Horrible bucking and shutter after clutch install
 

I have a 2014 FRS that I had a shop install a Comp Stage 3 clutch and lightweight flywheel about a month ago. First week was great and no problems. After the first week or so I started getting a very loud rattle when in neutral and clutch out. This happens intermittently and only when the car is warmed up to operating temps. It is so loud that I have to keep my foot on the clutch when in a fast food drive thru or I cant even hear the person in the window. Also around this time it started bucking and pulsating when starting from a stop. this "shutter" stops when the clutch pedal is fully let off. Its progressively getting worse as time goes by. This past weekend, the GF stabbed herself in the eye with her eye liner wand when I left a stop sign. If I dump the clutch it is smooth, but anything under 2,500 rpm is a horrible bucking and vibration nightmare. It does the same while backing up slowly too. When the car is cold, none of this happens, but warmed up is when the gremlins come out to play. What could be causing this issue? The shop is looking at it again Tuesday morning so I am trying to get your opinions and see what they say.

What kind of power are you pushing?

Bad throwout bearing? I misread it at first and thought it was the pilot bearing.

I'm boosted, around 300hp. I was boosted on the stock clutch for almost a year with slipping being the only issue in higher rpm

New pilot bearing and throw-out bearing came with the clutch kit. Hoping they wouldn't be defective out of the box

Well unfortunately I don't think you will find out what it is until you open it up. If it changes with clutch pedal pressure makes me think throwout bearing, but it's hard to know without taking off the trans to look at the clutch assembly. Any grinding going into gear or noises while driving?

No noises or grinding at all when driving. Once its fully engaged there is no issue at all. Its only from a full stop. If I am rolling it lets off perfect going up or down in gears. There is a high pitched sound that happens as I am slowly letting the clutch out from a stop. Almost like it's the sound of the clutch starting to make surface contact with the flywheel. It's the same sound as rubbing 2 pieces of paper together. That happens in both reverse and 1st. That could be normal though, but its done it since the install

Yep, an autopsy is in order......:sigh:

My guess is that the clutch disk itself is messed up (coming apart).


humfrz

That is kinda what I was fretting.... There goes another $800 in labor for another replacement to be put in

hmmmmm........a new clutch disk should last more that a week ...... no matter how much you hammer on it.

I reckon something was wrong from the get go. Either a defective part was installed or a part not properly installed. If so, one would think the installer or manufacturer of the defective part, should make it good. But, good luck with that ..... :(

Maybe it's something simple ..... like ...... the pressure plate is not bolted tightly to the flywheel .......:iono:

Keep us posted.


humfrz

Fingers are crossed that it is something simple

if it is making squeling noises, that to me is the throwout bearing. But again, It could be the clutch disk itself. I just find it hard to believe the clutch is the problem being brand new. I am really leaning on the throwout bearing being the culprit to be honest.






If you had a shop do the work, I suggest taking it back to them and telling them what the problem is and see if they will cover it since it sounds like something that wasn't your fault. Because if it's determined to be either a faulty piece or negligence on their part, they should be able to work something out that won't cost you anything. I would have taken it back as soon as I heard the noise though.

The shop that installed it is looking at it tomorrow. Hopefully we can work something out

Could the stock clutch fork cause this if it broke/deformed from the pressure of the new pressure plate? I've heard the stock unit is pretty flimsy and doesn't handle extra pressure too well. Velox has engineered a stronger unit because of it.

Curious, mine rattles occasionally while at a drive thru, shop told me my clutch fork was vibrating. I know it has some kind of aftermarket clutch, I just don't know what brand. It's done it since I've owned it for about a year now. 30k miles later and still going lol. Mine doesn't have any of your other symptoms tho.

I haven't heard of any clutch fork issues, but I will keep that in mind. I have a feeling the shop is going to end up tearing it back apart to see whats going on inside

ok so this thread and the billet clutch fork thread were both updated for me, so possible clutch fork damage? problem solving skills. I has dem.

I guess that is a possibility. The issue only happens from a dead stop. If it was the fork, I would expect this to happen in every gear and not only when its at operating temps. I could be majorly wrong though. Is there a way to test the fork without removing the trans?

I had the bucking issue when starting with an act clutch that was in my car for a short time. It eventually got to the point where it wouldn't go into gear when cold and then got even worse and the clutch wouldn't disengage at all. When we took it apart the throw out bearing was damaged and a group of the pressure plate springs did not fully return.

If the throw out bearing is slipping off the pressure plate it's going to bug the shit out of you with a high pitch squeal. Either adjust your pedal to increase pressure or your bearing is bad or installed wrong.

If a clutch install is that much money I'm in the wrong business. It took me 2 hours all by myself, 1 lift, 2 jack stands and 2 arms. Fun part is getting the damn shaft in the hole....:lol:

Really debating whether or not to change my sig to this.

are you single now?

No, it was her left eye. Fortunately she's all right now.

I would venture to say the clutch disc is to aggressive for your power / driving requirements, the rattle is normal for a lightened flywheel. My question is did they torque the pressure plate down or use a impact and warp your clutch disc.... Also you might try feathering your gas peddle and a quicker release, that should smooth it out some along with 1000 break in miles

Consider this carefully. Do you notice any new whining coming from the transmission in all gears except fifth?

The strange part is that is doesn't do it all the time. I must admit that the 12 year old sense of humor in me had to laugh at the last paragraph alot, lol

No, but for some reason I cant find my bass boat key or title..... j/k

The funny thing about it is that she didn't get hurt, but looked like she got "scope shocked" by a hunting rifle. That eyeliner wand gave her a makeup scope-eye! The reason I got in trouble wasn't because it happened, it is because I laughed.....

I have a 120 mile round trip commute to work and back each day. I am probably in the 3,000 mile range currently after install. I figured it would have "bed" in by now. I may have to drive it more aggressively and see how that goes.

No whining at all. After the initial engagement it is perfect. No whine, no grinding, no hard shifting up or down, its smooth as butter. I love the way it drives when it "behaves" from a dead stop.

So I had a mechanic from the shop that installed the clutch take a ride with me today. Of course at first I could not get the car to buck at all. No matter what rpm or throttle position clutch let off. finally after about 7 stop signs it did it about half as bad as this past weekend. His eyes got wide open and he had a confused look. I was then able to recreate it about 5 times, but of course less severe than it has been. He then said there were 2 things I could do....

1) Contact Competition clutch and try to get them to warranty it out and he would talk to the shop manager about discounted services to have it R&R'd

2) Its an aggressive clutch, drive it aggressively and see how that affects it.

Both of which are fine options, but what if they installed it wrong? I doubt Competition Clutch is going to warranty it without it being taken off and sent to them for inspection first.

ok I just looked up your stg3 disc. and that is your problem the hotter it gets the stickier it is. Its a ceramic disc if I were you I would by a stg 2 disc and slap it in there and it should fix your problem. Or just beat on the ceramic one.

I agree that they wont do a thing without it being removed. I am going to drive it harder and see what happens, then go from there

Thanks! I will look into that. I am going to try and drive it harder this week and see how that goes