Stripped a flywheel bolt hole in 304 crank

[cwiehle0]

Was tightening the flywheel bolts and one of them stripped right out before I even started torquing. Another one looks like it is ready to. What are my options? Helicoil? Drill out and re-tap?

One more thing. The bolts I was using were out of my I6. Are they the same for a AMC 304 . It appears as though the I6 bolts weren't fully penetrating the crank holes. Are the I6 bolts shorter, I don't have the stock bolts from th e304 , so I have nothing to compare to.

Thanks
Chris

 

[IOPort51]

are these holding the flywheel to the crank or the clutch to the flywheel?

 

[Scooter402]

If it were me, I'd helicoil them. I had to do that when I had a balancer puller jam into the snout of a 360 crank and break the tip off in it....

Come to think of it, I also had to do it on a 383 stroker, and the 402 I've got now...Those threads seem to pull out pretty darn easy.

 

[cwiehle0]

are these holding the flywheel to the crank or the clutch to the flywheel?

Flywheel to crank

 

[Saddle Tramp]

Can’t address your problem directly as I have not had the problem but I always use new bolts on the flywheel to crank; just seems like the right thing to do.

 

[cwiehle0]

Can’t address your problem directly as I have not had the problem but I always use new bolts on the flywheel to crank; just seems like the right thing to do.

Probably should have but idon't think it would have mattered in this case. Threads clean pulled out of crank.

 

[rr41mag]

Heli coil the bolt hole. Before you install the helicoil dip it in lock tite

 

[cwiehle0]

new bolts and helicoils coming from NAPA.

 

[73CJ]

If you just want to get by and not a long distance commuter CJ, go with a the Helicoil and do the opposite hole as well.

Keep in mind that baby can spin 5-6k rpm it doesn't take much. To to set a vibration. Vibrations equal fatigue cracks.

Since I keep my stuff forever, I'd put a new crank in.

 

[cwiehle0]

If you just want to get by and not a long distance commuter CJ, go with a the Helicoil and do the opposite hole as well.

Keep in mind that baby can spin 5-6k rpm it doesn't take much. To to set a vibration. Vibrations equal fatigue cracks.

Since I keep my stuff forever, I'd put a new crank in.

No thanks i paid 300 for this motor complete. If it dies it ll give me a reason to swap it for A better mileage motor