There are at least three uses for a feature like this at the back of the crank.

1) Support the trans input shaft- we've known all along that Fiero trans input shafts are "stubby" and don't interface with the pilot bearing- if they did, the service manual would say something about greasing the tip of the input shaft.

2) Provide a guide during assembly- clutch alignment tool, etc. I know that with a pilot bearing in the back of the crank my alignment tool centers the clutch disc pretty well- while I've read about people on here struggling to mate an engine to a trans, its never taken me more than 90 seconds to get the trans to mate.

3) Provide a pilot for the flywheel!!!- just like your wheels are hub-centric, so is your flywheel. The flywheel bolts are not shoulder bolts and do not have any design features intended to maintain the alignment of the flywheel to the crank and limit runout.

Sure, you can get lucky sometimes running wheels with a bigger pilot bore, and similarly you can get lucky running a flywheel with no hub to interface with, but the 100% sure way to ensure crank to flywheel concentricity is through the use of a pilot bearing.

If you don't use one, this can happen:


This is a 500 mile iron duke crank (believe-it-or-not) that came from a rebuilder with no pilot bearing. The PO put the engine in the car without it. The runout and imbalance caused fatigue at the joint. You can see the multiple broken bolts and rounded-out holes from the cyclic stresses of repeated loading due to imbalance/runout. This flywheel eventually broke loose.

Consider this failure in context to the huge explosion of parts in Bills car; what all can happen if the flywheel has runout relative to the clutch disc due to flywheel mis-alignment?

If the flywheel is "wobbling" because its not centered on a pilot then it can put load on the pressure plate, trans bearings and trans case itself- once you fatigue those parts things can let go spectacularly throughout the drivetrain, domino effect.

[This message has been edited by KurtAKX (edited 11-17-2008).]

So Kurt, are you saying that Bill may well be correct. I mean correct in the fact that is original Duke had a pilot bearing - although it was intended to keep the flywheel centered versus a pilot for the input shaft? If this is the case, it makes sense to me now. If during assembly of his new motor, the pilot bearing (the one that is ther for flywheel alignment) was not installed, then I can see why the flywheel bolts sheared and exploded the tranny. Does this sound like a reasonable interpretation? On the crank on my V6 there is a raised ring machined in the crank that the flywheel centers on. Am I correct in thinking that a Duke crank uses an insert (bushing) to accomplish the same thing? This would explain Bill's recolection of a bushing protruding from the crank! Just curious......

Pat

quote Originally posted by KurtAKX: There are at least three uses for a feature like this at the back of the crank. 1) Support the trans input shaft- we've known all along that Fiero trans input shafts are "stubby" and don't interface with the pilot bearing- if they did, the service manual would say something about greasing the tip of the input shaft. 2) Provide a guide during assembly- clutch alignment tool, etc. I know that with a pilot bearing in the back of the crank my alignment tool centers the clutch disc pretty well- while I've read about people on here struggling to mate an engine to a trans, its never taken me more than 90 seconds to get the trans to mate. 3) Provide a pilot for the flywheel!!!- just like your wheels are hub-centric, so is your flywheel. The flywheel bolts are not shoulder bolts and do not have any design features intended to maintain the alignment of the flywheel to the crank and limit runout. Sure, you can get lucky sometimes running wheels with a bigger pilot bore, and similarly you can get lucky running a flywheel with no hub to interface with, but the 100% sure way to ensure crank to flywheel concentricity is through the use of a pilot bearing. This is a 500 mile iron duke crank (believe-it-or-not) that came from a rebuilder with no pilot bearing. The PO put the engine in the car without it. The runout and imbalance caused fatigue at the joint. You can see the multiple broken bolts and rounded-out holes from the cyclic stresses of repeated loading due to imbalance/runout. This flywheel eventually broke loose. Consider this failure in context to the huge explosion of parts in Bills car; what all can happen if the flywheel has runout relative to the clutch disc due to flywheel mis-alignment? If the flywheel is "wobbling" because its not centered on a pilot then it can put load on the pressure plate, trans bearings and trans case itself- once you fatigue those parts things can let go spectacularly throughout the drivetrain, domino effect.

so all the v6's will do that too? I don;t think so. looking at that pic, I see a failure caused by improper torquing. note the bolt at the 1 o'clock position. see the rust on it? it was cracked thru a long time before the failure. since the 2 that are shown pulled out, with threads still on them, they were backed out to the last few threads, probably put in too loose. the other 2 sheared ones where lal that was holding it on.
I can;t imagine the duke being that much differrent as the later years all used the same trannies, and the pilot bearing I tried on the 86 did not even come close to contacting the flywheel hole. IRRC, there is a flange on the back side of the flywheel for the hub.
The duke also calls for a spacer for both the flywheel and the flexplate.
that pic looks to me to be more of an assembly failure than anything else.
Also I;ve never seen a single flywheel that fit snugly over a pilot bearing, so I don't buy that it is the alignment surface.

quote Originally posted by KurtAKX: 3) Provide a pilot for the flywheel!!!- just like your wheels are hub-centric, so is your flywheel. The flywheel bolts are not shoulder bolts and do not have any design features intended to maintain the alignment of the flywheel to the crank and limit runout. Sure, you can get lucky sometimes running wheels with a bigger pilot bore, and similarly you can get lucky running a flywheel with no hub to interface with, but the 100% sure way to ensure crank to flywheel concentricity is through the use of a pilot bearing. This is a 500 mile iron duke crank (believe-it-or-not) that came from a rebuilder with no pilot bearing. The PO put the engine in the car without it. The runout and imbalance caused fatigue at the joint. You can see the multiple broken bolts and rounded-out holes from the cyclic stresses of repeated loading due to imbalance/runout. This flywheel eventually broke loose. Consider this failure in context to the huge explosion of parts in Bills car; what all can happen if the flywheel has runout relative to the clutch disc due to flywheel mis-alignment? If the flywheel is "wobbling" because its not centered on a pilot then it can put load on the pressure plate, trans bearings and trans case itself- once you fatigue those parts things can let go spectacularly throughout the drivetrain, domino effect.

And just when I thought the thread couldn't get worse!

Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can!

quote Originally posted by KurtAKX:

That's insane. I haven't played with an iron duck before, but I've never even seen a crank that didn't have the flywheel pilot integral with the crank flange. Wow.

quote Originally posted by 84Bill: Fine... I think you are acting like an ass hole. For a person who seems a little more than average in intelligence I figured you would be less apt to go with the flow and ignore technical bulletins recommending the installation of a pilot bushing. Since you appear to be of weak character anymore you can kiss my ass all day and all night from here to eternity.

No, Bill, I'm not going to kiss your ass for all of eternity. Instead, I will just continue reporting your abusive vulgar PMs to Cliff, like the two more that you sent me after I asked you not to PM me anymore both here and via PM.

JazzMan

quote Originally posted by fieromadman: Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can, Trash Can!

OMG! He's figured out the secret bill-oodo. Once something is repeated 20 times, IT BECOMES TRUEEEEEEeeee ...dun dun dunnnn.....

As per the picture above, I too have to point out that one bolt is rusty where the others are clean. Also, I dont see any way for those other holes to be egged out at the top unless it was running on there very loose for a very long time. Thats long term wear there. I would propose that the bolts were likely over torqued or fatigued, and one snapped off at assembly,two others backed out, and the remaining ones couldnt take the load.

But the idea sounds plasuable. Its been a while for me, now that we can actually have a mature conversation (IE one where people address questions) in a certain someones abscence.... How about some pictures of the 'flanges' involved and how they interact. We see one without the pilot, now how about a duke with the pilot, a V6 crank, and a flywheel.

quote Originally posted by JazzMan: No, Bill, I'm not going to kiss your ass for all of eternity. Instead, I will just continue reporting your abusive vulgar PMs to Cliff, like the two more that you sent me after I asked you not to PM me anymore both here and via PM. JazzMan

Good then perhaps you and your buddies can **** off a die.

quote Originally posted by 84Bill: The engineers had these bushings installed in 2.5 engines for a reason...

yes they did...
for other cars.
not ours.

the engines were mass produced.
the assembly line didn't know what cars they were going to go in to. so they all got them.

[This message has been edited by buddycraigg (edited 11-18-2008).]

quote Originally posted by 84Bill: Good then perhaps you and your buddies can **** off a die.

Did you mean "and die"? Are you wishing death upon people, now? If you are, why don't you just leave PFF with some of your Dignity intact, Bill. You have turned into a complete fuktard.

[This message has been edited by Hulki U. My-BFF (edited 11-18-2008).]

Just in before the trashcan.

I believe that some engines came with pilot bearings. The reason as stated before as these engines are used in rear wheel applications some may have gotten them due to production for a different line that was reallocated due to demand. Also allot of Fieros had their dukes replaced under warranty. Some of these short and long blocks may have already had pilot bushings installed.

quote Originally posted by Fiero STS: Just in before the trashcan.

Ya.. real shame isnt it. Goes to show the level of respect the 2.5 owner gets on this forum.

They didnt install a bushing at the factory just to look pretty and waste money. It's obviously there for a reason.

quote I believe that some engines came with pilot bearings. The reason as stated before as these engines are used in rear wheel applications some may have gotten them due to production for a different line that was reallocated due to demand. Also allot of Fieros had their dukes replaced under warranty. Some of these short and long blocks may have already had pilot bushings installed.

The FSM and the P22 calls for a pilot bushing. Why is apparently anyone's guess but just don't argue.. "leave it out, it's useless."

quote Originally posted by 84Bill: The FSM and the P22 calls for a pilot bushing. Why is apparently anyone's guess but just don't argue.. "leave it out, it's useless."

The engine manuals themselves could also be just copies of prior manuals that used a pilot bearing. This is very common to take an existing manual and modify it to the new application instead of starting completely from scratch. This is also how we end up with mistakes and inccorect part numbers or parts listed that were never used on a particular model.

quote Originally posted by Fiero STS: The engine manuals themselves could also be just copies of prior manuals that used a pilot bearing. This is very common to take an existing manual and modify it to the new application instead of starting completely from scratch. This is also how we end up with mistakes and incorrect part numbers or parts listed that were never used on a particular model.

I would agree with that assessment but if that were the case then it is an across the board mistake... not with one manual but with all manuals and several technical bulletins.... not to mention a waste of money having it installed from the OEM.

Sorry but I dont feel this was a mistake with the publishers but rather mine for not installing it... and a VERY expensive one at that.

quote Originally posted by tjm4fun: so all the v6's will do that too? surface.

Beats me, but I don't think the V6s will do that. They actually have machined-in features on the crank to center the flywheel.

quote Originally posted by tjm4fun: looking at that pic, I see a failure caused by improper torquing. note the bolt at the 1 o'clock position. see the rust on it? it was cracked thru a long time before the failure. since the 2 that are shown pulled out, with threads still on them, they were backed out to the last few threads, probably put in too loose. the other 2 sheared ones where lal that was holding it on.

The rust is all over the part. Its been apart for years since this happened. I don't think this was put together so inconsistently that some bolts were so tight that they broke off while others were so loose they fell out.

quote Originally posted by tjm4fun: I can;t imagine the duke being that much differrent as the later years all used the same trannies, and the pilot bearing I tried on the 86 did not even come close to contacting the flywheel hole.

Nobody here has implied that the pilot serves that purpose in manual transmission Fieros.

quote Originally posted by tjm4fun: IRRC, there is a flange on the back side of the flywheel for the hub.

There is no flange feature to keep the flywheel centered radially. The back of the flywheel is flat. I have a stack of them in my garage to check against.

quote Originally posted by tjm4fun: The duke also calls for a spacer for both the flywheel and the flexplate.

I have seen some with shim stock spacer. I don't believe I've ever found one in a car from the factory, only those that have had a clutch job.

quote Originally posted by tjm4fun: Also I;ve never seen a single flywheel that fit snugly over a pilot bearing, so I don't buy that it is the alignment surface.

They do in Iron Dukes, but they're admittedly not typical engines. In a manual trans Iron Duke pilot bearing the only diameter that's critical is the outer diameter.

quote Originally posted by 84Bill: Ya.. real shame isnt it. Goes to show the level of respect the 2.5 owner gets on this forum.

No thats just the level of respect a hard headed troll gets on this forum. Im glad we got back to productive conversation, but dont sit there and act all innocent and try to make anyone believe the attitude you are getting is because of your engine. YOU ruined this thread, YOU started the personal attacks YOU ignored all the data and information posted by everyone and cluttered the thread up by just reposting the same irrelevant information over and over again. This thread goes to the trashcan because of you and your attitude and your actions, it has NOTHING to do with what we are talking about or what engines. Stop deflecting, I know thats all you can do, since a dozen people have given a dozen diffrent reasons why you cannot be right, but its annoying.

Now, I am not one to pointlessley repeat information over and over again, but since I posted this in another thread, allthough the conversations are near identical, some people might not read it, so here is my post from the other thread regarding the use of the pilot bearing to center the flywheel...

Well, after spending about an hour searching three diffrent parts stores, not a one listed a pilot bearing for the duke, not a book had an entry for it, nothing. And that's not just computers, the actualy manufacturer's spec books too. That being said, I dont stand on other people's information alone, we all know they can be wrong, but finding universal results acrost several diffrent parts stores and several diffrent parts manufacturers is a very strong indication.

BUT, I did find one clutch kit that had a pilot bearing, for the 84 Fiero 2.5L, and this is its story...



And an 84 Firebird 2.5 L clutch set.




Now the books did list 2 diffrent bushings for the 2.5 Firebird, and accordingly, I found the 2.5 firebird clutch set above to have 2 diffrent bushings, the larger being identical to the Fiero clutch kit bushing. I of course forgot to measure the depth of the bushing, but it doesnt much matter, its not large enough to touch the flywheel if it did extend, and the ID is completely too small to hold the input shaft. If someone measures the depth of the outer hole on a duke crank, I will go back and get the depth of this bushing, but you can estamate it from the pictures.

My ruling, even without measurements of a flywheel (which no one stocked) it appears the bushing is not large enough to touch the flywheel

I am still confused. Does the 2.5 require an insert in the rear of the crank to center/support/guide, etc. the flywheel? I found a part number for a steel insert which inturn supports the "pilot bushing" if needed depending on application so does this steel insert have the "centering" ring for the flywheel? I searched for the part but came up empty (100009785). I can't believe that the 2.5 crank is designed without a centering ring for the flywheel. Don't flame me, I'm just curious to get a definitive answer. I wish someone with pics of Duke parts in question would post here.

That is the whole confusion. The initial claim was that the pilot bushing supports the input shaft. It does not, the input shaft is not long enough, nor would it fit into the pilot bushing if it did. Those are two of the six reasons it cant be.

The next claim was that the pilot bushing centers the flywheel, like a hub centric rim for a tire. I do not believe it does. As you can see above, the OD of the bushing is only 1.1", the flywheel ID is much larger, and I do not believe it would protrude from the crank anyway.

The reason you can find parts for it is because the engine was also used in RWD, where the bushing is very much neccessary. Just about every entity in the automotive buisness is a little on the sloppy side when it comes to stuff like this, just because an engine can go in a car, doesnt mean it needs the parts it might if it went in another car, just because the thermostat cap fits, does not mean it seals against the relief perch, etc.

quote Originally posted by 86GT3.4DOHC: I propose that there is no way the input shaft pictured in bills car could possibly fit inside the pilot bushing. Nor any other Fiero transmission, they lack the smaller, longer tip needed.

I never said it went through or even all the way into the bushing... The purpose of the bushing would be to keep the input shaft as close to center as possible should it get to far out of center.

That would be the only time the input shaft would EVER contact the bushing... it's just enough to keep the clutch from flapping against the flywheel....

Thats not how pilot bushings work, besides there is no way the input shaft can move in relation the the transmission enough to cause any problems. Also, THE SHAFT DOESNT FIT INTO THE "BUSHING" What the hell is it going to do sitting face up against it?

Dude, cut your losses and tap out allready.

quote Originally posted by 86GT3.4DOHC: Dude, cut your losses and tap out allready.

No

quote Originally posted by 84Bill: No

For all those interested in how they too can be like bill.... INTRODUCING ... The "Think Like Bill Flowchart"!!!!!



Sorry, I hate to take this back to that level, its been rather productive today, but dammit, you piss me off.

quote Originally posted by 86GT3.4DOHC: Sorry, I hate to take this back to that level, its been rather productive today, but dammit, you piss me off.

Oh please
Dont lie... you love to hate and you love trashing things.... especially something that isn't yours.

You really need to look into anger management or something because I'm one of the easiest people to get along with that you would ever meet.


All you have to do it just let it go... just let go of the anger. Or just trash everything of mine you can... and hope you feel better now that you have managed to trash my thread with your anger and resentment. You sorry ass loser.

quote Originally posted by 84Bill: You really need to look into anger management or something because I'm one of the easiest people to get along with that you would ever meet.

Are you going for some sort of award for making the most ironic and/or hypocritical posts in one day?

quote Originally posted by GT86: Are you going for some sort of award for making the most ironic and/or hypocritical posts in one day?

No, I just call a spade a spade when I see it.. you however are not a spade... but an ass hole.


Now that I think of it weren't you the same ass hole who wanted me to go to Afghanistan and hoped I never came back? No... that was a different ass hole.. but thats okay because you are still a cross threading ass hole

[This message has been edited by 84Bill (edited 11-18-2008).]

quote Originally posted by 84Bill: . but thats okay because you are still a cross threading ass hole

Who started a 2nd thread?

[This message has been edited by GT86 (edited 11-18-2008).]

quote Originally posted by GT86: Who started a 2nd thread?

I did because I knew YOU were hell bent on trashing the first..

Instead of just letting it go you and your little friends decided to destroy that one too.... arent you just a fine bunch of dingleburries.

So by all means kiss my ****in ass douchebag.


So just get the **** out of my thread and leave me alone and we wont have any more problems... simple huh?

If it's any consolation to James, you are worse than he is... well just by a small margin.

quote Originally posted by 84Bill: I did because I knew YOU were hell bent on trashing the first.. Instead of just letting it go you and your little friends decided to destroy that one too.... arent you just a fine bunch of dingleburries. So by all means kiss my ****in ass douchebag. So just get the **** out of my thread and leave me alone and we wont have any more problems... simple huh? If it's any consolation to James, you are worse than he is... well just by a small margin.

It was worthless when you started it, and has gone downhill since. You don't know what you're talking about, and the longer this goes on the more of your ignorance you're putting on exhibit.

I'll be sure to work on that small margin

quote Originally posted by GT86: It was worthless when you started it,

Why?
Because it's a 2.5 or because you just enjoy being an ass hole?

There was no reason for you to act the way you did... If you don't agree then
say so and move one but don't trash my threads because
I refuse to get on one knee and kiss your royal omnipotent ring. Get over yourself, you dont mean **** to me.

At least Archie gets my respect over you.
He said his piece and moved on and that makes him a "much bigger man" than
you will ever be.... even if I disagree with him.

Grow up dewd.. or get a life or something.

[This message has been edited by 84Bill (edited 11-18-2008).]

quote Originally posted by 84Bill: Why? Because it's a 2.5 or because you just enjoy being an ass hole? There was no reason for you to act the way you did... If you don't agree then say so and move one but don't trash my threads because I refuse to get on one knee and kiss your royal omnipotent ring. Get over yourself, you dont mean **** to me. At least Archie gets my respect over you. He said his piece and moved on and that makes him a "much bigger man" than you will ever be.... even if I disagree with him. Grow up dewd.. or get a life or something.

No, it was worthless because you were offering information that is 100% no good. I don't care what engine you're running (or were running).

And the last thing I want is your respect.

I've been skimming this thread,and here is my experience with my 84 four speed Fiero. I bought the car from a guy that owned a transmission shop. He said he installed a new GM clutch in the car before selling it to me. I drove the car around hear for a few days, and then deceided to to drive it to New Jersey. Cruising on Rt. 80 I heard a noise like something fell out of the engine compartment, but the car was running fine. As I got off 80 and got on the exit ramp I found I had no clutch. Had the car towed back to PA and told the seller what happened, and put another clutch in at no charge. Long story short, the second clutch failed after about 500 miles. Took the car to another shop, and they said the clutches were beeing ripped apart because there wasn't a pilot shaft bearind installed. 12 years later that clutch is still in the car.

quote Originally posted by GT86: No, it was worthless because you were offering information that is 100% no good. I don't care what engine you're running (or were running). And the last thing I want is your respect.

No, it is good information for owners of 2.5 Fieros... of which you have little regard for.

Bad information is saying that GM never installed them and not to bother installing it.
It is there for a reason even if neither of us know exactly why.

One thing I intend to do is find out FOR MYSELF.
Not that I dont trust you.. after all you demonstrated such great judgment in this thread.

Your avatar speaks volumes, Bill.

quote Originally posted by 84Bill: No, it is good information for owners of 2.5 Fieros... of which you have little regard for. Bad information is saying that GM never installed them and not to bother installing it. It is there for a reason even if neither of us know exactly why. One thing I intend to do is find out FOR MYSELF. Not that I dont trust you.. after all you demonstrated such great judgment in this thread.

Persecution complex again. Now you're claiming I have no regard for the 2.5 owners?

It's been shown over and over and over and over and over why you're wrong, yet you continue to push this. If anyone has little regard for 2.5 owners, it's you since you're the one pushing information that is wrong.

quote Originally posted by GT86: Persecution complex again. Now you're claiming I have no regard for the 2.5 owners? It's been shown over and over and over and over and over why you're wrong, yet you continue to push this. If anyone has little regard for 2.5 owners, it's you since you're the one pushing information that is wrong.

Telling someone that "GM didn't install pilot bushings in FWD cars" and "don't bother installing"... Thats BAD INFORMATION.

Telling them to "disregard" the P22 and FSM which shows the parts and part numbers from GM... thats BAD INFORMATION

Telling them to IGNORE a technical bulletin that out outlines their use and cautions to ensure the CORRECT bushing is installed is ALSO BAD information.

So you can feel free to get the hell out of my thread any time you like.... Please take "your bad information" with you and leave mine the **** alone. Okay ass hole?

quote Originally posted by 84Bill: I did because I knew YOU were hell bent on trashing the first..

I do believe you were the one to pointlessly repost the same information a good ten times, and you were the first to drop the topic and start personal bashing.

AND PUHLEASE stop the bullshitting, NOONE believes that anyone is saything this because you have a 4cyl.


The only reason %90 of the people who posted in this thread did, was because you are trying to spread blatently wrong information. That was fine when it started and it was just a mistake, no biggie, no one cared.

And GM never installed a pilot bearing, they did install an "insert" that DOES NOT TOUCH ANYTHING IN A MANUAL VEHICLE


Just explain one thing, ONE THING, and I'll kiss your ass and I'll never post in another one of your threads. . If the input shaft is ~1" Diameter, and the "insert" has an ID of .55" (Both facts documented in this thread) HOW DOES IT FIT?

quote Originally posted by 86GT3.4DOHC: The only reason %90 of the people who posted in this thread did, was because you are trying to spread blatently wrong information.

Again...


Telling someone that "GM didn't install pilot bushings in FWD cars" and "don't bother installing"... Thats BAD INFORMATION.

Telling them to "disregard" the P22 and FSM which shows the parts and part numbers from GM... thats BAD INFORMATION

Telling them to IGNORE a technical bulletin that out outlines their use and cautions to ensure the CORRECT bushing is installed is ALSO BAD information.

So you can feel free to get the hell out of my thread any time you like.... Please take "your bad information" with you and leave mine the **** alone.