Disengagement issues - Street Twin
05-19-2008, 05:12 PM
#1
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Join Date: Jul 2004
Posts: 31
Disengagement issues - Street Twin
My clutch is not disengaging all the way. Or at least thats what the symptom appears to be. I have a tough time shifting through all the gears. No grinding or anything just a bit of delay when going to the next gear. I don't wanna rail on it cuz the tranny is brand new (Not rebuilt, brand new, prolly about 100-125 mile on it).
I have the McLeod Master Cylinder and have bleed the hydraulics like I always have and have used the mighty vac method. The system is well bled and yes the restrictor in the line has been removed. I should also add that a fresh pilot bushing is in there and I did reshim the clutch within spec. I did this years ago however I have not touched the car in years since I put this setup together.
Frustrated I call McLeod and they tell me I need a 1" throw at the slave for disengagement. I crawl under the car and I'm getting about 3/4" maybe a lil less. I took the hydraulics completely apart, cleaned them thoroughly, re-assembled and I still get the same result. Some people suggested running a modified stock master. I have tried that and I'm still getting the same result.
On the multiple attempts of bleeding, trying different masters and what have you I have tested it with the car running via revving it then hitting the clutch and trying to put it in gear - same result with tough shifting. No grindage has occured. The pedal seems to grab at the top and I've adjusted it all different ways and I get the most throw with it adjusted all the way out (obviously). The pedal has a good feel to it and all but for the life of me I can't get it to go into gear smoothly.
So before I drop my exhaust and pull the tranny, reshim the clutch and get a new pilot bushing does anyone have any suggestions or experiences to share? As thrilling as going through all that trouble, if the slave isn't getting its 1" throw I don't see how it will rectify the situation and it just could be all for nothing.
I have the McLeod Master Cylinder and have bleed the hydraulics like I always have and have used the mighty vac method. The system is well bled and yes the restrictor in the line has been removed. I should also add that a fresh pilot bushing is in there and I did reshim the clutch within spec. I did this years ago however I have not touched the car in years since I put this setup together.
Frustrated I call McLeod and they tell me I need a 1" throw at the slave for disengagement. I crawl under the car and I'm getting about 3/4" maybe a lil less. I took the hydraulics completely apart, cleaned them thoroughly, re-assembled and I still get the same result. Some people suggested running a modified stock master. I have tried that and I'm still getting the same result.
On the multiple attempts of bleeding, trying different masters and what have you I have tested it with the car running via revving it then hitting the clutch and trying to put it in gear - same result with tough shifting. No grindage has occured. The pedal seems to grab at the top and I've adjusted it all different ways and I get the most throw with it adjusted all the way out (obviously). The pedal has a good feel to it and all but for the life of me I can't get it to go into gear smoothly.
So before I drop my exhaust and pull the tranny, reshim the clutch and get a new pilot bushing does anyone have any suggestions or experiences to share? As thrilling as going through all that trouble, if the slave isn't getting its 1" throw I don't see how it will rectify the situation and it just could be all for nothing.
05-21-2008, 10:15 PM
#4
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Join Date: Oct 2006
Location: Rochester Hills, MI
Posts: 747
What is your mighty vac technique?
My street twin is 4 days old, about 100 miles. I had adequate travel using the stock hydraulics until today, and the pedal felt firm once the free play from the pedal was gone. Less than 1" pedal motion.
Today, I couldn't disengage fully, as indicated by difficulty shifting out of neutral when stopped. Also, the pedal was soft for 1", then medium for the next inch, then normally firm after that. I suspected bleeding was necessary. I mighty vac'd it with pedal pumping, but little or no change. Then I mighty vac'd it, and while there was vacuum on the system, I pulled the slave and pumped the piston all the way in by hand and held it a minute or two to let the air climb up the hose. Had to be careful not to let bubbles back into the system when I hit the vacuum release lever - I wound up overfilling the reservoir and just pulling the vac fitting out, rather than using the vacuum release lever. Repeated the process again. Back to normal.
How do you check this?
My street twin is 4 days old, about 100 miles. I had adequate travel using the stock hydraulics until today, and the pedal felt firm once the free play from the pedal was gone. Less than 1" pedal motion.
Today, I couldn't disengage fully, as indicated by difficulty shifting out of neutral when stopped. Also, the pedal was soft for 1", then medium for the next inch, then normally firm after that. I suspected bleeding was necessary. I mighty vac'd it with pedal pumping, but little or no change. Then I mighty vac'd it, and while there was vacuum on the system, I pulled the slave and pumped the piston all the way in by hand and held it a minute or two to let the air climb up the hose. Had to be careful not to let bubbles back into the system when I hit the vacuum release lever - I wound up overfilling the reservoir and just pulling the vac fitting out, rather than using the vacuum release lever. Repeated the process again. Back to normal.
How do you check this?
Last edited by JP95ZM6; 05-21-2008 at 10:24 PM.
05-23-2008, 09:59 AM
#5
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Thread Starter
Join Date: Jul 2004
Posts: 31
http://performanceworks1.com/ls1_clutch_bleeding.htm
So the clutch is disengaging for you now? Do you have the adjuster on the master all the way out for maximum pedal travel?
Another test to check if you're getting disengagement is sit there at idle with the stick in neutral. Give it a feather rev to about 3k, let off the gas and as the RPMs go down, hit the clutch pedal and try shoving it in third or reverse as some people like to do... If the car moves, gear grinds, or is hard to put in theres still an issue. For me the car moves a few inches before the stick goes in and is hard to go in as a result. I've had people suggest the transmission might be binding due to a bad pilot bushing or something - which may be true, however I'm still not getting 1" of throw at the slave that is required. I may still drop the tranny, redo everything and throw it back together but before I get into that I'd like to find a solution to the hydraulic issue. I'm tempted to buy McLeod's slave cylinder, it has a bleeder screw on it for quick line bleeding. This may help, I could have a bad slave, but it's a simple piston and all the seals are good but who knows...
I take the spacer or dust cover, whatever you wanna call it, off the slave cylinder. I put the slave back on and tighten the unit down to the same point it would be at if the spacer was still on. I then use a slim tape measure to measure the travel.
My street twin is 4 days old, about 100 miles. I had adequate travel using the stock hydraulics until today, and the pedal felt firm once the free play from the pedal was gone. Less than 1" pedal motion.
Today, I couldn't disengage fully, as indicated by difficulty shifting out of neutral when stopped. Also, the pedal was soft for 1", then medium for the next inch, then normally firm after that. I suspected bleeding was necessary. I mighty vac'd it with pedal pumping, but little or no change. Then I mighty vac'd it, and while there was vacuum on the system, I pulled the slave and pumped the piston all the way in by hand and held it a minute or two to let the air climb up the hose. Had to be careful not to let bubbles back into the system when I hit the vacuum release lever - I wound up overfilling the reservoir and just pulling the vac fitting out, rather than using the vacuum release lever. Repeated the process again. Back to normal.
Today, I couldn't disengage fully, as indicated by difficulty shifting out of neutral when stopped. Also, the pedal was soft for 1", then medium for the next inch, then normally firm after that. I suspected bleeding was necessary. I mighty vac'd it with pedal pumping, but little or no change. Then I mighty vac'd it, and while there was vacuum on the system, I pulled the slave and pumped the piston all the way in by hand and held it a minute or two to let the air climb up the hose. Had to be careful not to let bubbles back into the system when I hit the vacuum release lever - I wound up overfilling the reservoir and just pulling the vac fitting out, rather than using the vacuum release lever. Repeated the process again. Back to normal.
Another test to check if you're getting disengagement is sit there at idle with the stick in neutral. Give it a feather rev to about 3k, let off the gas and as the RPMs go down, hit the clutch pedal and try shoving it in third or reverse as some people like to do... If the car moves, gear grinds, or is hard to put in theres still an issue. For me the car moves a few inches before the stick goes in and is hard to go in as a result. I've had people suggest the transmission might be binding due to a bad pilot bushing or something - which may be true, however I'm still not getting 1" of throw at the slave that is required. I may still drop the tranny, redo everything and throw it back together but before I get into that I'd like to find a solution to the hydraulic issue. I'm tempted to buy McLeod's slave cylinder, it has a bleeder screw on it for quick line bleeding. This may help, I could have a bad slave, but it's a simple piston and all the seals are good but who knows...
How do you check this?
05-23-2008, 11:16 AM
#6
Registered User
Join Date: Oct 2006
Location: Rochester Hills, MI
Posts: 747
That is the method I tried first, with poor result. Pushing the piston in with vacuum applied got additional air out for me.
Yes, disengaging fine with STOCK m/c. My adjustable is on back order from Mcleod.
Thanks for explaining the travel check.
Did you check the shims for the floater disc to make sure all 3 are at .020 to .025 air gap between the floater and the bottom disc, per the instructions? I had to change mine to get it in spec. Wound up with 4 of the thin shims on one post, 2 on another, 0 on the 3rd. If your hydraulics are truly bled, I suspect the shimming is off, and the floater is dragging on one of the clutches.
Yes, disengaging fine with STOCK m/c. My adjustable is on back order from Mcleod.
Thanks for explaining the travel check.
Did you check the shims for the floater disc to make sure all 3 are at .020 to .025 air gap between the floater and the bottom disc, per the instructions? I had to change mine to get it in spec. Wound up with 4 of the thin shims on one post, 2 on another, 0 on the 3rd. If your hydraulics are truly bled, I suspect the shimming is off, and the floater is dragging on one of the clutches.
Last edited by JP95ZM6; 05-23-2008 at 11:19 AM.
05-29-2008, 09:10 PM
#8
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Join Date: Oct 2006
Location: Rochester Hills, MI
Posts: 747
Good luck. I didn't see this yesterday, so I hope it worked out, or you are not done yet. I PM'd you in case you want to call with any questions. I thought of a couple more tips, too, relative to how I did it:
Note that feeler gages are sensitive to the 'tightness' of the floater measurement. In other words, since the floater is on springs, you can get too big a feeler in there if you let the springs deflect much.
Also, I found that my clutch disc had slight thickness variation, and the measurement was only repeatable after I marked a spot on the disc, and used that same spot for each shim measurement.
Note that feeler gages are sensitive to the 'tightness' of the floater measurement. In other words, since the floater is on springs, you can get too big a feeler in there if you let the springs deflect much.
Also, I found that my clutch disc had slight thickness variation, and the measurement was only repeatable after I marked a spot on the disc, and used that same spot for each shim measurement.
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