428 flywheel index relaive to crank

[Rob Roy]

Looking for help
I removed my 428 to replace cracked exhaust manifolds.
So it was a good time to replace the clutch.
I thought nothing about removing the fly wheel to get it resurfaced.
Well when it was time to put it back on the crank I noticed the mounting holes on the flywheel were elongated.
I rotated the flywheel to align the holes with the crank and thought I had it right because there still seemed to be only one way.
Now after putting the engine back it and driving it I have a vibration through out the RPM range so I figure the fly wheel is not mounted correctly.  My question is which counter weight of the crank lines up with the weight on the fly wheel.  It must be either the front or rear counter weights of the crank which are obviously 180 degrees apart.  I figure once I know the orientation of the crank and know where to align the fly wheel I will all set. 
Thanks for the help
Rob
 

[blykins]

In normal form, there is only one way to bolt a Ford flywheel on.  You keep turning them until all the holes line up. 

You're saying that all your holes were elongated so it's possible to bolt it up any way?  If that's the case, buy a new flywheel man....

[ScotiaFE]

As Brent has said the flywheel holes will only line up at one spot,
if you were able to get to bolt on at different spots there is something
seriously wrong with your flywheel.
If it was resurfaced at a large jobber shop they may have just did an
exchange and may have given you a 390 flywheel.
Either way you must now remove the flywheel and inspect.
A new steel wheel is much safer and very inexpensive.

[jayb]

I agree on the bolt holes, but if what you said is correct about it bolting on only one way, then I don't know why you would be having that vibration.  I took a 428 flywheel that I have here and bolted it to an aftermarket crank, and took the picture below.  If the aftermarket crank has its bolt holes in the same place as the stock cranks, then from the picture it would appear that the flywheel weights are right at the top of the flywheel on the number one or number six firing stroke.  Note the position of the weights, and the keyway cutouts in the crank:



I also took the picture below after measuring the center to center distance of the holes on the flywheel, in case that would be helpful:



Note that one of the six holes is shifted on the bolt circle, causing two of the dimensions to be different than the other four. 

Good luck on finding the problem - Jay

[Rob Roy]

Thanks to every one who took the time to reply so quickly.
I have no Idea why they would of done this, that is elongate the holes.
The engine was nice and smooth before I removed the flywheel and had it resurfaced.
The picture tells me what I want to know the fly wheel weight lines up with the rear counter weight.
I do not beat on the car.  I am hesitant to just go by new flywheel.
The flywheel is a true 428 flywheel because it has the integral counter weight.
I am puzzled why they had to elongate the holes.
Calls into question what else is funky with the balanced assembly.
My plan is to see where the flywheel counter weight is relative to the rear crank counter weight and if it is off then to index it so its weight is aligned with the crank.
Sound ok?
Thanks all
Rob

[ScotiaFE]

First I must say, that if they did elongate the holes
THE FLYWHEEL IS SCRAP.
The flywheel locates on the shoulder of the bolts, if the holes are not a close fit
the flywheel will start to wobble around once you get the thing spinning.
There is no fix for that.

I will always advocate a new steel or aluminum wheel.
A stock cast flywheel from the 60's is a door stop now.
You have a $10,000 engine and you are going to cheap out on the
most important part of it?
jmo
 

[My427stang]

At this point, you hope that all they did was screw up the flywheel, if they added or removed metal from the crank to counter the butchered flywheel you may need a new rebalance.  It's likely worth a shot with a new 428 wheel though

Good thing is, it doesn't have the be an EXACT bobweight if you do it again/  If you have to rebalance, drop the crank out of the engine, calculate a bobweight with the parts you know you have, and then just spin the crank/wheel combo.  Balancing is an art and many guys tweak the bobweight anyway based on technique.  I have swapped cranks before and it takes a couple hands sometimes to keep the rods out of the way, but you can leave the top end intact

[blykins]

Howie's right, if they in fact did elongate the holes, get rid of it.   That flywheel will move around. 

[Rob Roy]

Let me follow up
The holes in the flywheel are not excessive.
When I reinstalled I thought there was only one way for it to go back on.
the holes are not over sized, Just elongated.
The engine has been running great. I purchased the car in 1998.
I appreciate everybody's input.
I am curious why they the machine shop who rebuilt it (Prior to my ownership) would mess with the holes in the flywheel.
Rob

[FloridaMack]

If in dought at all, I would change it. I run this one in my truck and its cheap. Has bolt pattern for 11 and 12 inch clutch too. I run the 12 inch because, , well because I can.
 http://www.ebay.com/itm/PRW-1642881-FLYWHEEL-SFI-BILLET-STEEL-FORD-332-428-FE-BB-1966-70-28-in-oz-/161843395880?hash=item25ae9e3d28:g:atIAAOSwsB9WC~fv&vxp=mtr

[ScotiaFE]

If I may request a picture of the flywheel in question?
There is enough experience on the forum to give you
excellent advice.
If you have any difficulties in posting a picture I will
post one for you.
Backside or engine side of the flywheel.
This is a safety issue and we just want you to be safe.

email 390fairlane@gmail.com

[KMcCullah]

The slotted holes are most likely from the 6 bolts coming loose. I've seen this before on a 360. But were the holes slotted before the machine shop did their work? Who knows..... I would hope that they would be savvy enough to know better. I personally would replace it.

The flywheel I used with my 504 is this one>>>> http://www.summitracing.com/parts/mcl-463215/overview/make/ford

It had an additional hole pattern for the 12" clutch/pp I'm running but more importantly it comes with a nice bolt on piece for the externally balanced 410/428 applications.

[Rob Roy]

Once again I appreciate the replies.
The engine has performed well for 20 years plus.
The holes do not look mushroomed in any way, they are machined.
When I installed it after I had it ground I new it had to go on one way.
When all the bolts were in and not tight you could not rotate the flywheel relative to the crank.
its not a pure oversize issue.
I slowly rotated it until all 6 bolts lined up.  There must be another position.
I did have the harmonic balancer rebuilt but that should not mater for a 428 PI.
I had in my mind that a McLeod flywheel is the way to go.
I cant take a picture yet. The concern is cracks right?
I don't want to beat a dead horse.  I will have the fun job of removing everything from under the car to get at the flywheel.
Thanks
Rob

[ScotiaFE]

Lets start over.
You have a vibration?
It started after you did a full clutch change and flywheel resurface?
Lets say that the flywheel is fine.
What about the clutch? All new, rebuilt?
Did you change the u joints on the drive shaft?
Did you index the drive shaft?
There are quite a few things that can cause a vibration.

[Rob Roy]

I like your methodical approach to this.
Clutch is brand new Mcleod 11.5 inch same size as what came out.
I changed the U joints, both front and rear.
Did I index the drive shaft? No, never had in any of my mustangs.
You bring up a good point.  I will pull the drive shaft tomorrow and check out the U joints.
I will get back to you.
Thanks again for the help and interest.
Rob