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13 Posts
Discussion Starter · #1 ·
short hand:i have a 64 283 M21. had a after market clutch, broke z bar. got a new z bar, reinforced it, 100 miles later, z bar breaks again. so i say f*** it im getting a stock clutch. dont need a aftermarket one anyway.

So, i made my jolly forty minute drive to classic industries to get ALL STOCK ****. I purchase a a new z bar and in the listings, it says:
PN187406 - '64-'67 - 283 CLutch Kit - 149.95
PN167510 - '66-'67 - 283 Heavy Duty Clutch Kit - 149.95

So, as far as i know, i dont have an or extreme exotic setup. these cars dont require a degree in mechanical engineering to work on em. a small block and a four speed. and aren't most sb chev clutches 10.5" anyway? whats the difference?, same motor, same tranny, the drivetrain doesnt know what car its in!
I ask the dude at the counter what is the difference between the two, because if it works, why not get the HD one?
He responded by saying the non HD for my car was backordered anyway.
He then reasurred me several times that as long as i had a muncie and a small block, the clutch would work.

day later...
open up the clutch box, i have a pilot bushing, a clutch disc, pp, and a big washer, a kind of wich i have nver seen or used. I DID NOT RECEIVE A NEW THROWOUT BEARING as stated in the KIT despcription. No instructions either. so i say watever, the one (throwout bearing) i have should work, cuz theyre both diafragm clutches.

end of the day, everythings ready to go, linkage is tight with no slop, not binding, no bending. adjust it randomly, pretty far out just for a starting point.

fire her up, and with the clutch on the floor, i cant even push the shifter into any gear. no disengagement whatsoever. then i adjust waaaayyy up, still not disengaging, so now, the clutch is adjusted so far up (in the way that would bring the pedal up) the fork arm is hitting the bellhousing. I can see the fork arm is not bent, and is properly popped onto it's pivot ball,i can see the throwout bearing presing on the clutch diafram and compressing it, but still, cant get enough travel to disengage the clutch.

I just dont understand, stock clutch, ctock linkage, nothing changed but the clutch.
Is there different height of throwout bearings?
IS this the wrong clutch for the car?
What the hell was the giant washer for?
What is wrong???? Im at a loss and ready to push my **** in the street. And s:mad::mad:et it on fire.

Premium Member
15,966 Posts
Yes there are very different clutch throw out bearings.

here is what the different is.
HD pressure plate has raised fingers and uses the short bearing.

The standard clutch has flat fingers and uses a long bearing.

Your problem is easy to diagnose.
Originally had a HD clutch, short bearing.

You know have a standard clutch (Flat type) that uses a long bearing.

The short bearing with a standard clutch will not have enough travel to release the clutch.

PS: Perfection clutch has a GM standard HD clutch that will have normal clutch pressure.

2,968 Posts
BlueBeast dont give on your car man, I've been down this road before too. Believe me, you'll remember this problem forever Lol! Thats a tranny re & re in what 20min?!:D I'm sure Al has it nailed.

13 Posts
Discussion Starter · #4 ·
the adventure continues

well you right on with the throwout bearing, dead nuts, thanks a million!! called all around and finally found one for $27. had a word with clasic ind. and they said to fax them the receipt and they would reimburse me so thats kool.

and thank you for the encouragement!

so got the correct (tall) throwout bearing in, button every thing up, time from jack up to jack down = 48 minutes! lol the clutch seemed to work fine, but every single time the clutch was coming in and out, (when it was slipping) it mad an awful noise, like a BAD metal on metal noise not matter what!!!

take it back apart.
throwout bearing fine.
proceed to take out clutch.
disc was fine.
pp was fine.
flywheel fine...wait! there's scrape marks on my flywheel bolts!
look at the clutch disc, there are scrape marks on the hub springs!!!
the flywheel has only been surfaced twice(including this time) !!!
the disc was in the correct way!!!!
didnt have this problem before, because my zoom cluch didnt have a sprung hub.
so all i can think of was that someone fell asleep while they were surfacing my clutch!
im goint to pull my stock flywheel out tomorrow and see if it hits the springs, beyond that, i dont kno!
dunno if it matters, but im running a lightweight 17lb STEEL flywheel if that matters?
any opinions?

Premium Member
1,304 Posts
Clutch Headaches Again! Please Help

Hey Now, Yep, Deryl Got it Right, The Clutch Disc was in backwards. As was said, this happens more than most people know. When you look at the disc, the minds eye, "logic" recessed hole in the flywheel, and raised circular part with chatter springs in disc. It has to install that way. WRONG the "outty" faces away from the "inny" The Clutch hub chatter springs face toward the rear of the car, toward the transmission. Respectfully, "Bill's" II

13 Posts
Discussion Starter · #7 ·
of course this was my first thought.:)
but i have pulled the tranny 10+ times by now and have made this mistake in the past. needless to say, i vowed not to rush my swaps anymore. lol
i would agree with the backward disc deal, except i KNOW it was in right.

so i checked and double and triple checked that i had it in the right way today.
the side marked flywheel side is ENGRAVED in the metal center of the disk, so it could not have just been carelessness of a factory worker who puts stickers on clutches all day.

so knowing i had it in right, and noting that the scrapes on the springs were in the side marked FLYWHEEL, i double know it was the right way. lol

so whoever however watever, the dude at the machine shop i had it resurfaced it took waaaaay too much off.:confused:

in the end, i just ended up "surfacing" :devil:the flywheel bolt heads a good 50 thousandths. threw it back together, problem solved!
just dont know what im going to do once i put a couple thousand miles on the clutch!!??

Velios Machine Shop, in Lawndale California=NOT RECOMMENDED!!!:bored:

anyway, thanks for the help!

26,231 Posts
you live in/around my old stomping grounds... i used to work at "HydroHead" which was on Hawthorne blvd, real close to Vellio's machine.

they're no longer in business sad to say...

i think your issue lay elsewhere if i may explain.

i think it's in the flywheel YES, but not due to Vellio's. it lays in the fact it's probably an aftermarket/possible E-Bay flywheel that's not only lightweight (you stated 17lbs) but specifically designed for a sold hub, NON Sprung clutch disc.

i've encountered these before and that'd make it incorrect for your application.

in my opinion though there are other issues that you're facing that haven't as of yet surfaced BUT WILL... i would highly recommend a Raised Diaphram clutch and not the flat diaphram as you say you now have.

neither the flat, nor the raised "stock style" diaphram clutch is even close to being heavy duty enough for your car if it's a high performance car but the flat one is even rated even lower in heavy duty class.

the bearings Al recommended are correct. short bearing/tall clutch... tall bearing/short clutch.

i'd recommend a heavier flywheel too, the mass will help you on initial launch.
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