I posted a thread last month about my 98 z28 having a clutch/transmission issue. I was finally able to drop the transmission today. I found that the springs in the hub of the clutch were torn up. Three were completely ripped out of the holes, and one spring was bent in half. The three springs were just laying in between the pressure plate and the clutch. Luckily the new flywheel & pressure plate seem to be unharmed. I have been searching online and found quite a few other people that have had the same problem as me with SPEC clutches.

I replaced all of the following approximately 2k miles ago: SPEC billet steel flywheel & SPEC stage 3+ super single clutch, along with a new slave cylinder, master cylinder, throwout bearing, and pilot bearing. I torqued everything down to correct specs, and put locktite on all bolts.

I was hoping that it was just a bad pilot bearing that was causing the clutch/trans issue (even though I just replaced it), but it is still in brand new condition. I was pretty disappointed to see the clutch blown apart like that after only 2k miles. I wasn't even driving hard at all when it happened. I was just cruising down the street. I did everything by the book - everything was installed perfectly (no shortcuts or rigging anything up), and it was properly broken in for 500-600 city miles before I even went above 3500RPM. The car only makes 422 rwhp 398 ft/tq. The clutch is rated at 967 ft/tq. It has never seen the track; it's only driven from point A to point B on the street.

I'm never usually one to complain, but I'm really hoping SPEC will chime in and possibly offer a replacement clutch disk. Unfortunately the clutch was purchased about two years ago, but it was only installed a few months ago. I tried to show the condition of the clutch in the pictures below to attempt to prove it was just recently installed.

 

Considering the fact that you are interested in our feedback relative to this you could have contacted us directly. Give me a call and I will be happy to speak with you. I will need to know when and where (I know you reference this above) the parts were puchased. Thanks!

 

I have done that to a clutch before...Hard take off/clutch dumps and I also over extended the pressure plate fingers.

Those springs are suppose to dampen with you release the pedal. If you do high RPM clutch dump....@$&^@*$^BAM!!!!!

 

Come on now...we all know everyone drives like a grandmother and never abuses their car! Though I doubt that this just "happen" without cause, I always try to work with existing customers and am more than happy to assess things as part of that process!

When you look at the parts you see a lot of things. You have a single rivet head that is sheared, you have at least one that is pulled through and others that are totally intact but the cage has cracked around them due to the force this unit saw. Excessive shock and or miss-alignment (eccentricity of the shaft may be to blame). I would like to see the friction surface of the plate if possible and the straps that retain the plate in the cover if possible!

 

It's supposed to handle the torque. Regardless of RPM, SPEC makes no mention of restricting RPM when engaging clutch. Over extending fingers is one thing, but high RPM launches shouldn't do that to a SPEC 3+. I'm guessing it's a cheap ebay knock off...well, hoping anyway.



IDK, that would have to be one hell of an eccentric & likely would have shaken the crap out of the car. Not to mention taring up the transmission. If that clutch is a true SPEC 3+ (not a cheap knock off), I'd say there's an issue.

I've posted an update every year as to the excellent performance of my SPEC 3+ & will again update after this season (year 5). So, I'm not just another hater looking to bash SPEC. It's important for you to continue to update the evaluation of what happened to this clutch & what SPEC is doing about it. Again, a$$uming that it's not a knock off.

 

I never made any mention of RPM limitations...so that isn't something I am worried about! A damaged pilot bearing (yes I know the OP says its good) or damaged internal transmission bearings could allow the shaft to have greater play than normal. But, my real concern is shock. I know the statement above is that the car was being driven normally but a missed-shift would shock the parts severely. Hopefully we will get pics of the pressure-plate friction surface and straps that retain it. We shall see!

 

from this side of the internet...the disc wear does look "normal". Something caused the hub failure but even with "clutch dumps" and drag use this should not happen unless the car is making more power than the clutch is rated for.

I ran a 2+ for a season but it died on the starting line 2nd year. use and abuse. I found SPEC customer service, previous to my dead SPEC, to be very good. They replaced a PP that was assembled improperly. When I removed it from the box the mating surface was angled and SPEC propmly replaced it.

maybe J can chime in on if their hubs are made off shore or they make them with non off shore parts. From the sounds of OP's post this should not have happened. How, if at all, possible transmission problems could have caused this I will leave to Mr Auvil to explain. "My" sense is this was a defect in hub materials

aggressive disc materials like 3+ do what they do well...grip. that ability does transfer loads to other parts of the clutch (hub) and or driveline parts down stream of the clutch

 

What were the symptoms when this happened?

 

These are not "off-shore" hubs.
Initially I covered the possible causes of spring cage wear/damage but as noted above my primary concern is shock, not eccentricity. When eccentricity is to blame it will normally wallow the springs in the cage and cause wear that looks corrugated on the spring windows. Shock (as is associated with a miss-shift or similar action) does not inherently relate to torque output. Ultimately it is the "rebound" event, when the assembly is momentarily snatched in the opposite direction of its rotation that caused damage to plates, discs, etc... This is why I am asking to see further details relative to the pressure-plate.

 

Though I agree with you an extent, its the friction surface that is rated to "hold" the power without slipping. I don't care how much power the friction surface can hold, that design is NOT a "racing clutch". Racing clutches do not have those springs. No doubt It can handle the a daily trip to the strip and some fun on the weekend, but hard core clutch dumps at high RPMs will destroy or at least damage a clutch like that eventually. I commend SPEC for investigating the issue, but IMHO its abuse and not a SPEC issue. It happens, I know we like to "drive" our cars. I know some people will chime and say I do this and that with my clutch and it's fine...Yea people are also pushing 500HP through stock T5 transmissions...

 

Ding...ding...ding...

 

We readily offer rigid hubs. In fact they the disc to be a bit lighter and they are more resistence to eccentricity and shock. Engagement isn't much different either, especially when using our Stage 3+ material. The disc you all show, and quote, appears to be Sintered-Iron which is like our Stage 5, which is a bit more aggressive than the Stage 3+.

 

Ah holy cow. I didn't mean for this to turn into a heated debate.

I will take pictures of the pressure plate and pilot bearing as soon as I get home from work.

I apologize. I just figured if I called and explained the problem, I would be asked when it was purchased. I would then say it was purchased about two years ago, and I would then be told that it was purchased too long ago to receive a replacement part. So I decided it would be a better idea to post pictures of the clutch to show it's still in basically new condition to prove it was just recently installed.

 

I left my house, got about 2 miles down the road, and all of the sudden I couldn't put the transmission into any gear. It didn't make any noise at the time, and the clutch still felt normal. I could however put the transmission into every gear without a problem once the car was turned off. But once the car was turned back on, couldn't put it into any gear. So I turned the car off, put it in 2nd gear, started the car, drove the 2 miles home in 2nd gear.

It didn't start to make any noise until I was trying to find out what the problem was. I let it idle and kept pumping the clutch, trying to put it into gear (without forcing it), etc. After about 30 seconds I could hear an intermittent rattling noise. I crawled under the car to hear where it was coming from - right from the clutch area. About 30 seconds later the intermittent noise became louder and more frequent. I turned the car off and haven't started it since. I think the noise became louder and more frequent because the springs were flying around between the clutch disk and pressure plate, getting jammed, and consequently breaking more springs free.

I'm not saying that the car isn't driven somewhat hard once in a while, but it has never been to the track. It's my daily driver. I have never dumped the clutch above 2k RPM (still has stock rear). The car was still warming up at the time this happened, so I was not driving the car hard at all. I always shift before 3K RPM until the engine is fully warm.

 

Well, it is technically out of warranty, based on the time-frame since purchase. As a side note, had you contacted us we would have asked for pictures to further assess this. I will do what I can to help you, but this is not a guarantee of warranty...and I am sure you can understand this.

 

Here are pictures of the pressure plate and pilot bearing. The pictures show the straps you are talking about, correct? All three straps are tight, no bends or anything.
Also, I checked the shaft of the transmission - very tight; no play at all. The transmission was rebuilt by Tick Performance the same time the clutch was replaced.

 

The PP looks pretty good. Doesn't even look like there is too much discoloration from heat. I must admit that even the possibility that SPEC can help you out outside of the warranty is pretty awesome.

 

Yeah, I will sure be happy if SPEC will be able to help me with a new clutch disk. The disk alone is $300 - and to me, that's a lot of money; money that I don't have right now.

I've tried to find every possibility that would cause the clutch to fail like that, but I can't find anything. I want to make sure I look into every possibility so it doesn't happen again. Quite a few people have taken a look at everything over the past two days (my garage is kind of the local hangout), and all of them came to the conclusion that it had a faulty clutch disk. And as with any company that produces a product, a small percentage of their products are bound to have some minor defects. I'm just trying my best to show that this clutch may have been part of that small percentage.

 

Despite the fact that it is out of warranty I don't mind issuing an RMA so we can assess this further. I will need to know when and where this was bought so I can proceed. Just give me a call at your convenience. Thanks!

 

What makes you think that we don't know that a racing disk has no springs? Your post is pointless. There's an issue beyond high RPM dumps going on here.