Broken bolt hell - Where do I go from here?

[tommys67]

So I broke a bolt installing a crankcase cover on my CBR.  How or why is not important, but I know precisely what I did wrong, and it won't happen again.

I get the crankcase cover off, and I have good access to the end of the broken bolt.  I'm able to drill a nice hole into the bolt, but using a screw extractor isn't working so well.  My buddy (who has far more skill than I in repairs) advises me not to twist too hard so I don't break the screw extractor.  It's getting snug, but my buddy takes over and promptly breaks the screw extractor in the bolt.

Now I am in hell.  Did I mention that this little fiasco is keeping me from a trackday tomorrow? 

I tried a few different titanium tipped drill bits of several sizes - nothing.  I tried carving at the bolt with a dremel - nothing.  Penetrating oil helping?  Not so much.

Before I did damage to my actual crankcase I gave up, got dinner, lined up a 6 pack of beer I'm going to drink tonight...alone, and started researching.

What kind of drill bit will get into this bolt / extractor mess?

How close am I - REALLY - to completely make the beast with two backsing up my crankcase?  Nevermind - I know the answer...

Any other thoughts?

[ducpainter]

A picture might help.

[tommys67]

A picture might help.

OK - gimme a bit.  Gotta run back over to the garage.  I'll give dimensions, too.

[suzyj]

If there's anything sticking out that you can get purchase on, you've got hope.

Have you tried heat?  A propane torch or similar on the area around the broken bolt will make the aluminium crankcase expand more than the steel bolt, both making it easier to get penetreen etc in there, and freeing things up.

Be patient though.  Soak it in penetreen, go drink beer for a few hours, come back and give it another soak, and then warm it up with a torch.

[tommys67]

Vice-Grips?

Not going to work.  Bolt remnants are flush - to a little below - the deck of the crank case edge.

[suzyj]

Not going to work.  Bolt remnants are flush - to a little below - the deck of the crank case edge.

Do you have a welder?  If so it's worth having a go at welding a tab onto the end of the bolt/easy out.

[Howie]

Ah, Tom...small fastener broken flush with an easy out stuck in it is not good.  You might be able to get it out with a carbide drill or by heating (with the expected paint damage).  Your best (safest) bet would be to get the bike to a good welder.  Have him weld a nut to the broken remnants of the bolt and extractor.  Now you have something to turn and the heat will probably loosen things up.  Speak to the welder first, some will not want to take on the liability.  You will probably need to chase the thread with a tap, or possibly might need a TimeSert or Helicoil afterward.

[He Man]

if you have a steady hand, you can litterly drill the bolt body to pieces, then use a pick and break the remaining shell. Easy with aluminum, not so easy with steel but doable. I wouldnt recommend this way unless u had no choice or had balls of steel and no fear. (worst case scenario, you drill the hole flush and retap it).

if its steel, then the easiest way to do it is to weld a rod onto the end of it via TIG welding. The welding prcoess is hot enough to melt the locktite on the spot and u can just spin it out, or if u need to, build up the pool, put a slot on it and knock it out.

Theres a few welding shops on 3rd ave that have TIG machines, ud have to push ur bike a few blocks though.

Alternatively, this is kind of risky since u dont know how tight the bolt is, but use a propane torch, heat up the bolt, then use a Left handed drill bit and put a hole through it. Heat it up again, and use an EZ out. Most of the times it will come out, but if it doesnt, dont force it.

[ducpainter]

if you have a steady hand, you can litterly drill the bolt body to pieces, then use a pick and break the remaining shell. Easy with aluminum, not so easy with steel but doable. I wouldnt recommend this way unless u had no choice or had balls of steel and no fear. (worst case scenario, you drill the hole flush and retap it).

if its steel, then the easiest way to do it is to weld a rod onto the end of it via TIG welding. The welding prcoess is hot enough to melt the locktite on the spot and u can just spin it out, or if u need to, build up the pool, put a slot on it and knock it out.

Theres a few welding shops on 3rd ave that have TIG machines, ud have to push ur bike a few blocks though.

Alternatively, this is kind of risky since u dont know how tight the bolt is, but use a propane torch, heat up the bolt, then use a Left handed drill bit and put a hole through it. Heat it up again, and use an EZ out. Most of the times it will come out, but if it doesnt, dont force it.

Didn't bother to read the original post...

did you?

[He Man]

Apparently not enough for it to register.

Well in that case, the most headache free way is to still TIG a rod to it and just spin it out. The extractor isnt really that stuck, it probably broke at the point where it was actually touching the bolt, so ive had luck with just picking it out with a stainless steel dental pick. how much of it is in the hole? and how deep is the hole? Your welcome to borrow my set of dental picks ill even drop them off to you, they are pretty tough and should work if you didnt got nuts on the not-so-ez-out


Howies way works best and is the most common if the bolt is large enough, otherwise u can just build up the weld pool and grab on that.

[tommys67]

Last night I ordered a carbide drill bit and a true center punch.  This bolt is maybe 5 or 6mm in diameter so the idea of welding is really, really dicey.

I will be doing this later this week because I need to save the case, and I will be asking for help.

I'll be posting pictures shortly.

[He Man]

Try a pick and a few heat cycles before you drill into it, the EZout is very conical and only a small portion of it ever gets stuck.

You can also heat it up and put a candle stick on it, the wax seeps into corners and acts as a lubricant.

[tommys67]

My problems began a month ago when trying to install a set of Sato rear sets properly.  The new stuff wouldn't go onto the splined shaft of the shifter and instead of adding lubricant I added a BFH and bent a particular tab in the clutch case. I'll get to that in a moment.

So here's a picture of the complete right crankcase:



(The big thing is the slipper clutch and basket, the tiny gear is the starter reduction gear, the middle one is the idle gear, the bottom one is another gear to the starter)

The clutch basket required a very special tool to hold it in place in order to get to a nut that held the assembly in place. I posted about this tool elsewhere around the internet, but it turns out this tool was back ordered from Japan. It's about $35 and all it is is an oiled piece of stamped steel.



When being used to get the nut out, the bike looks like this: (The long thing is your standard shop breaker bar - oh, and look at the pretty braided steel line and the Sato rearset I was able to install properly!)



I've had lots of problems lately with this bike - all my doing. A small sample of my frustration came about once I took the clutch basket apart and was trying to remove the basket itself. The shop manual says - you guessed it "remove basket". What is NOT in the manual is the reality that the crankshaft needs to be in the right position so there's enough room to let the thing come out. I took this picture:



I had to do all this to get to one little metal tab that costs $2.43USD and has the job of holding the shifting mechanism in place behind the clutch basket. This is a little tough to see but the shifter cable is pointing RIGHT AT the tab and the bolt that holds the tab. When you change a gear, the shifter linkage turns a shaft from the left side of the bike to the right side which moves the shifter mechanism and effects a gear change. Smacking at that shaft when installing the rearset pushed the whole mechanism and bent that tab - which made the entire bike unusable. Look in the center of the picture, a little up from the middle, to see the culprit.



Once that tab was replaced, my buddy and I tested the shifting mechanism by moving the crankshaft by hand to help the gears change.

The next major delay in this repair was the replacement of the main nut holding the clutch in place. In the manual, the suggestion is to replace it as it must be "staked" and have a piece of material bent into a notch in the shaft. Here's what the old nut looked like when I test-installed it - you can see how there needs to be material punched into the notch:



Well, I got all that sorted, got a new nut staked in, and then re-assembled the whole thing with a nice bead of RTV sealant. I let it set overnight, then put in some nice rich Rotella oil and test ran the engine for about half an hour. I shifted it (VERY CAREFULLY) on the stand, and it ran beautifully. After checking it out - it looked great. This was Saturday night after I felt really, really good about it.



Well, I did make one mistake - I snapped one of the bolts tightening it. Basically, I forgot I had torqued it down, and the little bastard snapped.

Sunday I wake up to an oil leak. It wasn't where the broken bolt was, so my best guess is in jockey-ing the case cover in place I may have either a) scraped off some of the sealant or b) I torqued the nuts down too far before the gasket had a chance to really set up - basically squeezing it out of place.

I have learned that as much as I love working on this bike - I'm not that good at it, and I need help from here on out.

Now here's the problem:



In the bottom right of the case is the snapped bolt. Unfortunately, in trying to help me fix this, a really experienced buddy of mine snapped a screw extractor in there.

I was supposed to be at the track today.

Am I upset? Oh yeah.

Do I have more work to do? Oh yeah!

[scduc]

Once you've snapped the extractor, your best bet may be to weld something to it or just try to get it out. At this point however, you may be screwed no pun intended. If you originally drilled the screw on dead center, you could have drilled to just under tread size. then go in there with a pick and little hammer. problem is, if you are not on center this will not work, as you may damage the threads. The other option is to find someone with a tap-zapper call the local tool shop. But with it on the bike, you could run into some electical issues. PS never ever use those extractor. I personally think they are garbage.

[mendoje]

Do a search on DISSOLVING a steel screw or tap thats broken off flush and stuck in an aluminum hole.  Basically use an acid solution using nitric acid or Alum (aluminum potassium sulfate) and water solution, which will dissolve the steel, and leave the aluminum intact.  You'll need to create some sort of reservoir (I'd try modelers clay) to hold a small amount of the solution above the screw, then watch the steel bubble and fizz.

Edit: here's a good thread:
http://www.advrider.com/forums/showthread.php?t=547390&page=2

Jeff