Inliners International
Posted By: 62Clyde Manual trans. grinds going to 1st and rev. - 08/23/03 01:10 PM
BACKGROUND: This 62 sat for 10yrs in a garage before I got it. The transmission was out of the car due to a bad throwout bearing and fork. I put in a new clutch/fork/ bearing. I shifted the tranmission on the bench before I put it back in. Put new gear oil in the tranmission.

This is the orginal 3 speed that came in them. I have adjusted the clutch per the shop manual. When the engine is running(at idle) and I try to start shifting into rev or 1st I get a gear grind as if the clutch is not fully disengauged. Now if I go into 2nd or 3rd it is ok.

I tried to disengauged the clutch more by taking out all the pedal play... but no difference. I read where these transmissions not sync on 1st. (I don't understand I am sure my 62 impala has the same transmission and you have to be completely stopped to go into 1st.
I jack up one rear wheel and started it gaian and the wheel spins with the clutch in or out.... A little faster maybe with the clutch engauged. It is quite though.

Help please! I thought I was going to get to drive this car for the 1st time this weekend :-[

Thanks, Clyde
So, if you put into 2nd, then go right into 1st afterwards, does it still grind?

Have you checked the linkage to see if you are actually throwing the lever far enough on the tranny to engage 1st or rev., seeing how they are on the same shift arm?
Gearhead,
It still grinds. I had my wife disengauge the clutch and I worked the transmission levers by hand without the linkageinvolved.

Thnaks, Clyde
UPdate: I put in 1st then started the engine. I drove the car a bit down the road... shifted into 2nd and 3rd. The clutch is engauging about 2-3 " off the floor.... but is also seems to slip > ... brand new stuff! Still can not go into 1st or rev without shuting off the engine... put in gear and restart. Well I know I have to pull the clutch back out.... but I have no idea what the look for?

Clyde
With the lower bellhousing inspection cover off, you should be able to tell if the pressure plate and clutch are working or not. Seems to me if 2nd and 3rd shift fine, then the clutch probably isn't the issue. Could be that the input shaft is binding up in the pilot bushing causing the input shaft to turn enough rpm's to prevent you from engaging the gears (because of no synchro). Too high of an idle speed may contribute to this.

The only other thing I can think of would be there is an internal problem with the first/reverse slider gear. Pull off the side cover and take a look.

How were these parts stored while it was apart?
I did not change the presure plate and I bought the car with this stuff dissassembled. I replaced the thowout bearing,Pilot bearing, fork, disk, bearing retainer.

If I start it sitting still in 1st with the clutch pedal down it is ok.... not enough drag to make the car roll. This is probley the pilot bearing binding then... huh. I did have a hard time getting the transmission the stab.

$177 for a kit....wishing I would have done that right now! The only variable that is not origial equipment ...is that the engine is a 230 from a camero. I only know this from the block stamping because the 230 came with the car. So the fly wheel could be from the camero.... different than the 194 that was stock... I have no idea. Other than that all is Nova.... well maybe except the pressure plate!

Thanks, Clyde
Posted By: Ducky Re: Manual trans. grinds going to 1st and rev. - 08/23/03 07:34 PM
Sounds like a pilot bushing/bearing, the only other thing that comes to mind is a bent/warped clutch disc, or a disc shedding the facing material
Clyde, How clean was the input shaft? Any rust to keep the disc from moving freely on it. Other than that I think Ducky is probably right.

Regards,
Larry
63 C20 Daily driver
Larry,
Icleaned the input shaft when I installed it the first time. Even now I do not see anything wrong with the pilot bearing.

I pulled the transmission this afternoon and took some pics if you guys could take a look. I have some suspensions about the pressure plate being the right one. After I pulled the flywheel I laid the disk on and then the pressure plate on top. How much space should be between the pressure plate and the flywheel? Look like about .080" or so. Meaning that .080" is what the bolts tight up when installed. The disk has a few shinny spots on the outsides edges on both sides but other wise look fine to me. Here is a link to the pics: http://community.webshots.com/album/86356492fGDxkm

Thanks, Clyde
Posted By: Frump Re: Manual trans. grinds going to 1st and rev. - 08/24/03 12:40 AM
as I recall, a '62 didn't have synchros in first and therefore the internals turned until a sychronized gear, 2nd or high, was engaged, stopping the second speed gear and allowing a scratch free engagement of first or reverse. Am I way off? Frump
Clyde, If the disc sits a little inside the pressure plate you shouldn't have any problems there. The only one other thing I can think of, and was trying to remember it on the first post. I've done it and it will cause your problem. Did you put the disc in backwards? The disc springs should be inside the pressure plate.

Regards,
Larry
63 C20 daily driver.

[This message has been edited by Lgriffin (edited 08-23-2003).]
Frump,
I don't understand how synchronizers work and I have never opened a transmission. So your post went over my head. I do know that my 62 Impala has the same transmission and must be completely stopped to be able to go into 1st or reverse without some grinding. Reverse and 1st share a shift lever on this transmission. Any way I can check the transmission for this kind of problem before I put it back in??

Larry,
The springs on this disk are not on either side... in the middle of the disk. The disk does have a side that the spline collar stick out more on. I placed that side toward the flywheel. I checked to be sure it did not rub the flywheel.

Thank for the help, Clyde
The clutch looks fine from what i can tell from the pictures.But one other you may want to check And that is the shift fork It self and make sure that it is not bent. Or has any cracks. If it is bent it can hold the slider gear off just enough to end up Not in gaugeing all the way. If there is a issue with the in sides. I think I still have one from a 66?67 That you can have if you wanted to pay for shipping. But with it being cast iron It may not be cheap to ship. But i have no use for it. Your more then welcome to it.
Hope this helps. }[oooooo]


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NovaMan/Twisted6/Larry
Larry,
Thanks for the offer. The clutch fork is brand new and looks ok.

Clyde
Hey Larry,
I pulled the flywheel I laid the disk on and then the pressure plate on top. How much space should be between the pressure plate and the flywheel? Look like about .080" or so. Meaning that .080" is what the bolts tight up when installed. Sounds like not enough to me after the disk wears some... What do you think??

Clyde
Posted By: Frump Re: Manual trans. grinds going to 1st and rev. - 08/24/03 10:33 AM
Clyde, I'm suggesting that it is working as designed. To avoid clashing the gears when shifting into 1st or reverse, put it in second then into the gear of choice.

If the gear clashing is not the problem, then I bow out...Frump
Posted By: Ducky Re: Manual trans. grinds going to 1st and rev. - 08/24/03 12:08 PM
Synchro first gear or not, the transmission gears should stop turning soon (2-3 seconds with a cold gearbox)) after dis-engaging the clutch due to internal friction and gear lube viscosity.

There may be some normal 'clicking' sound (and feel) as the gear teeth engage while the tranmission gears slow down after dis-engaging the clutch. Old-timers used to non-syncro 1st gears usally (by habit) will engage 2nd gear prior to 1st gear to stop the gears (I do it).

If this is what you experience, it is normal. If by 'grinding' you mean you cannot get it into gear without really forcing it and get a real 'grind/clash' something is very wrong. It is hard to explain what is 'normal' on a discussion board.

By personal experience, I had the same problem with one of my farm tractors (no synchro in ANY gear) where it would take forever for the the gears to stop turning. I thought I had a pilot bearing problem, but it turned out to be the wrong grade of gear oil in the transmission. I had drained it and refiled it with 90W, should have used 90-145. When I put the correct gear oil in the problem went away.

One last thought; if you can depress the clutch, shift into 2nd, then into 1st with no proplem, I'd say everything is OK. If you had a pilot bearing/clutch problem, as soon a you took the transmission out of 2nd, the gears would immeadiatly speed back up give you the grinding - again, I've had that problem with a disintegrating clutch disc.
Ducky,
I have a 62 Impala with the same transmission. This is not the normal gear clunk. I can feel the gears spinning in the shifter and a little pressure from the shifter does not slow them down. The oil I used is something I am not sure about. I think is was what I had around for my 95 chevy truck..... may have been 80W-90W (was a black bottle and had a JT on it). Going to look at a new pressure plate next and compare with mine.

Thanks, Clyde
I'm Not talking about the clutch fork But The fork That Moves the inside gears a slider fork. }[oooooo]

It is what your shift linkage hooks up too.


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NovaMan/Twisted6/Larry

[This message has been edited by Twisted6 (edited 08-24-2003).]
Update: Have Been dis-assembling and inspecting today. Try not to laugh...attention: Maybe this won't burn someone else. But I found at least one issue that could have been why the gears were spinning in the transmission. When I looked at the fork I found shinny wear spots that say the pivot ball had snapped out of the detent on the fork. This would move the fork closer to the throwout bearing and would bind up some.... So the clutch may not have been fully disengauged. I remember knowing that had to be snapped in the detent and did so.... but during installation of the transmission I must have pushed it back in out of place. Hindsite yesterday all I would have had to do is pulled it into place. This might have solved the issue with getting into 1st and rev..... but I think the pressure plate still may be the issue on the slipping. Does anyone know if the nova's had the recessed flywheel... where the disk surface is lower than the pressure plate mounting area?? I will post on ther other sites. I posted a pic of the fork on my site : http://community.webshots.com/album/86356492fGDxkm

Let you know how it works next week.
Thanks, Clyde
of all the std flywheels i have pulled from our L6 I have never seen a offset flywheel They all have been smooth/Flat across.194,230,250,292s Hope this helps.}[oooooo]



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NovaMan/Twisted6/Larry
Clyde,

After looking closely at pictures #16 and #17, there is something a little unsettling about the height of the fingers. They are not equal, and should be. Since the bolts can be seen installed in #16, I can only assume they are still there in #17, so the diaphragm spring is under compression. In addition, the wear pattern on the tips of the fingers is not equal. The ones in the upper right of the picture have a longer length rub area that has taken off the rust.

Considering your earlier description of the non-disengaging clutch, as well as the observations of the fingers, I'm betting the diaphragm spring is broken. You need to just go get another pressure plate and install it.

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David
newbie #4153
Hey David,
I would replace the pressure plate if I could find one. All the parts houses show is the 10 1/2 HD clutch kit. I would just change to the HD clutch but the flywheel I have has that recess for the 9 1/4" disk. I would have to change the flywheel too! May have to do that... but looking for other options. I fairly sure that the pressure plate I have is the right dia.... but is for a flat flywheel (no recess). That is why it slips... not enough pressure.

Thanks, Clyde
Here in Phoenix we have a company called Arizona Brake and Clutch Supply that rebuilds just about any stuff that you can imagine, from little garden tractors to cars to semi's. I looked on the internet real quick-like, and there is an Austin Brake and Clutch Supply that belongs to the same rebuilders association. Did you give them a try to see if they have or can get the parts to rebuild yours? They're over on 8151 North Lamar Boulevard. There is also another outfit listed called Triangle Clutch Rebuilders, but no address or city (just somewhere in the great state of Texas!)

And a broken diaphragm spring will easily cause slippage due to low clamping pressure on the disc. Only half to two-thirds of the plate is bearing down on your disc. Your question about 0.080" being enough... yes, it is for a lightweight car like yours. My trucks have all had only had about 0.080" to 0.100" of clamp on a new disc, even the 3/4 tons.

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David
newbie #4153
Yes... I know where that is. I will check them out tomorrow.

Thanks , Clyde
Update: Thanks for all the help!
FYI a new non-counter weighted flywheel for these cars between 62-68 is hard to find. They were even used on the V8's 283 and 327's but at least here in tx the local shops can not get you one. GM had one actually for $300.. steep for me!
I went digging through many junk yards and found a 10" one...had it turned (saw another 9 1/4" recessed one too! They did exist!). Got a complete 10" clutch kit. Changing everything out this weekend. Gona be real happy or real %^&&*#$%%&*.

Let you know, Clyde
I have the used 10" flywheel and new pressure plate/kit mounted. And have the throwout bearing/ bell housing/ tranny together and ready to put it back in. I was making some demensional checks first and found the following:
I estimate the thowout bearing will not start to push on the pressure plate fingers till it is flush with the end of the bearing retainer collar. The throwout will only push about .25" on the pressure plate fingers fully dis-engauged (as far as the fork will go). Does this sound right?? Is that enough to dis-engauge the clutch?

The pressure plate fingers are about 3 1/8" off the block surface (mating surface for the bell housing).

Thanks, Clyde
I found when my used flywheel is installed the disc surface to crank shaft(back side of flywheel-mating surface for the crank) measures 15/16".
This is 1/4 less than my old recessed fly wheel. How does this sound? Maybe the used flywheel I have has been turned way to many times?

Please help! Clyde
Clyde
Somethings Else that also comes into play is the Clutch Fork Ball. Because there is different ones (lenght) Now the Question I have for you is, The bell house that you got from me. When i sent it to you did it have a Fork Ball in it? Or are you useing the one that was in the our bell houseing? }[oooooo]



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NovaMan/Twisted6/Larry
Larry,
Good idea...The bell I got from you did not have a ball. I removed the one from my old bell.

So how tall should it be?? Any idea?

Clyde
Clyde
Email me the size of the one you have there and in the mean time I'll dig out the ones i have here.I'm sure i can find the one that came out of that bell housing.
Thanks }[oooooo]



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NovaMan/Twisted6/Larry
You know larry... I taller ball would help the total amount of possible throw of the fork... but still the bearing goes past the end of the throwout retainer. Check me... But that does not seem right. You agree? It would seem that the retainer should go inside the presure plate fingers when mated up. This would provide 100% ( not 80%)bearing support when pushing on the fingers.

My senario right now is... for the throwout bearing to push on the fingers it has to go past the end of the retainer some. How much compression on the fingers is needed to dis-engauge?? Dont know. So I dont know how much futher I need to go or if my flywheeel has been turned to much?

I'm diggin deeper than I would like to here...but I am stuck and have take that tranny out 3 times now.
Well when done maybe I can provide advise to other more! :-)

I will measure the ball height and retainer length later tonite.... spending so time with my kids now.

My boy sure wants to go for a ride ;-( Me too!

Thanks, Clyde
There is a longer throwout bearing for use with a flat finger pressure plate like yours. That is what you need. Joe
There is a longer throwout bearing for use with a flat finger pressure plate like yours. That is what you need. Joe
Yep... but have already found that I have the long one. It is about 1 3/4 long. Sound right?
Thanks, Clyde
Idea! I think I have seen pressure plates that the fingers are not straight.... mine are straight fingers and when the pressure plate is torqued down they are parallel to the flywheel and about 13/16 below the pressure plate cover... if that makes any sense. If the fingers had a bend in them toward the throwout bearing that wouls be better.... hummm Opinions?


Clyde
The bell housing ball is 7/8 tall. It is into a 1/2 tall boss on the bell housing. The bearing retainer surface that the bearing slides on is 2 1/4" long with the bearing being 1 3/4" long. That leaves a 1/2 of travel before the bearing protrudes past the retainer. When this is assembled the pressure plate fingers are about where the end of the retainer is... meaning the bearing has to go beyond the retainer to push on the fingers. I am starting to blame my renewed 10"(junk yard)flywheel I have. The disc surface is 1/4 further away from the bearing on it compared with the 9 1/4" recessed flywheel.
I posted some pics with notes below them to assist. http://community.webshots.com/album/86356492fGDxkm


Thanks to all!

Clyde
Well... I got an adjustable pivot ball and that works great..... but the clutch still does not dis-engauge. Because of the new adjustable ball the fork travel is not limited in any way.
I have the car with all 4 wheels off the ground. I start the engine with the clutch pedal to the floor and tranny in gear. The rear tires are turning and when I pull the emergency brake it loads the engine.
Using the pushrod to adjust and the pedal up.... I have the T/O bearing maybe 1/8" from the fingers to max out on the throw distance.
I am out of ideas here! The zbar is what controls the amount of throw(best I can tell). If the lenght of the arms on the zbar were off ...the throw distance would be different...right? Zbar is new purchased from chevy2only. I posted 3 more pics here of my setup: http://community.webshots.com/album/86356492fGDxkm
This weekend ... since I measured all the distances when I assembled the clutch I plan to drimel a hole in the lower part of the bell housing so I can see if the disc is being released(chevy2 bells do not have another way to view it)... I can put I rubber plug in it later. If someone could send me the length of the arms from their chevy2 62-67 Zbar I would like to compare it to mine.... Any other ideas of what else could control the throw...please send them!

Thanks, Clyde
UPDATE: I just tried adjusting the push rod where the T/O bearing is right up to the PP fingers. I can stall the rear wheels with the em. brake and can here the disc sliding. I know I can't drive it this way... but it proved I need more throw from the zbar some how?? If someone has a chevy2 zbar to compare here is the measurements from mine: Lower arm (fork pushrod end) 4 1/8 from pipe to rod connection..... upper (clutch pedal end) 4 5/8.

Thanks, Clyde
More measurements: The zbar/pushrod moves the fork end about .75" pedal top to pedal bottom. The fork is about 8" long with the pivot at 3" down the fork lenght. So with .75" on the forkend the T/O bearing pushes about .438" into the fingers. Sound right or wrong anybody??

Clyde
Posted By: Ducky Re: Manual trans. grinds going to 1st and rev. - 09/13/03 01:44 PM
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
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