My 70 Nova project (Formerly looking at this mustang)

Hello,
Don't know about the hydraulics either, but I've also heard a couple of complaints about pilot bushings being a problem. After doing as suggested by extropics it might not hurt to ream the bushing by another .005"-.010" or so.
 
Yes, barely push the pedal down and it releases, or engages at the very top of the travel. I have some adjustment on the clutch master push rod, haven't messed with this yet but I will. I don't think where it releases or engages is the problem, but I will adjust it later.

I'd love to dial the bell housing in, but as I said due to the design I don't see a way to do that. (see pic)

I can indicate the pilot bushing, will have help this weekend to try that.

Others have suggested that I have air in the hydraulic system. I don't. Tried for a long time to bleed it with pushing the pedal and nothing. Then found this on youtube. Had it bleed in just a few minutes. Solid pedal, doesn't pump up at all.


20220421_122914.jpg20220421_131144.jpg
 
Bone Head said:
Hello,
Don't know about the hydraulics either, but I've also heard a couple of complaints about pilot bushings being a problem. After doing as suggested by extropics it might not hurt to ream the bushing by another .005"-.010" or so.
Click to expand...
You posted when I was writing my last reply.

I'm considering doing that. It's just the spare input shaft I have slides in so easily. As a machinist I'd actually like to close the clearance up some.

You can see the nose of my input in the last pic above. Looks great, no galling or evidence of it seizing or bronze dust on it.
 
The picture of the BH educates me. LOL
I think I see two holes for dowels, in the BH trans flange, and I assume the dowels are in place in the trans?

The very high contact/release position of the clutch may be a clue that the clutch is not completely disengaged when the pedal is fully up.
I understand "I have some adjustment on the clutch master push rod". If the rod is too long, the pedal "up stop" may be keeping the throw out bearing pressing on the pressure plate (clutch not 100% engaged). Making the rod shorter should let the pedal fully release the throw out bearing and move the clutch engage/disengage feel further down in the pedal travel.

However, I don't see how having the clutch engage/disengage further down in the pedal travel will fix the "I couldn't get it into gear" issue.

Is it possible the clutch disc has been in backwards?

Ahh! I just made up this theory. The "too long" push rod is preventing the master cylinder piston from retracting enough to get a "full stroke". The shortened stroke is not fully releasing the clutch. That theory is congruent with your symptoms. I hope it's consistent with the way the system hydraulics are intended to function.
 
Both dowels are in the transmission. It was missing one when I put it together a couple of years ago, but I have a spare dowel in the trans I use for a test stand for my speedometer conversions and I stole one out of that.

The way the release bearing is made it has a spring on it and is in contact with the pressure plate fingers all the time. I've never seen one like that, but that's how they designed it. Wish I could change that somehow. From what I can measure the bearing is compressed 1.100 inches.

The clutch push rod has play, so not pushing down the master cylinder piston. I'll adjust the position later and as you say that pedal position shouldn't have anything to do with the problem I'm having. I remember when I put the T56 in my Camaro I had a very high pedal engagement on the clutch also. I modified the push rod to be adjustable and ran it like that for over 40k miles. But, it doesn't have the hydraulic release bearing like this one does, has a clutch fork setup powered by hydraulics and the same exact master setup.

The disk can only go in one way. I've seen people put it in backward and forced the pressure plate on before and trashed stuff.

I've posted this on a Nova LSX forum and several say it's that I've not bled the system. I've tried to tell them how to bleed these setups many times but you can lead a hot rodder to beer, but can't make him guzzle it. Tried to explain the problem that it works for a little while, then can't get into gear, start it in gear to "break" what ever it is lose and it works perfectly for a little while. If it wasn't bleed completely it wouldn't work at all, not even for one time much less for a couple of 3 mile test drives.

But I understand people are trying to help and I really appreciate that. They don't know what experience I have and that I've been a machinist for 30 years and busting my knuckles on cars for 54 years.

One person suggested getting a completely new clutch setup and go from there. It's a $500 gamble and if it doesn't cure the problem I can't really take the part back. Again, that would turn me into a parts changer and not a mechanic. But, I may have no choice. I can't find anything wrong with what I have now.
 
I'm stumped. Good luck. Be sure to educate us when you get it sorted out.
 
Thanks, I will et you know.

Someone on the LS swap group said since it's happens after I drive it and it sets for a few and heat soaks possibly the bronze bushing is closing up, and maybe the input shaft is expanding. If that's the case as it's closing up drag is increasing and building up heat and it gets worse as it sits when I shut it off. So makes some sense. But still there is no indication of it seizing up. But I'm ready to try almost anything at this point.

A stock 2000 LS camaro pilot bushing is a roller bushing. I have a cheap one but decided to go with a bronze one instead. I'm not sold on a roller pilot bushing. Been using bronze ones for 50 years now, hard for me to change now, but have to change something.
 
I don't know what the shaft/bushing clearance specification is. Is the bushing "Oilite" or some other type of bronze?
What Is the ID in the crank (for the bushing) and what is the input shaft OD?
I could calculate the size changes due to temperature change.
 
The input is.590. Bushing ID is .593. I can measure the hole in the crank on an extra engine i have tomorrow.

It is supposed to be an oilite bushing, but since everything is made in China it may not be. A few minutes ago someone said to check it with a magnet and if it's magnetic get rid of it. Haven't checked that yet, will tomorrow.

I appreciate your doing that for me.
 
Last edited:
The ID of the crank is 1.090. And the bushing is magnetic and in my garbage can. I didn't think oilite was magnetic.

I bit the bullet and bought a LS7 clutch, pressure plate, and flywheel. Supposedly it's good for about 450hp. I'm a little under than I believe. 403 from the factory, plus headers/exhaust and a tune. Stock LS1 clutch is good for 300hp. Probably best I changed it now. I am crossing my fingers this does it.

I didn't buy a release bearing. Hopefully that won't bite me in the butt.

So now the waiting game yet again :rolleyes:
 
You must log in or register to reply here.
Back
Top