In a rush to do something productive during my toddler's nap, I inserted the crank puller into the drive side crank arm. When I met resistance, I just gave it all the muscle I could. I snapped the crank puller off in the threads of the crank arm because I was too stupid to realize I didn't remove the crank bolt first!
This is an older cup and cone adjustable BB. If the crank bolt took an Allen key, no problem, but I can't get the socket in there to remove the bolt now because the broken crank puller is jammed in there.
Is there a way to remove the BB if I remove the left (non drive) BB components? I have that side dismantled but it still doesn't give me enough room to lock onto the drive side BB to turn that. Any suggestions are welcome. I am replacing both BB and cranks, so suggestions which destroy either are fine. Thanks.

Thats not an enviable situation! Unfortunately the drive side is ALWAYS the side thats most difficult ro remove, and to access it effectively you`ll need the crank arm off. The >> assembly can`t be removed otherwise.

So the easiest ( which will still be a pain) strategy will be to split the crank on the axle. Since the bolt is still anchoring it - it`ll need to be split on two sides around that bolt.

I wouldn`t suggest even trying to cut the axle - you`ll damage the frame in the process. Not a job that I`d love to do again but have done in the past . An Xacto saw will cut aluminum OK and a hammer and chisel will force the seperation. You`ll be good for a couple hours and if you lose patience you could end up damaging the frame so take it easy.

I am not sure if I understand corectly(a pic would help) but couldn't you use an easy out to remove the puller or drill it out?

Probably could drill the nut off the end. Then will need to use an automotive puller to pull off the crankset. Patience will be key. And of course this will detroy the bb spindle, and might destroy the drive side crankset as well (will take a steady hand).

+1 To below, post pictures before taking a drill or any other tool to it. There could be non-destructive options.

Oof! Before you resort to destroying parts, post a picture of the damage. There are any number of ways to remove screw threads without destroying surrounding surfaces. If we can see what's up, we can better suggest possible solutions.

Could you possibly get a small chisel point onto the inside or edge of the broken-off ring of the puller and tap it counterclockwise enough to loosen it? Then you can get a new puller head and do it right.

First rule of getting out of desperate situations is to stop and think, before making them worse. Odds are you can solve this with only the loss of the crank bolt.

Your mission here it to remove the bolt without collateral damage, because doing so opens up other possibilities.

Most crank bolts are too hard to drill, but if you have a Dremel tool, you can use the a cut-off disc to grind a screwdriver slot across the face of the bolt, and turn it out with a big screwdriver, using a wrench or pliers for torque. If you can't turn it, consider a screwdriver bit in an impact driver (favorite tool of the truly desperate). The beauty of this tool is that it drives the bit in as it turns it so it'll hold in a crappy slot.

Failing the Dremel, you might weld a stud to the face of the bolt and use that to turn it off. You can't braze this because it's too slow and will melt the crank arm.

Worst case, you can try drilling out the bolt, but they're usually hardened, and it'll still leave you with a stud to remove from the spindle.

Once the bolt is loose, you should be able to work the ring of the puller out of the arm. If you get that far, and can't get the ring out come back for the next step.

Whatever you do, don't destroy the crank arm or BB spindle until you've exhausted all better options. Splitting the arm by sawing or filing in from the side then chiseling is always an option, but that should be a last option and I don't think you'll need to do it.

Use a Dremel with a small cutting wheel to cut the broken ring out of the crank. Then remove bolt. If you can still thread a new crank puller in, use that, and if not, simply use a gear puller to pop the crankarm off.

If you're careful with the Dremel, you can re-use the arm, though I'd install a self-extracting bolt set.

I do have a dremel. Just went to the corner store and purchased the cutting disc. Hopefully the screwdriver slot scenario works. I'll let y'all know. Thanks for all the insights so far.

Take your time to make a deep slot full width, so the screwdriver has a good purchase, see if you can borrow a screwdriver with a 1/2" or bigger tip

BTW- stupid question. Who makes a crank remover with a thin enough wall at the business end to fit with the bolt in place? Your situation would be impossible with any of the crank pullers I've ever seen.

Made the screwdriver slot but I don't have a screwdriver with a wide enough tip, so I'm going to have to wait until tomorrow to get my hands on one probably.

As for the last question, it was a park tool crank puller. But I don't think it was the thinness that was the problem, after all a ratchet fits in there to get the bolt out. But I've never had any other crank puller so I can't compare.

Maybe I should be more optamistic. Or not.

Just can`t see a screwdriver having the leverage to loosen something that was forced in till it snapped. We have a souvenier at the shop from a former mechanic. Its a Park Tool crank puller firmly fixed in a non-drive crank. The guy apparently got carried away and instead of tightening the inner screw to press against the axle - came onto the outside shell that threads into the crank arm.

Well nothing broke and I`m surprised the threads in the crank arm didn`t strip - but no-ones been able to seperate those two pieces in the past two years and sometimes we try just for fun. A socket and extension bar and vice aren`t enough there so I guess I`m not too expectant for results with a screwdriver.

But I have split crank arms as described when nothing else worked including a wheel puller.

This may be a lot for a non mechanical but, fastenal sells (i'm sure others do also) left handed drill bits. I have drilled out a couple hundred harden alloy cap screws with them. Use oil and drill SLOW. If the screwdriver doesn't work.

As I said, there's always the destructive options, but that should never be the starting place. Last resort methods imply that other less desperate things be tried first.

FWIW, he's not trying to unscrew a part that broke from torque. He's unscrewing the crank bolt, and it will be difficult but not impossible with a wide blade screwdriver, aided with a wrench for torque. It has nothing to do with the part he broke, and his fortunes depend on how tight he tightened it when he installed the crank. The ideal tool for the job is the hammer impact wrench because it turns the blade while driving it in. (BTW, if he has an auto mechanic friend, many have these for similar jobs)

BTW- while the Dremel is handy, the OP could extend the slot into the ring of the extractor tool, making a small notch. If he threaded it in by hand only, he might be able to set a small punch in the groove and gently tap it around. Problem is he can't use much force because that'll drive the ring into the crank making it tighter. It's worth a go if done carefully.

The Dremel diamond bits are very handy for grinding off hardened bolt heads if things get to that point. We spent some time together with my wife's postal Subaru last week.

I'm also amazed that the puller broke before stripping out the crank arm's internal threads. Most of the requests for help we get here concern a crank arm that has had the threads stripped out but the puller remains intact.

That said, and since the OP plans to replace both the crank and bb, I think his best bet is to use the Dremel and a cut-off wheel to cut through the crank arm in two or more places at the bottom bracket eye and then it should just slip off. Use fiber reinforced cut-off wheels as these are far more durable and won't shatter if they are twisted slightly.

'he might be able to set a small punch in the groove and gently tap it around. '

That's what I was getting at, only with a small sharp tool like a chisel or staking tool you can usually forego cutting a notch.

A few words of encouragement. Don't beat yourself up
Within the last six months I have myself neglected
to remove the washer that accompanies some of these
bolts, much to the detriment of puller, washer, and
self esteem. Things happen. Even to those who are
supposed to know better.

This is about where I would start, because I
am notoriously cheap and would be about
reusing the arm as a priority. Sometimes the
guys that do this for money like Burton have a
tendency to unconsciously factor time spent
into the equation (rightly so, shop time being
a rational consideration in any repair.)
So they have a tendency to adopt the shock
and awe approach out of the gate.

Still, you may end up eventually at destructive
removal. If that becomes the case:


They used to sell these at Home Depot here
for 40 bucks and I see they still list them on
Amazon at that price. They work so well for
so many cutting applications that I would not be
without one.

This is the tool that singlehandedly made the U-lock
obsolete. Use eye and hearing protection, make
sure someone else is responsible for your toddler,
and as always, YMMV.

Empathetically,
Mike Larmer

p.s. My impression is that a decent quality crank
puller will strip the threads in an alloy crank before
it leaves a part of itself in your way. You might
want to go a little higher end with the replacement.

I have a tendency to be both appalled and fascinated at the
various tool abuse souvenirs that show up in my own shop
at the Sacramento Bike Coop. There's a tool aficianado who
also works there that will soon have a stroke, I fear, if one
more hosed chain tool is handed to him.

For a while we used to hang the unfixable ones on the wall,
but we ran out of wall.

Mike Larmer

For some mechanics there are only two tools. Everything is a hammer, except for screwdrivers. Those are chisels.

I had suggested the direct approach to this because as per the OP, this is an older cup and cone style bottom bracket and he plans on replacing both the bottom bracket and crankset anyway.

I guess the question at this point is : Are we done yet?