[Broncobill78]

So I go out this morning all set to swap out flywheels and start putting the new tranny in. Some of you may recall that I've had trouble starting it because the starter kept hitting the flywheel & making all sorts of angry noises but not starting the truck. I also picked up the new tranny because I thought the original had blown first because the engine was revving way high but the truck was only tooling along at 7 or 8 mph. So anyways, I'm looking at the flywheel and it struck me that the teeth really didn't look all that bad. I sat there for another moment or two staring at it and started to notice some radial cracks running out from the bolt circle. Looking at it a little more closely I realized that there were also some cracks *connecting* the 6 bolts in the circle. I finally looked at it closely and UNDERSTOOD. The entire center of the flywheel has sheared away from the outer ring, not only did the cracks connect all of the bolt holes creating two completely seperate pieces, an inner & outer flywheel, but the outer flywheel has been spinning around the inner. So when the starter engages the flywheel it's just spinning around which is why the damn thing wasn't starting very often and on the rare occasion when it did start I can't see how it could have been transfering more than 20% of the engine torque to the converter & transmission (making me think the transmission I just removed is just fine). Not only that but the 3 bolts still remaining are being held in place by the cracks. Cracked portions of the flywheel have raised up and are effectively locking the bolts in place. My first thought was to grab that 5lb maul, bang them down & get some satisfaction at the same time but then the reasoning centers of my brain kicked in & I remembered that said flywheel is actually bolted directly to my *crankshaft* and maybe wailing on the crank with a 5lb maul really isn't such a good idea. Sooooo, now I'm trying to decide if I want to grab the grinder & remove the bolt heads (but considering how hard the other three came out I'm concerned about how to remove the studs from the crank if I go that route, even though I DO have a stud remover) OR trying to more gently peen down the edges of the cracks with a cold chisel & use a larger impact wrench to twist them out.

Why do *I* always seem to get these trucks ?

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[Justshootme84]

Yep, I'd say that was your problem all along. Happened to me before on a Blazer, and it knocekd really bad when the studs backed out a tad. good luck taking those off, JSM84

[madmax]

you need a pin punch, use it to tap down the pieces of sheet metal then the bolts should come out. If you need a new flex plate lemme know, since the manual conversion I've had no use for my flex plate. I'd give it to ya for shipping. also hows your silver anniversary doing? I'm still doing body work on mine, just found some rot in the horizontal boxy tube like thing that runs across the back of the bed, (between the two rear pillars) gonna have to cut an access hole and shove the sandblaster in there, then it's probably flood Eastwood rust converter, then encapsulator then some duplicolor bedliner, it seems to stay rubbery, I put some on a pair of boots to keep them from leaking a couple years ago and it's still flexible.

[Broncobill78]

I tried the punch thing first with regular hammer & didn't get very far, that's what made me think of the maul & cold chisel but I'm real leery about wailing away at the crank with something like that, last thing I need is to get everything back together again & find I have a new leak in the rear main or worse still a rap. Right now I'm leaning towards grinding down the edges of the cracks using a Dremel w/a flex attachment or a die grinder. If I had a torch I'd go that route but of course Santa left *that* one off his list once again so I'm gonna have to write that old man a letter.

My Silver Anniversary was stolen, they found it 3 days later out on a trail 30miles from the city. It had been backed *hard* into a tree trashing the entire tailgate & bending the frame & then run into a another tree trashing the whole nose, then they squeezed it between a couple trees only a CJ or EB should have fit thru and ruined the entire drivers side while peeling the whole passenger doorskin & part of the quarterpanel off. Finally they got it stuck in a mudhole & revved it until it siezed trying to get out. It's the only one I've ever had stolen from me and about the only thing they *didn't* do to it was $hit on the dashboard. It was a real shame, I'd picked it up from the original owner who was 75 or so when HE bought it and it had less than 5K on it when it was stolen in 96'. It was red w/a grey leather interior. Leather wheel, dash, door panels, everything. It was a real kick in the nuts.

I've found that the Eastwood products are generally excellent, great company to do business with and they have some real hard-to-find tools as well. Great catalog to have.

[madmax]

Broncobill78, on Jan 13 2008, 11:23 PM, said:

I tried the punch thing first with regular hammer & didn't get very far, that's what made me think of the maul & cold chisel but I'm real leery about wailing away at the crank with something like that, last thing I need is to get everything back together again & find I have a new leak in the rear main or worse still a rap. Right now I'm leaning towards grinding down the edges of the cracks using a Dremel w/a flex attachment or a die grinder. If I had a torch I'd go that route but of course Santa left *that* one off his list once again so I'm gonna have to write that old man a letter.

My Silver Anniversary was stolen, they found it 3 days later out on a trail 30miles from the city. It had been backed *hard* into a tree trashing the entire tailgate & bending the frame & then run into a another tree trashing the whole nose, then they squeezed it between a couple trees only a CJ or EB should have fit thru and ruined the entire drivers side while peeling the whole passenger doorskin & part of the quarterpanel off. Finally they got it stuck in a mudhole & revved it until it siezed trying to get out. It's the only one I've ever had stolen from me and about the only thing they *didn't* do to it was $hit on the dashboard. It was a real shame, I'd picked it up from the original owner who was 75 or so when HE bought it and it had less than 5K on it when it was stolen in 96'. It was red w/a grey leather interior. Leather wheel, dash, door panels, everything. It was a real kick in the nuts.

I've found that the Eastwood products are generally excellent, great company to do business with and they have some real hard-to-find tools as well. Great catalog to have.

Shame about your SA, they only made 3000 with that package, probably half or more gone due to rot and accidents by now.

my personal favorite anti theft method, pop the distributer cap and put the rotor in the ash trey. Usually car thieves or joy riders try not to draw attention to when they are stealing a car. Also you could hit the firewall with a mallet by the brake pedal to cut power to the fuel pump, it might start but it won't get anywhere.

[bidibronco]

I like the anti theft on my truck. All the people I live around happen to actually like me and don't let anyone get to close to it and most of them like to carry. The had the tow truck guy shaking when he tried to take it once. Pretty cool if you ask me.

Now, I had the same problem on a B2 that had the flex plate brake like that. I tapped a socket on the heads of the bolts and used a breaker bar. Tapping gently will press the metal down, at least it did on the B2.

[madmax]

Yea I don't worry about it anywhere in my area, pretty much everybody knows my truck and knows me. It's more when I'm down in Philly that I worry about it.

[Broncobill78]

bidibronco, on Jan 14 2008, 08:00 AM, said:

Now, I had the same problem on a B2 that had the flex plate brake like that. I tapped a socket on the heads of the bolts and used a breaker bar. Tapping gently will press the metal down, at least it did on the B2.

Well, to begin with I've never been much of a "tap lightly" kinda guy, especially once I put down the ball-peen & pick up the maul. I gave the breaker bar some thought but haven't yet figured the best way to keep the crank from spinning. The only thing that's come to mind so far is to use one of the other 1/2" ratchets & a cheater pipe (to gain enuf length) to put a socket on the main pulley/harmonic balancer and lock the crank that way, otherwise it just spins away whenever I try to get any torque on it with a ratchet or breaker. I really need to spring for a better inpact wrench but we're still recovering from Christmas & the wife will be throwing empties at ME if I do that (and it hurts that my local outlet has a 700lb/torque impact wrench on *sale* right now, arrgh). However, being the clever fellow that I am, I figured that since the flywheel bolts are 3/4" (they ARE 3/4" aren't they ? That's what I used to get the 3 off that would budge and it seemed pretty tight on the bolt head but I don't have a set of metric impacts & never bothered to ck w/my standard sockets) and that just happens to be the size of many lug-nuts so my 4-way will fit and *that* will maybe give me a way to at least get the bolt to crack & then the impact wrench can finish it up. What a damn hassle.

I've googled this quite a bit in the last couple of days and I'm really surprised at how many various threads & articles I've found about broken flywheels. I'm really just amazed to see the thing broken the way it is. Ford wants $100 for a new one but I've already dumped more into this than I wanted to and I hate to spend that much for a new one but I'm almost wondering if it's worth calling some of the local performance rebuilders to see how much it would be to have my used replacement flywheel magnafluxed. While I'm sure something like this takes a few years to happen I'm not in any rush to go thru this again anytime soon. The only real advantage I see to the whole freaking debacle is that I think I have a relatively unscathed AOD on the floor in the garage that I can have upgraded for a lot less than it would cost to rebuild AND upgrade. I figure I'll bulletproof the thing,maybe change out the planetary gearset for one with better rations and slap it back in when I add the lift & tires. Not much of an upside but I'm grabbing at straws here.

This post has been edited by Broncobill78: 14 January 2008 - 10:53 PM

[madmax]

a c clamp on the plate though the starter hole will keep it from spinning, though with yours im not sure, i guess you could put some kind of clamp on the harmonic balancer.

[Broncobill78]

Well, actually my approach was somewhat unorthadox and probably falls into the "crude but effective" catagory. I took a 2' stub of an old lathe leadscrew and fed it thru a slot in the flywheel then rotated the assembly until the whole freaking thing jammed up against the head then used a 4-way tire-iron to break each of the remaining bolts loose. With the bolts cracked the impact wrench took them out w/no trouble. It took a few tries because the broken-off inner part of the flywheel wanted to rotate separately from the outer flywheel but eventually I got the three remaining bolts out. See the attached photo.

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This post has been edited by Broncobill78: 16 January 2008 - 01:09 AM

[bidibronco]

Now aint that just a purdy sight?

[crazyhorse85]

YEP,HAD THAT SAME PROBLEM 3 YRS.AGO WHEN I REBULIT MY 351W...MY SON MISPLACED MY FLEX PLATE AND WENT AND PICKED ONE UP FROM AUTOZONE I THINK...WELL WE PUT'ER BACK TOGETHER AND IT CRANKED ONE TIME...AFTER THAT EVERYTIME YOU'D HIT THE KEY THE STARTER WOULD GRIND OR MAKE SOME UNGODLY SOUNDS...BUT I DID FIND OUT THE PLATE HUB HAD STARTED TO SEPERATE DUE TO IT CRACKING ACROSS TWO CENTER BOLT HOLES...ALSO FOUND OUT THERE IS A DIFF.BETWEEN AN AFTERMARKET FLEX PLATE AND AN OEM STYLE...ABOUT A 1/16 TO 1/8 DIFF.IN DIAMETER AND IT REALLY SEEMS TO MAKE A DIFF.IN THE WAY THE STARTER ENGAGES.....WE PUT ON THE OEM AND BEEN DOING GREAT SINCE.....

This post has been edited by crazyhorse85: 16 January 2008 - 10:40 AM

[madmax]

If you want my old flexplate I'd like that one, just cause some freinds would get a laugh at it.

[Broncobill78]

Well I'm not for sure that I *need* your flywheel but hell, I've got more than enuf broken parts on display in the shop after 20yrs of building trucks but after seeing this one I wouldn't mind having a spare GOOD flywheel to hang on the wall especially seeing as I now have a spare *good* AOD sitting on the floor (for anyone missing the irony of that comment, I purchased a used AOD to swap in because I was sure I'd blown first gear from the way the truck was driving, I had NO idea the flywheel had broken like this and the outer edge was just spinning and not transfering any engine torque to the transmission. The tranny I pulled is probably just fine, it just wasn't getting any power from the engine). I'm happy to part with it if it will make people who appreciate this sort of thing smile <grin>. If you want to trade I'll be happy to swap just shoot me a PM w/your address and I'll box it up & send it out.

This post has been edited by Broncobill78: 16 January 2008 - 09:40 PM

[Jakes85bronco]

Glad to see you got it off. Same thing happend to my FSB about a month ago right after putting a new 351 in it. It started fine for about 20 starts then it started making that famous ungodly grinding noise. Just prior to that happening I went through a few starters. But yeah in the end it turned out being the "flexplate" Crazy seems to be a more than common issue...

[Broncobill78]

Well I just put the new ring-gear on yesterday and while I was torquing the bolts down I started to wonder if over-torquing wasn't maybe the problem. When I pulled the tranny I found the back of the block was all primer which led me to believe that it was a replacement. When the engine was replaced I wonder if maybe the flywheel bolts were over-torqued causing them to eventually crack & fail. It's certainly one of those slow-motion failures but that was the best I could come up with for a root cause that made any sense. You'd think we'd have heard about a bad batch of AOD flywheels or something but they guys who've written to me about this have had trucks from all over the timeline so mechanically speaking, poor shop practice would seem to be the base of the issue. If anyone else has a theory or an idea I'd love to hear it. As strange as it sounds I'm really having a great time with this truck. I wanted a project so I found myself a $400 Bronco and what a mongrel it's turned out to be. I wanted something to keep my busy so I wouldn't be rattling around the house with nothing to do and in that regard it's paid off in spades

[BB33's]

WOW! I work for my father at his Truck salvage Yard and as youd expect we see some pretty "ingenious"/"innovative"/ and to be honest down right stupid things that people do to thier vehicles and the damage that ensues. But I have never seen a flywheel crack at the bolts like that.

This post has been edited by BB33's: 27 January 2008 - 10:10 PM

[ironranger433]

Broncobill78, on Jan 13 2008, 01:21 PM, said:

So I go out this morning all set to swap out flywheels and start putting the new tranny in. Some of you may recall that I've had trouble starting it because the starter kept hitting the flywheel & making all sorts of angry noises but not starting the truck. I also picked up the new tranny because I thought the original had blown first because the engine was revving way high but the truck was only tooling along at 7 or 8 mph. So anyways, I'm looking at the flywheel and it struck me that the teeth really didn't look all that bad. I sat there for another moment or two staring at it and started to notice some radial cracks running out from the bolt circle. Looking at it a little more closely I realized that there were also some cracks *connecting* the 6 bolts in the circle. I finally looked at it closely and UNDERSTOOD. The entire center of the flywheel has sheared away from the outer ring, not only did the cracks connect all of the bolt holes creating two completely seperate pieces, an inner & outer flywheel, but the outer flywheel has been spinning around the inner. So when the starter engages the flywheel it's just spinning around which is why the damn thing wasn't starting very often and on the rare occasion when it did start I can't see how it could have been transfering more than 20% of the engine torque to the converter & transmission (making me think the transmission I just removed is just fine). Not only that but the 3 bolts still remaining are being held in place by the cracks. Cracked portions of the flywheel have raised up and are effectively locking the bolts in place. My first thought was to grab that 5lb maul, bang them down & get some satisfaction at the same time but then the reasoning centers of my brain kicked in & I remembered that said flywheel is actually bolted directly to my *crankshaft* and maybe wailing on the crank with a 5lb maul really isn't such a good idea. Sooooo, now I'm trying to decide if I want to grab the grinder & remove the bolt heads (but considering how hard the other three came out I'm concerned about how to remove the studs from the crank if I go that route, even though I DO have a stud remover) OR trying to more gently peen down the edges of the cracks with a cold chisel & use a larger impact wrench to twist them out.

Why do *I* always seem to get these trucks ?

yep.. it happened to me on my 80 f100, 300-6, c4
but it sheared while it was doing 50mph, scared the shit outta me

[bidibronco]

Hey, looky what I found when pulling my engine! Just couldn't help myself to share!

Maybe I'll turn it into a clock or something? :-

[Broncobill78]

Goddamn, we're gonna have to start a club or something.