Throw out bearing always makes contact? - Page 3

coosawjack · #41 (**permalink**) 04-13-2010, 03:37 PM

FWIW...I had a '92 Mustang 5.0 that I put 90K miles on with the throw out in constant contact with zero problems!!

My Cobra is the same way with many miles on it over 10 years with zero problems!!

Whoever gave the wheel bearing analogy was spot on....it ain't a problem and won't hurt a thing!!!

Excaliber · #42 (**permalink**) 04-13-2010, 05:30 PM

I recently ordered a TKO from Blykins (Brent, B2 Motorsports).

Well my new clutch and trans parts have been arriving the last few days. TKO-600 with big Ram clutch, pressure plate, all that. I'm looking over the paperwork that came with the clutch. Typed in BOLD under "clutch adjustment" is this little blurb.

Quote:

90% of clutch related problems/warranty claims are due to improper release bearing adjustment.

The paperwork goes on to specify a minimum 0.250 clearance.

patrickt · #43 (**permalink**) 04-13-2010, 05:32 PM

Quote:

Originally Posted by Excaliber

I recently ordered a TKO from Blykins (Brent, B2 Motorsports).

Well my new clutch and trans parts have been arriving the last few days. TKO-600 with big Ram clutch, pressure plate, all that. I'm looking over the paperwork that came with the clutch. Typed in BOLD under "clutch adjustment" is this little blurb.

The paperwork goes on to specify a minimum 0.250 clearance.

No doubt written in blood from Brent's very finger.

tcrist · #44 (**permalink**) 04-13-2010, 05:37 PM

OK, So I have a cable clutch so there is really no adjustment. The throw is what ever the clutch pedal is designed to give. This design has been working for Classic Roadster since the begining of CR. I agree that I don't like it. So, how do I fix it without re-locating the clutch pedal. Any ideas Ernie, Brent, Mike, ect?

mpanten · #45 (**permalink**) 04-13-2010, 08:02 PM

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

Excaliber · #46 (**permalink**) 04-13-2010, 09:15 PM

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....

blykins · #47 (**permalink**) 04-14-2010, 02:45 AM

Quote:

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 · #48 (**permalink**) 04-14-2010, 06:28 AM

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 · #49 (**permalink**) 04-14-2010, 07:18 AM

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 · #50 (**permalink**) 04-14-2010, 07:33 AM

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 · #51 (**permalink**) 04-15-2010, 08:58 AM

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

mpanten · #52 (**permalink**) 04-15-2010, 09:15 AM

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 · #53 (**permalink**) 04-15-2010, 01:33 PM

so.... does the bearing always spin?

patrickt · #54 (**permalink**) 04-15-2010, 02:05 PM

Quote:

Originally Posted by maxum_101

so.... does the bearing always spin?

If anyone is interested, there is a nice outline of the differences between "continuous contact" TOBs and "non-continuous contact" TOBs in the book Light and heavy vehicle technology by Nunney. You will see that they are two completely different animals. Here's a link that I think will work, and you should go to page 274 and start there. http://books.google.com/books?id=eL6...page&q&f=false

jhv48 · #55 (**permalink**) 04-15-2010, 02:43 PM

If I read that right, both systems are just fine.

maxum_101 · #56 (**permalink**) 04-15-2010, 03:07 PM

hahahaa this is just nuts,

patrickt · #57 (**permalink**) 04-15-2010, 03:16 PM

Quote:

Originally Posted by jhv48

If I read that right, both systems are just fine.

Both are just fine. But they are two entirely different systems, with entirely different components. It is imperative that you know what system you have in your car. I know what system I have in my car (non-continuous) but I don't know what you, or someone else, has in their car. Once you know what system you have, only then can you determine whether it is set up correctly and functioning properly. So, the correct answer to the question "should my TOB be in continuous contact" is "it depends."

jhv48 · #58 (**permalink**) 04-15-2010, 03:18 PM

I give up!

patrickt · #59 (**permalink**) 04-15-2010, 03:25 PM

Quote:

Originally Posted by jhv48

I give up!

I'm really not trying to be difficult, but if we had the actual part numbers that would help track down what car set up they were made for. Absent that, you'll have to track down the guy that actually installed the parts and ask him whether the setup is for a continuous contact system. They're two different systems, like hydraulic and solid lifters. They both do the same thing, but they're different and you adjust them differently.

EDIT -- In other words, if you do have a continuous contact system, you should NOT install a fork return spring -- it would defeat the purpose of the whole design.

mpanten · #60 (**permalink**) 04-15-2010, 04:28 PM

They way I understand it is that yes it will spin but it will not be under pressure as the ford set up. I guess there is a difference in spinning and having it spin under 7-10 lbs of pre load. Again, this comes directly from Mike Fortes and he has forgotten more about these things than I will ever claim to know.