhat said, it chattered like crazy. got progressively worse until i said fck em, I'll do it myself.

clag

Sadly, my experience in my Accord as well. 350,000+ miles on the original clutch and it has had shudder for about, ohhh, the last 275,000. Some mornings worse than others and it settles down after driving a bit but comes back pretty regularly. I just keep telling myself the clutch will need replacement any day now so just wait. Yeah, I have been telling myself that for 10 years now.

ts80

Ouch, doesn't sound like good news.

Oh well. It's not violent shaking and it doesn't really bother me. It only happens when I ride the clutch in 1st from a stop, if I'm extra careful (sub 1.5k starts) it feels normal and if I engage quicker (not a launch mind you) it feels fine.

I guess the only thing I can do is give it until the 500 mile break-in, and as long as it doesn't get worse it's not a huge deal to me.

VaderS2k

What kind of disc is it? Puck or Full disc?

I installed a 6-puck in my hatch and it chatters a lot. Might just be the stage of clutch you put in.

ts80

ACT calls it their "Heavy Duty Pressure Plate" and "Street Disc" so it's a full disc. I also had the Prolite flywheel installed.

As a quick update, it only seems to happen when I'm engaging the clutch in 1st while giving it a decent amount of throttle. If I do it with very little throttle it's super smooth.

Best way to describe it would be if the clutch can't simply slip smoothly, it's either engaged or off, and if I consciously try to slip while giving it more throttle (feather the clutch on a more spirited take-off...but nothing that'd be considered a hard launch) it slips then grabs then slips then grabs.

The feeling is similar to when taking off over dead leaves or in the wet. Except it's the clutch slipping rather than the tire.

I tried a little experiment today, I did a very low RPM clutch-dump (about 2 to 2.5k) and there was no shudder at all, but if I tried to feather the clutch from 2.5k it'd shudder.

All other gears are perfect with no shudder at all.

Anyone have any idea about this?

To be honest, I'm not too worried about it. It's not really that bad but I'm just being cautious since it's a new clutch and I don't really know what to expect out of it.

Thanks.

dagle

i would bet its your pressure plate, and how light is your flywheel?

it appears your pressure plate isn't as street friendly as you'd like it to be, and your flywheel explains the slipping feeling.. the idea of a lighter flywheel is to accelerate and decelerate faster because there is less rotational mass.

if you've driven a true performance-oriented clutch, something like a 6puck, with 7lb flywheel, and a stiff pressure plate you'd know the friction point is very touchy and there's little room for error. (you almost always preload a little bit)

but i also have good news for you, my old ACT setup on the prelude lasted 15k with a lot of abuse (previous owner installed it and went to drag). so on a spirited daily driver, it should last a good while.

ts80

Thanks for the input everyone.

An update:
I have put about 140 miles on the new clutch setup.
It is starting to smooth out. When I first got it it'd slip-grab about 5 or 6 times before finally grabbing (shudder/chatter). Now it does it exactly twice. It literally feels like I just drove over a pile of wet leaves, but not as violent...maybe just one wet leaf.

I'd like it to be smoother, but it's at an acceptable level now.

Engagement is right where it should be. It engages quick, but nothing too different from stock. Pedal pressure has slightly increased during break-in, but barely.

The noise level on decel is louder than with the stock setup. The clutch buzz is still there. It's louder, but less annoying. The sound is slightly lower in pitch and more bearable. It almost sounds like exhaust resonance now...I'd rather it was gone, but it's better than stock.

There are new noises that weren't there with the stock clutch while cruising at a constant speed, but all are pretty quiet and you really have to listen. The noises have gotten quieter as break-in continues. During acceleration it is definitely louder but nothing seems out of place.

The flywheel helps with downshifting a lot. Revmatching took a couple minutes to get used to the new responsiveness. RPMs climb much easier now, and they drop just a shade quicker than before. I haven't pushed it yet (still in break-in period) so I can't say if it accelerates any quicker or is more responsive.

All in all, the clutch/flywheel combo is pretty good. Very street friendly. It took all of 5 minutes to adjust to the new setup. Haven't stalled it once in 140 city miles.

The tranny fluid was also replaced. It's a little smoother. Nothing to write home about. But after reading other posts, I may be a little lucky. Never grinded, just a little notchy when cold.

The stock clutch lasted over 100k and wasn't slipping at all yet (even if I chirp 2nd). If this one is supposed to be beefier and longer-lasting then this may be the last clutch I'll have on this car.

In summary: the shudder/chatter is annoying but has been getting better. I only hope it continues to smooth out as it breaks in. If it doesn't, no biggie, I can live with it.

The flywheel was well worth the money just for the rev-matching.

Noises are louder. Doesn't bother me.

I can't give my seal of approval on the kit or the shop until break-in is over and I give it some more aggressive use. But so far it's a good replacement for the stock clutch. A little more responsive but still extremely good for daily street use.

I'll probably update again in a few days.