Clutch Fork Geometry Question

Terrorist 5.0

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Hi everyone, more of a continuation from my last post on the matter. Replaced the clutch in my 95 GT. All is well except for a slight vibration in the clutch pedal and a rattling throw out bearing. The fork shakes a little too. This is not all the time though. Intermittently, if I let the clutch out fast, the pedal is pretty smooth and no more rattle from the throw out bearing. This confused me. I couldn't find a conclusive answer on any forums, and anybody I knew, so I figured I'm on my own for figuring the issue out. Upon watching a couple videos, I noticed something a little different on everyone else's transmission. The pivot stud screwed straight into the bellhousing. I had a lock washer, probably about a millimeter thick, on mine. I figured that is how they came from the factory so I put it under my new pivot stud. I understand this can throw off the geometry of the clutch.

Using this, my only explanation for this issue is the bearing is having a hard time self centering (possibly maxing its range out) and is shifting around in the clutch fork to maintain center due to the possibly bad geometry. Also, moving the clutch in or out at high RPM's makes a slight hollow grinding noise (I say grinding but it is actually a smooth tone, difficult to describe). I can only imagine this is the bearing retainer being loaded from the bearing pushing on it harder than it should, also due to the possibly bad geometry. This is more of a far fetched one since without the cable on, the fork moves pretty smoothly, and without resistance.

Now, I am not a professional in setting up cable clutches, but I have a couple questions. I have already decided I am going to tear the transmission and bellhousing back out to fix this, but as I prepare to do so, I wanna know: is this logic reasonable? Is having the pivot stud out too far a reason for the symptoms I am facing? Secondly, if the new rotating assembly of the clutch measures differently than the stock setup, how would one figure out proper geometry? If there is a proper way with measurements I would be down to try, but if there is a simpler way, that would be nice. How is it supposed to be? I imagine the fork should be exactly perpendicular to the pressure plate when the pedal is out, but please correct me if I am wrong.

I will be buying a new throw out bearing, clutch fork, bearing retainer, and for the heck of it, a pivot stud. I imagine all these parts (minus the pivot stud) have been subjected to a lot of unnecessary wear from driving like this for the past month and a half. I don't want to have to pull the transmission out anytime soon as I live in an apartment, and apartments have rules. I'm just bending and contorting those rules to a point that I could make a yoga instructor jealous, but I would prefer to stay out of trouble. Thank you everyone.
 

weendoggy

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I have a YT video
that I did while doing a job on a SBF. Most of these are all the same and the measurements carry over to my '02 with 4.6L and also the 5.0 Coyote I installed. I think a lot has to do with zero freeplay, but other factors can attribute issues. I've seen springs on wrong side of the ball as well as the fork, so be mindful of those. Hope this will help.
 
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Terrorist 5.0

Terrorist 5.0

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I have a YT video
that I did while doing a job on a SBF. Most of these are all the same and the measurements carry over to my '02 with 4.6L and also the 5.0 Coyote I installed. I think a lot has to do with zero freeplay, but other factors can attribute issues. I've seen springs on wrong side of the ball as well as the fork, so be mindful of those. Hope this will help.
Thank you. Although McLeod doesn’t include instructions for setting the height, I am going to take a rough measurement and see what I come up with, with and without the lock washer.
 
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Terrorist 5.0

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So today I took the transmission and bellhousing out of the car today and took some photos along the way, along with what I found. I am still planning to take the measurements that weendoggy (lmao) mentioned earlier, although the flywheel measurements are going to be difficult without taking it back out. I may email LMR since I bought their flywheel (SVE), and ask them to measure it. In the pictures shown, the clutch fork position with my 8lb preload dialed in, the position with no preload (just the fork up against the fingers), and whatever I found in the bellhousing. Keep in mind, all these components are brand new, and have only been in use for about a month and a half. I cleaned off all the parts with brake clean prior to taking the photos for better clarity.

Before I took the transmission out, I looked at how the clutch fork sits. It seems to be ever so slightly biased to the rear.

So, beginning with the my main suspicion, the pivot stud (lengthwise), the head of the ball is pretty shiny in some spots, and is beginning to have a notable flat spot. It had a lock washer under it, as mentioned before. I feel that with how long it has been used, it shouldn't look like this, although I didn't use much grease on it. The fork already had some on it.

The clutch fork shows some signs of wear in the form of shiny spots on where the throw out bearing rides. This doesn't look out of the ordinary to me, unlike the pivot ball.

The throw out bearing itself still turns very smoothly, and doesn't make a noise.

The bearing retainer really caught my attention. There is a shiny spot where the throw out bearing rides, and is beginning to make a slight ridge which I can feel. It is the same all the way around. I attribute this to the hollow sound when the clutch is used at higher RPM.

All the pressure plate fingers appear to be sitting evenly.

The reason I posted this is because I cannot tell exactly what to do with what I saw. My current gameplan is new components all around. They are cheap and good insurance. As for what is causing this, I do not know. Can anybody provide any input on this? I will be taking measurements soon, and comparing them to my old setup. Happy holidays.



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weendoggy

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The only thing that stands out here is the picture of the input shaft sleeve. It looks like it has a slight ridge to it, which can cause TO hang-up, so maybe time to replace that. The ball doesn't look bad and I'm guessing that's grease on the end. If so, good. The fork looks o.k. and just make sure the spring is in the "valley" of the TO and not behind it. See attached pics I took when I did a persons clutch/trans job. You can see where the fork spring is "behind" the TO which is incorrect. The ball height from the "ball end" to the imaginary surface of the bell housing is pretty much the same at 3.650" give or take. You can use the straight edge method shown in my video for reference. I also removed the weight on the clutch fork when I installed my TKX. Not worried about the rear skew of the fork as long as dimensions are good and the TO bearing is riding the forks.
 

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Terrorist 5.0

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The only thing that stands out here is the picture of the input shaft sleeve. It looks like it has a slight ridge to it, which can cause TO hang-up, so maybe time to replace that. The ball doesn't look bad and I'm guessing that's grease on the end. If so, good. The fork looks o.k. and just make sure the spring is in the "valley" of the TO and not behind it. See attached pics I took when I did a persons clutch/trans job. You can see where the fork spring is "behind" the TO which is incorrect. The ball height from the "ball end" to the imaginary surface of the bell housing is pretty much the same at 3.650" give or take. You can use the straight edge method shown in my video for reference. I also removed the weight on the clutch fork when I installed my TKX. Not worried about the rear skew of the fork as long as dimensions are good and the TO bearing is riding the forks.
In all honesty, the retainer and the pivot ball were the only two that really concerned me. I cleaned the ball off with brake cleaner, so what you are seeing is not grease. It is shiny, rubbed through metal. The retainer really surprised me. Keeping mind that this stuff has only been in use for a month and a half, I think it’s safe to say something is wrong. I will go take measurements for the ball to bellhousing plus the spacer plate today and see where to go from there. The flywheel measurements will be taken last, as I would rather not mess with what I have right now as it seems to be working perfectly. Thank you.
 

cobrajeff96

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Just some general pointers that served me well back when I used cables...

The fork needs to be right in the middle of the inspection window, with 5lbs preload give or take (a good reason to have a firewall adjuster).

There should be high temp red grease on the following contact points:
-Bearing to fork tongs (moderate)
-Bearing face to pressure plate fingers (very light)
-Pivot ball to fork (heavy)
-Input shaft tube (light to moderate)
-Input shaft splines (light)
-Cable end to fork (moderate)

Do make sure the inside of the bell and just everything in general is reasonably clean before greasing.

I've never had a queaky or rattling TOB until many tens of thousands of miles or basically right before it was about to pop.
 
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So today I went down and measured the pivot ball tip to the bellhousing. I do not have precision measuring tools, but working with what I have, I took my tape measure and lied a breaker bar straight across the bellhousing face. I came up with roughly 3 and 5/8 inches. Adding the 0.065 that you got for the spacer plate (this is wrong to do, but I have nothing that is accurate enough to measure my spacer plate), it comes to 3.69 inches. I am going to contact LMR to measure their flywheel. My setup is working great and I would rather not disturb it.
 

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OK, the ball hieght dimension is good. I'd look at the input sleeve and make sure it doesn't have a edge thatcould keep the TO from free movement. Not much else to point out that hasn't been mentioned. If the clutch setup was new and flywheel either new or surfaced it should be smooth.
 
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Terrorist 5.0

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OK, the ball hieght dimension is good. I'd look at the input sleeve and make sure it doesn't have an edge thatcould keep the TO from free movement. Not much else to point out that hasn't been mentioned. If the clutch setup was new and flywheel either new or surfaced it should be smooth.
In that case, I will wait until after Christmas to contact LMR about the flywheel measurements, and going off of your Centerforce sheet, I will see if those numbers line up like you did in your video. Thank you for your help.
 

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Sounds like your clutch quadrant may be giving you some issues . Nothing else is to alarming . I’ll go out and measure my pivot ball height later or tomorrow as my trans and everything is out of the car .
 
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Terrorist 5.0

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Sounds like your clutch quadrant may be giving you some issues . Nothing else is to alarming . I’ll go out and measure my pivot ball height later or tomorrow as my trans and everything is out of the car .
SWEET. Thank you. What makes you say it is the quadrant though?
 
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Terrorist 5.0

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After a long while of putting the Mustang aside, I decided to go pay my automotive teachers a visit, to get some more opinions on what steps I should take. While I was there, an important detail was brought up that immediately raised one teachers suspicions. I used a McLeod clutch kit, with a Ford throwout bearing. I didn't use the bearing from the kit. I had always read about the horror stories of short lived throw out bearings and how only a Ford bearing should be used and all that, so I bought an OEM Ford bearing. Now, when I originally put the clutch in, I looked at the two bearings to make sure they were the same. When the teacher said to always use the bearing that came with the kit, I decided to take another look between the two, and ended up smacking my forehead in disbelief so hard it turned red...

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The bearing on the left is the McLeod bearing, supplied with the stock style replacement kit I used. The one on the right is the Ford bearing. Notice the taper on the end? I sure didn't. Talk about a lesson that will never be forgotten! The fingers on the pressure plate look the same, but I am probably going to end up measuring to see if there is a difference. The top parts of the bearing are a 0.2 CM difference, with the McLeod measuring 6.6 CM, and the Ford measuring 6.8 CM, but the taper is there for a reason, and I am tired of investigating this issue. I went ahead and ordered some new parts to replace the ones that were damaged, and even though I am very confident I can get away without measuring for the pivot ball and just running it the way it is, I am going to measure my clutch setup to see if it works well with my pivot ball to bellhousing measurement, just to see what I come up with, especially considering the flywheel is not a McLeod part. I will post back with measurements soon hopefully. Another thing I figured I would do was grease the pivot ball more. When I took the fork off, the pre-applied grease was almost untouched. I figure the fork may have been barely jumping on and off the pivot ball, which may have been the culprit of my noise. I will give further updates when the new parts come.
 
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Terrorist 5.0

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Today, I finally had the time to finish the car, and I am happy to say my issue is almost completely eliminated! The clutch still grabs closer to the floor, just a little higher than before as I dialed in my preload. I measured my clutch stack up and after comparing the numbers, my setup was in spec. I put it together and used more grease this time. I dialed in my preload by feel, although I measured it after to check. With about an inch to an inch and a half of “free play” at the pedal, and the throw out bearing firmly against the pressure plate and spinning at the same speed, it comes to about 8 and a half pounds of preload, give or take a pound before the fork begins to move.

While I was under the car, I did notice one of the pressure plate fingers was just barely too low compared to the others, maybe a quarter of a millimeter. I don’t think this is enough to cause vibrations, but I could be wrong. I will come back if I run into any issues, although I am hoping I won’t, not only because I don’t want to pull a transmission on the ground again, but because my apartment complex is not too happy with me. Oh well. Thanks to everyone who took the time to post anything that could help.

All in all, I don’t think my throw out bearing was the issue, rather a lack of grease. I may have done all this work (taking my transmission back out) for nothing, as I could have tried adding grease before, but live and learn. Hopefully, anyone who has a vibrating clutch fork (a lot of people judging by how many forum posts there are about it) sees this post and is able to fix their problem using information in this post.
 
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cobrajeff96

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One of the PP fingers being out of alignment means that the corresponding bolt is either too tight or loose compared to the others. A lot of people throw around torque specs, but I always go by the visual alignment. Once all the fingers lie down flat, that's when the wrench stops turning. But of course with blue loctite on the threads.
 
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Terrorist 5.0

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One of the PP fingers being out of alignment means that the corresponding bolt is either too tight or loose compared to the others. A lot of people throw around torque specs, but I always go by the visual alignment. Once all the fingers lie down flat, that's when the wrench stops turning. But of course with blue loctite on the threads.
I used blue loctite on all 6 bolts for the pressure plate and tightened them cross pattern to 22 foot pounds. I was that careful to the point I can tell you off the top of my head. The fact that it is only 1 out of however many there are makes me think it is a defect. If all the fingers were out of alignment (like a wave shape) then I would think that it was installed incorrectly. That’s too bad anyway, because it looks and performs pretty good.
 

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