quote Originally posted by katatak: 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

Edit add - YES Page 7 Ownage.... How many more pages will we get out of this?

This is what I was trying to get to!

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

Well, okay, I hate semantics, but that is a "crankshaft insert" not a pilot bearing, the pilot bearing sits at the rear of the crank bore. Still, you may be correct that it has a function. We could have gotten here a lot faster if people would accept reality and move on. We spent %90 of this thread trying to explain the dozen diffrent ways the input shaft could not interface with the 'pilot bearing'. The main contention of this thread has been the refusal to accept what we could prove as fact with the information at hand. What we lacked was a means to confirm or deny this "hub centric" theory. Namely the measurement of the ID of a flywheel. I have the measurement of the OD of the "insert"

One thing that I wonder, the "insert" I measured was 1.1" OD, this is what is called for as the "bearing" and this is what is included in the clutch kits.

What is the ID of the flywheel? I cant tell from the flash




What is the ID of your crankshaft, the bore that is in the middle of your 'insert' in the picture. Im trying to figure out where this one I measured plays into things.
.. oh yea, forgot
Just explain one thing, ONE THING, and I'll kiss your *** 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?

[This message has been edited by 86GT3.4DOHC (edited 11-18-2008).]

I may be wrong but I believe that what Kurt has shown in his pic is called a "Crankshaft Flange Insert". As posted a few pages back and I have also read in other manuals that GM uses 3 different "Crankshaft Flange Inserts" on the 2.5 depending on year and tranmission. Also that this insert is intended for support of a pilot bushing and/or torque converter alignment. Wait a minute and think about it before you jump... I am not in anyway saying that a pilot bearing is or is not needed. My point is that I believe that the Duke crank would require this flange insert for centering the flywheel. Without it, the crank bolts could vibrate loose, shear off and just maybe cause the damage that Bill has experienced. Bill himself said early on that his old crank had a bushing that protruded from the crank. We are talking about 2 different parts here. The flange insert and a pilot bearing. I think that Kurt has proved this in his post. Just my observation....

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

quote Originally posted by katatak:

That seals the deal right there, cant argue with that

Yes I posted the wrong pic.........

quote Originally posted by katatak: The flange insert and a pilot bearing. I think that Kurt has proved this in his post. Just my observation....

Could be, we never rulled that out difinitively, we started a pretty good discussion in the other thread. Though now I want to know where that part I measured plays into this, because it would appear, guessing from the pic, the ID of the flywheel is 1.25", that bushing with the kit doesnt come close to that. And the real question, if you bought the insert from the Fiero store, is it the part I measured, or the part Kurt measured? Because it would appear mine is what companies think the insert is.

Another question, is that 'insert' in the pic definitely removable?

[This message has been edited by 86GT3.4DOHC (edited 11-18-2008).]

quote Originally posted by 86GT3.4DOHC: Could be, we never rulled that out difinitively, we started a pretty good discussion in the other thread. Though now I want to know where that part I measured plays into this, because it would appear, guessing from the pic, the ID of the flywheel is 1.25", that bushing with the kit doesnt come close to that. And the real question, if you bought the insert from the Fiero store, is it the part I measured, or the part Kurt measured? Because it would appear mine is what companies think the insert is. Another question, is that 'insert' in the pic definitely removable?

I'm curious as well. I can't find any reference to this in my 86 service manual, but I could be looking in the wrong place. I've replaced more than one clutch on a 4-cylinder, and don't recall seeing the "factory installed" insert. Now, it's possible the cars I worked on had already had the inserts removed, but one of my first was on an '85 back in the late 80's (my sister burned it up learning to drive stick), and was most likely the first time that clutch had been changed. That car to the best of my recollection did not have that insert.

A few years ago, I did a clutch on an 87, and the replacement clutch kit did come with something that looked very much like what 86GT3.4DOHC posted. However, it was NOT a snug fit to anything, not to the flywheel or the crank.

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

quote Originally posted by KurtAKX: Everyone in this entire thread except for Will and I have made unfounded statements. Check yourselves.

I do however take exception to the attitude. Everything (technical) I have said in this thread was %100 true and supported by facts. If you check my posts, you'll see everything I said was backed up by data, information, or refrences.

Well, except for the first post I made where I agreed with him. that was before I looked into it and I was going on "well duh if it said you needed it and it broke because you didnt put it in, of course" mindset. Once I looked at the information, of course I realized that was incorrect.

Most everything else others said was also correct, maybe not everything, but most.

I dont think I posted this in this thread (I could have), but in the other thread, I came to the assumption, which I did state was based on the limited information I had, that the insert was not used to locate the flywheel on the measurements I got from the insert that was supplied for the 2.5L, being visibly too small for the flywheel. I didnt have pictures of a 2.5 crank to see there was no locating ridge like other cranks. I never said "you're a moron if you dont believe this". Now, I did say that about the input shaft part, because, well you cant fit a "1 solid steel plug into a .55" hole. Had certain unmentionable people here with access to the parts been willing to accept thier own humanity, and measure said parts, a more accurate solution could have been gained... What I needed was a measurement of the ID of the crank bore. So thanks for providing it, though in reality you raised new questions, lol.

[This message has been edited by 86GT3.4DOHC (edited 11-19-2008).]

quote Originally posted by 86GT3.4DOHC: I do however take exception to the attitude. Everything (technical) I have said in this thread was %100 true and supported by facts. If you check my posts, you'll see everything I said was backed up by data, information, or refrences. Well, except for the first post I made where I agreed with him. that was before I looked into it and I was going on "well duh if it said you needed it and it broke because you didnt put it in, of course" mindset. Once I looked at the information, of course I realized that was incorrect. Most everything else others said was also correct, maybe not everything, but most. I came to the assumption, which I did state was based on the information I had, that the flywheel was not hub centric based on the measurements I got from the insert that was supplied for the 2.5L, being visibly too small for the flywheel. I never said "you're a moron if you dont believe this". Now, I did say that about the input shaft part, because, well you cant fit a "1 solid steel plug into a .55" hole. Had certain unmentionable people here with access to the parts been willing to accept thier own humanity, and measure said parts, a more accurate solution could have been gained... What I needed was a measurement of the ID of the crank. So thanks for providing it, though in reality you raised new questions, lol.

This thread was about the need for a pilot bearing to support the input shaft. That is not the case, regardless of the possibility that there may be a need for a crankshaft insert to align the flywheel.

quote Originally posted by GT86: This thread was about the need for a pilot bearing to support the input shaft. That is not the case, regardless of the possibility that there may be a need for a crankshaft insert to align the flywheel.

Very true, but the spirit of the thread is about supplying information. I dont want to say "you dont need a pilot bushing" and have people omit the required 'insert'. There is no point in installing a pilot bearing, but should you somehow get a crank without the insert, then you may need to find one, question is, can you?

quote Originally posted by 86GT3.4DOHC: Very true, but the spirit of the thread is about supplying information. I dont want to say "you dont need a pilot bushing" and have people omit the required 'insert'. There is no point in installing a pilot bearing, but should you somehow get a crank without the insert, then you may need to find one, question is, can you?

I agree - I have spent a lot of time today searching for the "flange insert" - I can't find one!

All I have found is the one I pictured before. None of the parts books list them, none of the computers show them, I wonder what the FieroStore is selling, I'll have to ask what the OD of that is.

I suppose I could check with GM in the morning.

Now I'm curious, and would like to know the dimensions of what the Fiero Store is selling. I'll soon be helping a friend change out the engine on an 84 that's been sitting forever. I'll have to remember to check and see if this insert is there.

And yeah, the flywheel was mentioned numerous times, but Bill smacked it down about as hard as we smacked down his idea about the input shaft needing the pilot bearing. I know at first I was interested in trying to figure out what happened, but after reading the same busted theory over and over, I lost most of my interest.

Yea, I would have liked to have seen some actual information, and determined the true cause, see what happened and what it caused and how that went. Plus the gory car-nage pics. Oh well

Ok, Glad you guys figured this one out for us... My conclusion: skip the duke...

What I was looking at in the back of the crank is what comes out of the box when you order a "pilot bearing" at the auto parts store.

Its Federal-Mogul part number PB650. I don't know what technical verbage is used to describe it, but I ordered a "pilot bearing" and that's what came when I made my stroker crank.

quote Originally posted by KurtAKX: OK, I've seen way too many A$SHOLES post in here who are full of opinions one way or the other; people that don't have enough background working on 2.5 cars to have a valid opinion worth listening to. Here's what the pilot bearing does: This is a picture of an iron duke flywheel installed on the back of a crankshaft which has a FACTORY INSTALLED pilot bearing in it. The engine is in a "normal" orientation. The only thing holding the flywheel on to take this picture is the "snug" fit of the flywheel bore being piloted by the bearing. It is the only feature which keeps the flywheel centered; there are no dowel pins or shoulder bolts to do the job!!! If you don't believe me, pull out your Iron duke and do the following: 1) Get a measurement off the flywheel bore 2) Take calipers over to pilot bearing; note that bearing diameter is the same as flywheel bore diameter (duh, that's why it was put there for stick cars.) Everyone in this entire thread except for Will and I have made unfounded statements. Check yourselves.

Seems to me that if it fulfills the function of a flywheel centering bushing but not the function of a pilot bearing then it would be best to call it a centering bushing. Does this same exact part also act as a pilot bushing on longitudinal trans applications? Or does an actual bushing or bearing insert into this piece when used on longitudinal apps? In other words, is the inner hole of the centering bushing actually machined as a bearing surface?

In any case, without any more info from 84Bill to go on and based on what he said about having to carefully center the flywheel when installing the bolts, my best guess is that he didn't have or use his centering bushing and the resultant eyeball-alignment of the flywheel created an imbalance that failed the bolts.

JazzMan

quote Originally posted by JazzMan: I foresee more than one occasion where a Fiero owner argues with a shop doing a clutch job on it about the need for the pilot bearing based on info in this thread. Some shop owners would probably just install one and charge a lot extra for it even though they knew that it accomplished absolutely nothing since the input shaft isn't even long enough to reach the back of the crank. It would be free money. Well, not to the poor bloke paying for it. JazzMan

Sure... I would agree with that but GM isn't in the habit of wasting money when it doesn't have to. As I have said MANY time this bushing was installed for a reason, it not there to look good or net more money for shop owners.

quote Originally posted by 84Bill: Sure... I would agree with that but GM isn't in the habit of wasting money when it doesn't have to. As I have said MANY time this bushing was installed for a reason, it not there to look good or net more money for shop owners.

Bill it has been explained about a dozen times. That engine in your Fiero, the one before it on the production line, went into a firebird, the one after it, maybe a buick or a S10 or something FWD. The bushing is there because its cheaper for GM to spend 10 seconds to pop in the (to them) .005 cent piece of metal, than it is to have a huge production change, new part numbers for the FWD engines, and to manage all those changes, then deal with the recalls when a FWD engine gets put in a RWD car and the input shaft rattles. If someone puts a bearing in a FWD car, no one notices or cares. If a RWD car ever got one, you're looking at $5000+ in costs per car by the time you get done with it, and lost customer loyalty.

So, by making a production change, they would be wasting literally millions of dollars. Or, they can order 10,000,000 pilot bushings for a fraction of a penny a piece, and put them all in, knowing that maybe %75 of them are going to be RWD engines anyway, so they are 'wasting' maybe a couple hundred bucks when you factor in tens of millions of cars.

The piece in the crank that is needed is not a pilot bushing, it is an allignment insert, which should never for any reason on any car, not be there. Maybe a reman engine, or a reman crank could have it mistakenly removed. We could have talked about that if you would have ever faced reality and accepted it could not inerface with the input shaft.

The part you would recieve if you ordered or asked for a 'pilot bearing' would be completely useless. It does not touch the input shaft, and it would not touch the crank either.

Oh, and Bill,

Just explain one thing, ONE THING, and I'll kiss your *** 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: Bill it has been explained about a dozen times.

Look here you angry little boy, the reason for the bushing is to locate the flywheel. THEY WERE INSTALLED AT THE FACTORY.... GM is not in the habit of wasting money. ALL 2.5 engines HAVE THESE BUSHINGS. So 86GT3.4DOHC you can kiss my ass... and have a nice day.

NUFF SAID.

quote Originally posted by 84Bill: Look here you angry little boy, the reason for the bushing is to locate the flywheel. THEY WERE INSTALLED AT THE FACTORY.... GM is not in the habit of wasting money. ALL 2.5 engines HAVE THESE BUSHINGS. So 86GT3.4DOHC you can kiss my ass... and have a nice day. NUFF SAID.

Okay, forget drinking, are you on crack?!? Thats exactly what I said, and totally not what you have been screaming at the top of your lungs for the last three days.... EVERYONE reading this thread knows that, you're not going to fool anyone, lest you go back and edit out all of your posts... Which I could see you doing.

Wow man... just wow.

So just answer the question then

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?

You can say "it wont", but you'll never do that, because then you would have to admit you were wrong.

Take note... this is the post of a very angry little man. Angry because I would not admit defeat even when called names and made the object of unfounded accusations such as the ones made below.

When you know you are on the right path... do not give up and never let these people get in your way... they aren't right in the head and they will try to knock you off the path... they are hate filled and just plain nasty.

quote Originally posted by 86GT3.4DOHC: Okay, forget drinking, are you on crack?!? Thats exactly what I said, and totally not what you have been screaming at the top of your lungs for the last three days.... EVERYONE reading this thread knows that, you're not going to fool anyone, lest you go back and edit out all of your posts... Which I could see you doing. Wow man... just wow.

Wow is right... you tried to stop us from finding out the truth about the bushing because I refused to accept your answer.. Now we know what it's purpose is so your time in this thread is nothing more than a personal vendetta you harbor against me for not bending to your will. I hope you find peace in that angry mind of yours.

Have a nice day

Not to beat a dead horse but I still say that unless the flywheel is located concentrically on the crank by means of some kind of hub ring, there will be a problem with the assembly. From the pics posted a few posts up which were originally posted by KurtAKX, there seems to be a confusion as to what is being called the pilot bushing. The pilot bushing that KurtAKX refers to is not a pilot bushing, that is the concentric ring i spoke of that the flywheel locates on. It seems to be missing from Bill84's crankshaft. The pilot bushing is smaller and goes inside the bore of the crank(inside of the concentric hub feature). Could it be that all of this confusion is because what some people are calling the pilot bearing is not really the pilot bearing at all?

The FWD trans do not need a pilot bearing because the input shaft is too short to go into it. HOWEVER, THE FLYWHEEL NEEDS A CONCENTRIC RING ON THE CRANK TO BE INSTALLED PROPERLY. There is no way that one can expect a flywheel/clutch/pressure plate assembly rotating at 5000 rpm to stay together just relying on 6 standard boltsto keep the assembly concentric.

quote Originally posted by 84Bill: Take note... this is the post of a very angry little man. Angry because I would not admit defeat even when called names and made the object of unfounded accusations such as the ones made below.

ROTFL Bill you are THE most hypocritical person I have ever met. The funniest part is you are just defacing your name more (if thats possible) because unlike you, other people actually read the posts, they're going to see what an ******* you were, what you said, and laugh when they read that.

And I admitted I was wrong a couple of times in this post, see thats what adults do when they are wrong. As I said, my initial "duh" statement was based on common sense when you first think about a pilot bushing, that and always hearing how the 4cyl needs one, and knowing personally the V6 does not.. After looking at it, and thinking about it being FWD I realized I was wrong, unlike you, I dont go back and edit previous posts to go allong with what Im saying later in the thread.


SO HOW ABOUT THAT PICTURE OF YOUR CRANK?
Why are you so afraid to post it huh?

Theres one other thing on my mind...

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?

Still afraid to admit that you were wrong? Okay, Ive macro'd that, it only takes two keystrokes to post it.

7 pages between 2:30 PM on the 16 th and 11:30 PM on the 18th has got to be a record for posting. I'm jealous, my Twin Turbo 3900, 6 spd thread is more than a year old and all I have is 4 pages. Damn.

quote Originally posted by Joseph Upson: 7 pages between 2:30 PM on the 16 th and 11:30 PM on the 18th has got to be a record for posting. I'm jealous, my Twin Turbo 3900, 6 spd thread is more than a year old and all I have is 4 pages. Damn.

Most of that comes down to us explaining things, and Bill's ever poinant "Nuh-uh" So in reality, it would have been 1/4 page if he had the mental capacity to admit he was wrong

quote Originally posted by 86GT3.4DOHC: Most of that comes down to us explaining things, and Bill's ever poinant "Nuh-uh" So in reality, it would have been 1/4 page if he had the mental capacity to admit he was wrong

I agree. If he had been able to move past the whole "the input shaft needs a pilot bearing for support" idea, this would have come to a much more useful resolution. It was explained early on why the Fiero doesn't need a pilot bearing. It was even pointed out early on that the flywheel coming off was the most probable cause of all this, and that time would be better spent figuring out why that happened.

Too bad the OP wasn't looking for answers, as some important information seems to have resulted from the thread. I know I didn't know (or didn't remember, one or the other) that the 4-cylinder didn't have a flange/hub on the crank to center the flywheel. I can't recall another engine I've worked on that is like that.

[This message has been edited by GT86 (edited 11-19-2008).]

Wow.....Bill Got Banned.......Go Figure!