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Discussion Starter · #1 ·
I plan on checking the clutch air gap when I put my tremec in. I am being told this possibly the reason why I have lost 3rd/4th in the t-5. What gap widith am I looking for and how do I adjust it if it needs to be. Clutch in question will be centerforce dual friction on stock flywheel. UPR quadrant with firewall adjuster and cable are also already installed.
 

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Never heard of checking clutch disengaged gap. The idea is not to create an air space between the disc and friction surfaces, but to relieve the pressure so that the disc can rotate with some drag. Or am I thinking of the wrong place to measure gap?

Either way I doubt you are having problems with the clutch because of 3rd or 4th gear not working... You would definitely notice problems in ALL gears. Any details on that?
 

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Discussion Starter · #3 ·
Here is why I am asking. I too haven't heard of this. But when I started shopping a rebuild of my tranny this is what I was told. To me this made a little sense as I haven't missed alot of shifts with this car since I got it. Basicly what they are saying is the clutch isn't full disengaded when I shift. This makes some sense. I have also seen people memtion that different quadrants move the clutch faster or slower aiding the air gap. This is why I would like to know what I should look for when putting the car back together. Syncros are gone in 3rd and 4th. With the short throw shifter I can now grind 2nd gear(but boy do I hit the shift light fast now!) I don't want to spend all the money to upgrade to the Tremec and assoctiated hardware, only to have the same thing happen.
 

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I don't see why we need to be so scientific when all you have to do is adjust the clutch linkage if you need less grad during disengagement. Besides, how are you going to measure the gap when you don't have the bellhousing on to use the throwout mechanism? I don't think there is any access hole for that, is there?

When you shift gears, you could rev match the engine speed to wheel speed for the gear you are selecting while you're on the clutch pedal. I do this automatically while driving and it makes gear engagement easier and smoother because when the transmission is in neutral the gears will tend to be spun up or down to match engine speed because of the light drag on the clutch disc. Kind of like double-clutching a truck transmission.
 

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Wow that is quite a explanation Ray

To make it shift as good as possible air gap is need. If you have no air gap the clutch is not disengaging properly and the car will not shift correct. I had all kinds of problems with clutch adjustment. I had the Steeda stuff. I was not able to get more than 3 passes before the car would not shift under power. I installed a Pro Motion quad and fire wall adjuster and the problems went away. I made 22 passes with out touching it.
The promotion parts do two things they release the clutch faster and farther due to ramp speed on the quadrant. The fire wall adjuster has a stiffener for the fire wall and jam nut for the adjuster. I used the same cable and it was a night and day difference.
When you see the difference between the two quadrants you will see why the Pro Motion stuff works so much better.
Fire wall flex is a huge contributor to air gap problems. also the rubber grommet that the cable goes through the fire wall in also creates problems. A small amount of firewall movement or that rubber moving can cut the air gap by 2/3. That is the difference between being able to power shift smoothly and the car not going into gear.

Tim
 

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Discussion Starter · #6 · (Edited)
Thanks Tim, I think you are the one I remember saying something about the speed and release with different companies stuff. Now the question is how do I adjust the gap, or is this going to be totally dependent on the parts being used. My main concern comes from the fact that I have missed very few shifts since I bought this car, and until the car started getting stuck in either 3rd or 4th gear, I never heard it grind. The car will still bark 3rd very well, and fishtail in 2nd, telling me the clutch is grabbing well, further puzzling me why 3rd/4th gear would just kinda give up on me. Any thoughts?
 

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A mis-adjusted clutch has nothing WRONG with it; it just has either too much or too little grab. It needs to be just so when you have the pedal nearly to the floor the clutch disengages fully, yet it also engages fully before the pedal is all the way up. If you're having difficulty getting into gears, it's probably got good grab when you're not on the pedal but when you step on it it doesn't start to disengage until the pedal is already a good ways down, and when it hits the floor it still has not fully disengaged. On the other hand, a slipping clutch can be caused by the clutch being fully disengaged when it is all the way to the floor but not starting to engage until the pedal is partway up, so when the pedal is at the top the clutch isn't yet fully engaged.

Air gap shouldn't matter, so long as the clutch is adjusted to do what it is supposed to do within the travel of your clutch pedal.
 

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also when the synchros fail you will grind gears regardless of how much the clutch comes apart, as there is simply no mechanism to equalize the speeds of each half of the transmission. This is why I recommended revving the engine with a little clutch engagement to bring the transmission into sync, like you would with a nonsynchronized transmission.
 

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Discussion Starter · #9 ·
Ok Ray your missing what I am saying though. In talking with transmission rebuilders it has been said that the lack of clutch diengagement has caused the snyrcos to fail, because the clutch was not fully disengaged. This is what I want to prevent with the new install. The one thing I have not liked about the car since I got it was the clutch has seemed like an on/off switch. I think this is part of the reason my 60ft's suck so much. It is very dificult to slip the clutch, it is either engaged or disengaged. Even with my crappy 60ft times, my et's never seemed to make sense. I could run 97 mph but my et's were 14.7-14.9. the 60's were 2.2-2.3 on street tires. Even with those terrible 60's I would expect to run 14.4-14.5, and this seems to be what I see with others running that 60ft, and et on street tires. I traced part of the problem back to the clutch cable loosening and causing the clutch to slip. Grinding on the clutch fork so I could get wrenches on the nuts and tightening them fixed the loosening problem. Addition of pulleys and CAI with a little bit better weather I managed my best Et on a 2.08 60ft. What doesn't make sense about that is I lowered my 60 by 2 tenths, meaning I should have seen 4 tenths in the qrt. I only saw a 2 tenth drop in the qrt with a lower mph. The shift point was changed on that run, but 1/8th mile et's and MPH are nearly identical than the normal shift point. Does my explanation make sense as to my concern? It seems something is slipping yet the engagement is on/off. The current grinding is a non issue, as I am replacing the trans, my concern is what caused the grinding to start with and preventing it from happening again.
 

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oh I'm sorry for not getting it. Maybe your clutch is glazed over and doesn't grab until you give it a certain amount of pressure. It's possible that the clutch had previous problems, and the disc got messed up but when the problem was corrected the clutch was not bad enough for street driving as to need replacing. ya know. Whatever it is I agree that something is wrong with the clutch if it is acting like that.

As to the air gap to prevent wearing out synchros... personally I never heard of checking that. The idea is to get a clutch pedal free play -- the travel during which no force is being exerted by the throwout bearing to disengage the clutch -- that is short (maybe 1/2") but not too short, which ensures that the clutch is fully engaged just before the top but when you step on it all the way you know it can't go any farther so the clutch must be fully disengaged. I'm real curious as to how you check this clutch air gap if you ever find out.
 

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BTW, I don't know if the rate of clutch disengagement is adjustable with these setups, so if it is, then I can see why there would be enough uncertainty that you would want to actually check the disengagement at the disc.
 

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Ray
I think that you need to do some reading on how clutch and transmissions work before you start telling someone what is right and wrong.
Air gap is the direct realtion to clutch disengaugment. If there is no air gap the clutch is still partialy engauged. Yes it may alow the car to be shifted but not as smothly or as fast as one that has at least .030" air gap.
The idea height for the pedal is personal preferance. I like mine to start to engauge about half way up. that is controled be the quadrant and has nothing to do with air gap. what controls the air gap is the tension of the clutch cable. That can be changed by either the the adjustable cable or the quadrant that is installed in the car. case example pro motion vs. Steeda. Cable is pulled futher and faster due to the ramp on the quad. the movement of the pedal is the same just the cable moves at different rates due to the quad.
The way to prevent the clutch from not fully disengauging is to not over tighten the cable at the bellhousing with the pedal in the full up position.
You have to have air gap on the clutch for it to shift the way it is designed. if not you are going to wear out blocker rings faster the car may shift ok just not perfect.
Where all this comes in to play is when racing the faster that you can disengauge the clutch the faster you will be able to shift the car. you can force the car into gear with the clutch not fully disengauged and that is when it starts to wear parts.
I have the problem with destroying blocker rings once a year due to power shifts. I look at this like changing the oil in the car just one of the things you have to do when you beat on it. It costs me about $70 to do this so the money is not the issue. If you don't power shift you won't damage them when the clutch is adjust correctly.

When you pull the car appart look at the clutch if it has good material and is not slipping it should be good to go.
I recomend that you run the promotion stuff. it worked for me and was much better than the steeda.

Tim
 

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as you can see the quadrant shape is totaly differnet

Tim
 

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Discussion Starter · #14 ·
gray86hatch said:
The way to prevent the clutch from not fully disengauging is to not over tighten the cable at the bellhousing with the pedal in the full up position.
Ok Tim this seems to be what I am looking for. How do you know when the cable is over tightened? Is this why a lot of people recommend using the stock Ford cable? Would it make sense to adjust the cable at a pedal height other than full up position?
 

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No but if you are not carfull it is possible to not have the pedal all the way up when installing the cable.
What I do is just make sure that there is no slack in the cable. the cable should move about 1/4" side to side. it needs to have a little tension on the throwout bearing.

Tim
 

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gray86hatch said:
Ray
I think that you need to do some reading on how clutch and transmissions work before you start telling someone what is right and wrong.
I'll be sure to do that.
 
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