Clutch chirping/knocking??

Hybrid707

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Hello, I made a thread about this a couple of months ago. My transmission area (can be heard through the shifter) is making sort of a knocking noise until I push the clutch even the tiniest amount. I replaced the clutch, flywheel, tob, pilot bearing and all bolts and the noise went away for a while until recently it’s come back but not as loud. The tranny doesn’t grind or pop out of gears and the noise goes away when I even touch the pedal or when I pull up on the clutch pedal to let the stock cable adjust itself, though this only makes the sound go away until I use the pedal again. Any suggestions that could maybe point me in the right direction? I’m thinking maybe the cable is just really bent as it’s the stock one and is causing it to not apply enough pressure on the clutch fork?
 
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Hybrid707

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Feb 26, 2020
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Hello, I made a thread about this a couple of months ago. My transmission area (can be heard through the shifter) is making sort of a knocking noise until I push the clutch even the tiniest amount. I replaced the clutch, flywheel, tob, pilot bearing and all bolts and the noise went away for a while until recently it’s come back but not as loud. The tranny doesn’t grind or pop out of gears and the noise goes away when I even touch the pedal or when I pull up on the clutch pedal to let the stock cable adjust itself, though this only makes the sound go away until I use the pedal again. Any suggestions that could maybe point me in the right direction? I’m thinking maybe the cable is just really bent as it’s the stock one and is causing it to not apply enough pressure on the clutch fork?
Really stretched * not bent. sorry
 

revhead347

Apparently my ex-husband made that mistake.
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That's usually a bad throwout bearing. The ones that come in the kits aren't very good.

Kurt
 

Hybrid707

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That's usually a bad throwout bearing. The ones that come in the kits aren't very good.

Kurt
That’s what I’ve thought about but it kinda sounds like rod knock, I’ve personally never heard a throw out bearing sound like that so I could be wrong. The weird part to me is that the sound goes away whenever I pull up on the pedal to self adjust the cable. Then comes back whenever I use the clutch again
 

revhead347

Apparently my ex-husband made that mistake.
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That’s what I’ve thought about but it kinda sounds like rod knock, I’ve personally never heard a throw out bearing sound like that so I could be wrong. The weird part to me is that the sound goes away whenever I pull up on the pedal to self adjust the cable. Then comes back whenever I use the clutch again

I've seen them so bad the pedal starts jumping off the floor. It could be a bad tooth on the clutch diaphram, but it's much more likely to be the the throwout bearing. If you leave it like that it's going to mess up the clutch. Stinks that you have to pull the transmission again.

Kurt
 

Hybrid707

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I've seen them so bad the pedal starts jumping off the floor. It could be a bad tooth on the clutch diaphram, but it's much more likely to be the the throwout bearing. If you leave it like that it's going to mess up the clutch. Stinks that you have to pull the transmission again.

Kurt
I have one more piece of information, sometimes the sound is nonexistent and it sounds normal, so it’s not like a 24/7 thing as it used to be but is slowly getting there again. Just thought i should add that and see if anything changes because I really don’t want to drop the trans again haha
 

revhead347

Apparently my ex-husband made that mistake.
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I have one more piece of information, sometimes the sound is nonexistent and it sounds normal, so it’s not like a 24/7 thing as it used to be but is slowly getting there again. Just thought i should add that and see if anything changes because I really don’t want to drop the trans again haha

You can usually put it up on jackstands, pull the dust cover, and look in there with a flashlight and see if you can recreate the problem.

Kurt
 

Hybrid707

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You can usually put it up on jackstands, pull the dust cover, and look in there with a flashlight and see if you can recreate the problem.

Kurt
So after some investigation, I found out it is my clutch fork not having enough preload on it so it is moving around and chirping, I’m going to try and replace the clutch cable to see if that fixes my problem as all the sounds go away and the clutch fork stops moving when the clutch is pressed. With that being said do you know if a foxbody clutch cable will work with a 94 sn?
 

Hybrid707

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You can usually put it up on jackstands, pull the dust cover, and look in there with a flashlight and see if you can recreate the problem.

Kurt
I believe the only difference between the transmissions for the fox and 5.0 sn is the bell housing length by a small amount if I’m not mistaken
 

revhead347

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I believe the only difference between the transmissions for the fox and 5.0 sn is the bell housing length by a small amount if I’m not mistaken

Yeah, they are the same cable. There shouldn't be any preload on it. The clutch release bearing should not be in contact with the pressure plate when the clutch is engaged.

Kurt
 

doobismaximus

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So after some investigation, I found out it is my clutch fork not having enough preload on it so it is moving around and chirping, I’m going to try and replace the clutch cable to see if that fixes my problem as all the sounds go away and the clutch fork stops moving when the clutch is pressed. With that being said do you know if a foxbody clutch cable will work with a 94 sn?
Look at the pivot knob that the clutch fork uses
 

jozsefsz

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I post this pretty frequently for chirping. Stock setup, the throwout bearing is preloaded onto the clutch plate fingers. This causes it to wear out much too soon. Aftermarket quadrant / adjuster setups typically leave an air gap, which is much better for the throwout bearing. However, there's nothing in the mechanism to maintain that air gap. So the fork will move back and forth giving you that chirping noise. The throwout bearing may be perfectly fine. Your cable may be perfectly fine. There's just nothing holding that air gap unless your input shaft is really grimy.

You'll either want to preload like the stock setup (if you have a stock cable and quadrant, pull up on the pedal to have it re-adjust, if the cable is bad replace it). Or if you have an aftermarket quadrant / firewall adjuster or adjustable cable, you'll want to install a return spring to push the fork away from the pressure plate fingers to maintain that air-gap and eliminate the chirping.

When I post this I usually get responses like 'mine doesn't do that.' That either means you don't have an air gap, or that your input shaft is coated with dirt and is keeping the throwout bearing from bouncing around. From an engineering standpoint, in the non-stock / non-preloaded (better) setup, the fork needs something to pull it back if you want to maintain the air gap. A return spring does the trick.

They used to make a kit for this, but any right-sized, not-super-stiff compression spring installed between the housing and the fork will do the trick. Here's a link that helps explain what I'm talking about. https://www.svtperformance.com/threads/ldc-chicago-clutch-freeplay-correction-kit.170779/ (It was advertised as taking up the slack on the clutch pedal top-side to keep your pedal from rattling if you keep an air gap, which it does, but it also completely eliminates chirping with an aftermarket quadrant and adjuster while maintaining a proper air-gap).

I hate to think of how many cables, TOB's, and forks have been pulled out because of the chirping when they were actually fine. This is just a less-known element to replacing the stock setup with aftermarket (non-self-adjusting) components that most people don't know is a really good idea.

Edit: to clarify, I don't believe that kit is available any longer. I bought mine about 7 or 8 years ago. But you can use the pictures as a guide to what to pick up at the hardware store.
 
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revhead347

Apparently my ex-husband made that mistake.
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I post this pretty frequently for chirping. Stock setup, the throwout bearing is preloaded onto the clutch plate fingers. This causes it to wear out much too soon. Aftermarket quadrant / adjuster setups typically leave an air gap, which is much better for the throwout bearing. However, there's nothing in the mechanism to maintain that air gap. So the fork will move back and forth giving you that chirping noise. The throwout bearing may be perfectly fine. Your cable may be perfectly fine. There's just nothing holding that air gap unless your input shaft is really grimy.

You'll either want to preload like the stock setup (if you have a stock cable and quadrant, pull up on the pedal to have it re-adjust, if the cable is bad replace it). Or if you have an aftermarket quadrant / firewall adjuster or adjustable cable, you'll want to install a return spring to push the fork away from the pressure plate fingers to maintain that air-gap and eliminate the chirping.

When I post this I usually get responses like 'mine doesn't do that.' That either means you don't have an air gap, or that your input shaft is coated with dirt and is keeping the throwout bearing from bouncing around. From an engineering standpoint, in the non-stock / non-preloaded (better) setup, the fork needs something to pull it back if you want to maintain the air gap. A return spring does the trick.

That's just poor adjustment. The release bearing should not be touching the clutch fingers in the neutral position. That kit is probably not sold anymore, because it is completely unnecessary.

Kurt
 

jozsefsz

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That's just poor adjustment. The release bearing should not be touching the clutch fingers in the neutral position. That kit is probably not sold anymore, because it is completely unnecessary.

Kurt
Kindly explain to me what part of the mechanism pulls the release bearing back away from the TOB (to create the air gap) when you release the pedal and I'd buy you a drink Kurt. What is poor adjustment is if you don't have the chirping, it means you're likely preloading your TOB. Which is fine if you don't mind replacing it every 40k.

I've had the spring in place (which Ford also thought to have in every manual transmission setup in the past that didn't have that 'wonderful' self-adjusting plastic quadrant and TOB pre-load) for several years and it works perfectly. Also keeps the clutch pedal from bouncing up and down when you go over bumps while you maintain an air gap.

But, by all means, if it makes you happy to wear out TOB's and pull transmissions to replace them when they chirp, then don't give it a try. That $0.50 the spring will cost you and the hundreds of posts online from people who use them in the T5 would be worth a shot to me before I suggested someone unnecessarily pull a transmission.

As I mentioned, I get this feedback every time. :) Unfortunately, this feedback has no engineering basis. It's why there are still consistently chirping-clutch posts years after folks started installing aftermarket quadrants and adjusters.
 

revhead347

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Kindly explain to me what part of the mechanism pulls the release bearing back away from the TOB (to create the air gap) when you release the pedal and I'd buy you a drink Kurt.

I'm not saying it's a bad idea, just that it's not necessary. I've had throw out bearings go more than 100,000 miles. There are Mustangs on the road today that have 200,000 mile clutches and throw out bearings. So long as the bearing has no pressure on it, it shouldn't wear. My Ford truck is actually the opposite way, there is a spring to keep the release bearing pushed up against the clutch. It failed of course, and the surface of that bearing looked like it had gone 3 rounds with Mike Tyson.

Kurt
 

General karthief

wonder how much it would cost to ship you a pair
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I'm not saying it's a bad idea, just that it's not necessary. I've had throw out bearings go more than 100,000 miles. There are Mustangs on the road today that have 200,000 mile clutches and throw out bearings. So long as the bearing has no pressure on it, it shouldn't wear. My Ford truck is actually the opposite way, there is a spring to keep the release bearing pushed up against the clutch. It failed of course, and the surface of that bearing looked like it had gone 3 rounds with Mike Tyson.

Kurt
So the tob had teeth marks?
 

revhead347

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Let me rephrase that, because I am not trying to offend anybody. The kit you are suggesting is not going to fix a knocking problem. The car has something broken in there, like a throw out bearing, or whatever. So buying that kit isn't going to fix the OP's problem. 99% of the Mustangs out there do not have a spring on the clutch cable to get an air gap, and they work fine.

This is going to blow people's minds, but there was a time in Mustang history where the TOB was not considered a problem. The chief cause of failed throwout bearings is cheap (cough, Chinese) throwout bearings. I worked as a parts manager for a few years. It's a price driven industry. So the parts stores only keep the cheap ones in stock. If you buy a clutch kit, it's going to come with a cheap bearing. If you want a good one, you are going to have to wait a day or two for it.

Kurt
 
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