My SPEC clutch failed after exactly 2700 miles in my SBC V8 (366 rwTQ). I didn't abuse this clutch at all (compared to previous) mainly because it was slipping somewhat when cold and some at peak torque once warmed up. Like my previous one it popped a spring. All hub rivets were loose. This was like I said in my 6 speed. I can see that the flywheel surface didn't seem to mate well with the clutch so I attribute the slipping to that. But not sure what (other than torque or mfg problem) could cause these springs to fail. Actually it is not the springs but what holds them. Seems like the metal fatigues with time. My previous clutch at the bottom failed the same but with my 5 speed. I guess my next one will be spring less. I talked to SPEC and I'm sending the parts to them for analysis. Will see. Here are a lot of pictures of it. Please tell me what you think.

This is how it looked when I took the trany of;


Soemthing missing here;



What I found when I took it off...

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Red: TPI V8 + 6-Speed Yellow: Nitrous 3.4 + 4 speed Auto
304rwHP/366rwTQ

Clutch;


Disc clutch side;


Flywheel surface;


Disc flywheel side;

[This message has been edited by Alex4mula (edited 09-17-2007).]

I dislike SPEC. My clutch had the splined hub installed backwards and they did nothing for me - basically said I had to mail it down there at my expense so they could press it back in the right way. Then charge me for mailing it back up here.

Stupid.

I ground off the interfering flange, lol... it works.

Never buying SPEC again. Especially after seeing this.

I would seriously look into having a clutch built using the G6 hub that was designed for the transmission after two experiences like that. It's my understanding that a solid hub is not good for daily driving and in this case you shouldn't have to resort to that, the problem causing the disaster needs to be identified and corrected. From the looks of it my suspicion is either some form of coil bind or flex, pressuring the spring out of its seat. Some may argue, but if you didn't abuse it as you have stated, slipping suggests there was a problem from the start, especially with a performance piece like that noted for its holding capacity. The thicker areas of metal you pointed out apparently offer little protection against the undetermined stress that is causing the failure.

quote Originally posted by Joseph Upson: After a second look it appears your release spring tabs on the pressure plate came in contact with the springs and pushed them out of place, possibly into contact with one of the flywheel bolts which could rip it out of place.

I agree that the pressure plate fingers were rubbing on the springs, possibly to much slave travel? However, it looks like they were only just rubbing, only a few thou perhaps. I dont think any of the flywheel bolts could have contributed to it because they are so far away. I've heard of quite a few problems with the larger power guys busting the springs out of their clutch disks. A few have gone with solid hubs with great success and say they're not much different to drive. I think this is the route i will be taking with my 6 speed swap. I think i'm going to turn my stage 3+ fiero disk into a solid hub with a ranger spline.

[This message has been edited by Zac88GT (edited 09-17-2007).]

quote Originally posted by Joseph Upson: After a second look it appears your release spring tabs on the pressure plate came in contact with the springs and pushed them out of place, possibly into contact with one of the flywheel bolts which could rip it out of place.

Nothing touched the flywheel side. Yes there is evidence that the diaphragm fingers touched the springs but I'm still not convinced it happen before or after. The second clutch shown was with a 5 speed and it didn't touch the diaphragm.

that is exactly why you should buy a spec stage 4 if you are considering a stage 3... the 4 has a springless hub b/c these clutches are known for their weak spring perches. when something happens to my stage 3 the next phone call is going to be ordering a stage 4. everything else is the same between stage 3 and 4 (same clutch material and everything) just a springless hub design.

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1986 Silver 5 speed Fiero 3.4 DOHC
Bored .30, Fully balanced and blueprinted
13.93@101mph as it is on the street. FOR SALE - MAKE OFFER!
... ... !
355cid 400hp/tq N/A SBC, 4 bolt main
Nitrous Oxide: 1st stage - 125shot direct port. 2nd stage - 75shot plate.
87 GT, Cryo Treated 5-speed Getrag, Spec Stage 3 clutch.

Looks like this was caused by overextended pressure plate fingers. You have too much travel at your slave cylinder.

quote Originally posted by Zac88GT: I agree that the pressure plate fingers were rubbing on the springs, possibly to much slave travel?

This is one of the problems Archie came accross when trying out the SPEC clutch. He found that there was actually too much travel. There is an easy fix though. Rodney dickman's adjustble clutch banjo. Here is the thread from when they first tested it out. Sorry I don't know the exact page number.

https://www.fiero.nl/forum/A...030204-2-021911.html

quote Originally posted by Fieroseverywhere: This is one of the problems Archie came accross when trying out the SPEC clutch. He found that there was actually too much travel. There is an easy fix though. Rodney dickman's adjustble clutch banjo. Here is the thread from when they first tested it out. Sorry I don't know the exact page number. https://www.fiero.nl/forum/A...030204-2-021911.html

Overextending could be a possibility. But this clutch being designed for this specific application I would expect that to be designed in already. This is not a regular Fiero clutch hacked and thrown in there. Spec designed it for Archie's kit. It should have the dimensions to fit without risky small clearances.. I do already have Rodney's adjustable banjo and can adjust. But no one told me I had to. Rodney's banjo is usually a Band-Aid to a bent pedal or other hydraulic problems. Also it still doesn't explain the other clutch that failed with the 5 speed.

I think now is the time to invent a limit for the clutch arm on my 5 speed. I cut down my slave rod but it would be nice to just put a stop in place to know I wont have disengagement problems as the clutch wears out.

Does the 6 speed use a hydraulic throw out bearing?

The exact same thing happend to my stage 3+ Mine only had a couple hundred miles on it. I sent spec some pictures of it and they told me to send it back and they would evaluate it. I had to pay for shipping the clutch to Bessemer, AL but they sent me a whole new clutch. Send a email to Jeremy at Jeremy@specclutch.com with some pictures and he will take care of you.

I think this thread means a lot to all of us - we all know the hard work and disappointment of having to pull the engine again. My ZZ4 spun a bearing prematurely and I'll go through this soon as I make the rebuild decision along with clutch choice for a 355 or 383. This is a good opportunity for SPEC by addressing this problem openly and making things right. Let's see what they have to say after they have a chance to examine the failure and run failure analysis. Is this a quality problem, a design problem, an application problem, or an installation problem or some combination? I'm sure we're all watching.

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88GT ZZ4 Sequential EFI www.bigstuff3.com - 275 RWHP Dyno'd,

quote Originally posted by Jake_Dragon: Does the 6 speed use a hydraulic throw out bearing?

Yep.

quote Originally posted by Alex4mula: Overextending could be a possibility. But this clutch being designed for this specific application I would expect that to be designed in already. This is not a regular Fiero clutch hacked and thrown in there. Spec designed it for Archie's kit. It should have the dimensions to fit without risky small clearances.. I do already have Rodney's adjustable banjo and can adjust. But no one told me I had to. Rodney's banjo is usually a Band-Aid to a bent pedal or other hydraulic problems. Also it still doesn't explain the other clutch that failed with the 5 speed.

Precisely my point, if it's designed for the transmission and power level you have, you should not have to go to a springless hub for dependability. Either the problem needs to be fixed or the application rating changed. I wouldn't be this diplomatic in a discussion about it given what it takes to replace a clutch especially one with as little miles on it and no abuse that seems to be developing a pretty good history of the same kind of failure. Sorry guys, in my opinion a solid hub is a substitute not a fix. If the sprung hub is not strong enough they shouldn't be selling it to anyone as if it is. I'd be cuss word mad right now especially with a second of the same kind of failure and others with similar examples. You wouldn't get a third chance at my blood sweat and tears over your product from not doing its job for me. Hope they take care of you on it.

Any spring contact with the flywheel or pressure plate should have caused some difficulty shifting.

quote Originally posted by Fieroseverywhere: This is one of the problems Archie came accross when trying out the SPEC clutch. He found that there was actually too much travel. There is an easy fix though. Rodney dickman's adjustble clutch banjo. Here is the thread from when they first tested it out. Sorry I don't know the exact page number. https://www.fiero.nl/forum/A...030204-2-021911.html

You are correct that overtravel was a problem in the thread you referenced. However that thread ended nearly 4 years before the 6 speed became available.

The diaphram piviot points on the SPEC clutch are farther outboard than a CForce (for example). The farther out the diaphram piviot points are then the less travel it takes to engage or disengage.

Archie

I'd like to know what caused these ......



I don't think the clutch is overtraveling. I spent weeks determining where the clutch needed to be inside the bellhousing to get the right travel.

I think from viewing the pics that the failure was not caused by how much power was put to it. It was caused by a failure of componets.

The curoius thing is that we've built about 13 or 14 of these in house & they're all still running & everyone is happy. This is the 1st one completed by a customer.

Makes me wonder if there's something I could have done better. But I always wonder if there's something I could have done better.

I'll be making this topic the topic of discussion at the shop tomorrow & see what ideas we come up with.

Archie

[This message has been edited by Archie (edited 09-17-2007).]

Spec would not release the cause of my failure, but they would not have sent me a new clutch if it was not a mistake on their behalf. My theroy of the failure is as follows: If you look at your disc where the springs are, on the side I'll bet you will see that the disc made those groves in the fingers. I took my clutch to several trans places intown before I sent it to spec and they said it might be a defect in the deck height of the disc which causes the disc to grind into those fingers of the plate. Which results in excess heat on the disc causing the deck where the springs are located to expand, causing the spring to be able to fall out of its hold down on the disc. I cannot say that this is the problem, but since spec won't release any info to me about the failure, I can only assume that this might be the problem.

I have called Dave at Spec over 10 times and left messages and haven't been able to get a hold of him I'll have to try their regular tech to explain and get the RA#.

Here are some other pictures I took of it. Look at how these rivets got deformed. Most are like these except one;



This is the only good one at opposite side.


Then look at how the spring is eating up the metal here;


The one that pop off didn't do that

Just from looking at these 2 pics and the latest one showing a close-up of the spring eating up the metal looks like the pressure plate fingers pushed on the springs.
In the second pic below all the springs look like they were rubbing as they are silver/shiny (compared to the FW side) and the one on the bottom right even looks like it has flat spots worn into it.

It looks to me like the clutch fork/throw-out bearing travel is too far causing the pressure plate springs to rub the hub of the clutch disc.
The "notch" on the spring holders looks to be made by the edge of the clutch hub that sticks out past the surface of the clutch and the spring fingers looks like they were pushing on the clutch hub springs. So when you pushed in the clutch the pressure plate was trying to push the clutch hub springs out the other side of the clutch plate. This would cause the springs to push out the metal on the flywheel side creating slop in the spring. The springs would then beat the heck out of the mount (eat away the metal) on the flywheel side until the metal fatigued and the spring popped out on the same side.

So in my opinion, Either the fork/throw-out bearing is traveling too far, or the pressure plate itself has a defect/design flaw which caused the clutch plate to wear abnormally and fail.

That is just my observation based on the pictures.

quote Originally posted by Alex4mula: Clutch; Disc clutch side;

[This message has been edited by Oreif (edited 09-18-2007).]

quote Originally posted by Oreif: Just from looking at these 2 pics and the latest one showing a close-up of the spring eating up the metal looks like the pressure plate fingers pushed on the springs. In the second pic below all the springs look like they were rubbing as they are silver/shiny (compared to the FW side) and the one on the bottom right even looks like it has flat spots worn into it. It looks to me like the clutch fork/throw-out bearing travel is too far causing the pressure plate springs to rub the hub of the clutch disc. The "notch" on the spring holders looks to be made by the edge of the clutch hub that sticks out past the surface of the clutch and the spring fingers looks like they were pushing on the clutch hub springs. So when you pushed in the clutch the pressure plate was trying to push the clutch hub springs out the other side of the clutch plate. This would cause the springs to push out the metal on the flywheel side creating slop in the spring. The springs would then beat the heck out of the mount (eat away the metal) on the flywheel side until the metal fatigued and the spring popped out on the same side. So in my opinion, Either the fork/throw-out bearing is traveling too far, or the pressure plate itself has a defect/design flaw which caused the clutch plate to wear abnormally and fail. That is just my observation based on the pictures.

I can tell you that the metal removed by the springs is not caused by an overtravelling of the TOB. After seeing these pictures, and knowing i'll either be getting a different clutch disc or modifying mine to be solid hub i decided to dissassemble my stage 3+ disc. It only has 100-200 kilometers on it and already shows signs of wear in the same area. This was being used in my getrag behind my northstar.

quote Originally posted by Zac88GT: I can tell you that the metal removed by the springs is not caused by an overtravelling of the TOB. After seeing these pictures, and knowing i'll either be getting a different clutch disc or modifying mine to be solid hub i decided to dissassemble my stage 3+ disc. It only has 100-200 kilometers on it and already shows signs of wear in the same area. This was being used in my getrag behind my northstar.

Very interesting....

quote Originally posted by Alex4mula: Very interesting....

i have a spec stage 3 setup on my 4.9L 4 speed muncie setup, and the clutch has failed in it, i havent been able to get to it yet, but the clutch had about 1000 miles on it, thats it, and its already failed, i'm thoroughly pissed. the stage 3 was overkill for the swap, i probably only needed a stage 2, but i was planning on rebuilding the 4.9L for more power, so i bought the stage 3 based on its reputation, and now i got ****ed, so i guess im not the only one ehh? I will post pics as soon as i pull it

Some please correct me if I am wrong but didn't a few people have problem with the throwout bearing that came with the SPEC clutches. I dont remember the details exactly but I remember it causing pre-mature failure for quite a few people. I am about to install my stage 3 in a week or so and I will not be using the SPEC throwout bearing. If these clutches are having multiple problems I would much rather go with something else just to help avoid problems in the future. I know this probably isn't much help but I have yet to use one and this is all I can contribute at the moment. Watching intently.

quote Originally posted by Zac88GT: I can tell you that the metal removed by the springs is not caused by an overtravelling of the TOB. After seeing these pictures, and knowing i'll either be getting a different clutch disc or modifying mine to be solid hub i decided to dissassemble my stage 3+ disc.

That may be in your particular case, But on Alex's pics you can clearly see that the pressure plate arms were rubbing/pushing on the clutch hub springs and that the spring came out the flywheel side.

Side note, I have had my SPEC III clutch in my 4-spd for almost 3 years now and have not had any issues with it at all including many laps around road courses thru the same time frame.

quote Originally posted by Oreif: That may be in your particular case, But on Alex's pics you can clearly see that the pressure plate arms were rubbing/pushing on the clutch hub springs and that the spring came out the flywheel side. Side note, I have had my SPEC III clutch in my 4-spd for almost 3 years now and have not had any issues with it at all including many laps around road courses thru the same time frame.

Mmmm... I wouldn't say so. Look at my previous one with the 5 speed. Similar marks.

quote Originally posted by Alex4mula: Mmmm... I wouldn't say so. Look at my previous one with the 5 speed. Similar marks.

Yes, But even in that picture, it looks like the spring has a flat side on the edge. Maybe it's just the way the spring is made, or the reflection from the camera, On the other pics you can see that there is signs of the fingers rubbing on the clutch springs.
See where I circled in red, Is this a wear pattern or just the way the spring is made?

quote Originally posted by Oreif: Yes, But even in that picture, it looks like the spring has a flat side on the edge. Maybe it's just the way the spring is made, or the reflection from the camera, On the other pics you can see that there is signs of the fingers rubbing on the clutch springs. See where I circled in red, Is this a wear pattern or just the way the spring is made?

In this case I'm sure it is not. The PP didn't have any marks like the current one. Too bad I threw it threee weeks ago. I should start a wall of shame

If you can't get ahold of Dave, try calling Jeremy Auvil at Spec. The number he gave me was 1-800-828-4379 He was very helpful with my clutch problem.

quote Originally posted by prostreet505: If you can't get ahold of Dave, try calling Jeremy Auvil at Spec. The number he gave me was 1-800-828-4379 He was very helpful with my clutch problem.

Thanks I got a RA# today. Clutch is on its way. Probably will be there Monday. Let's see how quick they are and if they have me ready to be back and running for that weekend.

This all looks to be caused by the rivets getting loose. Those don't look to be seated and crushed correctly. Once loose, they would jack hammer the parts, including the springs. Normally, the springs should never touch the clutch plate stack like that.

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62 Buick Special
86 GT, 5-Speed
87 GT, 3.4l DOHC Turbo 415 HP @ wheels
88 Toyota Supra Turbo

quote Originally posted by Alex4mula: Thanks I got a RA# today. Clutch is on its way. Probably will be there Monday. Let's see how quick they are and if they have me ready to be back and running for that weekend.

I would like to suggest that when you install the new clutch, Take some measurements between the clutch hub springs and the pressure plate fingers and see how much clearence there really is. I would also try Archie's method listed in the archived thread of pushing the clutch it and see if it is dragging by rocking the car.

quote Originally posted by Oreif: I would like to suggest that when you install the new clutch, Take some measurements between the clutch hub springs and the pressure plate fingers and see how much clearence there really is. I would also try Archie's method listed in the archived thread of pushing the clutch it and see if it is dragging by rocking the car.

I will. Also I'll take both flywheels to be check for flatness and cut as needed.

Curious ...
Was the clutch installed with spring dampener facing the pressure plate side or facing the flywheel side?

Greg and Tina

quote Originally posted by Tina: Curious ... Was the clutch installed with spring dampener facing the pressure plate side or facing the flywheel side? Greg and Tina

If you have installed a typical spring hub clutch in an Archie V8 flywheel you would know that there is no way you can get it wrong.

quote Originally posted by Alex4mula: If you have installed a typical spring hub clutch in an Archie V8 flywheel you would know that there is no way you can get it wrong.

Peace: I think Tina was just trying to help.

She's had the same clutch in her car for about 2 years & it's holding up even with Tina & Greg taking it to the track, so they're trying to look for simple answers.

In fact her Fiero is the 1st Fiero to get that version of the SPEC in a Fiero.

Archie

[This message has been edited by Archie (edited 09-21-2007).]