View Full Version : Tell me what happened????
I was driving my four speed the other day down an on ramp, and I was going about 10mph in first when I floored it, hit second at 5,300rpm and then went for third and the clutch pedal stuck to the floor and would not come up. It was like the car was in neutral, rev engine and still coasting. I thought I broke the Z bar or other linkage but everything is connected and moves. I can bring the clutch pedal up with my hand. I get it towed home and remove the inspection plate. I move the clutch linkage and I can see that the throwout bearing is moving back and forth on the input shaft and clutch fork. The clutch disk is not in contact with the flywheel it is a if someone is pushing the clutch pedal in???I have a Centerforce dual friction pressure plate and disk with 4,000 miles.
Can anyone tell me what happened before I pull the tranny???
Thanks
Tim
pphil
10-12-2010, 06:56 PM
now this is a mystery
i have had the pressure plate collapse but it would still pull (still be engaged)
with the petal out how could the clutch be disengaged
i mean the throwout bearing is the only thing that could press against it.
please let us know how this turns out
scott
cstanley-gs
10-12-2010, 07:06 PM
ok someone school me...
isnt the pressure always on the flywheel? And when you press the clutch, it pulls it away? so it sounds like something is preventing the the clutch from returning to the flywheel...
I know its no help, but a learning opportunity for me :)
buick64203
10-12-2010, 07:17 PM
Im not sure why the clutch pedal wouldnt come back up to the top. Do you not run a clutch pedal return spring?
Almost sounds like the diaphram springs on the pressure plate bent or popped the opposite way if that possible. But it sounds like you have a bad pressure plate.
I do have a light return spring on the pedal so it does come back up half way .
:3gears:
David Hemker
10-12-2010, 09:20 PM
The pedal return spring should have nothing to do with this as it's only purpose is to pull the throwout bearing away from the fingers so it does not prematurely wear out. This is why there is free play in the pedal/linkage.
It sounds like the pressure plate malfunctioned. I have heard of this but never had it happen to me. Either the clamping/pressure springs went bad and will not engage, the leverage mechanism between the fingers and springs broke or locked or the diaphram finger springs gave way.
Golden Oldie 65
10-12-2010, 10:01 PM
That's odd. The Centerforce dual friction clutches had weights on the diaphram fingers so the higher the rpm, the higher the clamping force. How far can you move the throwout bearing before it contacts the pressure plate? Or rather, do you have full travel of the pedal before it contacts the pressure plate? I've never heard of one of these going over-center but I suppose anything is possible.
Had the same thing happen on a tractor.(1950 Furguson) Once I seperated the bellhousing from the motor I found all the fingers stuck in so the plate was pulled away from the disk. As soon as I losened the first mounting bolt the plate snaped back against the disk. I dont know what caused it to do that. I replaced it due to it being such a pain to get to. Never had another problem.
That's odd. The Centerforce dual friction clutches had weights on the diaphram fingers so the higher the rpm, the higher the clamping force. How far can you move the throwout bearing before it contacts the pressure plate? Or rather, do you have full travel of the pedal before it contacts the pressure plate? I've never heard of one of these going over-center but I suppose anything is possible.
I do have full pedal travel but it seems like it never hits the fingers on the pressure plate. I am assuming that the fingers are stuck pushed in rather than out. If this is what happened, then why did it happen? Is my clutch linkage too long and it pushed the fingers in too far, is this even possible? I will tear into it this Friday. I wonder if it would return if I loosened a few pressure plate bolts??? I
Golden Oldie 65
10-13-2010, 09:27 AM
Is my clutch linkage too long and it pushed the fingers in too far, is this even possible? I will tear into it this Friday. I wonder if it would return if I loosened a few pressure plate bolts??? I
Same thing I was wondering. Before I pulled the transmission I would see if I could get a pry bar in there and try to release it, or if you have to, loosen the bolts like you mentioned. If that works then perhaps you could re-adjust the clutch linkage so it wouldn't push it in so far in. Worth a try.
Jclstrike
10-13-2010, 04:59 PM
Not to hijack this and I have no clue why myself..but wondering what the springs are being mentioned? I know my car has no springs on anything at all since Ive owned it.
buick64203
10-13-2010, 05:07 PM
Not to hijack this and I have no clue why myself..but wondering what the springs are being mentioned? I know my car has no springs on anything at all since Ive owned it.
The clutch fork should have a spring on it that goes to a hole in the frame. It keeps the bearing from riding on the pressure plate. Here's a pic-
Jclstrike
10-13-2010, 05:23 PM
Thanks I will have to find one for my car.
BadBrad
10-13-2010, 05:46 PM
Probably have a broken piece of something jammed there preventing the diaphram from returning to resting position. Very odd, yet I've had stuff break inside the bellhousing and get tossed about making a hella racket until stuff finds a new home. Have also removed pressure plates and found stuff in there that was not exactly as the factory intended. Most likely you broke something and jammed up the mechanism; it doesn't take much. Have you always had smooth clutch action; never a sticky pedal or rotational noise?
As mentioned earlier a collapsed pressure plate will fail to disengage the driven disc (not your problem); you'll be unable to stop the vehicle without forcing it out of gear or shutting off the engine. I nearly had a car go through a store front for this reason. That's pretty much an "OH SH!T!" moment. Only fast thinking prevents disaster.
staged70
10-13-2010, 11:19 PM
Most likely culprit is the pressure plate. You will be pulling the trans. Let us know what you find with pics
snowman4839
10-13-2010, 11:33 PM
If you still feel the pressure against your foot when you press in the clutch pedal, then that's just weird and I'm not sure.
But if you don't feel pressure (or hardly any because of the clutch return spring), the fingers of the pressure plate are stuck in and are not applying any pressure to the clutch disc and therefore the rest of the your powertrain.
All signs point to your pressure plate being defective for some reason or another.
For the person asking about the spring, the spring pulls the throw-out bearing off of the pressure plate fingers. This prevents premature wear. The first part of when you press in the clutch petal and you hardly feel any resistance, that's the throw-out bearing return spring.
Then when you get to the hard part and you actually have to apply a good bit of pressure on the clutch pedal, then your throw-out bearing has made contact with the pressure plate fingers and as you push through, it is releasing the pressure that the pressure plate has on the clutch disc. The clutch disk is the only thing connected to the transmission. The pressure plate is bolted directly to the flywheel.
Sorry if that was a useless and lengthy explanation but I spent a few weeks trying to understand how all that fit together and I finally just got under my car and replaced the clutch/pressure plate/throw-out bearing over a few days after school and that made everything a lot clearer.
wkillgs
10-14-2010, 09:24 AM
Give Centerforce a call and speak to someone in Tech Support. Maybe they've seen the problem before.
Give Centerforce a call and speak to someone in Tech Support. Maybe they've seen the problem before.
I did call Centerforce and the tech thinks that something broke and has jammed the pressure plate. He is also very curious on what happened and wants me to call him back when I find out. I am hoping that if it is a defective pressure plate that they will warranty it.:TU:
speedtigger
10-14-2010, 04:22 PM
Back in the day when I was a gear jammer the diaphragm style pressure plates would stick to the floor at high RPM (typically above 6k). We always used the 3 finger clutches for that reason. Then they started adding weights to the diaphragm style clutches for better high RPM performance. However, once the RPM dropped low enough on the diaphragm style units, the clutch would re-engage. Had me scratching my head the first time it happened.
Ok I pulled my trans and wouldn't you know it, I hear a faint pop and the pressure plate engaged. So now the disk is touching the fly wheel. I took pictures of the pressure plate. Does anyone see if there is something wrong?? I feel like putting it back together and adjusting the clutch pedal so it doesn't have so much travel.
????
Golden Oldie 65
10-15-2010, 12:07 PM
Other than the fact that it doesn't look like a Centerforce dual friction clutch. I've put at least a dozen of those clutches in musclecars and they all have had a ring and a series of weights attached to the diaphram fingers. Certainly if it came off you would find it all inside the bellhousing somewhere. If it was never there then I would be tempted to do as you suggested, put the transmission back in and try it like it is.
I sure hope it is a Dual friction clutch as I have my receipt from Jegs with the part number Centerforce DF148552 - Centerforce Dual Friction Clutches .
:Do No:
ardun53
10-15-2010, 02:27 PM
I see the weights in the second picture. It's a dual force. I would bump the motor over by hand and make sure all the weighs are still attached, they are the little square blocks on the od of the clutch fingers.
There are 5 weights not attached by a thin wire. I called Centerforce and they want me to return it for inspection. What would cause this?
BadBrad
10-15-2010, 03:01 PM
What the hell is that big gouge on the diaphram fingers? I have to presume that you've removed the throwout bearing from the fork; you were using one, yes?
Ditto that this does not appear to be a Centerforce. I have one; yours looks as if something is missing. :eek2:
OK - now I agree you have a Centerforce and yep, its broken worse than the economy.
Here are more pics and a link to the jegs website
http://www.jegs.com/i/Centerforce/183/DF148552/10002/-1
speedtigger
10-15-2010, 03:29 PM
There are 5 weights not attached by a thin wire. I called Centerforce and they want me to return it for inspection. What would cause this?
You know, I never used those weighted diaphragm clutches. I just could not see any reason to get away from the 3 finger design although I had been told that the weighted diaphragm clutch were easier to depress. And, I have to admit. I wondered if the centrifugal weight retainer wire could break. I guess there is my answer.
The only thing I might check along with sending that pressure plate back to the manufacturer is to make sure the clutch fork is not contacting those weights anywhere in its travel range.
Good idea...I will check the clearance!Thanks
What would you recommend for a clutch?
Tim
BadBrad
10-15-2010, 03:39 PM
You know, I never used those weighted diaphragm clutches. I just could not see any reason to get away from the 3 finger design although I had been told that the weighted diaphragm clutch were easier to depress. And, I have to admit. I wondered if the centrifugal weight retainer wire could break. I guess there is my answer.
The only thing I might check along with sending that pressure plate back to the manufacturer is to make sure the clutch fork is not contacting those weights anywhere in its travel range.
My last Borg & Beck (3 finger) was a probable cause of a remarkable vanishing thrust bearing (as well as broken clutch pedals and bending linkage parts). A premature engine rebuild proved to be enough to move me away from that brutal clutch.
I have this new clutch laying around, is it any good? Should I use it?
Thanks
speedtigger
10-15-2010, 04:22 PM
I have this new clutch laying around, is it any good? Should I use it?
Thanks
I don't see anything wrong with that clutch. The only problems you might encounter with that clutch is lack of clamping force that might lead to slippage and high RPM malfunction. Your Centerforce clutch has weights on it for a reason. The weights stop the clutch from sticking to the floor at high RPM. Now, your Buick may not turn enough RPM for this to be a problem. I really don't know. When I was racing stick shift, my cars were turning 6,500 to 7,000 RPM and it was a problem on those vehicles above 6k. It is very possible you could have no such problems. The Buick gear jammers on here could probably tell you better.
As for what clutch I would recommend these days, I don't know. Back in the day I Zoomed Zooms, Hayzed Hayses and Ruined Rams. So, all of my clutches were custom built by a local Clutch re-builder special for me. I bet some of the other guys on here will have suggestions.
Golden Oldie 65
10-15-2010, 05:25 PM
That's a dual friction clutch alright but the weights are way far away from where they should be so something is broken, probably the ring that holds them. First I've heard of one of them going bad. How old is it? Call Jeg's and see if they'll replace it.
BadBrad
10-15-2010, 06:33 PM
I'm still happy with my Centerforce; I think you just happened upon that one in a thousand of anything that goes bad for any number of manufacturing defects. Did you happen to run an adjustable ball stud? I installed one to take up the slack (so to speak) that comes from a flywheel that has been surfaced any number of times in 41 years. The ball stud allowed me to get back to OEM clutch linkage geometry. As the flywheel gets thinner the clutch gets further away from the transmission.
FWIW - I've heard that the OEM clutch in these cars was manufactured by Hays; I do know that it was a diaphram type for their pedal ease. Most new car buyers would not want a King Kong clutch, which is what you get with a Borg and Beck style. Trust me - if you've never used a Borg and Beck style from new you don't know pedal pressure. I wouldn't use one again unless I primarily raced and planned to pull the motor every 2 or 3 years. In that application it is a stupendous design.
Steve Yahnke
10-15-2010, 07:59 PM
Noticed another big problem,hopefully its just a bad picture...pilot bushings are round in the center,if it is oblong as it appers to be in the picture you probably have an alignment problem..replace the bushing also make sure you have enough free play away from the pressure plate,...also send the clutch back to centerfource have them inspect and advise on you problem..also diaphram clutches are far better than finger,more even pressure and force with less pedal pressure thats why chevy used them on there L88 motors,that goes back along time ago,and that is why centerfource uses them...good luck
John Chitwood
10-16-2010, 09:33 PM
I dont think your car is fixable and you should sell it to me...LOL.
I have never had a plate go "over center" but it does sound like a pressure
plate problem..What ever you do , do not put in a borg and beck style.
They are hard on everything and not worth it for a street car. Lots of options on plate style and disc material. I had a brake and clutch reline shop in my area reline the disc for me. It started out as a Zoom 11" Kevlar deal that would not hold the power. They put a brass material on one side and stock type on the other. This worked well for my car. They call it a velvet touch clutch. my .02 good luck
buick64203
10-16-2010, 09:44 PM
That's a dual friction clutch alright but the weights are way far away from where they should be so something is broken, probably the ring that holds them. First I've heard of one of them going bad. How old is it? Call Jeg's and see if they'll replace it.
The ring definitely broke. Once the pedal was pushed in, the weights jammed themselves between the housing and the fingers, esentially keeping them depressed.
Floydsbuick
10-17-2010, 07:25 AM
Has anyone considered that the ring broke because you over-centered the PP? Engaging your clutch is not an exact science. If anything in your linkage is altered, you risk this. I went through this years ago with the BBB Chevy truck, so I ain't talking out of my rear.
PGBuick
10-18-2010, 11:52 AM
I have heard a lot of guys are most happy with locally made, custom clutches. Cost less and better longevity than the big name brands. Ask around your area.
joracer12
10-18-2010, 11:16 PM
Ive had this problem twice with Centerforce clutches,both in customers cars,02 vette w/long tube headers,04 Mustang w/long tube headers also,both were customers cars,both failed within two weeks of install,I ate the labor and the tow on both and swore to never use another.On both units the weights broke free from the ring and wedged the fingers.I thought driver error at first, now believe defect product.Ive used a couple of the Mcleod double disc units,expensive @700,but very durable,trouble free.
I just received my replacement clutch and pressure plate from Centerforce at no charge under warranty. They told me that there was a bad weld that broke loose and caused the wire that holds the weights to break free and the weights got caught under the pressure plate thus keeping it from engaging.
Tim
cstanley-gs
11-02-2010, 12:49 PM
I just received my replacement clutch and pressure plate from Centerforce at no charge under warranty. They told me that there was a bad weld that broke loose and caused the wire that holds the weights to break free and the weights got caught under the pressure plate thus keeping it from engaging.
Tim
Now that's customer service!
Glad to hear it.
speedtigger
11-02-2010, 01:08 PM
You are back in business!:3gears:
Here is a picture of my new pressure plate. You can see the bigger metal ring that broke. Compare it to the pictures in my earlier posts and you will see that the fingers are compressed.
If you look closely on the new clutch you can see where the metal ring is welded. I believe that is the weld that broke on my clutch, which let the weights move outward and get caught under the clutch plate.
I hope this weld holds up! :3gears:
Tim
I got it back together and everything is great!
Tim
ellyka112
11-26-2010, 05:59 PM
Thanks I will have to find one for my car.
Probably have a broken piece of something jammed there preventing the diaphram from returning to resting position. Very odd, yet I've had stuff break inside the bellhousing and get tossed about making a hella racket until stuff finds a new home. Have also removed pressure plates and found stuff in there that was not exactly as the factory intended. Most likely you broke something and jammed up the mechanism; it doesn't take much. Have you always had smooth clutch action; never a sticky pedal or rotational noise?
Probably have a broken piece of something jammed there preventing the diaphram from returning to resting position. Very odd, yet I've had stuff break inside the bellhousing and get tossed about making a hella racket until stuff finds a new home. Have also removed pressure plates and found stuff in there that was not exactly as the factory intended. Most likely you broke something and jammed up the mechanism; it doesn't take much. Have you always had smooth clutch action; never a sticky pedal or rotational noise?
The ring that holds the weight broke and sent a few weights up under the fingers which prevented the clutch from releasing. Centerforce blamed a bad weld and replaced it for free even though it was over two years old!!!:TU:
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