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.