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[This message has been edited by 2feido (edited 04-25-2009).]

what is your application?

Joe

[This message has been edited by Team Race-Tech (edited 01-25-2009).]

240 hp engine, 4 spd trans, rolling on 185/75/14 tires. lol

I would suggest checking the run out on the tranny...

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[This message has been edited by 2feido (edited 04-25-2009).]

Both...

My guess is there is some mis-alignment between the engine crank and tranny input and you are fatigue failing the centers on these clutches.

quote Originally posted by fieroguru: Both... My guess is there is some mis-alignment between the engine crank and tranny input and you are fatigue failing the centers on these clutches.

Yep, that's what a clutch looks like when the centerline of the engine crankshaft & the centerline of the transmission input shaft are not on the same axis.

Does your engine & transmission have alignment pins in them?

Archie

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[This message has been edited by 2feido (edited 04-25-2009).]

Most certainly something was not right for the clutch hub to be chewing on the throwout bearing sleeve. Any pics of the flywheel?

If it was my car, a new clutch would not go back in it until I knew exactly what happened.
Wipe out 1 clutch, blame the clutch. Wipe out 2 completely different clutches... probably not the clutch.

the clutch plate was either installed backwards or the centerplate was inmproperly manufactured. it is not positioned properly on the spline. so, either installer error, or manufacturing error. that last pic says it all.
that hub caused the issue, rivets are not made to take a load pushing on them, so they will not hold, they are meant to only take side loads. so the hub being pushed into the plate, which is the obvious fault here is deforming the plate surface towards the flywheel, which works against the peened over end, lossening it and causing play, then shear.
so either the hub is improperly spec'd or was assembled backwards, like all those Spec clutch plate failures.

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[This message has been edited by 2feido (edited 04-25-2009).]

Anyone else notice how messed up the splines look in the hub of that clutch?

They should be a lot beefier than that, fully interlocking with the input shaft, looks like they were just barely grabbing, maybe they're worn down from some misallignment?

The failure of the rivots was a rubbing failure. Notice the small clean section and the outline of the overlapping holes. Relative movement between the hub and the disk just cut through the rivots over time. The clean part on the rivots is from when they finally let go.

The severly worn clutch splines, wear on the end of the input shaft, and motion sheared rivots are all from mis-alignment of the engine center-line and the tranny... the adapter plate between the ford engine and the fiero tranny must not be precise enough and does not properly locate those two critical parts.

The worn throwout bearing sleeve could be from a mismatch in flywheel and adapter plate thickness (not providing enough room on the input shaft for the clutch disk hub) or the clutch disk installed wrong... which from the pick above it might have been installed wrong. Normally, the deepest part of the hub goes to the flywheel side.


If you did this to the tranny, might want to check the main bearings on the engine.

[This message has been edited by fieroguru (edited 01-25-2009).]

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[This message has been edited by 2feido (edited 04-25-2009).]

quote Originally posted by 2feido: Direction disc was installed. Gotta be right?

Somebody check me on this...
Isn't the flat side of the hub (which we're viewing here) supposed to be facing the throwout bearing?
This was a big problem (one of the many) with Spec discs. The hub was installed backwards, and extended too far out from the disc.
This caused the end of the TOB sleeve to become mushroomed.

In this case, since there is no sprung assembly in the hub, it would be easy to flip it around.

[This message has been edited by Raydar (edited 01-25-2009).]

wow, those pics do show alot of info.
Look at the corrosion on the rivets in that pic, and the last shear point, this was having issues from the get go, or the rivets were stress fractured right from the factory. that rusted area right up to the shear point says they were cracked thru long before the actual failure event.
I really, really doubt that the rivets were hitting the flywheel bolts. there would be wear marks across the entire face of the bolts, and there is no such marking, just edge hits likely from when the heads finally popped off the rivets. note that the markings are not uniform, some are in the center, others are on the outter edge.
the 2.8/v6's did not use a pilot bearing or flywheel mounting bushing in the flywheel, so that is not the issue.

As was pointed out by 86gt3, those splines are really bad, alot of wear for no milage or they were not hardened properly. There is a spec for the clearances for the spline to hub, but I owuld have to go dig it out.

As for the installation pics,that doesn't look right to me. too much spline showing, and while that might be the right orientation, that does not mean it is made correctly. the wear on your previous pics of the tranny input shaft is not something that happened quickly.

now one other thing, if this is not a stock motor, it is possible that there needs to be a spacer plate for engine to tranny mounting that is either not thick enough or not there.

A spring hub will be alot more forgiving with mis-alignment than the solid hub will be, but neither will last as long as a properly aligned setup.

What was your method for maintaining proper shaft alignment when making the adapter plate?

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[This message has been edited by 2feido (edited 04-25-2009).]

quote Originally posted by fieroguru: A spring hub will be alot more forgiving with mis-alignment than the solid hub will be, but neither will last as long as a properly aligned setup. What was your method for maintaining proper shaft alignment when making the adapter plate?

I had a mock up engine (junk free engine) and a mock up trans (84 case with input shaft).

i drill the holes for the engine bell housing pattern out of 1/4 steel metal, bolted it engine, then i installed a machined bushing to fit in the crankshaft and a the input shaft would go into the bushing. I was hoping that keep it there. Then i drilled the trans holes in the 1/4 plate. It worked once so i figured it work a second time. LoL

0.830" from the bellhousing face on the block to the face of the flywheel on a fiero 2.8... but unknown if the flywheel face had been surfaced prior.

From the pic it looks like yours is about 7/8" which would be around 0.875".

quote Originally posted by fieroguru: 0.830" from the bellhousing face on the block to the face of the flywheel on a fiero 2.8... but unknown if the flywheel face had been surfaced prior. From the pic it looks like yours is about 7/8" which would be around 0.875".

.045'' difference? Damn i was close, but that still doesn't explain how my hub is ending up so far on the input shaft. I tried installing the disc backwards and it fit, but only because of the crank dimensions. And if it was turn around then the disc would be riding at the very tip of the input shaft. Still no good?

sorry, I wan;t aware that this was a homebrew swap. I just can;t keep track of this stuff.
I think Dodgerunner has a bunch of measurements when he had issues with his 4 speed ontot a 3.4 swap, that may help you out.

quote Originally posted by 2feido: I had a mock up engine (junk free engine) and a mock up trans (84 case with input shaft). i drill the holes for the engine bell housing pattern out of 1/4 steel metal, bolted it engine, then i installed a machined bushing to fit in the crankshaft and a the input shaft would go into the bushing. I was hoping that keep it there. Then i drilled the trans holes in the 1/4 plate. It worked once so i figured it work a second time. LoL

Both the crank and tranny input shafts will have some side to side motion and could be +/- some distance from true center - especially on used parts. By using them as the alignment devices the +/- variations can easily result in an adapter plate with excessive mis-alignment. Also, there is much more precision at the dowel pin locations from block to block and tranny to tranny than the actual location of the bell housing bolt holes.

I have 3 SBC/fiero adapter plate setups, but I am getting ready to build my own. I am using a spare block with no crank or bearings and just the bellhuosing side of an an isuzu tranny. I am turning down a shaft that will precisely fit the main bearing bores of the engine and accept the thowout bearing sleeve that is machined into the tranny case. This shaft will maintain proper alignment as the dowel pin locations are precisely bored. The main reason I am doing mine this way is to allow the tranny to be rotated relative to the engine.

quote Originally posted by tjm4fun: sorry, I wan;t aware that this was a homebrew swap. I just can;t keep track of this stuff. I think Dodgerunner has a bunch of measurements when he had issues with his 4 speed ontot a 3.4 swap, that may help you out.

Not everyone has money. I have more time then money. And I am a DIY'er that is always trying new things.

quote Originally posted by 2feido: Not everyone has money. I have more time then money. And I am a DIY'er that is always trying new things.

haha, sorry, I think you misread that, I was apologizing for any offense, I have no issue with homebrew, I just wasn't aware of that when I was looking at the pics as to what you had going.
I also noticed (from other threads)that there seems to be some disagreement on the actual measurements for flywheel face to block and even the bell housing face to input shaft end. it doesn;t take much to what out an installation.
Good luck sorting it out!

quote Originally posted by 2feido: .045'' difference? Damn i was close, but that still doesn't explain how my hub is ending up so far on the input shaft. I tried installing the disc backwards and it fit, but only because of the crank dimensions. And if it was turn around then the disc would be riding at the very tip of the input shaft. Still no good?

A machinist or engineer would cringe at .045" being considered close...
I have never messed with the 4 speeds much, but that much of a difference on an isuzu and the pressure plate would most likely be hitting the back side of the trans.

What I suggest doing is bolting the clutch hub back to the clutch disk and placing it on the flywheel. Then measure the location of the hub face on both sides relative to the bellhousing face. Then flip it over and do it again. Then with ruler across the tranny, measure the start of the splines and the edge of the throwout bearing sleeve. This will let you "know" how the hub will engage the splines - shoot for 100% engagement of the hub. There must be room between the hub and the sleeve, and there must be room between the flywheel crank bolts and the rivots or hub on the back side. If you have clearance to both of these and spline engagement for the entire length of the hub you are good (since you already know the pressure plate fits the tranny and currently haven't had any over extension issues).

Then you can get busy working on the engine/tranny alignment issue.

quote Originally posted by fieroguru: My undergrad is in Mechanical Engineering, but I am not trying to be high tech. For success in an adapter plate application (especially in a FWD configuration) precision is a requirement. Since the stay at home wife and 2 daughters have come along, I, like you, do not have the luxury of excess $$$ for my fiero hobby. My anceint brake lathe cost me $65 at a close out auction. It is far from perfect and has its own limitations, but it is better than eyeballing it.

LoL your funny....

If you have no other means of aligning the engine/tranny, try this.

Stand the engine up so the flywheel is facing up.
Drill the plate for the engine and dowel pin locations.
Use your original method with the coupling linking the crank and input shaft.
With the two coupled, push the tranny to one side and scribe both sides of the tranny case.
Push the tranny to the other side using as close to the same amount of force as possible and scribe the sides of the tranny again.
Remove the tranny and make a new scribe line between the two previous marks on each side. This should center the tranny side to side.
Put the tranny back on and while lining up the case to the new scribe lines, push the tranny down and scribe
Then do again after pushing the tranny up.
Remove and add a new scribe line between the two at the top.

Now reinstall the tranny doing your best to line the case up to the center scribe lines on 3 side of the tranny. Clamp the tranny down and drill the dowel pin holes (drill them out on the tranny case 1st so you can drill the adapter plate through the dowel holes in the tranny.

This method is far from perfect but it is better than nothing.

[This message has been edited by fieroguru (edited 01-26-2009).]

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[This message has been edited by 2feido (edited 04-25-2009).]

Well, i been busy, but i have a new adapter plate using the engine and trans dowel pins and machined a new alignement tool, (basically an polit bearing bored to the input shafts diameter of .474''.


I tested fitted the trans to the engine and fits like a glove, with the pilot bearing. I think im going to leaving the bronze pilot bearing in there. Would it hurt?

Clutchnet Warrantied the disc, it should be arriving in the mail shortly.

Just out of curiosity, why are you using a solid hub disc?

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62 Buick Special
86 GT, 5-Speed
87 GT, 3.4l DOHC Turbo 415 WHP, 11.9 @ 118
88 Toyota Supra Turbo

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[This message has been edited by 2feido (edited 04-25-2009).]

quote Originally posted by 2feido: Well, i been busy, but i have a new adapter plate using the engine and trans dowel pins and machined a new alignement tool, (basically an polit bearing bored to the input shafts diameter of .474''. I tested fitted the trans to the engine and fits like a glove, with the pilot bearing. I think im going to leaving the bronze pilot bearing in there. Would it hurt? Clutchnet Warrantied the disc, it should be arriving in the mail shortly.

Did you compare it to the previous plate to see how close they are to each other?

The only issue with leaving the pilot bushing it, is if the centerlines are still off... you will kill the tranny or main bearings vs. just a clutch. If it was my car, I would leave it out and run a spring hub clutch.

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[This message has been edited by 2feido (edited 04-25-2009).]

quote Originally posted by 2feido: If the centerline is still off then wouldn't the input shaft not fit in the pilot bearing. I rotated the crank and input shaft and seemed to be no binding.

It depends on how much play is on the tranny input shaft, since it was used to center the combo. If there is significant play in the shaft, the input shaft could fit within the pilot bearing, but still not have the tranny and engine centerlines perfectly lined up.