Clutch fork shaking... what?

[destrux]

I've been chasing after a vibration on my car since I put it together. It happens all the time, clutch in or out, in gear/out of gear, cold/hot, with the serpentine belt off, moving/sitting still.

I checked compression to rule out a bent rod, and the motor doesn't tap. The head and cams are fine, I had those apart to do valve seals and everything was OK.

So I was looking at the clutch and flywheel last night and with the motor running in neutral the clutch fork is wobbling side to side about 1/8" in time with the motor RPM. it stops if I pull the fork so the release bearing is backed off of the pressure plate fingers. This is a MKIV W58 clutch mind you, it's a push type clutch. It's a Comp Clutch Stage 4 pressure plate, but I'm using a stock disc.

So I'm thinking my clutch pressure plate is somehow broken and the fingers on the spring are not all in the same spot? How does that happen but the clutch still feel and works fine? :aigo:

I think I'm going to run the motor with the clutch off to see if the vibration goes away, if not maybe the flywheel I bought is out of balance too. I got it from the same guy I bought this clutch from (both were used). He was selling them cause he blew his W58 with a 500whp 2JZ.

Bleh. :nono:

 

[Radial]

I think you have a loose pressureplate... loose or missing bolts. That would explain all your problems (sound, vibration, clutchpedal, fork...everything)

 

[destrux]

All the bolts were tight and nothing was broken (kind of).

Apparently if the pressure plate fingers are full of burn clutch disc pieces it makes the car vibrate, lol. A stock disc can only handle so many burnouts and powerslides I guess.

The clutch fork was shaking because the pressure plate was clamped down crooked on the melted clutch disc. I'm putting the whole new clutch in though, just cause I already bought it. I'm going to hold onto the CC pressure plate though, it's still fine to re-use if I need it in the future.

The vibration was pretty much gone after I took the clutch off. Pretty neat that you can run the engine in this car with the transmission out.

The little bit of vibration that's left will probably go away once the flywheel is cut and rebalanced.

Edit:

The pressure plate was also warped, which shifted the diaphragm spring off center. That was the actual main source of the vibration. It also wore the flywheel unevenly, which was why the vibration only went away completely after it was resurfaced (no re-balance was required).

I'm guessing some of the warpage was from me, but the guy I bought the clutch from was using it in a 2jzgte powered drift car (and he was using it with a 6-puck and broke his W58).