sheared bolt help pls

Hi folks. Disco 1 200tdi. Removing 5 bolts from rear axle half shaft hub and one of the bolts just sheared with no force at all.

Bolt is stuck in the hub assembly. I have tried drilling and using a screw extractor tool, but i found that to be useless.

If i drill out the M10 all together, i guess i will need to tap to make it an M12? Can i do this? Is there another option? Or do i need to buy a new hub assembly?

Is there any stud protruding that you can weld a nut over it, the heat then helps it to loosen?

You could try left-handed drills? These tend to work better than screw extractors at grabbing hold of the bolt. If it doesn't manage to grip it, you've then drilled it out anyway

Can you get at it with a sharp centre punch and hammer to get it turning in the 'undo' direction. Can take a while but I have been successful on many occasions with this method.

Lefty drills, I love ,em

If you drill to just under the bolt size it is often possible to start a tap in the hole so that its threads line up with the ones in the hole to clear the remainder of the bolt out. So you don't need to tap out to a larger size, necessarily. Those bolts are made out of something tough (after all, it is their shear resistance that has to push the car along) so tend to blunt drills rather readily. The best thing is to treat the drill as a sacrificial item. After all, even a good drill is less expensive than a new hub or taking to it be spark eroded, which are the other options. Having said that a new hub casting is typically around £35 - £60 so it's not catastrophic. Just more satisfying to get it out yourself.

Thanks for the replies.

There is no bolt sticking out at all, so that limits my choices. The 'easy out' tools just stripped their own threads...

I am going to try your suggestion, Brown, by drilling and tapping to an M10 size. I currently have no idea how i can tap threads to line up with the other ones, but its my last option just now.

How about a heli coil? That could be the next step before replacing the hub?

just get a used hub on the bay of e, cheap enough and a lot quicker and easier than farting about trying to remove something and possibly fecking it up, remember those things spin round at some speed and are what give you drive.

If the bolt has broken off below the surface that might give you a couple of turns of exposed thread to get the tap started. When I do this sort of thing I try and drill so that the hole is as large as I can get it without damaging the threads. Often you can just see the tips of them showing through.Then I pick out the first couple of turns with something sharp and pointy to give the tap a start. But it's not worth spending days on it. If it's not going to work, just give up and get a new hub.

If you get the drill right in the centre and use the right size drill you may be able to drill out most of the bolt only leaving the threads plus a thin bit of bolt and then break them up and reuse the original threads

Replacement hubs arent expensive though