Throw out bearing always makes contact?

[mpanten]

I really wish someone would post the correct answer to this one. I have almost the exact same problem. I am using the pull type set up f. Fully extended the rod coming out of the slave is 3 and 3/8 inches. Fine and dandy I can adjust the with the proper clearence and the clutch works. the problem is that after the slave is actuated the rod will only extend about 2 1/2 inches and the bearing is riding. It does this hooked to the fork or not hooked to it does not matter. Im am going insane trying to get this thing to work. Im about ready to switch to a cable set up

[blykins]

Originally Posted by mpanten

I really wish someone would post the correct answer to this one. I have almost the exact same problem. I am using the pull type set up f. Fully extended the rod coming out of the slave is 3 and 3/8 inches. Fine and dandy I can adjust the with the proper clearence and the clutch works. the problem is that after the slave is actuated the rod will only extend about 2 1/2 inches and the bearing is riding. It does this hooked to the fork or not hooked to it does not matter. Im am going insane trying to get this thing to work. Im about ready to switch to a cable set up

Mark, I think your case would necessitate a return spring. If the slave cylinder isn't extending back to full stroke, then you'll probably need to help it.

[mpanten]

Brent,

I have one, Forte tells me I shouldn't need one but better safe than sorry. To much force is required to push it back with a return spring, I can do it by hand by pushing on the fork or pulling on the rod. Am i correct in assuming that if the slave is not hooked to the fork that it should automatically return to full extension?

[Excaliber]

My ERA is an early one, #154, Pats is a late one #732. Many years apart, same slave cylinder, simple, effective, works. I've had this same basic setup, slave and spring on many different kinds of cars over the years. The biggest problem I encountered was where to hook the spring? Sometimes a hose clamp on a header tube, funky, but gets the job done.

I don't know why some guys are having trouble with the spring not being able to return the fork to it's lowest position. Thats a head scratcher....

[Excaliber]

Some of these slaves must have a very powerful spring inside them? An internal spring will indeed push on the fork until the throw out bearing stops that action by contacting the pressure plate fingers. Normally a modest external return spring, properly affixed, is enough to overcome both the internal spring AND force the hydraulic fluid out of the slave, up the line and back into the master cylinder. A restriction in the return of the fluid to the master cylinder, therefore, would also have to be a consideration in this scenario.

The ERA uses a BMW slave, I have had mine apart. That spring isn't very strong, it's quite mild in fact. But it's strong enough to slowly push the slave piston forward and the throw out bearing against the P.P., which is why I run a return spring and an adjustable rod to set the allowed clearance of the throw out.

[mpanten]

I here what you are saying and agree, mine is a pull type which i need to push the fork and bearing away from the pp when i release the clutch but it is not fully extending back to it's original positon when I release it, it's about an inch short, even when not hooked to the fork it wont fully extend to it's original position.

[maxum_101]

got to bump this one back up.... we need to resolve this once and for all

[mpanten]

In case anyone is interested here is what I found out. This comes from Mike Forte himself not me so it should count for something.

The throw out bearing initial specs are clearence before start up with the slave fully extended. According to Mike the rod on the slave will not fully extend back to the full length (at least on his model) after the clutch is engaged and release. In other words if you press the clutch, the length the rod exteneds out of the slave will change.

If you can reach up and move the rod farther by pushing or pulling on the fork then it is working properly. The extra air gap/movement in the slave is there to allow the fingers of the pressure plate to expand. In other word the slave and throwout will return to it's preffered or so to speak natural position.

I hope I explained correctly and Mike or Brent if you are reading this please correct me if I am wrong.

[maxum_101]

so.... does the bearing always spin?

[Excaliber]

MOST of replicas have an after market clutch system, it's simple. Follow the manufacturers recommendation.

About the only guys that might have an OEM stock unit (Ford) would be a "donor" type build, like an FFR or maybe a Classic Roadster. Your first clue would be a "cable clutch". Many of those WITH a cable clutch either replace the cable with an adjustable after market unit or figure out how to get the clearance. Not everyone believes Ford has a better idea, especially when they just installed that new $500 after market clutch!

It's really not complicated at all, you need to follow the clutch manufacturers specifications (.100 to .300 clearance generally speaking, 1/4"). 95% of replicas will be running an aftermarket clutch.

[CobraEd]

much ado about nothing.


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[patrickt]

Originally Posted by CobraEd

much ado about nothing.

I agree. Even if you rag your TOB out so it only lasts 10k miles that means most of us will only end up changing it out once or twice in our lifetime. And even then it's a weekend job (an afternoon's job for ERAChas....).

[ERA Chas]

-and then head to the haberdasher...

[Excaliber]

...much ado about nothing.

Do you have a clue how often this question is asked, a new thread started? This is like the third one in the last month. The question comes around every few months. The easy and typical answer is "don't worry about it". The RIGHT answer is, "Ask the manufacturer of your clutch." Don't know who that is, don't know how to find out? Then the answer for you is "don't worry about it, your to stupid to fix it anyway."

[CobraEd]

Yes the question has been asked and the answer is that for most environments, this is not an issue. It is not a fuction of HP, but of throwout bearing/clutch design. Asking the question and getting the wrong answer by telling people to fix what is not broken are not the same thing. There are millions of cars in the world that have gone hundreds of thousands of miles like this with no issues.

Ford would not "overlook" this for decades and millions of cars. There have been no problems or recalls whatsoever.

Yes I istalled my own RAM aluminum SFI flywheel, Ford Racing King Cobra clutch and McLeod SFI rated bellhousing. Did you install yours?


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[patrickt]

Originally Posted by Excaliber

Then the answer for you is "don't worry about it, your too stupid to fix it anyway."

Ernie -- I thought we were all trying to be nicer to one another.

[Excaliber]

I know Pat, I'll try one of the pink pills....

Sometimes, the truth hurts. Most of us could likely ignore the whole issue, but someone, somewhere IS going to get burned. Know the truth, then make an informed decision that your comfortable with.

[CobraEd]

I am going to recomend that everyone jump through their ass to replace their throttle cables with drive by wire systems. There have been reports that due to the inner cable and outer sheath of the throttle cable rubbing together during throttle use, there is a chance that the cable could wear out after 1,000,000,000 miles. THIS IS UNACCEPTABLE !!!!!!



Sorry, . . . I had to do it !!


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[Excaliber]

So what throw out bearing did you run Ed? OEM Ford? After market? Off the shelf from NAPA? It makes a difference. I've seen throw out bearings go out in as little 4,000 miles.

From the web site "ModedMustangs", where you can find plenty of threads about folks who have had to replace their throw out bearings in a few thousand miles.

Recently i had a king cobra clutch kit installed and after about 2500 miles the throw-out bearing started making noise.

[lal Naja]

Stallion112,

Thanks for the enlightening TOB historical report. It is based on your post that I now feel confident about the pre-load on my TOB.

Arthur