# strange noise from clutch



## Chris-Austria (Dec 23, 2010)

Hi!

Yesterday I noticed a strange noise that probably comes from the clutch.
It's a rather loud rattling noise that sometimes appear in 1st or reverse gear when I start to release the clutch pedal. If I push the pedal as soon as I hear it, change to neutral and put in the gear again it will not appear again for some time. If I stay in gear when the noise appears I can also make it come and go by releasing or pressing the pedal. Does this sound like a bad TO-bearing?

The clutch is new, flywheel is resurfaced, TO-bearing is new..

When I drive the clutch pedal vibrates a little bit, this was even before the engine was overhauled. The gear stick also has some vibration in it.. just like with the old clutch, but I'm not sure if a little vibration is "normal". Maybe I'll have to adjust the clutch linkage.. but the loud noise I described doesn't seem to have any relation to the other problem.
As long as I drive the car in any gear there is absolutely no noise that don't belong there. 

I found out that there are some springs in the linkage, can they cause such a rattle from time to time? Maybe if something hits the spring? Or could a oil leak cause this? I found out that the rear oil pan is a little leaky, but I retightend the bolts and now it seems like it's sealing well.

Any idea would be appreciated! It seems I always run into new problems as soon as every problem I know has been solved.. but I have no clue how to determine what could cause this rattle.. especially since I cannot find out what causes it to appear sometimes and not to appear all the other time.


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## BearGFR (Aug 25, 2008)

It's hard to tell without actually hearing the sound (and maybe even then). There's such a thing as adjusting the free-play travel on the clutch linkage. Too much and things will be loose (and also the clutch may not fully release), too little and there'll always be some pressure on the throw-out bearing that will cause it to have a very short life.

If the noise happens mostly when you've got pressure on the clutch pedal, suspect the throw-out bearing or something closely related to it. If it happens mostly with no pressure on the pedal, suspect excessive looseness in the clutch linkage.

Noise can 'travel' in strange ways through all those metal components too. Excessively worn and sloppy components inside the transmission for example can show up as noises/vibration in everything that's attached to it -- shifter linkage, clutch linkage, etc.

I know it's frustrating to keep finding problems long after you thought you were "done", I'm right there with you. Just this last weekend I wound up replacing the upper ball joints on the Beast...

Bear


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## Chris-Austria (Dec 23, 2010)

I cannot imagine what could cause this sound. If it would appear every time I release the clutch pedal it would make more sense, but it happens sometimes when I come to a traffic light after driving vor some minutes or it will not appear at all for a hour until it decides to be back.
The shop said they adjusted the linkage and the pedal works just fine (not too hard to press or too much travel). Maybe it's best to give my GTO to a shop and let them try to find the problem.
The noise never showed up with no pressure on the pedal (clutch fully engaged). Funny thing I noticed today (maybe its just by accident) but the noise appeared in reverse when I got out of my driveway and when I turned the steering wheel to the left with the clutch pedal pressed to the floor the sound appeared, when I turned the steering wheel to middle position it was gone?! But the other times when it appears (for example at a stop light) I have the steering wheel always in middle position.

Very strange 

Your are right Bear.. it's a neverending story with these cars.. but they are worth it. Anyway.. sometimes it can be frustrating... especially if you don't know what is wrong.


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## Chris-Austria (Dec 23, 2010)

Just drove the car a few miles and noticed that when I let the car roll in 1st gear with the clutch pedal pressed to the floor the noise appears sometimes. It sounds a little bit like the grinding noise if you make a mistake when changing gears but it's a deeper (and louder) tone. The gear won't slip out or something.. if I relase the clutch pedal so that the connection between transmission and engine is applied the noise will stop immediately and the car drives just normal.

So I can now tell when I exactly think the problem is present:

- a gear must me used (got the noise with 1st, 2nd and reverse)
- it will appear sometimes, not every time! (but I think I can hear something everytime I let the car roll or idle with the clutch pedal depressed and a gear put in)
- the loud grinding noise only appears with the clutch pedal depressed (no connection between engine and transmission)
- if I release the pedal and the clutch is fully engaged there is no strange noise any more, on the way until the clutch is fully engaged there can be a noise, but not all the time
- the pedal and stick will have some vibration while driving with clutch fully engaged, I guess more than "normal".. for sure more than for example last year

If you think of only these symptoms, where should I start my search?


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## BearGFR (Aug 25, 2008)

If it only happens when you have your foot applying pressure on the clutch, my first suspect would be the throwout bearing.

Bear


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## Chris-Austria (Dec 23, 2010)

Thank you Bear! Do you have an idea why it only happens from time to time? Is this possible with a bad throuout bearing?
Can a bad TO-bearing also cause vibration? Or do I have more problems? Linkage, fork, springs...?

I'll bring it to the shop on Monday and tell him what I suspect. Would be pretty strange because the clutch and throwout bearing are new. What can cause a TO-bearing failure after just a few miles?
If it's really bad.. can I use another TO-bearing and keep the clutch? (it's a Centerforce). If I need a new clutch as well, I won't use Centerforce any more.. probably I'd check out the McLeod clutches. Would it be a big advantage to use a 11" instead of the 10.5"? I didn't want to buy a new flywheel but I also don't want to have any kind of problem with the clutch within the next 1000 miles


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## leeklm (Mar 11, 2012)

As Bear mentioned, I would focus initial efforts on making sure the "slop" is taken out of the clutch linkage. Also, you could install an anti-rattle spring, which goes between the zbar arm and clutch fork, ensuring that your fork rod is not rattling around. These were standard in 66.

My linkage was wore out and sloppy last year, which I overhauled over the winter. AMES and others sell a little plastic bushing that goes on the main push rod where it connects to the clutch pedal. I bought a couple of extras, and installed them on the zbar end of the push rod, as well as on the fork rod where it connects to the zbar.

I am not sure how long the plastic bushings will last (factory was just metal on metal), but for now, everything is nice and quiet!


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## Chris-Austria (Dec 23, 2010)

The shop will check my linkage tomorrow. I have a catalog from Ames, I'll give it to them so they can mark the parts that are bad or maybe missing (anti-rattle spring).
I'm a little nervous because of the noise it makes, hopefully it's a linkage problem and can be solved.. Thanks for the info!


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## Rukee (Feb 8, 2007)

Possibly the throw out bearing is going too far in and forcing the pressure plate to hit the disk?


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## Chris-Austria (Dec 23, 2010)

How can it go in too far? Bad linkage? The car is at the shop now.. if he cannot find the problem I'll ask if he checked this.
What doesn't make sense to me is why it sometimes works fine and sometimes it's really bad. Also the viabration at the pedal/stick is sometimes really bad and sometimes almost normal.


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## Chris-Austria (Dec 23, 2010)

I have another idea, but don't know if it's possible...
Can the starter cause this noise? It sounds a bit like if you try to start when the engine is already running... What would happen if the clutch pedal hits a wire that engages the power to the starter and when I remove the foot from the pedal it will stop?

The mechanic checked the clutch and everything looks good.. he said the TO-bearing isn't bad and the vibration is caused by the springs (both are missing!). So I ordered new springs and he will put them in...

Today I wanted to start the car and the starter didn't hit anything.. second try and it started just normal... do you see any chance that the starter causes my problem??
I drove about 30 minutes today and there was no noise while driving or at stop lights.. even with the pedal pressed..


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