You drilled and tapped the main shaft or just elongated the last couple holes in the flywheel?

If you re drilled the main shaft and off center of the bolts original positions, you relocated two of the bolt holes, you might not be able to fit a new flywheel (I'd by one from the bone yard).

What you'll probably end up having to do is line it up to its original position use 4 where they should be (6 bolts total on that one right...or is it 8?) then elongate the remaining two bolt holes in the flywheel to line up to your new bolt locations in the main shaft. While it would technically be off balance by amount you've moved them, you've moved two bolts out of their original positions changing things, that little bit it wouldn't be enough to worry about flywheel lined up as it should be. In other words, it'll either last or it won't, nothing else you can do about it main shaft in the motor motor in the truck.

 

Of the 6 holes that mount the flywheel to motor 4 bolt holes lined up but 2 didn't and in my haste (after repeated attempts to start last 2 bolts) and especially in ignorance I figured to drill and tap the last 2 holes to next size larger which I did and since the have learned that this flywheel is balanced and without proper placement back onto motor the vibration will "shake the motor apart"...My question is how do you align a brand new flywheel if there are no marks the only answer I can come up with is the alignment of the offset bolt pattern... I probably come close but no cigar.. wonder what I do now... my work truck so need it running thanx everyone w/ a heart to help..God Bless .. Chas (and don't tell me I should of bought a chevy)

 

Pull one from a motor at a bone yard, bring number one piston up on the compression stroke, mark the very top of the flywheel then pull it off.

Then to put it on your motor bring your motor to TDC #1 cylinder on the compression stroke then install the flywheel with your mark at the top, that way you know the factory bolts would line up as they should.

Slightly enlarge those two holes in the flywheel as to get the factory bolts into the holes you slightly relocated but take no more than absolutely necessary doing so, you want some clearance but not much.

Will it be perfect? no but it will be close enough as to not create a problem and the system will be in balance without having to replace the crank to do it.

Make sure you use a good quality thread locker, use a good torque wrench to tighten the all bolts to spec.

 

There is no need to drill anything out when mounting a flywheel or flexplate. All of the holes will line up perfectly when you get it in the right orientation, to figure that out put the flexplate up to the crank and look at the hole alignment, if its not perfect rotate it 1 hole and look again, and keep doing that until they all line up.

 

He didn't line it up right the last time, drilled and tapped last two holes into crank that remained slightly "off".

Won't get a replacement on it now without elongating couple of the holes to do it, line those two up to their new locations.

Doesn't sound like he moved them much but enough, also to accept larger bolts in the process those two.

He understands now if he had simply rotated the flywheel until all of the bolts lined up he would have avoided the problem.

 

yes you are right I have everything apart and will take it (this time) to a clutch shop and let them test and evaluate everything .. With proper parts I will probably re-use the orig flywheel just keep rotating it until the offset pattern matches then I will at the worst put washers on the 2 stock holes I enlarged in the flywheel and elongate the 2 bolt holes that line up with the enlarged crank holes. I was told JB Weld would keep the bolts from coming out and it proved to be true as when I was taking out the 2 largest bolts (new holes) that I had put JB Weld on proved to take a 1/2" drive set up with an extension bar for leverage and just barely broke them free w/ all my strength....must work...and yes at this point I will acquire a torgue wrench (clicker) and set the bolts to what I am told is 65 ftlbs. Even though w/ that JB Weld I probably surpassed the 65lbs....thanx to everybody and will let you know the end result.....God Bless ya'll

 

found out not 65 ft lbs but 80 ft lbs

 

Now why would you do something like that? Leave the bolt holes in the crank alone already just put some thread locker on the bolts and torque to spec.

 

I am not going to do any more drilling in anything but flywheel to accommodate shift in oversized holes. probably use red loc tite for bolts. thanx.