I did a full engine rebuild earlier this year. I also installed a new clutch, slave, and master cylinder. I'm almost done with the break-in period so I'm getting ready to run the engine a little harder and rev up to higher RPMs. The engine has been solid so far but I've noticed that occasionally there's a pretty strong vibration coming from the clutch area. I had my stock flywheel resurfaced and balanced with my new McLeod RST clutch so I'm not too convinced it's what's causing the vibration. I haven't revved above 4k yet, but the vibration usually starts around 2500 RPM and will immediately go away if I press the clutch. What else could cause the vibration? I shimmed the slave cylinder and believe it is installed correctly. I used a scope to look into the bellhousing and didn't see anything loose. Could it possibly be the torque tube bearings? Like I mentioned, the vibration is not consistent. Sometimes I can rev up to 4k without any vibration while other times it rattles the whole car. I'd like to get this fixed before driving the car too hard so any input is appreciated.

 

Intermittent Vibration is odd, that should rule out the loss of a pressure plate balance weight - if used on you clutch pressure plate

I'e completed a few C5 Clutch kits, the first time is the toughest.

Recheck the Torque tube to bell housing bolts.
Check the header exhaust pipes clearance to bell housing.

There's a pesky wiring harness bracket on the passenger side near the top, a near impossible location to get that bolt into the bracket. I've now got an intermittent vibration but only when accelerating but not all the time. I have a long gravel driveway so I think a rock kicked up and it sitting on the bracket.

Also some shops don't install this bracket with the bell housing bolt, a good Vib can result. It can be very Challenging to get this bolt installed. It is very short on space and at an inconstant angle. I used 9/16 U-joint Socket. ...

Good Luck,

Michael..



If you have a two piece bell housing ,then check the pressure plate bolts. Unlikely, because the vibration go away with the pressure plate disengaged. But the disk is not rotating.

The with a flywheel tool, rotate the flywheel and look at the clutch disk against the pressure plate and flywheel side,,,- look for any dissimilitudes,, like a small section of the disk friction materiel on both surfaces.

Last that I can think of is the hydraulic release bearing. Most OEM failures are Leaking seals. My C5 and my Son's both starting leaking at realty the same time a couple off years ago and both close to 25 k miles.

Aftermarket release bearing can be very troublesome. If you installed an after market release bearing, Did you go though the measuring sequence to check to see if the bearing needed shims ??? If not that your most likely problem.

If you don't have a two piece bell housing then it's a tear down.

Michael..

 

Thanks for the good input. I finished my 500 mile break-in and revved to higher RPMs yesterday... fortunately I was near my house because something happened and I lost clutch fluid pressure. Going to tear down today and examine what the cause was. I went ahead and ordered torque tube couplers and bearings. I'm hoping that's what was causing the intermittent vibration.

I know the bracket you're talking about that is secured by the bellhousing bolt. That one is a pain to get to but I believe it's tightened down. I'll inspect when I'm under the car.

I measured the slave cylinder to determine if I needed a shim. I did shim it and have about 5mm space between the release bearing and the clutch. I'll measure again to double-check. I'll examine the clutch too but I don't think it's what was causing the vibration.

Hopefully the vibration will be gone after rebuilding the torque tube. If you can think of anything else to check while I'm under the car let me know. I'd hate to do all this work and not fix the vibration.

 

I removed the torque tube and the propeller shaft wobbles when I rotate it so I believe that's the cause of the vibration. Going to fix the wobble and think that should resolve all of my problems.