Sprung Hub Spec Clutch Dies in < 5000 miles ?!?!

[RayPeters]

I've been at this a long time, and I've not has this issue before. When I swapped from the Twincharged engine to this built 2.0 I opted to put my Spec stage 3 plus disc in. That was ~5000 miles ago. This week while driving it to work I started noticing random engagement issues and a much slower shift, it acted like the clutch wasn't releasing fully. Attached are pictures of the disc and some closeups of the sprung hub. I'm not looking to trash talk Spec, as I've not asked them about this yet. I am curious what people think caused this rapid failure. I don't drag race the car, I've got 2 rally's on it and daily transport duties.
Also in the photos are the Ralliart disc I ran against the twincharged engine, and the new clutchnet disc I'm putting in it. I'm tired of sprung hub failures. Also not visible in the photos well is the amount of play in the splines. The shaft is perfect still, no wear and the disc will rotate almost an inch at is outer edge without turning the splines.


Comments anyone?????

The 4 puck cutout disc is the clutchnet unit, the Ralliart disc in on the far right. The pressure plate is a 2900 lb lightweight unit.

 

[bpestilence]

My SPEC stage 3 wore down my flywheel bolts on my Rio and several of the spring mounts on the disk were also wore down when I removed it. Also, their "high pressure" pressure plate had less clamping pressure than my OEM pressure plate. My friend Matt's SPEC stage 4 blew apart at the track. Pretty catastrophic, I wish I had pictures. SPEC aren't the best clutches out there.

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[Savage Talon]

That is what happened to all 3 of my Comp clutch puck discs. I think it is cheap stamped steel that is the problem. I got a South Bend/Exedy clutch disc and the hub looked like it was thicker metal and it covered the springs more. It was just better quality in general.

 

[twicks69]

Funny, a Spec clutch failure....

Ray, I have seen that before several times with the disks tossing springs. The clutch disk thickness is a little on the thin side, and probably doesn't use the best of materials to keep those darn springs in their home.

Also, I just recieved a transmission (well, whats left of it at least...) and longblock from a guy that had a NEW spec stage something sprung hub clutch that EXPLODED in less than 2000 miles. He called spec up, and they told him he must have mis-shifted from 3rd back into second, instead of going into 4th -- he definitely did not.

The catastrophe created a very nice patio door opening (exploded the bellhousing, took out the front motor mount, the thermostat assembly, radiator, hood, etc.

The pressure plate shattered and delaminated the pressure plate side of the disk, along with shearing the step surface completely off of his fidanza flywheel.

Spec denied defect of their clutch, and said that it was his fault.

Personally, I will stick with my Quartermaster, or an ACT2600 with a SBC kevlar sprung disk.


I have also had the same experience (tossing springs) from my Clutchnet sprung 6-puck, and from an old RPS sprung 6-puck.

 

[mitsumissile]

I got a SPEC Stg3 disk faileed on me also.
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But they send me a new disk. I didn't put it back in and get Exedy stg2 cluctch kit instead. still running goood now.

 

[RayPeters]

Thanks for your input guys, It would seem that I'm just done with sprung hub clutch discs. Everything seems to be in order. I checked the following:

The dowel pins into the bell housing fit well.
The pivot ball isn't worn and it is at the proper height for the pressure plate I am using.
The clutch fork is not worn or bent.
The flywheel is stepped to the correct height, 0.609
The clutch disc is the same thickness and not bent.
The input shaft isn't bent.
The crank isn't bent.
Master and Slave cylinders are working properly.

So in the end it looks to be that this Spec clutch disc is ill suited to our application. I'll be having words with them next week to see what they will be willing to do about this issue.

Attached are pics of what I ended up using.


Ray

 

[gsx951]

When your clutch spits out it's springs, it is an installation error-The friction disc needs to be perpendicular to the shaft or the hub of the friction disc will flex until it dies.

 

[RayPeters]

So how does that situation develop unless the transmission is loose on the block?

 

[twicks69]

Hey Ray, how old are the input and intermediate shaft bearings in the trans?

Usually this is a tranny killer only, but I have seen it once where the input shaft bearing and race were worn out causing issues; but usually that only shreds the splines on the input shaft. In your case, the splines look freaking new!

Also, did you replace the friction surface on the fidanza flywheel when you installed it?

Personally, I don't think it is an installer problem; it is likely the crap that Spec puts out.

I think Ray has more than plenty experience behind him.


Keep us posted!

 

[RayPeters]

Hey Ray, how old are the input and intermediate shaft bearings in the trans?

Usually this is a tranny killer only, but I have seen it once where the input shaft bearing and race were worn out causing issues; but usually that only shreds the splines on the input shaft. In your case, the splines look freaking new!

Also, did you replace the friction surface on the fidanza flywheel when you installed it?

Personally, I don't think it is an installer problem; it is likely the crap that Spec puts out.

I think Ray has more than plenty experience behind him.


Keep us posted!

The trans has a nice gentle 130,000 miles on it. Jon at TRE is a GOD amongst men. It is tight and quiet still. With a clutch that releases properly it still takes 7000 + rpm shifts without complaint.

That isn't a Fidanza wheel. The friction surface only has 5000 miles on it. no hot spots or anything. I really haven't beat on this engine yet, I started to but then this release issue.
The new disc seems to be fine now.

Thanks for the kind words.

Taking it for a drive in the twisties tomorrow, I'll keep you posted.

Ray

 

[project_tsi]

ClutchNet EZ puck 6 puck sprung disk FTMFW. You cannot pop out the springs.

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[gsx951]

ClutchNet EZ puck 6 puck sprung disk FTMFW. You cannot pop out the springs.

But they have in the past, hence, the redesigned hub.

I believe the biggest cause of these failures is brought on by loading the splined hub on the clutch disc at an angle when installing the transmission. The thin , stamped hub is easily bent. If the spline on the disc is anything but 100% perpendicular, the run-out will tear it up.


There have been almost countless posts , and failures to every brand of clutch have been seen. What I am unfamilliar with are failures to hub of the origninal factory clutch.
This is curious, mostly because until recently, the OE clutch disc and aftermarket disc were all Daikin (Exedy).


This video from Exedy cautions installers to observe correct bolt tightening and to not use an impact to prevent misalignment:
MT Clutch Movie

I also wonder how much of an additional load we are placing on the damper springs in the hub when we remove our balance shafts.
Damper Movie

 

[Artago]

Does anyone have any more feedback on the ClutchNet clutches?

Thanks,

Tom