Transmission noise - DualMass or Throwout?

[S.hafsmo]

On a recent test drive I heard a rather disturbing noise coming from the transmission when the clutch is depressed, and the input shaft has a higher speed than the motor/flywheel.

If I just depress the clutch, there is no noise, but if I rev slightly in neural, clutch enganged, then depress the clutch, a loud rattling/grinding noise appears, and continues until clutch is engaged again.

If it was the throw-out bearing, would it not make noise every time clutch is depressed? Is my dual mass flywheel failing?

A quick and rather poor video of the noise; https://youtu.be/yHi75CXl2lM

[GOLDCYLON]

Originally Posted by S.hafsmo

On a recent test drive I heard a rather disturbing noise coming from the transmission when the clutch is depressed, and the input shaft has a higher speed than the motor/flywheel.

If I just depress the clutch, there is no noise, but if I rev slightly in neural, clutch enganged, then depress the clutch, a loud rattling/grinding noise appears, and continues until clutch is engaged again.

If it was the throw-out bearing, would it not make noise every time clutch is depressed? Is my dual mass flywheel failing?

A quick and rather poor video of the noise; https://youtu.be/yHi75CXl2lM

Hmm sounds like a bad throw-out bearing however I sent your you tube link to the ZF DOC to see what he thinks. GC

[Paul Workman]

Well, in any case it sounds like you're gonna be "in there" soon and find out for sure. But, I'm gonna guess it is the TO bearing or possibly the pilot bushing. (I once has an input bearing on a M21 go bad - sounded pretty bad like the video - but it was worse w/ the clutch OUT than with it depressed, For What It's Worth (FWIW).

Might as well...

...have a new disc on hand when you go in there - sorta mitigates the trouble of going in there in the first place - call it a "clutch overhaul" - freshen everything up at the same time.

And...unless the clutch PP or FW surface was burned or worn as result of metal to metal contact/damage to the PP or the FW, there's no concern for "turning" either. The new disc will quickly break-in after a 100 miles of so of use with normal driving. (The Veleo PP is slightly beveled in toward the center. So, you want to avoid any drag race type clutch engagements until the disc has a chance to assume the shape of the disc/FW surfaces.)

[S.hafsmo]

Thanks GC. Qurious to hear what he has to say on the matter.

Paul,
Sure seems I'll be going in there. Really hoping it's not the input shaft, but surely that would make noise (as you mention) when clutch is out as well?
I'm considering to get a clutch kit from ecklers or something. They're about $400 including pressure plate, pilot-, and throwout bearing.
I kinda want a new DM flywheel as well, but then we're in a different league cost-wise. Not that the price is a problem, but annoying if the old FW is still good. Can you tell if it's busted with the tranny/clutch removed?

Anything else one might need in there? clutch fork pivot ball?

[BigJohn]

Woodpeckers them dern woodpeckers again!

[Ronstar]

i have a similar noise (hard to tell from video) in my car. I have a single mass flywheel. let me know what you find out

[BigJohn]

You know with a single mass flywheel and a centerforce clutch my trany sound like a shaking box of rocks when in neutral!
But there is nothing wrong.

[Mystic ZR-1]

So, it's a box of rocks!
I always thought it was your Roy Rogers lunch box
half full of nuts and bolts?
��

[BigJohn]

Originally Posted by Mystic ZR-1

So, it's a box of rocks!
I always thought it was your Roy Rogers lunch box
half full of nuts and bolts?
��

So you have been looking!!!
Old Roy can really get you out of trouble when needed.
You have your ZR-1 together yet?
We had five cars out in the rain Saturday.

[Ronstar]

Originally Posted by BigJohn

You know with a single mass flywheel and a centerforce clutch my trany sound like a shaking box of rocks when in neutral!
But there is nothing wrong.

I'm used to the normal box of rocks. I also have a sound like the OP