froggy47

I "think" my throwout bearing is going bad. I've been under the car (running) listening and feeling around and it does not seem to be exhaust, cats, suspension, etc. I don't think it's engine.

The rattle comes from the clutch area, not really left or right. Once I hop out from underneath it's not much different if I'm in gear (with pedal in) or in neutral. Once I am rolling I can't really hear/feel anything.

It's loudest when cold started then decreases a little but can still be heard.

A friend very familiar w/ c4 suspects the throwout bearing. 65k miles orig. clutch etc. The clutch is NOT slipping, tranny shifts pretty good (a little hard going into reverse since I got it with 50k miles), tranny gear oil is changed & clutch fluid also. New slave cylinder. I am thinking of getting a few more miles out of this before I do the whole thing as I have a couple of other mods going on right now.

I don't think it is "gear rattle" but I suppose it could be?

The question is, if I live with this for a while will any additional damage happen that could have been avoided?

How do you know it the throwout bearing really takes a dump?

Also, is there a way to definately diagnois this without dropping the tranny? Inspection cover?

TIA

AGENT 86

A bad throw out bearing should really only be noticeable while the clutch pedal is depressed.

froggy47

That is interesting, good point. Darn I have got something that is rattling down there.



I guy I trust on another forum (certified tech) thinks maybe the dual mass f/w is the noise.

The sound does not chg as clutch is pushed in/out - in neutral.

GREGGPENN

Mine sounds like its grinding gravel after it sits a few days. Been like that for 6 years. Asked Bill @ZF doc about it. His response:

"I would suspect that the pilot bushing is causing the noise that you
described when the vehicle is cold. Some day eventually when you replace the clutch, R&R the pilot bushing with GM P/N 10125896 which is a fluted type pilot bushing."

Maybe yours is worse (I assume this is not the throw-out bearing). Sounds like it won't hurt anything but you might contact Bill at www.zfdoc.com. There are several symptom/answer problems listed under his FAQ page. You might read them as well.

I believe the dual mass flywheel is more of a clunky/rattle sound. I can hear mine rattle a little at shut-down. So that might be your problem. Neither will cause damage.

JEFNLSA

Just a thought...

Right before I put on my headers (eliminated the cats) I had a bad cat that caused a "rattling" type sound that I couldn't pinpoint for the life of me.
Clutch....motor...tranny...?

Took it by Bill's (ZF Doc) and he checked under there w/ his funky stethoscope tool and voila....CAT! If you can, I'd recommend tryin' to get under there w/ a "scope". Bill looked under there first w/o it and couldn't pinpoint the sound at all. Once he used the scope...bingo.

froggy47

I'm going to get a scope & listen around next time it's up in the air.

Duntov85

BS - I had a throwout bearing go bad in 4000 miles. It worked fine. Was quiet with the clutch in and noisy as heck with the clutch out. When I had the tranny out I confirmed that the throwout bearing was bad. It was SHOT.

rick lambert

I've had throwout bearings rattle whether the clutch was depressed or not-if that's what it is I wouldn't worry about it until clutch time-I never had a throwout bearing do any harm-but I suppose they could.

stubbs

I had a throw out bearing go bad a sieze to the pressure plate fingers in my Mustang, you don't want to go there, its why I had a T56 after that to give you an idea

SJW

If the noise occurs only when the clutch is disengaged, the pilot is definitely suspect.

If the noise will occur when the clutch is fully engaged, it can't be the pilot, as the pilot sees no activity when the clutch is hooked up.

Be well,

SJW

froggy47

Thanks for all the post guys, how's this for weird, the last few times I have used the car (and autox'd the car) the sound HAS GONE AWAY.

Does that lead you to believe it's one thing rather than the other? I'm not going to take anything apart (obviuosly) until it's clutch replace time.

SJW

I'd say it lessens the likelihood that it was the T/O bearing making the noise, but it's still possible.

I'd also guess it's not as likely that the DM would be intermittently noisy.

It wouldn't surprise me a lot if the pilot turned out to be intermittently noisy.

Be well,

SJW

froggy47

Thanks SJW