badformulaLS1

iTrader: (1)

My clutch pedal vibrates when pushed in about 3/4-1". When pushed past that point it stops. Just does it right in that spot. I've had the car for a couple months and it's only recently started doing it the last couple days. Anyone else's pedal do the same thing? What might be causing it and is it an issue? Everything else is fine, and car runs great.

Jonathan@Tick

iTrader: (5)

Every time I've experienced a pedal that vibrates or pulses at the top of its travel the issue is loose pressure plate bolts or a damaged pressure plate itself. The reason you would feel the vibration through the pedal is the fact that the 'fingers' on the pressure plate aren't level....as the throw out bearing contacts it at first it will vibrate until the pedal is pushed to the point that it forces all the finger to become level.

Anytime you would have a bolt or two come loose those fingers will not all be exactly the same level and could cause the vibration.

With either, a clutch disengagement issue would eventually occur but if it has just started disengagement issues may not show up yet. It would probably be best to pull the transmission and take a look at things before something bad happens to your bellhousing, floor board, or feet!

badformulaLS1

iTrader: (1)

Wow... Not what I wanted to hear but thanks so much for the info. Just got done dumping money into the car fixing other things. Pulling the trans would be costly. How long would you guess I have before it starts to become a more major issue? Can the pressure plate and pressure plate bolts be checked/tightened without dropping the trans?

garys 68

iTrader: (1)

I agree with Jonathan. Since the car is new to you, are you sure it wasn't there before? Pretty common symptom of a bent finger on the pressure plate caused by damage installing.
Either way, trans has to come out.

badformulaLS1

iTrader: (1)

Master cylinder was replaced about 800 miles ago with an OEM one (tech replaced it before giving me the chance to tell him to get a Tick master...). I don't remember if it was there before the master was replaced but it definitely wasn't there after up until a couple days ago.

Can the pressure plate be damaged due to improper down shifting? I've been practicing rev matching and downshifting a lot lately. Haven't had any grinds or really bad screw ups at all. I actually feel like I'm getting the hang of it pretty good but could this cause damage to the pressure plate if Im not doing something right?

Also just today, its a little hard to get in gear at times, which was the main problem when the master cylinder was bad. Could it be that the oem one is already going bad again? Or improper install which resulted in the pressure plate damage?

badformulaLS1

iTrader: (1)

So yeah today the car has been hard to put into gear particularly 1st and reverse. And the clutch disengages (or engages? might have it mixed up) very early. When I have it pushed to the floor, it takes hardly any lift and no gas at all for the car to start moving forward. All the issues I had when the master was bad before so Im pretty convinced that its gone bad again...Complete waste of 300 bucks less than 1k miles ago.

Only thing is I still can't remember if the pedal vibration was there before. Could it be caused by the bad master cylinder? Or could it be both the master cylider and the pressure plate?

2 Stroke Racer

iTrader: (11)

Bent fingers?

badformulaLS1

iTrader: (1)

What exactly are fingers?
I've already concluded that the crap oem master cylinder has gone bad again... Just not sure if the pedal vibration is related or not. I'd like to assume it is since all the issues arose at pretty much the same time, but I'm just going to put a Tick master in and then see how it is from there.

garys 68

iTrader: (1)

Since the master or throwout bearing is going bad, I'm going to guess the vibration was always there. You just didn't notice it since the TO bearing was either off the PP fingers or quickly fully engaged the cluth.
The fingers are the spring loaded levers on the PP that the TO bearing presses on to disengage the clutch.
With the failing hydraulics the TO bearing is probably contacting the fingers lightly and or slower to engage, so you're feeling it more.
Typically a bent finger is caused by hitting it with the trans input shaft when installing.
Try fixing just the hydraulics. It wont fix the finger, but might make it tolerable.

2 Stroke Racer

iTrader: (11)

^ what he said!

SNLPerformance

iTrader: (15)

Sounds like the bolts are backing out if it's getting progessively worse and having disengagement issues. You can't retorque without dropping the trans and removing bellhousing as you do not have an inspection cover like the C5. If you don't address it not only are you doing damage to the synchros in the trans, the dowel pins will eventually eject themselves if used initially and put holes in your bellhousing as well damage clutch. Worse case is the bolts actually break and the pressure plate comes loose, not a pretty sight as you can imagine. I'd get pulled apart ASAP if it was mine and be sure loctite was used on them. Chris, 817-750-2000

badformulaLS1

iTrader: (1)

So are you saying my issue is not cause of the master cylinder? I'm experiencing all the issues associated with a bad master. I also have a spec stage 2. Been reading that the oem master cylinder doesn't hold up well with an aftermarket clutch. The clutch is fairly new (2500 miles) and the issue originally arose shortly after that. Replaced the cylinder, car ran perfect until now I'm having the same issue less than 1000 miles later. So I'm pretty convinced I just need a tick master to handle the upgraded clutch. What do you think? Should I try getting a tick master first? Or are you pretty convinced that its the bolts?

SPEC-01

iTrader: (2)

If the pressure-plate bolts are loose then the clutch will have issues with release, engagement will be varied, and pedal feel will be inconsistent. These symptoms can also be similar to those of bad hydraulics.

You can always disconnect the line that feeds from the master to the slave and apply slight pressure to see if the pedal drops. If it does then you are seeing pressure-loss in the master cylinder. Give it a try and let us know what you find. Thanks!

badformulaLS1

iTrader: (1)

Any pics? Where exactly is that line? I don't really feel comfortable trying that without being totally sure of what I'm disconnecting for the sake of making things worse. The pedal feels a little soft, and the fluid in the reservoir was black. The pedal has to be pushed into the floor to be engaged. All the way down. I changed it following the steps in this video.

That black rubber diaphragm thing was not in my reservoir... Anyone know where I can get one?? Could that be causing problems?

Anyways, I changed the fluid repeatedly and pumped the hell out of the pedal. It seemed to get better but only for a short time. The vibration was greatly reduced (but not completely gone) and the pedal became firmer and it was easier to put into 1st and reverse only for a short time and then after about 5 mins of driving it went back to soft pedal, and difficult gears. I also noticed that giving the pedal 10-20 pumps at stoplights and stuff helped when driving on the street but again only for a very short time. The early disengagement however remained the same throughout all of this.

SNLPerformance

iTrader: (15)

Sounds like it may be more hydraulics, really hard to diagnose from behind the keyboard. You can try the Tick to see if it helps first and it is a good upgrade regardless, just know that the pedal will be stiffer from the larger bore master and removal of the assist spring.

SPEC-01

iTrader: (2)

There is a single line the goes from the master to the slave and it has a quick-disconnect at the juncture. I don't have a pic accessible right now, but again, there is only one line that connects these cylinders.

badformulaLS1

iTrader: (1)

Update on this. Had it looked at. Apparently my master is not the issue. The trans has to be pulled to determine if it's a bad clutch, pressure plate (like you guys said, loose bolts?), or both. Now all the gears feel very difficult, but mainly first and reverse still. Switched briefly back to the stock shifter to rule out my MGW being the culprit. 3,4,5 grind occasionally. Don't have money for this crap. FML!

Previous owner claimed only 1500 miles on the spec stage 2 set up. Either he burned the **** out of it, lied about the mileage, or Spec is just garbage. I'd also be extremely pissed if I bought a new clutch kit, pulled the tranny, and all thats needed are to tighten the pressure plate bolts...

badformulaLS1

iTrader: (1)

No one ever answered this question. Possibly all my fault?

BrainFreezE

iTrader: (2)

I have had 4 manual cars and never damaged the clutch due to downshifting.or aggressive driving. if you can then maybe I got lucky to not damage it. I have also been reading up on spec and haven't got any feedback I was looking for just read a bunch of mixed opinions. but I do tend to live by the " you get what you pay for". If you are going to drop the tranny like me you might as well just replace the clutch with a decent known one and save you the trouble of something happening later along when you could have fixed it in the first place. that's my thinking though.

BALLSS

once the tranny and bell housing are pulled, checking TQ on the PP bolts would only take a minute to rule in/out if that is the source of your issue. With that said, given you don't know for a fact wtf the clutch age is or wear on it, I would pull the clutch and inspect. Confirm wear issues and also carefully look to see that the clutch fingers are all uniform and at the same angle/height and the mating surface of PP is not at a angle.

FWIW I had a SPEC 2+ where the PP shiat itself by the contact surface moving causing one major vibration. This was after the clutch had been in for a few thousand miles and, until then, worked fine. I pulled it out and after looking "closer" saw the PP mating surface was at a slight angle. SPEC promply replaced it. Unfortunately that clutch did not live long but their customer service was good.

if after looking at clutch and everything looks "normal"...might want to re-visit your hydraulics. given when you "pump" pedal clutch operation improves some...that indicates a hydraulic issue.