Relax
Well-known member
You don't want to use a disc. You want to use the bits in the back row of your kit that you linked to for grinding out the extractor piece from the bolt head.
Broke bolt extractor - what to do?
- Thread starter NuggyBuggy
- Start date
You don't want to use a disc. You want to use the bits in the back row of your kit that you linked to for grinding out the extractor piece from the bolt head.
The nice thing this guy has, is a guide for the drill. I don't have a way to fit a guide in there. Maybe if I drill/dremel the head off and then make one from something that fits that recess perfectly.
He made his drill guide and tells you how. In your case, I doubt you have enough recess to solidly locate a guide like his (maybe on the bottom but often not).
There are many ways to skin a cat. A piece of 2x on the fork leg with a piece of pipe attached to it would be more than enough to drill the head off while protecting the leg. I wouldnt trust that to drill the shank though.
I need to get some machine tools. My reaction to the first 30 seconds of that video was "I would rather buy a new bike than drill through the length of a stainless steel bolt with my hand drill to make a drill guide". 
The abrasive hole saw is an interesting idea though. Confession time: my first bike had a snapped exhaust header stud, and I broke off an extractor trying to get it out. I learned a valuable lesson about metal hardness ratings after wasting many hours trying to drill out the broken extractor with cheapo 'titanium' drill bits. I ultimately ended up getting so frustrated that I just ground the whole thing out with a rotary tool and a grinding stone bit. I capped it all off by drilling and tapping up to some weird size like 7/16th, cut some threaded rod as a new exhaust stud, and for some inexplicable reason used a coupling nut to reinstall the exhaust. My apologies to whoever ended up buying that bike; I was young and dumb.
The abrasive hole saw is an interesting idea though. Confession time: my first bike had a snapped exhaust header stud, and I broke off an extractor trying to get it out. I learned a valuable lesson about metal hardness ratings after wasting many hours trying to drill out the broken extractor with cheapo 'titanium' drill bits. I ultimately ended up getting so frustrated that I just ground the whole thing out with a rotary tool and a grinding stone bit. I capped it all off by drilling and tapping up to some weird size like 7/16th, cut some threaded rod as a new exhaust stud, and for some inexplicable reason used a coupling nut to reinstall the exhaust. My apologies to whoever ended up buying that bike; I was young and dumb.
There is no reason to make the guide stainless. Make your life easier and use a crap mild steel bolt as the guide. Coat with oil and it will be good for your entire life.I need to get some machine tools. My reaction to the first 30 seconds of that video was "I would rather buy a new bike than drill through the length of a stainless steel bolt with my hand drill to make a drill guide".
The abrasive hole saw is an interesting idea though. Confession time: my first bike had a snapped exhaust header stud, and I broke off an extractor trying to get it out. I learned a valuable lesson about metal hardness ratings after wasting many hours trying to drill out the broken extractor with cheapo 'titanium' drill bits. I ultimately ended up getting so frustrated that I just ground the whole thing out with a rotary tool and a grinding stone bit. I capped it all off by drilling and tapping up to some weird size like 7/16th, cut some threaded rod as a new exhaust stud, and for some inexplicable reason used a coupling nut to reinstall the exhaust. My apologies to whoever ended up buying that bike; I was young and dumb.
Mad Mike
Well-known member
I still say the easiest removal is to drill from the back side. If you do a pilot hole the size of a torx bit you can try pounding that in then turning out the bolt. If that strips out, drill again the drill spins in then turning direction of removal, and remember if you put a torx bit into the end of a bolt, it unscrews clockwise (righty-Lucy!)
I think this is the way I'm going to have to do it. Planning to:
1-cut the bolt in half through the slot. This should relieve most of the pressure on the threaded part.
2- if I didn't catch the side of the hole with my extractor, I should be able to pull the top out easily.
3- Use a left-handed to drill out from the bottom and (LOL) maybe use an extractor or do the Torx bit thing you suggest, turning counter-clockwise from the bottom. Hopefully, this will draw the bolt out through the bottom (I checked, the threaded part of an M6 will pass through the hole at the bottom). I figure this is easier than trying to pull the entire screw through from the top. I'm going to make darn sure I centre punch this time.
I've already been hitting the bottom of the fork leg with a heat gun - not sure how hot or how long I can go here periodically.
Today was the day I was hoping to be able to do this. I had bit the bullet and ordered the fittings for my Skylift, which will allow me to lift the front end nice and high so that I can have good access to the bottom of the fork leg. My wife called me the other day that the parts had come in, so I drove to Toronto and back from Orillia to get them.
But - It looks like the Canadian company I bought them from didn't send me the proper retail kits, but instead just picked the parts out of a set that contains all the parts - their so-called "technician's kit". Unfortunately, it looks like they picked *the wrong fittings* out of that kit. Since the parts come from the UK - I am worried this will take on the order of weeks to get the right parts in.
Not too happy about that.
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Is there a risk that banging on the Torx bit will compromise the threads and create another problem for me?
Mad Mike
Well-known member
Always a risk… but it’s probably your lowest risk procedure.
Use a small hammer and gentle taps. The tapping loosens corroded threads. I’d also apply heat from a small map or propane torch, expanding the metal helps if threads are galled.
Mad Mike
Well-known member
Left handed drill from the top, right handed if drilling from bottom. (Reverse lefty Lucy to righty Lucy when attacking from the bottom of a bolt).
Except he's trying to come out the bottom. A right hand drill bit from the bottom would encourage the bolt to retreat out the hole it started from.
I'm not sure which way would be better. The last few threads on the bottom may not be clear as they may not have been chased in a long time.
Mad Mike
Well-known member
You want it out the way it’s supposed to go out. The top of the bolt has a shoulder and small untapped area that won’t come thru the threaded part of the fork.
He was going to cut the shank in the compression slot. I don't know if that will leave any of the larger shank or if he will just be left with a threaded rod. I suspect he will just have threads as you wouldn't want the shank bottoming on the fork leg (although you could counterbore the fork leg, I suspect they threaded it all for more meat).
Mad Mike
Well-known member
If that’s the case a right handed drill from drill bit from the bottom could work.
I don’t see much benefit in making that cut, there is no bite on the bolt head slide of the compression slot - unlikely it’s locked there. Plus you fight the gummed up threads at the end if you exit the bottom - more potential trouble.
You can see the threads in the slot so cutting in there will leave me with just threads - no shoulder.
Now I fully acknowledge I’m a newbie doing this so happy to hear opinions- that’s what’s great about this forum, so many knowledgeable people.
My thought in cutting there was to relieve the pressure on the seized threads. This should make it easier to drill out.
I can run a longer M6 through the bottom threads of at least one of the other bolt holes so I know those threads are clear (didn’t check the other two, but I can).
I guess one risk is that cutting it creates a burr or something which then jams my threads if I try coming out the bottom. If I try to bring the screw out the top, that’s not a problem because it looks like the hole is wider in the top part of the fork leg than in the bottom.
Either way, it looks like I’m going to be drilling out the bottom - whether it’s to use an extractor to pull it out the bottom, or to drive something like a Torx bit in and use that to force it out the top.
So there’s really no reason I can’t try @Mad Mike’s idea first. If that doesn’t work, then I can cut the screw and try it the other way.
Make sense?
Now I fully acknowledge I’m a newbie doing this so happy to hear opinions- that’s what’s great about this forum, so many knowledgeable people.
My thought in cutting there was to relieve the pressure on the seized threads. This should make it easier to drill out.
I can run a longer M6 through the bottom threads of at least one of the other bolt holes so I know those threads are clear (didn’t check the other two, but I can).
I guess one risk is that cutting it creates a burr or something which then jams my threads if I try coming out the bottom. If I try to bring the screw out the top, that’s not a problem because it looks like the hole is wider in the top part of the fork leg than in the bottom.
Either way, it looks like I’m going to be drilling out the bottom - whether it’s to use an extractor to pull it out the bottom, or to drive something like a Torx bit in and use that to force it out the top.
So there’s really no reason I can’t try @Mad Mike’s idea first. If that doesn’t work, then I can cut the screw and try it the other way.
Make sense?
For some reason, I was excited by this realization that might seem obvious. This fastener has probably been seized for a while, and THAT’S why the cap head was rounded in the first place!!
Mad Mike
Well-known member
Sounds like a reasonable plan. Use some heat, and give the bolt a sharp rap with a punch and hammer first.
Relax
Well-known member
Seems like you're hitting dead end after dead end. Have you gotten a quote from anyone to bring the bike in and have them handle it for you before you back yourself so far into a corner that nobody will be able to get you out of? Even if it's only remove the broken extractor so you can use a properly sized and quality extractor that won't break?
That exists? Afaik, they are all a dice roll.
