At wits end with clutch bolt!

I finally got my firewood under control, have nearly 12 full cords bucked, split and stacked under cover. Thought I would finish the clutch job on the 94 before the weather turns, so I removed the clutch, easy enough, and went after the 18mm flywheel bolts. Right away I notice one is odd and another is really rounded off. (I think this is why the PO sold the truck!). The odd bolt backed out easy enough and the others came loose with a breaker bar. The rounded off head is giving me fits. I punched it with a center punch to hopefully loosen it and pounded a 17mm onto it but could not get it to budge. I have applied heat with propane with no luck and have tried coaxing it with a cold chisel. I was reluctant to try to drill it out but couldn't think of anything else so I used a cobalt 1/8" for a pilot hole, drilled slowly with steady pressure and cutting fluid but hardly made a dent. The bolt is low shouldered and has "11" stamped on it. Any ideas?

12 cords!!?? Good LORD, I'm envious!

Tough call on that bolt. In that situation, I'd be doing overnight soaks with PB Blaster. The forced 17MM would be my next move.

Can you get behind the flywheel to get Blaster on both sides? Doubtful you'll get a tap into it, but hope springs eternal, and miracles happen every day.

Keeping my fingers crossed for ya, lush90. I'm guessing vice grips are out of the question, but a PB Blaster soak first will at least increase your chances, whichever way you go.

In a similar situation, after the soak, I also replaced and tightened the other bolts, to take some stress of the stubborn one, then managed to get it off. The other bolts then were removed.

Again, this is simply stacking odds in your favor.

Good idea re-tightening the other bolts, I'll do that. I have been soaking it in PBB but it's vertical so I'm not sure how effective it is. I wish I had acetylene so I could really get some direct heat on it. My most extreme plan is to pull the engine and weld a nut on it, or, heaven forbid, admit defeat and tow it to a buddy's shop. I would never hear the end of it, though! As for the 12 cords, they're widening the road close to my house and it was easy pickings of fir, maple, cherry and hemlock. It's enough to last me about 3 years, so it takes the pressure off to scrounge next year unless it is really convenient again.

heat was a good idea, but propane is not hot enough - try Mapp gas or an acytelene torch with a spreader tip. Then use one of the sockets made for rounded off bolts to spin it out. To drill it out, use a cutting fluid called anchorlube - made for cutting exotic metals - I have drilled 1/2" stainless with standard drill bits using that and could touch the end of the bit when done without getting burned! Those are hardened bolts, so once you get them out, get a new set of the correct bolts, not hardware store ones.

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Good idea re-tightening the other bolts, I'll do that.

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Yah, with the others off, all the stress falls onto the Problem Child bolt. And so far as I know, Blaster works in all variants. It's partly made of testosterone, so it wants to get into tight places. Frequently. Over and over again.

Hang tough, ol' buddy.

Only other thing I can think of is try using a cut-off wheel and do your best to make a new head and then knocking a socket onto it.. Ive only tried it once and was lucky I got it to work..

I had to Drill and Tap 6 of those mother*&%$. I drilled out with as large as a drill bit as I could manage, then the ez-out was bigger and actually deformed what was left to make removal easier... I would also recommend a bottom tap to chase the threads afterwards...Yes they are hardened bolts and "special" so the woodworking drill bits barely scratch them, need the good steel drill bit. doesn't hurt to smack the bolt with a hammer also, helps loosen up the corrosion in the threads also.

Attachment 11441

This was the aftermath of turning 8000 RPM with a Cast Iron Flywheel...the rev limiter is set a 7500 now and using a aluminum Flywheel.

Mike, what size bit did you start with? The 1/8 almost seems too big to start with.

If you have any of the old bolt head on there I would use a MIG welder and weld on a nut or bold then remove it.