irregular noise from clutch...??

CaifanSC

SCCoA Member
I've search the forums but all I find is the typical grinding of the transmission due to bad syncros and nothing like what i'm experiensing. Sometimes, regardless of the car's temperature, there is a nasty grinding/ slight vibrating noise that seems to come from under the car. The noise is present only when the clutch pedal is not being pressed on, and it goes away once the pedal is pushed. From inside the car it sounds like the noise comes from the center section of the car, but from outside the noise is louder from under the passingers side. The noise sounds kinda nasty but i've noticed no change in the how the car functions or shifts. Regardless, if the noise is there it means taht there is something happening that is not supposed to. Any suggestions are greatly appreciated guys. Thanx
 
My friend's 97 M3 does the same thing and has made that same noise ever since he got a lightweight flywheel. I don't think you're hurting anything though, so I wouldn't worry about it.
 
Check it out.

There is an inspection hole in the drivers side of the tranny. It has a black rubber plug about 4 x 2 1/2 inches. Pull it out and take a look inside. You can see the clutch pressure plate, slave cylinder and through-out bearing now.

Jack the car up, slither under there and have someone pump the clutch with the car running and I'll bet you'll find out what is going on.

Could be some damaged fingers on the pressure plate or a variety of other things.

I know it's not fun getting under a running car but when duty calls...

Good luck
Bob
 
silvercoupe: i dont know b/c the tranny is stock...no mods, factory flywheel, etc

bob: i guess i can crawl underthere this weekend or something to see whats going on. I've been under cars before while running...actually did that this weekend trying to find a leak on dad's taurus' steering lines. Good thing its winter, b/c in the summer that heat can get really nasty. specially when the cats are right there in your face! Anyways, you suggested lookiing for damaged fingers on the pressure plate, any other things i should keep my eye for? Some type of rubbing or wear?

thanx for the help guys...i was getting worried b/c no one had responded but now at least i have something to check for
 
i'm about 90% sure that it would be the pilot bearing in the crank. Only because when the clutch is out, in neutral, the input shaft is still spinning. The tip of the input shaft is actually in the pilot bearing. A bad bearing could cause this noise for sure. IF it was the throw-out bearing then it would make the sound when the clutch is depressed. I'd point my finger at the pilot bearing, which is about 12 bucks, but the tranny and clutch have to come down to replace it. In that case, i'd take a good look at the clutch and pilot bearing and replace that while its down.
 
Throwout bearing

It is the throwout bearing. The reason it get quiet when you push on the pedal is because you are pushing it into the pressure plate fingers and applying resistance to it and stopping it from chattering. I've seen this time and time again. Yuo will still have to drop the tranny to replace it though. Depending how bad it gets you might want to replace the pressure plate due to the wear being inflicted on the ends of the fingers. Of cause then with the new plate you should put on a new clutch disc. And while your at it, you need to replace the pilot bearing in the end of the crank. .....So, in short, time for a clutch job. If you recently did a clutch job, hurry up and change the TO bearing. Make sure you not how it is put on the shaft so you won't have to drop the tranny twice.!!!
 
Oh yeah.....

If it was the pilot bearing it would do it constantly, not just when the pedal is released. And your clutch would most likely be smoke do to vibration.
 
Oh man...you guys are scarign me now! I'll check the receipts for the car b/c i know my frat brother changed the clutch not too long ago, the darned thing went out in the middle of campus. I'll double check what else was changed at the same time. This would suck man, b/c i just sprang a leak on my radiator and thats going to be a good $200 to replace, and now this! Sheesh, not to mention the money i have to dish out to get the 89 back on the road.
 
Chances are....

Chances are they didn't change the throw out bearing when they put in the new clutch. There fore the strength of the new Press plate on the old bearing is causing it to go sour. If the cluthch is new (less than 10k) you could leave it alone but If you have the cash you might as well replace it while your in there.
 
Throw out for sure

For the reasons stated.

A pilot bearing will only make noise when the clutch is depressed.

Because this is the only time the pilot bearing would spin, otherwise the input shaft and the flywheel are rotating at the same speed.

When you buy a clutch set it comes with a new throwout bearing. I had the same thing happen in the wifes Ranger. Changed the clutch but left the slave cylinder because I couldn't get the line loose from the trans. Told myself it would last. 2 months later the slave started leaking washed the grease out of the throwout bearing, then it started making noise (but only when you pressed the clutch in).


Jeff

Change the Slave cylinder while you are there, or you will be doing it all over again.

It's really not that big of a deal you can do it in a weekend with little more than a wrench set, screwdriver and a set of ramps.
 
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Damn, I really don't like to read this. Because mine is doing the EXACT same thing. It doesn't do it all the time when the clutch is not depressed, only occassionally. But when I depress the clutch, the sounds slowly disappears.

And I just did a clutch job on it, and the TO bearing was replaced (not the slave cylinder, though).

Dale
 
Dale,

Did you replace the pilot bearing? Do you have problems getting the trans to go into gear? Are you leaking fluid?

Jeff
 
I had the this same sound in my capri. It was the throwout bearing. My buddy had the same thing in his t-bird, it was the throwout bearing. Had the same thing in a pickup, it was the throwout bearing.

It also could be as simple as a loose fit on the clutch fork allowing the bearing to "rattle" in which case it would be more of an annoyance than anything of a problem.


Only speaking from experience.
 
Jeff,

1) No. The one that came with the clutch was more of a bushing, not a bearing. And the old bearing didn't have any play, so we kept the old bearing.

2) At first it didn't at all, but very occassionally it'll hang trying to go into first from neutral. I can let out on the clutch just a bit and then it'll allow it to go into first. Other than that, it shifts just fine. My other '89 always hung trying to go into first, so....

3) No fluid leakage that I've been able to see.

Dale
 
"It also could be as simple as a loose fit on the clutch fork allowing the bearing to "rattle" in which case it would be more of an annoyance than anything of a problem."

Nope, no clutch fork here buddy.


Only speaking from experience.

Jeff

DAle it should have had a bearing stock and you should have gotten a bearing in the kit. You can change from a bushing to bearing and back. The bearing is better, but I wouldn't go changing it just yet.
 
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Whats the thing called that holds the bearing and pulls it into the pressure plate? In a t-5 mustang it has the hole for the cable. I've always called that a clutch fork.???? Whats the proper name.
 
Edman1000 said:
Whats the thing called that holds the bearing and pulls it into the pressure plate? In a t-5 mustang it has the hole for the cable. I've always called that a clutch fork.???? Whats the proper name.

On the M5R2 it's the Slave cylinder. It is not the same as a T-5. No cable it's hydraulic. It’s a whole nother animal.
 
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