Tracking down engine vibration

[ruckman101]

Fresh engine in Gretchen Ghia, and unsettling vibration at higher rpms. Engine, as the vibration is there in neutral. Not the fan, as vibration was there with the fan belt off.

Really really really annoying as I had the drive-train balanced as a unit. Pistons, connecting rods, pulley, flywheel and pressure plate to the crankshaft.

Got the engine pulled today and I certainly got the pressure plate properly mated to the flywheel based on the yellow marks.





So how about flywheel to crankshaft.







Yep. Gland nut isn't showing any visible cracks or issues.





So I'm scratching my head. Should I not have used the paper gasket?





Only thing left is the clutch plate itself.





Hmmmm. What the hell is that thing? Why? Whafor? Could that be it? A rubbery chunk of something. None of the other springs seem to have a rubbery chunk, so I don't think it worked out of just the one spring, didn't see anything on the other springs. Is the rubber part of the clutch plate assembly?


neal

[vdubyah73]

looks like something's up. whats the fiber looking shtuff in the right spring and behind the rubbery shtuff? time to look at the p/p, eh?

[ruckman101]

Still perplexed. Father in law was of the opinion the rubber chunk wasn't hefty enough to be the issue, but wasn't a good thing. Fiber looking strands I think are slivers of rubber. Frustrating.

Will give things a better looking over tomorrow.



neal

[Amskeptic]

Still perplexed. Father in law was of the opinion the rubber chunk wasn't hefty enough to be the issue, but wasn't a good thing. Fiber looking strands I think are slivers of rubber. Frustrating.

Will give things a better looking over tomorrow.neal

1600 does not use a paper gasket. It uses an o-ring. You maybe maybe had a flywheel not exactly mated to crankshaft. But again, this is today's world, and what people say they do may not be exactly what happens. I am sorry you have this predicament. If you have the flywheel off and the pressure plate off, I would hie them to the balancer and have a re-check with verification. I would press for validation of correct balance.
HerrKolin

[ruckman101]

The balance job was done probably a good dozen years ago at Dan Hall's. Confident of the integrity of the work. They did bulk work for local reputable repair shops at the time. The vibration isn't violent. New O-ring is there. I guess I need to visit and hopefully run my issues past the folks there now with hope of insight. How can you check the balance of parts of the assembly balanced as a whole? Nothing was loose in terms of pressure plate or gland nut torques. Dowels are tight.


neal

[Bleyseng]

Have you run it without the rubber bits in the clutch plate? Seems like just those would throw it off enough at high rpms.

[SlowLane]

What would worry me about that clutch disk is that those are the rubber bits that you can see. Leads me to wonder about what you can't see hidden in the crevices of the disk assembly sandwich.

[ruckman101]

Well I do have other clutch plates, but used. One looks doable, or wait until Monday and get a new one, or pick the rubber out of the one I have and give it a go.


neal

[vdubyah73]

have you taken the p/p off? whats the disc look like? where did that shtuff come from?

[ruckman101]

Pressure plate is off, flywheel is off. I suspect the "shtuff" was there from manufacture. I have a solid clutch plate I could use, but suspect the spring style would give us smoother operation.

[SlowLane]

Or it could be that the springy disk is what is causing your vibrations. Like you hit a harmonic at certain RPMs that sets the springs to singing.

Jest speculatin'

[Amskeptic]

Or it could be that the springy disk is what is causing your vibrations. Like you hit a harmonic at certain RPMs that sets the springs to singing.

Jest speculatin'

Unlikely. The clutch disk springs are to absorb radial torque shock at engagement. They are free to sit there and rotate slowly or rattle a bit, even. The disk pilots the hub to the friction plate pretty carefully. I have not seen a clutch plate that uses rubber though.

Neal, if the vibration occurs with your foot on the clutch pedal as you rev the engine, it is not the clutch disk as it sits stationary in those moments.
Colin

[ruckman101]

Did not have sense enough to do such a test that would have helped isolate issues. Dang. Waiting to pick up a new clutch plate Monday.


neal

[ruckman101]

We have resolution. Joy!


neal

[ruckman101]

Lugged pressure plate and flywheel down to Dan Hall's. Apparently the pressure plate had a bit of play at the edge, so wasn't centered on the flywheel. That would do it.








So they put in a couple of guide pins and rebalanced it for me this afternoon, despite their three week back-log of work, to "make it right". Fantastic! I can't say how impressed I am, big bundles of impressed. What a great guy!

Tomorrow we'll get it back in.



neal