Author Topic: Screw Snapped, Now Extractor Snapped. What Next? (Read 5832 times)

Popwood · « **on:** September 06, 2009, 09:03:25 am »

My son is finishing up rebuild of a '73 CL 360 (sorry not a 4) and had a 6mm screw break while putting the valve cover on. He tried a bolt extractor and now that snapped on the first turn-- thanks Irwin tools. Question is, now what? The extractor is hardened steel, I presume. Both the screw and extractor are essentially flush with surface of the head. Should he try to drill it all out? Need a special bit to drill the extractor? Try another another attempt with extractor? Or just forget it and rely on the Honda Bond and 13 other screws to do the job?

mystic_1 · « **Reply #1 on:** September 06, 2009, 09:06:24 am »

You won't have much luck drilling through an extractor. You could have the broken bits removed through EDM also known as spark erosion, but that'll cost something. I'm not sure on the CL360 but I know that on the CB350 the rocker arms live in the valve cover so I wouldn't half-ass anything.

mystic_1

Industrial Rat400f Killer · « **Reply #2 on:** September 06, 2009, 09:11:43 am »

Here in Seattle we have a Tacoma Screw and Fastenal, both are industrial screw,nut and bolt supply. They have better quality of easy outs, extractors and stuff then the box stores have. Find a place like that and buy 2-3 of each option. It'll cost around $20 but with some persistence one of them will work.
FYI extractors break, I usually break 1-2 before getting the bolt out that's stuck.
Keep at it, good luck.

I've had the best luck with the ones that come with a drill bit and a reverse thread bit.

Popwood · « **Reply #3 on:** September 06, 2009, 10:58:37 am »

Quote from: mystic_1 on September 06, 2009, 09:06:24 am

You won't have much luck drilling through an extractor. You could have the broken bits removed through EDM also known as spark erosion, but that'll cost something. I'm not sure on the CL360 but I know that on the CB350 the rocker arms live in the valve cover so I wouldn't half-ass anything.

mystic_1

Thanks, Mystic, but so long as no oil leaks out what is the harm of leaving one screw out? How could that affect the rocker arm if it is like the 350, which I'm not sure of. Seems like the alternatives presented so far could be costly. I mean, is there a potential for internal damage even in the absence of no oil leak?

manjisann · « **Reply #4 on:** September 06, 2009, 02:11:18 pm »

I would be wary of leaving a screw or bolt out of the head as I would think with the heating and cooling it would eventually warp and you'd have a lovely oil leak.

As for getting the broken bits out here is my take on it. Soak the whole area in some sort of penetrating oil, I use wd-40 but thats just cause there's a half dozen cans around the shop. Soak a paper towel in the stuff and let it sit at least over night. Get a reverse twist drill bit so (instead of spinning clock wise it spins counter clockwise), center punch the busted extractor and pray like mad that the reverse bit will grab it and spin it out. The extractors are hardened steel so you won't actually drill through it. Hopefully that works, if it doesn't I'm afraid I'm out of ideas.

One thing to note with extractors. In my experience people use ones that are too small and so when torqing them around they snap. Used the biggest one you can get away with that won't risk drilling into the threads.

HTH and good luck.

Brandon

BuffaloBill · « **Reply #5 on:** September 06, 2009, 02:29:56 pm »

Could you knock the extractor around some with a small punch & hammer? The screw is soft enough that maybe the extractor would loosen itself enough to get it out.

Popwood · « **Reply #6 on:** September 06, 2009, 03:45:46 pm »

I just talked with my son and he's been working on it without any luck most of the afternoon. He's frustrated, of course, and wants to do the right thing fixing this problem. I will proudly say he's done a remarkable job rebuilding this bike, taking everything apart, motor and all, repainting it all and reassembling. His work looks terrific. His perfectionist tendencies show through.

I'm going to his place tomorrow to help and we'll try some of the suggestions you all have made. Appreciate your good thoughts and encouragement. Was wondering one thing, if anyone knows. Is carbide tough enough to cut the hardened steel extractor? I have tons of experience woodworking and could rig a solid carbide end mill in a plunge router set squarely over the busted extractor. Could carefully plunge a solid carbide cutter milling away the extractor? From what my boy tells me, it's about 1/4" deep and as is typical, tapered. I have no doubt I can rig the plunge router so it stays put, and cuts straight down at a very slow plunge speed if need be.

Kirby · « **Reply #7 on:** September 06, 2009, 05:03:36 pm »

I, too, have an extractor snapped off in the head of my CB500. I have tried drilling, punching, whatever, to get something started...it all wanders over to the aluminum. Anxiously awaiting an idea on how to get this out. I am ready to cut ear off, have aluminum welded on and then tap or heli-coil. Arrgghh!, this project is killing me. Kirby

CBGhia · « **Reply #8 on:** September 06, 2009, 05:15:42 pm »

Left -handed drill bits. They are the greatest extractors. Usually it catches before drilling through and backs it out anyway. They are a must-have tool.

Hinz · « **Reply #9 on:** September 06, 2009, 05:16:31 pm »

I've had this happen a few times and first thing is to get that extractor out. You're never going to be able to drill through that tool steel. If you have a Dremel, get the smallest cutoff wheel in there and cut a slit into the top of the broken off extractor. I have some tiny, ground down (around 1/4" diameter) cutoff wheels that I keep around for this exact purpose. They cut into that tool steel no problem. Now, If you cut into the surrounding aluminum some, it's not the end of the world, just don't cut all the way through the wall. You won't be able to see it once the valve cover is on anyways. Then, use a flat head screwdriver to unscrew the extractor. It will surprisingly come out real easy. A regular drill is just going to try and push it in there more.
Once the extractor is out, then keep at the broken off screw with the drill.
If you mess up the threads bad enough, you may have to drill out everything and get a 6mm steel insert (available at PepBoys)
Hope some of this helps

new2novas · « **Reply #10 on:** September 06, 2009, 05:20:25 pm »

get a carbide bit for dremel or small die grinder, takes a few minutes but its easy and painless, try and not nick the threads unless they are already beat, get enough of the ectractor out and you can pick the rest out or run a tap to clean it up

gane · « **Reply #11 on:** September 06, 2009, 05:28:39 pm »

Popwood, I've had good luck removing broken extractors and taps using small automatic (plunger type) center punches. simply click any accessible portion of broken bit in "get loose direction".this highly concentrated (tho small area) impact often breaks off bits of tap/extractor eventually allowing working loose/removal. bringing you back to original prob. only compounded by the fact that extractor has probly also expanded broken bolt/stud making it tighter than ever. with luck your' 1st drill attempt was close to center, even if not, using original hole as guide, drill hole progressivly larger w/ prefferably l/h drill bits until broken bolt either comes out, or remaining bit is small enough to be worked out. at this point, you'll probly have a slightly oversized and/or ovaled hole. relax.unless things have gotten truly out of hand you should be able to use the un damaged bottom of hole as a pilot to straighten bore (again sightly oversize) Emphasize SLIGHTLY, once hole is as close as possible to original possition, install a timesert insert ( 6mm 1.0 inserts are @ 8mm in outer diameter) even if new stud position is slightly off, slight reaming of valve cover should allow fit. Timesert kits are expensive.roughly $60.00 a set should you need one, but still cheaper than having a pro install 1.. and handy to have in reserve.. hope there is something here you can use.. luck G

bucky katt · « **Reply #12 on:** September 06, 2009, 05:34:48 pm »

Quote from: CBGhia on September 06, 2009, 05:15:42 pm

Left -handed drill bits. They are the greatest extractors. Usually it catches before drilling through and backs it out anyway. They are a must-have tool.

as many years as i've been working on cars and bikes (30+ years) i've never heard of a left handed drill bit, i learn something new every day

Popwood · « **Reply #13 on:** September 06, 2009, 07:14:00 pm »

Thanks everyone for the suggestions. Some seem really doable. Think I'll thy the Dremmel cut off tool to make a slot for screwdriver. Will keep hyou posted on progresss and appreciate everyone who's chimed in here to help us solve this nasty problem. This site rocks!!!

razor02097 · « **Reply #14 on:** September 06, 2009, 07:19:43 pm »

Quote from: Popwood on September 06, 2009, 07:14:00 pm

Thanks everyone for the suggestions. Some seem really doable. Think I'll thy the Dremmel cut off tool to make a slot for screwdriver. Will keep hyou posted on progresss and appreciate everyone who's chimed in here to help us solve this nasty problem. This site rocks!!!

IMO

screwdriver... no

Impact driver... yes

Bill/BentON Racing · « **Reply #15 on:** September 06, 2009, 07:30:54 pm »

They make carbide tip drill bits,easy out super hard,but have drilled enough to use Snap On stud extractors(the little ones)and sucessfully drilled out easy outs and swore to try and never use them again,they snap/break way to easy,next time just try the little stud extractors.Good Luck,Bill

Mdub · « **Reply #16 on:** September 06, 2009, 08:53:27 pm »

You said the screw broke while putting the cover on.
It should be easy to remove the cover, and then remove the offending piece with vice grips.
Hope you get it resolved,
Mike

Hinz · « **Reply #17 on:** September 06, 2009, 09:16:52 pm »

Quote from: razor02097 on September 06, 2009, 07:19:43 pm

Quote from: Popwood on September 06, 2009, 07:14:00 pm
Thanks everyone for the suggestions. Some seem really doable. Think I'll thy the Dremmel cut off tool to make a slot for screwdriver. Will keep hyou posted on progresss and appreciate everyone who's chimed in here to help us solve this nasty problem. This site rocks!!!

IMO

screwdriver... no

Impact driver... yes

nope, no impact driver necessary. the broken off bit of the extractor will pop right out with a regular flat blade screwdriver. Just make sure you're turning the "right" way.

the crappy part is....once the extractor is out, you're still back where you started.
good luck and let us know how it turns out.

Frankencake · « **Reply #18 on:** September 06, 2009, 09:51:37 pm »

I haven't had the opportunity to try this, but an experiment in crystalline metal structure alteration seems appropriate. I have a tiny jewelers torch that has a small flame that I always wanted to use for just this situation. If I could use the torch to heat just the extractor I could get it hot enough to change the crystalline structure and take the hardness out of it or at least get the end of it soft to make a slot in it..
A question for the more knowledgeable: would it work? Or is the metal of the extractor an alloy that wouldn't lose it's hardness?

manjisann · « **Reply #19 on:** September 07, 2009, 05:43:11 am »

Quote

I haven't had the opportunity to try this, but an experiment in crystalline metal structure alteration seems appropriate. I have a tiny jewelers torch that has a small flame that I always wanted to use for just this situation. If I could use the torch to heat just the extractor I could get it hot enough to change the crystalline structure and take the hardness out of it or at least get the end of it soft to make a slot in it..
A question for the more knowledgeable: would it work? Or is the metal of the extractor an alloy that wouldn't lose it's hardness?

I am by no means a scientist or engineer or even that knowledgeable about metal. But what I do know is that aluminum melts at a much lower temp than steel, and in order to change the temper of a metal piece I believe you have to get it red hot, so you'd run the risk of melting the aluminum. Or, since aluminum dissapates heat better than steel, you'd never get it hot enough as the aluminum would act as a giant heat sink. As I said, just my thoughts on it.

OP, good luck on getting it out, let us know what you finally do. Screw extractors aren't bad. Unlike popular wisdom, Size really does matter

Brandon

new2novas · « **Reply #20 on:** September 07, 2009, 08:25:42 am »

suggestions are running rampant with changing crystalline structures and such....if the extractor is truly stuck use a damn carbide burr and be done with it, you will most likely have 0% success at trying a drill of any kind due to the inability to center the drill over the hole....trust me i have tried every method imaginable, but there is more than one way to skin a cat

i would use the B1

Popwood · « **Reply #21 on:** September 07, 2009, 04:05:33 pm »

Here's the update, but first thanks to all who have weighed-in with possible solutions and good wishes. Again, this is a wonderful forum.

To tell the end first, the extractor piece and and busted screw are out. Whew. Not a perfect ending but good enough, I think. I picked up a tungsten carbide Dremmel tool that is identified as C.2 in the previous post. I have a Ryobi type "Dremmel" tool. It handled the hardened steel in the extractor without too much trouble, just slow going, easy does it. Now I know how a dentist feels drilling out a cavity

. Once I got that out I continued using the tool to center as best I could the bottom, then began drilling out stepping up drill sizes until I felt I was threatening the threads (actually, some threads near the bottom of the broken screw did get buggered). I then went back with the Dremmel and worked the top of the hole very carefully until just barely touching the original threads. Picked out the bolt pieces from the threads, then moved down two, three threads more and picked those out. Once I had enough threads exposed I retapped the hole. The tap chased out some more remaining bolt steel as it went down.

This was not a perfect process, as I mentioned. The top of the bolt hole is too large to grab the bolt properly, but deeper in, the bolt does start to catch and hold. I suggested to my son that he get a replacement 6mm bolt that is actually too long but then cut it off to get another 1/4" depth or more of thread. At least at this point we feel our solution will work. But if for some reason it doesn't, we can always go back with the next size bolt up, drill and tap again.

I should add that we did our best to clean up all ground bolt debris. That was almost as much of a pain as working on the busted bolt and extractor

bucky katt · « **Reply #22 on:** September 07, 2009, 06:31:59 pm »

i would now heli-coil the hole if it were mine. cant be too safe when youre working on a motorcycle

razor02097 · « **Reply #23 on:** September 08, 2009, 07:47:14 am »

Quote from: Hinz on September 06, 2009, 09:16:52 pm

Quote from: razor02097 on September 06, 2009, 07:19:43 pm
Quote from: Popwood on September 06, 2009, 07:14:00 pm
Thanks everyone for the suggestions. Some seem really doable. Think I'll thy the Dremmel cut off tool to make a slot for screwdriver. Will keep hyou posted on progresss and appreciate everyone who's chimed in here to help us solve this nasty problem. This site rocks!!!

IMO

screwdriver... no

Impact driver... yes

nope, no impact driver necessary. the broken off bit of the extractor will pop right out with a regular flat blade screwdriver. Just make sure you're turning the "right" way.

the crappy part is....once the extractor is out, you're still back where you started.
good luck and let us know how it turns out.

I thought he wanted the screw out also... if its all nice and flat with a slot cut in it then it could take the bolt and broken piece out at the same time.

Hinz · « **Reply #24 on:** September 08, 2009, 09:52:02 am »

Quote from: razor02097 on September 08, 2009, 07:47:14 am

Quote from: Hinz on September 06, 2009, 09:16:52 pm
Quote from: razor02097 on September 06, 2009, 07:19:43 pm
Quote from: Popwood on September 06, 2009, 07:14:00 pm
Thanks everyone for the suggestions. Some seem really doable. Think I'll thy the Dremmel cut off tool to make a slot for screwdriver. Will keep hyou posted on progresss and appreciate everyone who's chimed in here to help us solve this nasty problem. This site rocks!!!

IMO

screwdriver... no

Impact driver... yes

nope, no impact driver necessary. the broken off bit of the extractor will pop right out with a regular flat blade screwdriver. Just make sure you're turning the "right" way.

the crappy part is....once the extractor is out, you're still back where you started.
good luck and let us know how it turns out.

I thought he wanted the screw out also... if its all nice and flat with a slot cut in it then it could take the bolt and broken piece out at the same time.

ahh i see where you're coming from.
with MY luck, I'd probably snap off the impact bit in there too

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Author Topic: Screw Snapped, Now Extractor Snapped. What Next? (Read 5832 times)