Extracting Recessed Bolt (Broken, Too!)

This is one of the bolts for the control arm bushing on the passenger side in a CS turbo 9000. It is to the rear bushing, one of the two 13mm head, front bolts to the 4-bolt retainer. What do I use to get down in there (roughly 2 1/2" I guess) and extract the broken tip?

Reply to
Valjean
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Penetrating oil, and then a left-handed drill bit, would be how I'd start. Have you tried swearing rather a lot? That sometimes helps.

Reply to
Dave Hinz

By left-handed drill, do you mean a drill bit which is designed to cut in the opposite direction of rotation to a convention drill bit? What is the aim of drilling out the broken fastener? I presume if the correct drill size is used enough of the fastener can be removed that the small bit left engaging the thread of the original hole can be easily removed?

Regards,

Craig.

Reply to
Craig's Saab C900 Site

Yup. It adds heat, makes a hole, and rotates the fastener in the direction you want it to turn on the off chance that the heat and torque loosen it up.

Well, there are several approaches for a stuck fastener. The key is to preserve options, and to do that it's imperitive that the hole be drilled in the exact center of the stuck fastener. First, drill with the left hand drill bit, of a diameter of the appropriate easy-out tool for the fastener you're trying to remove. If you're lucky, the heat, torque, and kroil that you've put on to soak will act together and it'll come out. If you're less lucky, then you can use the ez-out which is kind of a left-twist, tapered corkscrew kind of a deal. It wedges into the hole & digs in, hopefully bringing the fastener out with it.

When that doesn't work, enlarge the hole you started, and gummed up a bit with the ez-out, to the minor diameter of the bolt, or as close as you can get to it given how far you missed the centerline. In an ideal world, you'll hit it dead-nuts, and drill out everything but the long spiral of threads, which can then be removed with a pick or similar pointy tool. That never happens, but you can usually get it close. Again, left-hand drill bits help unless it's a through-hole, and then you can just thread it further in by drilling if it moves.

When _that_ doesn't work, then drill it for the minor diameter of the next larger rated fastener, re-tap the hole, and use an M12 instead of an M10, or whatever. Not always an option, though.

In any case, liberal use of good penetrating oil, and/or heat, and/or swearing, often helps.

Dave Hinz

Reply to
Dave Hinz

Dave I do not understand your reference to a left handed drill bit. You use a normal twist drill of the correct size and then a special bit for the removal of the screw. These bits had the trade name of Ezy Outs in the UK many years ago. The proper name is Screw Extractors. Once in the hole in the broken screw you turn them anti clockwise and they lock into the screw and out it comes. In the real world that does not happen. This thread (thats clever!) reminds me of some of the struggles I've had and thinking about it makes me wonder if such a thing was ever made for LH threads, I rather think not. Of course removiing broken taps is the hard one especially if its in tool steel.

Reply to
John Hudson

Reply to
John Hudson

Are you in the US? Go to Home Depot and pick up the Blue Mol drill bits if you decide to extract the screws. The Blue Mol cuts through metal like butter. But with the drill bits being very hard, they are also quite brittle. So be prepared with some spare bits on hand.

Removed the drivetrain of my 95 9k cse turbo this past weekend to do clutch, timing chain guides and all seals. Had to extract two torx screws on the sump pan. The Blue Mol makes an otherwise aggravating task very easy.

Reply to
yaofeng

Well, sure, you can use a normal drill bit if you don't have a set of the left-twist ones, but what I'm saying is that sometimes just using the left-twist drill bit will be enough that you don't have to move on to step 2, with the ez-out.

If you're lucky.

Yes. Whatever caused the bolt or tap to stick in the hole, is still holding it. A stuck tap is a real bitch to deal with. But, if you get a set of left-twist drillbits, they're useful for the rare situations where you have to do all this. Worst case, they work no better than the right-twist drills. Keep 'em with your ez-outs, and you're half way there.

In the US, you can buy those drills from the Eastwood company; they sell car restoration supplies and tools. Pricy but a good catalog with otherwise hard to find stuff.

Reply to
Dave Hinz

Thank you Dave for the information. Unfortunately being a poor Englishman and not a rich American my bench and pillar drills are non-reversible (How the other half lives!) so rendering LH bits unuseable except in my cordless drills. In the meantime I will try not to be too heavy handed when tightening studs and so avoid using even my trusty Ezy-Outs. Best wishes to you.

Reply to
John Hudson

Sometimes, you will find, as dave said, the heat and vibration of drilling will actually unscrew the outer part of the bolt as you enlarge the hole.

Reply to
Sleeker GT Phwoar

Talk to a welder about it.

I had a broken antiroll bar bush on the celica go and the retaining bolt broke while changing it.

It would have taken me hours with a drill to do, but, the welder I have used in the past, heated it up with the Oxy torch untl it glowed red. This burns off any crap, and breaks any rust seal through expansion.

Then he took the mig welder, with a lot of Amps for penetration, and built up a good sized blob on the end of the broken bolt. Once that was done, he was able to lock a set of vice grips on, and use them to twist out the bolt remains.

Reply to
Sleeker GT Phwoar

Well, I've got a full machine shop in the basement, but even cheap cordless drills can run in reverse...you can get Japanese tools in Blighty, can't you?

Well, there ya go. If you have a source, that is.

Oh, you'll break something, don't worry about that. It's never fun.

Reply to
Dave Hinz

We certainly can, I have 5 Makitas at the last count, generally I look for the made in Japan label as a form of guarantee. The Chinese are now the big importers into the UK, machine tools and electronic gear at very low prices. I have just bought a bandsaw from China that I am well pleased with. Their computer gear seems extremely good. The western world is in for a shock in my opinion, still we have had it good for quite a while but our manufacturing jobs will surely go.

Reply to
John Hudson

With "highly variable" as a good description of the quality, as here, yes?

Well, I'd like to think that at some point, people will refuse to buy things that don't work. When you buy out of a catalog, though, it's impossible to decide that ahead of time. With the cheap Chinese tooling, you never know what you're going to get. If you buy something with a known source, you at least have that company's reputation to work from to start forming an opinion.

Me, I'm happy with my Rockwell machinery, and will only buy cheap Chinese tools/tooling for one-off jobs.

Reply to
Dave Hinz

All good, but I'm with Dave on the swearing bit, very cathartic. I often find with machinery that won't play, cars, computers etc the threat of physical violence against said object works, but only if you really mean it.

Reply to
Al

Here we see the true beauty of capitalism. Sit back and use an apprentice. Hehehe.

Seriously though, 1/ all the suggestions offered will probably come into play, 2/ Ezy Outs often aren't, 3/ in critical situations removing the part and paying someone else to fix it (or else make good their stuff up at their expense) is often the most time & cost effective way in the end. Cheers

Reply to
hippo

Watch "Gourmet night" if you can get your hands on any "Fawlty Towers" videos/DVDs.

Describes it perfectly.

Reply to
Sleeker GT Phwoar

Absolutely. They know when you're bluffing, which only makes it worse of course.

Reply to
Dave Hinz

I remember there are only two bolts with a bolt head of 13 mm on the control arm bushing. Anyway, if you haven't solved your problem yet, you may want to remove the control arm altogether to leave the shank exposed.

I'd imagine when the bolt head is sheared off, there will be very little tension to keep the shank firmly stuck in the hole. This will make extraction much easier.

I had on two occasions the top bolt of the serpentine belt tensioner on my 9k snapped, leaving the shank in the hole. I was able to remove the shank with a pair of needle nose pliers without drilling and bolt extraction. But luck may have been with me.

Reply to
yaofeng

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