Well last spring my 4.9 with the Isuzu 5spd blew something up. Was not sure exactly but it sounded like a hand grenade going off in the bell housing. I parked it and today I finally had the time to tear it down.

I don't think I will ever buy another Centerforce clutch again. Thankfully my flywheel looks like it will be fine with a surfacing. The only area that got scored was near the center where there is no contact with a clutch.

Note this clutch has only about 6000 miles on it. It never saw slicks or heck I never really took it to the track. Just played on the street. At the time of failure I was only running 225/50/16's on it.

Well here are the pics and there are lots of them, so I hope you have broadband.

I was baffled when I pulled the trans off to find this mess. I could not see where the metal had came from. The clutch LOOKED fine.


To start off here are the bell housing / input shaft pics.













Here is the Pressure Plate both on and off the car.





Then we get to the really broken stuff.
The Clutch Disc.







Then a few group shots of the parts. Notice the springs are in pieces.












Well the next clutch will be one of 3 things. A cheap one to get the car on the road. Or a Spec or a Bully Clutch from Alberta. With the current USD / CDN$ rate the way it is, I might just splurge on a Spec stage 4.
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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

[This message has been edited by Capt Fiero (edited 12-30-2007).]

holy **** ! I feel bad for you, centerforce is normally a good name. I have seen some spec 3s loose one spring in the hub but ive never seen ALL the springs colapse and fail at the same time like those ones. Im surprised the izuzu could hold up longer then a centerforce, have you contacted them about it yet? that might have been a manufacturing error in the hub itself, you might be able to get some money back or something with those pics... how many miles was on it? it doesnt look like that much.

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1987 Pontiac Fiero GT
SBC dual stage Nitrous injected
built 5-speed getrag

your lucky you got 6000km... i had a beretta gt back in 88 that the clutch went so i put in a new one and only made it about 1 mile down the road and that one disenegrated the disc to a powder and took out all the prongs of the plate. lucky never hut the tranny at all..

sometimes **** happens

later
jimmyb

wow...thats really messed up...like it was said above for all those to let go ..thats just not right..i would definitely drop them an email with pics and see what happens...i am begining to think you have manual tranny gremlins chasing you around dave...geeze that sucks....hope they do right by you...tim

Oddly with as much damage as it looks around the throw out bearing, it still spins freely, even can be moved a small distance up and down the input shaft before it its the block of metal. Heck even the small wire clip that holds the bearing to the clutch fork is still in tact.

I have had a few people look at it in person, and it looks like the rivets that hold everything together just ripped out of there sockets and then the metal went everywhere. The flywheel is in remarkably good shape there is no ridge on the flywheel, even where it looks to be heat scored its just a minor surface marking. No grooves or anything.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

That's ugly alright. In defense of the Centerforce product, it would appear that this unit has seen a ton of excess heat and clutch chatter. Maybe I've been lucky, but my Centerforce set-up has held up well over the years.

If you do go with a Spec, get in contact with them first and go over what you are running and they will match up a clutch that will hold for ya.

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88 GT, 3800SC, Getrag 5sp. 12" Vette Rotors,Custom stuff done

...my Centerforce didn't even last that long (same setup), mine made it to just over 2000 km - contacted them and they wouldn't do anything about it, the attitude that I got was "too bad, too sad"...

I since went with the Spec Stage 3 - had a problem with the disc after a couple months, but they sent me out another one with no questions asked - and that is what I have been running for the last 2 years with no problems (so far).

I too had a Centerforce clutch come apart but instead it was the pressure plate. The large outside rivets let go and struck the bell housing. I now have a Spec clutch but it is not as smooth as the Centerforce clutch was.

https://www.fiero.nl/forum/A...050119-2-054259.html

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Red 88 GT T-Top 3800 INTERCOOLED SUPERCHARGED


Click here to read the History of Skitimes Car

oh yeah i am running a spec stage 3..works well with no problems yet..and you know how i drive ..hehe...tim

What a PITA!

Since you're in Canada, why not call http://www.bullyclutch.com/

They have a sintered iron clutch which is pretty much bullet proof. Their website is not showing the Fiero currently but they build one for both the 5 and 4 speed trannies.

My Bully Clutch has had some hard use and it has held up perfectly. The local rice burners often sidestep their clutches and the Bully Clutches have not been failing them at all.

Good luck with a replacement, whichever you end up with

Arn

Has anyone tried the Ram Clutches? I have run a few of them in my gtos in the past as has my father with no problems at all. my last 65 gto had a pretty well built 428 that made real good power it had ram air 4 heads and the ram clutch never slipped in fact i broke the trans (muncie 4 speed) and the clutch was fine. I'm doing a 3.8 swap in my 87 gt and i contacted Ram from their web site they have a tech dept. that you can e-mail with questions and they responded very quickly. for my application they recommend their hdx kit that is sopposed to work and fit just like the original but with a lot more holding power. i found one at performancecenter for 182.51 shipped. I'll let you know how it works for me.
I'd also like to know any feed back you guys have if you have used the Ram clutches thanks.
Ant

quote Originally posted by RichLo: holy **** ! I feel bad for you, centerforce is normally a good name. I have seen some spec 3s loose one spring in the hub but ive never seen ALL the springs colapse and fail at the same time like those ones. Im surprised the izuzu could hold up longer then a centerforce, have you contacted them about it yet? that might have been a manufacturing error in the hub itself, you might be able to get some money back or something with those pics... how many miles was on it? it doesnt look like that much.

WAS a good name, I have been hearing more and more stories like this one with those who have used a CF clutch in the past few years. Sad to say the ever changing times of our economy are at fault here since companies are more worried about profits than quality. Accel was a known quality product and now look at it today! Near impossible to find a thread here on the forum that was made in the past 7 year to say one thing positve about the product and Cf has folowed along that same path it seems.
My favorite story was Edelbrock when it went public. The share holders kept wanting more and more profits and soon quality suffered and thier stuff was junk for a few years. The result was a discusted owner who had built a company and put a lot of pride on the fact that his name meant something to the after market crowd. When the name was tarnised for the sake of profiits Edelbrock bought back his company and took it off the open market and restored quality to what his company produced.
Just wish more companies would do the same and not just in the automotive industry, we need this across the board on all companies.

The blue spots on the flywheel are areas where the metal heated up enough to change structure, and indicate localized overheating. This kind of heating is usually indicative of extreme clutch slipping, either deliberately or by failure.

JazzMan

The pics of the flywheel are kinda miss leading. The flywheel is a custom machined solid billet steel flywheel. Any marks that are on it, pretty much rub off with a bare hand. I am going to try and spray it down with brake clean and wipe it with a soft cloth and repost the pic to get a better example of what it really looks like. The area between the clutch surface and the ring gear is smooth and does not have any ridges at all.

My driving habits were usually to baby the car out of first gear and then matt it from a rolling start as anything else would liquefy the rear tires. Then a soft shift into 2nd as not to hit the tranny hard and then punch it again. In most cases a stoplight to stoplight race was over by the time I hit the top of 2nd gear. So the clutch slipping issue "should" not be an issue. However after I clean it up if it still looks bad, maybe there were times that it slipped and I just did not realize it. In either case, wouldn't clutch slip have caused much more wear on the friction material instead of exploding the hub? It was obviously biting quite hard in order to tear the hub apart like that.

what motor are you running? i second the flywheel looks like its been overheated and chattered, i pull clutches off like this all the time for people who dont disengage the clutch all the way or god knows what they do. the exploded springs are from too much pressure plate and shifting really hard. ive done the same thing where i shifted so hard and i popped out all of the springs, didnt get the flywheel markings though. youre deffinatly going to have to resurface the flywheel at a machine shop, just using an airtool to deglaze it wont help. the surface is uneven(to a machinist) and since youre investing so much in a clutch like that i imagine your gonna want to have it last.

also high power clutches like that are street driveable but traffic wise its really murder on them. unless you dump it all the time, even at low speeds, its going to bounce and jerk around which doesnt help them. the cops done like it when you dump the clutch either so that doesnt help either. i have a spec stg 3 and it really really sucks in traffic, really sucks.

he has a 4.9.

I was wondering what happend to the inputshaft and why you think the trans is gone?

That flywheel will need a good resurfacing at a machine shop. I see a lot of dirt/oil around it so you may be getting some oil in it which will aslo cause those spots (contamination). Get rid of those springs and get a soid hub Spec stage 4. I just have it and love it. No chatter and grabs excellent for my 366 rwTq

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

Yep the flywheel will be sent off to be resurfaced. The motor is a 4.9 Caddy motor as in my sig. I have composed an email to Centerforce and will await a response from them.

I do agree with the suggestion I get an unsprung clutch. Because the car is not a daily driver anymore I believe going a little overkill should be fine.

As for the oil contamination, Hmm. I have the oil lines running directly over the bell housing..... However there did not seem to be much oil inside the bell housing area. I may go ahead and make a shield for future installations just in case that could be an issue.

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85GT 5spd ,93 Eldorado 4.9 Dual O2 Custom Chip, Archie Clutch. Custom Exhaust. MSD Everything 245/50/16's Not Your Average 4.9 Capt Fiero Com --- My Over View Cadero Pics Yellow 88GT 5spd Stock.

quote Originally posted by Arns85GT: What a PITA! Since you're in Canada, why not call http://www.bullyclutch.com/ They have a sintered iron clutch which is pretty much bullet proof. Their website is not showing the Fiero currently but they build one for both the 5 and 4 speed trannies. My Bully Clutch has had some hard use and it has held up perfectly. The local rice burners often sidestep their clutches and the Bully Clutches have not been failing them at all. Good luck with a replacement, whichever you end up with Arn

cindered iron disks are pretty much exclusively for the track,,, they dont last but 15-20k miles under street use, not to mention they are extremely unfreindly in feel.

[This message has been edited by aaronrus (edited 01-01-2008).]

JUST FYI.....Most after market clutches in North America get ther parts from LUK or Valeo. So anytime I look at a Centerforce, Spec or whatever, I still see those two brands. I had a clutch custom built for my car and the guy showed me both Centerforce and Spec and explained that they get their parts from the other two. So in reality your getting painted and reboxed parts. I know you have a "performance" clutch but you can have the same thing made for less money than buying a re-packaged box.

Now your problem here is LACK OF CLAMPING FORCE. Jazzman's right about the heat marks. That was due to slippage due to lack of clamping. When I had my clutch made i went with a s-10 pressure plate which increased my clamping force from 1050lbs (stock) to 1450lbs. and a basic 6 button clutch with a fiber tough and bronze button combination. I'm loving it. Still has great let off and grips like a race clutch when peddle is dropped.

There is another possible cause and that would be the through out bearing leaving pressure on the presure plate. If the clutch arm (slave pushes) is re-clocked where all the pressure is not released then the friction plate will slip. Thus cause heat, scaring and failure.

Hope this helps. I would find a clutch/brake shop that can build the clutch for you. My clutch cost me $225.00 USD and same setup as a reboxed (with a sticker) would have cost $450 plus. Most good clutch shops can estimate the torque rate and set you up with a good combination.

Good Luck.
Bob

Oh before anyone ask.. When the friction plate gets hot enough the heat swells and creates a sudden lock down. This heat transfer to the hub. The rivets, being the softest metal, could sheer off with a sudden jolt. At this point everything else is history.

Just an update on this thread. The trans axle that came out of the car is toast.

Note the input shaft and then note what is missing from the input shaft. Hint, its laying at the bottom of the bell housing.






6th Isuzu getting ready to install it. Not painting this one red.

Why are you using an Isuzu?

My 85GT is my only stick Fiero and it uses a Luk Clutch w the Muncie but it is a 2.8L. With a 4.9L you are doubling the amount of torque and going up in horsepower about 33%. That is in reality over the design limits of the drivetrain that you have.
I've never been a big fan of the Muncie, Getrag or Isuzu but if I did run a 4.9L I would use the stronger late model ( Beretta) Getrag and a Spec stage 3 clutch. We are now completing a 3800SC swap and used the spec clutch. The disc looks much stronger than the Centerforce

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87GT - with 3800SC Series III engine, 4T65eHD
87GT - 3.4L Turbocharged engine, modified TH125H
" I'M ON THE LOOSE WITHOUT THE JUICE "

[This message has been edited by Dennis LaGrua (edited 05-15-2008).]

I run the Isuzu's due to the gearing in 5th gear. I like to drive sustained speeds well above 80mph. You just can't do that with any other trans. Well I guess you can, but the revs would be way too high. I actually had a getrag and chose not to use it, due to the 5th gear not being high enough.

Thats pretty ugly man. Glad to see you getting it put back together. I can't remember but what kind of clutch are you going with this time? I know the flywheel is fixed now so hopefully you will not have as many problems as you've been having. Later man.

Check out this link, this is the clutch I am using. Its made by Clutchnet in California

https://www.fiero.nl/forum/F...2/HTML/090893-2.html

quote Originally posted by Capt Fiero: Check out this link, this is the clutch I am using. Its made by Clutchnet in California https://www.fiero.nl/forum/F...2/HTML/090893-2.html

That clutch disc does look much better then the SPEC 3 one I'm using. Keep me posted on how it works out for you. I'm hopeing I won't have any problems but you never know what the future holds.

Was there oil in the bellhouse ?

When my t/o bearing ring was broken it came oil in the bellhouse and the clutch started to slip. And i got the same mark as you on the flywheel. Burned oil mark.

But my clutch didnt look like that lol.

[This message has been edited by FieroGeneral (edited 05-16-2008).]

abuse!!!!!! thats what caused that clutch to grenade.