Inliners International Forums General Discussion Drive Train Manual trans. grinds going to 1st and rev.

Clyde;

Reading your posts is making me NUTS!!

I really wish I could help, but I'm totally out of ideas. Texas is just a little to far away for me to stop over and take a look.

Maybe you could find some old, gray-haired Chevy mechanic..............seriously, it might not hurt to ask around.

Clyde, that sounds like it should work fine as described. I've got 2 questions though, that you may have already checked, but I'll ask them anyways:

1. is the pilot bushing seated in the crank or is it sticking out of the end some distance?

2. are you sure this trans came in that car?

The reason I'm asking is that after all you've done to check and recheck, there is a possibility that you have an interference fit lengthwise. I'm picturing 2 places where the problem may be.

First is the amount of shaft that is poking into the bushing. There should be a little telltale bit of grease on the shaft tip that shows you where the bushing rides. Basically, it should ride in the middle lengthwise of the tip. If the shaft is too deep into the bushing and rides on the shoulder, then it can't freewheel. Also, if the bung hole in the crank isn't deep enough, then the input shaft could be bottoming against the crank.

Second is the length of spline that sticks out of the trans front bearing retainer. Most of the car 3-speeds are all spline, and the trucks usually have a shoulder where the splines stop. If your disc needs deeper splines, then the disc cannot slide back far enough on the shaft to clear the flywheel when the plate is released.

Take a look at these areas for peace of mind, if nothing else.

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David
newbie #4153

Well have no way to know if the tranny is the orginal one. It is all spline though. I have measured the shaft in reference to the pilot bearing all looks good to me. I have also looked at the pilot when I removed the tranny and the front face interance of the pilot looks clean and rounded... not scared ...so the shoulder is not hitting it.

New news: Sachs says the clutch kit is the right one per their books for the Nova and the amount of travel need on the diaphram to dis-engauge is .455". I know that my car does not deliver that much throw (maybe .350"). I have asked them to look into other pressure plates that would require less throw also... but waiting.
Either my cars zbar/padal hardware has some mismatch of parts or Sachs books are wrong.
If someone could measure their (Nova)fork rod travel I could narrow my search. Mine is about 3/4".
I am posting on a couple of Nova sites also... maybe someone here has a 62-67 Nova?

Thanks for the input, Clyde

Clyde, I had another brain f**t on the way home last night and thought of an idea that may work to give you that extra throw you are looking for.

Your zbar uses a stud on the input end, that if moved closer to the center of pivot will result in more throw. The new stud can be located some ratio closer, say 75% of the current distance. That would give you 1.33 times the current throw. 66% would give 1.5 times the throw, etc. You wouldn't have to remove the stud there now, just drill a hole, insert a new stud, and plug weld it in place from the back side of the bar. Sound reasonable?

You could either do that OR move the attachment point of the OTHER end of the input rod AWAY from the pivot on the clutch pedal. I remember seeing zbars and throwout forks that had 2 holes in each for use in mutiple applications that had different mechanical ratio requirements.

A last option is to weld a longer tab on the zbar output arm with another hole for a longer ratio. That might stick down too low under the car to be viable, but it's an option nonetheless.

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David
newbie #4153

Yea! I decided last night that if I don't get anywhere soon... I would extend the lower arm on the zbar. I looked and if I extend it a inch or so it would line up even better with the fork. I need to do the math so I dont damage the diaphram. I have had someone confirm the lenghts on there xbar arms and mine are the same... but this to me looks like a improvement as far a pushing straight into the fork. It also sounds better to me right now than pulling the tranny again for anything else I find.

The top arm looks a little harder mod because the nova zbar arm is curved to go around the streering box and is a tight fit.

Thanks for the input, Clyde

Thought I would reply with an update on what the solution and cause to this problem seems to be. Thanks to all that provided feedback.

1st The Solution- for me at this time is to remove the tall rubber bumper under the dash that is the pedal stop. This provides more throw and the clutch seems to grab at the right distance from the floor and disengages properly. Tranny goes into gear too. I am replacing the bumper with a thin one to prevent the metal-to-metal contact. I know the pedals will be at different height… but I should get used to it for now.

2nd Cause- I think the cause is that someone welded some flat steel plate over the floor pan in the driver side. Rust of course! Since they just welded the plate over the old pans it made the floor pan not deep enough for full pedal throw. They welded at the curves of the pan .. so the plate is not flat against the bottom/back. So an inch or more could have been lost easily. I added jute for insulation when I replaced the carpet too. I saw the plate when doing the carpet… but did not realize such an effect. It is not obvious when sitting in the car and the carpet fit ok too. So I did not expect any issues and was deleted in my memory bank.

Man I got GOOD at removing that tranny… 1:15 min tops! On a positive note I know more about clutches now! Hope to get to drive the car for the 1st time this weekend….. we will see what other bugs appear.

Clyde

62Clyde...You using reman parts ???..If so junk the whole set up and buy a new kit with matched disc..pressure plate and throw out..I have been thru this a hundred times I swear...Not only did GM make a hodgepod of different clutches after the years went by the rebuilders mixed them even worse..And then and then the pressure plates have been turned who knows how many times and they would make up for that by building the disc thicker..There were at least three different throwouts all of different lenght and style depending on if the pressure plate was diaphragm or three finger type..If you are using the full circle bellhousing it can be a real pain because you can't see whats going on when all together..I have found them with too long of a throwout that actually hits the disc and shoves it back to the flywheel and not allowing the main shaft to stop fully.I drove a Chevy for years that when going into first or reverse I pushed the pedal only half way down to get going and after that the syrncros did the rest in the upper gears...Buy a new kit..Good luck..Al...

Well... right now the clutch seems to be ok. The kit is a sachs kit and they actually assisted me in tech support quite well. At this point I think most of my troubles were related to the floor pans. Time will tell! Could have started for the begigning and purchased the flywheel from GM... but $300 for that would have hurt. But if all GM would have fixed things.... I would have done it knowing the effort I have in that clutch!

Thanks, Clyde