Stripped crank bolt

[Waldo]

I stripped the allen hole on a self-extracting crank bolt. Way stripped. No allen wrench can get any purchase in there. Any suggestions for extraction? I have no qualms about destroying the rest of the bolt to salvage the crank arm.

[Louis]

Dremel tool cutting disk to create a slot in the head which might allow you to use a big screwdriver? You might not have sufficient access to get the cutting tool in there.

Good Luck

[SummitAK]

You may want to consider an "easy out" type extractor before trying the slotted allen head. I've seen the square flutted easy out small enough for an allen head before. I'm not sure how small of diameter the more durable round serrated versions come in. The square type probably has enough strength for you to remove the bolt from the spindle. Then you can replace it with a new one for crank extraction.

[PaulE]

that come with left-handed drill bits and use a reversable drill in reverse to go in with the drill bit to help the easy-out get better purchase also.

[Richard]

Take an allen that fits as closely as possible, then epoxy/JB weld in into the hole. Let it cure, then do your thing.

[Too Tall]

You may discover that the bolt is not held very tightly. Once a crank is wound onto the spindle you can pretty much remove the fastening bolt with not alot of force.
Use the dremel to make a notch or just take a prick punch and tap tap tap lefty loosey I bet it comes right out....been there done that. Good luck.

[Kervin]

I'd find a Torx socket that you can tap into the rounded allen head. It grips better and should get the allen head out for you.

[RudAwkning]

I'd find a Torx socket that you can tap into the rounded allen head. It grips better and should get the allen head out for you.

+1

[gregclimbs]

lot's of good ideas above, but FIRST remove the rest of the self-extractor. none of the above ideas should/would handle the torque to pull the crankarm.

use a traditional crankarm extractor for that.

I had a crank recently that had the extractor threads strip and THAT was a pita...

the extraction consisted of a hacksaw and a pair of vise grips. not pretty. i have pics :(

g

[PacNW2Ford]

I've had good luck with the Craftsman extractors from Sears. Even luckier since the middle of the bolt was made of a special soft French steel, just like the head that stripped.

[maunahaole]

I've had good luck with the Craftsman extractors from Sears. Even luckier since the middle of the bolt was made of a special soft French steel, just like the head that stripped.


An exotic Gallic alloy of brie, chromium, carbon and iron.

[PacNW2Ford]

Yup, that's sounds like it. Either that or it was a special magnetic aluminum. I had to check it with a magnet to convince myself it wasn't aluminum.