Clutch fork travel - Page 3

lippy · #41 (**permalink**) 02-02-2014, 09:11 PM

Patrick, we are thinking along the same lines. First, I took the clevis out of the master cylinder link (outer hole, BTW) and rotated the arm to move the clutch pedal toward the seat, so I get maximum travel. Then, I put the nose in the air and bled the slave again after tapping gently with a plastic hammer. With all of that, I got 0.80" of travel where the rod meets the fork, and my clutch wouldn't disengage (even though McCleod tells me it should need only 0.35" at the bearing). This *feels* like I'm not getting enough travel at the fork. I'm really confounded.

lippy · #42 (**permalink**) 02-02-2014, 10:05 PM

I preloaded it by about 0.25" - maybe a bit more. So with the preload, position of the clutch pedal, and slave stroke, I'm getting probably 1.10". Still no dice. I put it in gear, had my wife press the clutch, and it was still engaged (couldn't move the car). Bummer.

DanEC · #43 (**permalink**) 02-03-2014, 04:38 AM

Quote:

Originally Posted by lippy

I preloaded it by about 0.25" - maybe a bit more. So with the preload, position of the clutch pedal, and slave stroke, I'm getting probably 1.10". Still no dice. I put it in gear, had my wife press the clutch, and it was still engaged (couldn't move the car). Bummer.

I guess you are putting it in a higher gear (5th) to try to turn by the rear wheels - correct? Hate to ask as it should be obvious, but you definately have something odd going on here.

Since Brent installed the clutch and flywheel, I assume he used the proper ARP bolts and they are not too long and binding on the back of the block or bellhousing plate when the clutch is pushed and the thrust bearing clearances are taken up. Have you rotated the engine by hand at all since receiving it? It's not locked up by the starter motor is it? I guess a test would be to pull the plugs and try to rotate the motor from the balancer bolt while someone is pushing in the clutch.

I'm kind of afraid this is all pointing back to the input shaft length again or something on the clutch installation.

http://www.mcleodracing.com/info/?id=5027

patrickt · #44 (**permalink**) 02-03-2014, 05:19 AM

Last ditch effort -- remove the slave rod and fasten a ratchet strap to the rear frame area of the car and the front of the strap to the end of the clutch fork. See if you can normally disengage the clutch by ratcheting the strap tight. If that fails, then you must pull the bell housing off and look inside to see wtf is going on. Who knows, it could be something really bizarre like a bolt from the factory that is stuck inside the pressure plate somehow. But if you can't disengage the clutch manually, by eliminating the entire slave/hydraulics/master/pedal assembly side of the equation, then the problem is inside the bell housing.

Dominik · #45 (**permalink**) 02-03-2014, 06:50 AM

I also would try to activate the clutch fork manually to get a feel of the needed travel.
My memory tells me it must be about 2" - which depends on the ratio of the fork, of course.

That 90 deg fitting at the slave can be a bear to bleed. Those kinks lead to cavitation (bubbles), if you don't bleed very slowly. How did you bleed? By pumping the pedal?

I would make a new line, without that union and a 45 deg bend on either end, or at least a 90 deg bend - not a kink.

What diameter is your feed line from the reservoir? Fluid needs to run freely when you bleed.
5/16" ID is good.

blykins · #46 (**permalink**) 02-03-2014, 07:09 AM

I suspect something with the trans fitment, maybe the bearing retainer is binding on the pressure plate??

Even if the engine was locked up solid, you should be able to push the clutch in and break the connection between the engine and trans. All you're trying to do is hit the fingers and spring the plate out enough that you have an air gap between discs.

McLeod has specific directions when assembling the clutch, where to check if the discs are spinning freely, etc., and I did not notice anything abnormal. I assemble clutches with my own billet steel alignment tool from RAM, not a cheap plastic tool, so it's as aligned as it's going to get.

lippy · #47 (**permalink**) 02-03-2014, 10:12 AM

Quote:

Originally Posted by DanEC

I guess you are putting it in a higher gear (5th) to try to turn by the rear wheels - correct? Hate to ask as it should be obvious, but you definately have something odd going on here.

Since Brent installed the clutch and flywheel, I assume he used the proper ARP bolts and they are not too long and binding on the back of the block or bellhousing plate when the clutch is pushed and the thrust bearing clearances are taken up. Have you rotated the engine by hand at all since receiving it? It's not locked up by the starter motor is it? I guess a test would be to pull the plugs and try to rotate the motor from the balancer bolt while someone is pushing in the clutch.

I'm kind of afraid this is all pointing back to the input shaft length again or something on the clutch installation.

McLeod Racing - How To Properly Install The "Original" Street Twin.

Dan, it shouldn't matter what gear it's in or even if the engine is locked. When I press the clutch with the trans in gear it should disengage the trans from the engine and I should be able to roll the car (or turn the wheels if they are jacked up). I can turn the wheels when it is in neutral, so I know there is no problem on that end. Thanks.

Jerry Clayton · #48 (**permalink**) 02-03-2014, 11:11 AM

Well---------------it does matter what gear your in because you are dealing with a new clutch with dual discs and a first time install-------- possibility of bent disc center, disc facing wrong way, hub not clearing bolt heads, etc, etc--------without the engine running/car rolling ot is a fairly common occurrence---there isn't enough movement to free the dual discs completely and you are dealing with the rear end ratio times the gear ratio of the gear the trans is in when you try to turn them-for example---a 3.90 rear gear times a 3.xx first gear would mean that you would turn the clutch discs aprox 12-14 revolutions for one rear tire turn-------

Also ---does the car have a posi???? both wheels off the ground???????
I would suggest getting under the car with a strap wrench around the drive shaft and see if you can turn the shaft with trans in the direct drive gear (what trans???? might be 4th with a overdriven 5/6 speed)

And you also can also try rotating engine with starter while clutch depressed /trans in gear

blykins · #49 (**permalink**) 02-03-2014, 01:23 PM

It could be that easy, but my only concern is that it's a stacking of tolerances between the bell, the trans, the block plate, etc, and that when he bolted the trans up, it mashed everything together. In that scenario, I wouldn't want him bumping the starter or starting the engine, just in case it's got the crank up against the thrust bearing.

DanEC · #50 (**permalink**) 02-03-2014, 01:35 PM

Quote:

Originally Posted by lippy

Dan, it shouldn't matter what gear it's in or even if the engine is locked. When I press the clutch with the trans in gear it should disengage the trans from the engine and I should be able to roll the car (or turn the wheels if they are jacked up). I can turn the wheels when it is in neutral, so I know there is no problem on that end. Thanks.

Lippy - you're right - other than what Jerry added in my defense my thinking took a detour.

Parking brake is off - right? I'm out of here.

Dan

patrickt · #51 (**permalink**) 02-03-2014, 01:58 PM

Quote:

Originally Posted by DanEC

Parking brake is off - right?

I'm now waiting for the "oh yeah, parking brake, uhhhh wait a minute while I run out to the garage and check.... ahhh, jeez, I can't believe it...."

DanEC · #52 (**permalink**) 02-03-2014, 02:04 PM

double post

lippy · #53 (**permalink**) 02-03-2014, 02:19 PM

Quote:

Originally Posted by patrickt

I'm now waiting for the "oh yeah, parking brake, uhhhh wait a minute while I run out to the garage and check.... ahhh, jeez, I can't believe it...."

Yeah, parking brake off. I solved that problem when the wheels weren't turning with the trans in neutral. Scratched my head for a minute and then figured it out. I wish this problem were that simple, and would clearly trade the embarrassment for the PITA of backing out the trans later tonight. Stay tuned.

patrickt · #54 (**permalink**) 02-03-2014, 02:48 PM

Ratchet strap the fork first before you pull your transmission. If you disengage the clutch with a strap, then you should be able to do it with a properly functioning master/slave.

frdfver · #55 (**permalink**) 02-03-2014, 04:52 PM

Its been my experience over the years if you have to pull the trans in with the bolts something is to tight or not right in the clutch, pilot bearing input shaft clearance, clutch hub spline interference, etc. I would also check the total travel on the slave by itself. It looks like the slave mount is held on the slave with clamp bolts, are they tightened down to tight deforming the cylinder?

Paul T.

lippy · #56 (**permalink**) 02-03-2014, 06:13 PM

Quote:

Originally Posted by frdfver

Its been my experience over the years if you have to pull the trans in with the bolts something is to tight or not right in the clutch, pilot bearing input shaft clearance, clutch hub spline interference, etc. I would also check the total travel on the slave by itself. It looks like the slave mount is held on the slave with clamp bolts, are they tightened down to tight deforming the cylinder?

Paul T.

What I keep coming back to is that I get almost an inch of travel from the slave right now. Even more when I preload it. McCleod says I only need 0.35-0.4" at the clutch, and the fork ratio is 1.75:1. I should have more than enough travel. I'm suspecting it's something else, as you point out.

lippy · #57 (**permalink**) 02-03-2014, 11:03 PM

At Brent's suggestion, I pulled the trans mount bolts, supported the car and engine, loosened the trans bolts about 0.25", and pulled the trans back about that far. Everything worked fine. The clutch released, and there was plenty of travel at the throw-out bearing. As a check, I then pushed it back in so there was only about 0.1" between the bell and the trans mount, and it didn't release. It seems like there is something up with the pilot bearing. I also rechecked the clearance for the trans input shaft and it seems like I'm fine there. After that, I pulled the trans.

tkb289 · #58 (**permalink**) 02-04-2014, 03:09 AM

lippy,

Sounds like you have found the problem area, seems like the transmission input shaft is engaging too far into the crankshaft / pilot bearing and bottoming out. Not sure which bell housing you have, but on page 12 of the ERA FIA manual (same as the 427 manual?) it states for the TKO 500/600 that some bell housings require a 5/8" spacer.

I used a quicktime bell housing & TKO 600 and had no fitment issues on my 302. What bell housing are you running on your 427?

If you pull the transmission all the way out, you should be able to measure how far the input shaft protrudes past the bell housing / engine block mounting plane. There should be a spec for what the maximum length is for that dimension. If it's too far, then you need the spacer.

blykins · #59 (**permalink**) 02-04-2014, 04:12 AM

No spacer needed here as it's a standard length TKO bellhousing with an RM-6056 Quicktime.

At least he's finding more clues though.

Here's a couple of thoughts that I have:

The portion of the input shaft where the pilot end meets the splined end is hitting on the pilot bushing, or the bearing retainer on the trans is hitting the pressure plate. A couple of quick measurements can rule both out.

He's already measured to make sure that the pilot end is not bottoming out in the crank, and a pilot bushing is thicker than 1/4", so I think the pilot is still in the bushing, even when he scooted the trans back.

DanEC · #60 (**permalink**) 02-04-2014, 04:52 AM

Quote:

Originally Posted by blykins

or the bearing retainer on the trans is hitting the pressure plate.

Brent - do you mean hitting the outer clutch disc instead of pressure plate?

I notice that the bearing retainer is .6 inch longer on the GM version versus the Ford version. I don't guess you managed to get a GM version by chance?

http://www.jegs.com/p/Hurst-Drivelin...13608/10002/-1