Sheared DA crank bolt

tunney

Despite using a torque wrench the head of a DA crank bolt sheared off. Anyone any experience of removing a sheared bolt like this?

onthefringe

tunney wrote: »

Despite using a torque wrench the head of a DA crank bolt sheared off. Anyone any experience of removing a sheared bolt like this?

the bolt on the side of the crank as per 7800/7900/9000 hollowtech??

ednwireland

Managed to do the same thing with titanium bolts (managed to mangle the heads on the originals and these seemed a decent replacement ) had a pair of cheap needle nose pliers which I ground down to fit the slot that closes up when you tighten the bolt. Then eventually managed to unscrew the rest of the bolt. Took a bit of fiddling round mind. That was on 105 crank though.

godtabh

I've done it on a 105 group set. Bike shop had a tool to get it out. I think it was a counter tap screw

Brian?

You can get an "easy out" screw extractor. Straight forward enough job, but you'd probably have to buy a set of them.

tunney

ednwireland wrote: »

Managed to do the same thing with titanium bolts (managed to mangle the heads on the originals and these seemed a decent replacement ) had a pair of cheap needle nose pliers which I ground down to fit the slot that closes up when you tighten the bolt. Then eventually managed to unscrew the rest of the bolt. Took a bit of fiddling round mind. That was on 105 crank though.

That's a reasonable idea. Was considering a left threaded drill bit.... This seems less dangerous

triggermortis

Easy out is what you need.

Your local car mechanic might be able to help you out or you could pick up a set cheap enough (picture is a snap on set = NOT cheap)

ednwireland

tunney wrote: »

That's a reasonable idea. Was considering a left threaded drill bit.... This seems less dangerous

I would offer you my custom made tool except it's in donegal and I'm in gozo

DublinDilbert

tunney wrote: »

That's a reasonable idea. Was considering a left threaded drill bit.... This seems less dangerous

Drill it with a normal drill bit, start with a small pilot hole then make larger. The thread the easy out in, the easy out has the left hand thread.

The bolt is probably in there quite tight, hence it braking. So make sure to soak in penetrating fluid (or full fat coke) over night before trying.

tunney

DublinDilbert wrote: »

Drill it with a normal drill bit, start with a small pilot hole then make larger. The thread the easy out in, the easy out has the left hand thread.

The bolt is probably in there quite tight, hence it braking. So make sure to soak in penetrating fluid (or full fat coke) over night before trying.

Thankfully it sheared inserting it so was well greased and loose. I bought an "internal circlip pliers" and that fitted in the gap as suggested.

Crazy thing is i used a torque wrench. Sheared at 14nm

tunney

Thanks all. Bolt out. Replacement in and SRMs saved.

ednwireland

tunney wrote: »

Crazy thing is i used a torque wrench. Sheared at 14nm

Good to hear you got the bolt out. The titanium ones I got I was told by the manufacturer were only rated to 10nm. Steel replacements have been no problem.