Are flywheel bolt holes made to lock the bolt in?
 

I was test fitting some 3/8 Grade 8 bolts to bolt the pressure plate to my flywheel, and I found that, from either direction, the bolt makes it about half way and then you can't turn it by hand anymore.

I found this in multiple (all of the) holes, and I hate forcing fasteners.

I'm wondering if this is a "design feature" to help retain the bolts, like a lock-nut built into the flywheel? Anyone run into it before?

This is on a newer GM replacement flywheel, not a vintage piece.

Thanks,
Dave

Re: Are flywheel bolt holes made to lock the bolt in?
 

Run a tap into them, Usually there is some thread damage or some left over Loctite that needs to come out. They need to go in easy so the proper torque is achieved

Re: Are flywheel bolt holes made to lock the bolt in?
 

Brand new flywheel from GM, never been installed! I'll run my cleaning tap though though, but it's every hole, halfway down the hole. If you run the bolt in from the backside, same thing, easy spin till it hits the center. So it sure seems like its by design but I've never heard of it before!

Re: Are flywheel bolt holes made to lock the bolt in?
 

I ran the cleaning tap through them a number of times with a driver, freed them right up. Since it's a cleaning tap and not a real tap, not much metal was removed at all.

Other than what looked like maybe anti seize (!) nothing came out, but it was every hole, so I'm thinking it might still have been some kind of retention system - but it certainly would screw with the torque values.