Thread: clutch engagement

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I am in the process of transplanting a EFI 302 with a tremec 3550 from a mustang into my 71 pickup. Im facing all the usual problems associated with a swap. I now have the engine wired and running, however, it is on jack stands and does not have a drive shaft yet. I modded the clutch cable from the mustang and It seems to work good but it is tight. To install it I had to engage the fork about 1/4 inch., which I thought was not too much to disingage the clutch.
Heres my question: With the engine running I can shift into all the gears without pressing the clutch cable. Is my cable too tight or is this normal when the engine and trans are not hooked up to the rear end? Is the lack of resistance form the rear end due to not have the driveshaft allow the gears to be engaged without a clutch?
As Ive written, the cable is tight but I was told that the bearing was designed to ride on the fingers and thus the cable needs to be alittle tight.

mike

I've always set clutches up so there is a little play in the cable/linkage . You want the clutch fully engaged.

Thats the way I have done it in the past also, however, I was told that my throwout bearing was designed to ride on the fingers and thus needs alittle tension. I alway thought that haveing the bearing riding on the pressure plate would cause it to wear out faster. So you think that the little tension I have is disengageing my clutch. Whats throwing me off is the fact that the trans shifts effortlessly into every gear like the clutch is fully engaged and as Ive stated the clutch fork was depressed only about 1/4 ".
mike

Originally posted by mike schramm
Thats the way I have done it in the past also, however, I was told that my throwout bearing was designed to ride on the fingers and thus needs alittle tension. I alway thought that haveing the bearing riding on the pressure plate would cause it to wear out faster. So you think that the little tension I have is disengageing my clutch. Whats throwing me off is the fact that the trans shifts effortlessly into every gear like the clutch is fully engaged and as Ive stated the clutch fork was depressed only about 1/4 ".
mike

mike, it will be hard to know what the clutch or trans. is doing untill you have a way to stop the trans. output from turning and the only safe way to do that is with the drive shaft and brakes. without something to hold the output shaft it going to freewheel all the time and should scrape when you try to shift gears. sounds like you have the clutch to tight now, and i wouldnt wont my throwout turning all of the time.

Thanks for your replies. This morning I removed the clutch cable completely and tried the shifting. With the motor running the trans shifts as smooth as it did with the cable attached without the clutch disengaged.
mike

what is the output shaft doing all this time? you are saying that you can go from first gear to revers gear with the motor running and the clutch engaged without any problems. you need to get under the car, dont start the motor, put the trans. in a gear and see if you can turn the output shaft by hand, then put it in neutral and try to turn the shaft. you should not be able to turn it in gear and it should turn in neutral. sounds like to me the clutch is disengaged all of the time. hope im not makeing this to complicated, but let me know what the output shaft is doing. thanks, michael h.

Not to complicated at all.
With the motor running and without a driveshaft I can shift through the forward gears 1,2,3,4,5 without pressing the clutch cable. However, I did not try shifting into reverse. This seemed strange to me and I thought it was due to my clutch cable being to tight. I removed the clutch cable completely and It still performs the same. Now, since I drove the mustang with this motor and trans without any clutch problems up until last week and all I did was pull the motor and trans as one unit and drop it into the truck I have to assume that this situation is normal.
I will check the output shaft as you suggested, as I did not think of doing that, and let you know. Thanks for your help
mike

you might be able to shift through all the foward gears that way but not to revers. you can do that i guess because the input shaft and the output shaft would be turning the same speed, but you need to get the drive shaft in before you condem the clutch and cable. i still wouldnt wont the bearing turning all the time, thanks, mike

yea, I decided I will let off on the cable tension a bit. It was on a mustang forum where it was the consensus that it is a myth that the bearing should not ride on the pressure plate fingers. Alot of people on that forum belived that the pressure plate was designed to be slightly preloaded and thus the bearing spins instead of "jiggling" around.
mike

Originally posted by mike schramm
yea, I decided I will let off on the cable tension a bit. It was on a mustang forum where it was the consensus that it is a myth that the bearing should not ride on the pressure plate fingers. Alot of people on that forum belived that the pressure plate was designed to be slightly preloaded and thus the bearing spins instead of "jiggling" around.
mike

ok mike its your car and you can do what ever you wont to, but the person that told you to preload the pressure plate so the bearing wouldnt "jiggle" around is smoking something he ant suppose to.

I know, I know, I said I would slack the cable up some.
Just so you dont think Im the one smoking crack here is a link to a tech article about adjusting your clutch cable.
http://www.50stangs.com/techarticles...djustment.html

Ive also been told "ford spec says there should be at least 3lbs of force being applied to the bearing with the clutch pedal at rest."

mike

i was just jokeing about smokeing something and that looks like a nice way to adj. your clutch cable, but if god told me to preload the bearing i wouldnt do it. its hard for me to belive ive been doing it wrong for the last 45 years and most every throwout bearing that i have put in was because there wasnt enough clearance, not to much.i dont know but i belive if you put 3 lbs. of pressure on the pp it would slip under load. you sure these people dont sell bearings? i think this guy is telling you how to adj. the pedal height in the car. there is no way that you would preload the bearing to dictate when or where the pp would engage the clutch i know you dont know who to belive but if you have a way to adj your clutch leave a little slack in the cable and you cant go wrong, hope it works out. thanks michael h.

Originally posted by lt1s10
ok mike its your car and you can do what ever you wont to, but the person that told you to preload the pressure plate so the bearing wouldnt "jiggle" around is smoking something he ant suppose to.

Hello all!!!
While I am not well educated on other makes/kinds of clutches, i have a lot of experience dealing with cable driven t5 transmissions and clutches.

Having preload on the pressure plate is a must. It was designed this way. A quick search on any mustang board, or even with Ford will verify this.

The reasoning is simple, and if you don't believe me, you will find out anyhow that you'll have to do this. If you don't preload the pressure plate, the throwout bearing will essentially be loose. Quite often this will cause an extremely annoying squeak and rattle that comes from the pressure plate. this arrises from the t/o bearing being loose and scraping against the pressure plate fingers. Partial pressure on the clutch pedal usually relieves this annoying sound. Clutch cable must be tight enough to put slight pressure on the t/o bearing, that's why it's making noise. (however, the t/o bearing will not always make this sound when too loose) I can't tell you how many people have ripped out their trannies and replaced the t/0 bearing because of a squeak, but didn't know it was a simple clutch adjustment problem.

It's almost impossible to not preload the setup in a t5/cable driven application. If you don't tighten the cable enough, the clutch will simply not disengage all the way. This will cause the clutch to pick up RIGHT off the floor, it will be difficult to push it into first gear, and the other gears, and reverse will have excessive grind.

To adjust correctly, my best advice is to adjust the cable tight enough so that you have maybe an inch or two movement of the pedal up from the floor before it begins to engage. This will ensure that the clutch is disengaging all the way upon pressing down with your foot, and will ensure that you haven't placed excessive pressure on the pressure plate.

To the original poster: sounds like it could be too tight. First of all, be sure your cable is not binding at all. IT MUST have the longest possible and smoothest arc possible down the the clutch fork. To tight of an arc, and it will bind and stick.

When pressing on your clutch pedal, as mentioned, you must feel a little slack. If the entire thing is extremely firm, you are way too tight. It must have at least a tiny bit of slop on the top, or slack. If not, you are constantly disengaging due to too tight of a setup, and you are gonna smoke your clutch.

You have a custom setup, so I can't tell you much more, other than the sn95 (newer mustangs) have a near identical setup, but the clutch cable is a little longer, and may give you a little more slack if you need it. to order the longer sn95 cable, you can go to www.maximummotorsports.com, and they sell the oem cables there. Use it with the firewall adjuster and alum quadrant if you don't have that already. That cable is identical to the fox cars, just longer.

Jeremy