I just got my car together, and put about 300 miles on the new motor. I had taken apart my Street Twin during the downtime and cleaned it up. It was previously working fine. After about 300 miles I developed this grinding vibration when driving and while stopped clutch pushed in and reving the motor. Clutch still engaged and disengaged fine. Fearing the worse (something went wrong in the engine) I removed the tranny and clutch (kept the flywheel on) and started the car. Motor runs smooth and no vibration or grinding. I was figuring on a bad throwout bearing or something, but that looked OK as well. It was pretty loose flopping around in it's spring retainer inside the PP spring fingers, but it still spun fine. I had the flywheel ballenced with the crank and the harmonic ballencer. Could the PP be off ballance, and if so why did it wait till 300 miles to start having a problem? The disks looked a little worn, one close to the rivits. I'm thinking of just sending it in to have McLeod rebuild it. Any comments?

Bill

 

If its grinding, then the clutch fork is hitting the PP. It needs to have a little less pedal travel. Try backing off the rod end on the master cylinder by a half a turn.

 

It does it with the clutch in or out. Release is right at the top of the clutch travel. Everything was fine with the stock crankshaft for 10K miles. Now with the new crank I'm having problems? I have the clutch out of the car now. I'll take a look and see if I can see where it was rubbing. I'll try adjusting the master and see how that works.

Bill

 

Well I took a look and found no rub marks. On a closer inspection of the throwout bearing I think it is shot. It does spin, but feels very "gritty" and it does wobble slightly when you hold the outside housing.

Can you just get a regular LT1 throwout bearing for the street twin? I know it still used the Valeo pressure plate, so maybe? I'll have to give McLeod a call on Monday.

Bill

 

Yes, you can use stock thorw out bearing. I did'nt see that part about the clutch in or out. How bad is the vibration. Somethng like that might happen if you dont like up the blue marks.

 

Blue marks??? Well if there was any blue marks they are gone now... Clutch is 4 years old or so, just not alot of miles on it. Been cleaned when it was out.

 

the Twin is balanced as a entire assembly.. so chance's are the floater is not where it used to be.. The blue mark's are there.. just gotta look.. they stay for quite awhile.. Best bet if you have it out is to just send it back to mcleod and let them neutral balance it..

 

I can have it ballenced here locally, but not neutrally ballenced. The flywheel was ballenced to the crank and hub. The machine shop that did the ballencing marked the flywheel with what it was supposed to be. I'll take the entire thing back and have it all ballenced.

Bill

 

It would just be better to let mcleod balance it than. The flywheel, floater and pressure plate all have a blue mark on them that is supposed to line up when assembled. If it's not put back together that way, it will be out of balance and cause those vibrations.

 

yea i'm willing to bet the floater is not balanced properly.. if you get the floater and the pp neutral balanced separately youmight be fine w/ leaving the flywheel alone.. But it needs to be perfect!