OK. I am not sure if this is a drivetrain issue or engine issue, but here goes. I have a manual 2005 Mustang GT, 1 piece drievshaft, CHE-K member brace, Spec 2+ clutch, and Spec Billet Steel flywheel. I have other mods but I feel that with my problem these are the only ones needed to mention....I have what I can only describe as a vibration in 3rd and 4th gear, at low rpms it is worse than at higher rpms. In fact at really high rpms I am not even sure if it is still there. I had the driveshaft checked, it is good. Pinion angle -2 degrees. Took the K-member brace off, no real big change. Then tonight I sat in the car, the car was in neutral, and I revved the motor slowly and at 1500-1800rpms is when I get the vibration through the drivetrain. I thought maybe a miss, so I swapped the plugs out with a set a buddy of mine gave me, no change. Could it be coils? I thought maybe my tune, so I changed that back and again no change. I had a slight vibration before I installed the 1 piece driveshaft and now it is probably double what it was. But again I also get this vibration with the car sitting still. Is this kind of stiff vibration normal with the mods/clutch I have. Any help or advice would be greatly appreciated.

 

Hmmm...is it chatter from the clutch? How new is the Spec clutch as it has an unusually long break in time from what I have read on the forum. I doubt it is the one piece DS and the tune and plugs dont sound like the problem either.... I am stumped but I know others with way more knowledge will chime in soon..... J

 

DEFINITELY the spec II. I've had the EXACT same symptoms since the day I installed it, and I have a similar mod list. Just out of curiosity, how many miles do you have on the spec? I've just completed the break in period (450 miles) and I still get clutch chatter in 3rd and 4th.

 

I think it is clutch chatter, the question in my mind is---is this kind of clutch chatter normal? I have about 1400 miles on the clutch and the chatter has actually gotten worse in the last 200 miles.

 

That's exactly what I was hoping NOT to hear. When I reported the problem to spec, they responded by telling me that it is a normal vibration that goes away in the first 1,000 miles. I've heard from many people that it does go away, but I've also heard from many people that it doesn't. It seems like spec clutches are hit or miss. Wish I would have known that when I bought it...
Oh well, I guess I'll be springing for a mcleod twin disc in a couple of months. I just hope that if the problem persists, spec will stand by its product and offer a refund.

 

The more I think about my issues the less I think it is clutch chatter in mine. I was thinking maybe something is out of balance, but again it doesn't happen all the time, just at around 1500-1800rpms. I just spoke to Spec and they are saying that they do not think it is the clutch, of course the problem is that the only way to prove it is the clutch is of course to take it out and install a new one. And if I am wrong then I am out that money, if I am right then I would hope they would stand by their warranty and give me the money back. But again my confusion point for mine is that it happens even when the clutch is not engaged, that just doesn't seem possible.

 

Is it just a vibration, or are you hearing a metallic rattle as well?

 

It is just a vibration. It is not a standard clutch chatter like you normally hear. No metallic sound. But I went and talked to a friend of mine today. He has a 1995 Cobra with quite a few suspension mods. And after driving in his car I think that maybe the vibration I am feeling just might be inherent to all the stiffening I have done to mine. His has a similar feel to it. But I am taking mine to the shop that installed my clutch either tomorrow or Friday. They said they will be more than happy to pull the trans. down and look at everything for me for free. They want to make sure that they didn't screw anything up during the install. So once I do that, depending on what they find of course will dictate how I proceed from there.

 

That's a real stand-up shop. Most shops wouldn't stand by their work like that.

 

OK. To make things even more confusing, I get the same vibration with the car sitting dead still, and the car in neutral. I get it around 1800 rpms normally, and if reinstall my CHE K-member brace with the torque limiters, it is twice as bad, and I feel it at about 1500 through about 1900 and then it gets less. Trying to troubleshoot this issue I have taken any and all mods I can off the car and it is still there. I now have no CAI install, the tune is out, the Underdrive pulleys were pulled off, I changed back to my stock coils. So if anyone has any inputs as to what it could be please enlighten me. The only things left on the car now are Borla Stingers, the Spec flywheel, and clutchand of course the driveshaft. But again since the vibration happens while the car is still I have to assume the driveshaft would be out. And the transmission place said that they didn't see anything wrong and of course mentioned that if it was the flywheel I would have it the second I start the car and it would not go away. The only theory I can come up with is that I am hearing the exhaust resonating and that the 1500-1800rpm mark is just the worst part. Any other theories are of course welcome....