TTHJames Posted June 30, 2009 Share Posted June 30, 2009 Hi, the 2 allen bolts that attach the exhaust to the engine are in very bad condition and have rounded off slightly so that an allen key won't grip. There's not enough room to get a bolt remover drill bit in there because the pipe is in the way. I've tried mole grips which only just fit on the bolt and slip even if they are on as tight as I can get them. There's not enough room to get an angle grinder in there to cut a slot in the head, also the dremel won't fit to do the same thing because of the angle, although I could get a milling bit in but obviously cutting a slot that way is going to be very difficult indeed. I thought about welding a bar on to the bolt and getting it out that way but I don't have a welder and it would be a few days before I can borrow one. I really, really don't want to drill out the bolts but I think that's the only way I'm going to be able to do it unless I wait a few days for the welder. Has anybody got any ideas? Cheer, James. Link to comment Share on other sites More sharing options...
shed hermit Posted June 30, 2009 Share Posted June 30, 2009 i would go with welding a nut onto the head of it, the heat will help loosen it aswell. if you start cutting at at it, it may give you more hassle by having to drill it later. if you cant get a dremmell into it how are you going to drill it out if it breaks? good luck Link to comment Share on other sites More sharing options...
Cov_AL Posted June 30, 2009 Share Posted June 30, 2009 rost off or acf-50. spray on every day for a few days - by which point you'll have the welder. Link to comment Share on other sites More sharing options...
YPVS TONE Posted June 30, 2009 Share Posted June 30, 2009 My neighbour had the same problem a few months back on his gsx600 and found that using a blowlamp to heat the bolt and tapping an old socket onto the round part of the allen bolt then useng a rachet and just keep turning the socket to and fro it eventually came undone. Remember to put new bolts in and put some copaslip on the threads to prevent it happening again. Hope this helps .Tony. Link to comment Share on other sites More sharing options...
TTHJames Posted June 30, 2009 Author Share Posted June 30, 2009 if you cant get a dremmell into it how are you going to drill it out if it breaks? I can get a dremel in but not side on, but I'd use the drill with a long drill bit if I had to drill it out. I think I'm just going to wait a few days for the welder. Cheers for the replies. Link to comment Share on other sites More sharing options...
Moderator Airhead Posted June 30, 2009 Moderator Share Posted June 30, 2009 I can get a dremel in but not side on, but I'd use the drill with a long drill bit if I had to drill it out. I think I'm just going to wait a few days for the welder. Cheers for the replies. It might be wise to disconnect and remove the CDI before welding... Link to comment Share on other sites More sharing options...
shed hermit Posted June 30, 2009 Share Posted June 30, 2009 It might be wise to disconnect and remove the CDI before welding... and the battery Link to comment Share on other sites More sharing options...
barkwindjammer Posted June 30, 2009 Share Posted June 30, 2009 the things you can do with a dremmel, hours of mindless endless fun for (the black-sheep) all the family http://www.youtube.com/watch?v=Eqoz-6xLY9c ouch! Link to comment Share on other sites More sharing options...
Moderator DirtyDT Posted June 30, 2009 Moderator Share Posted June 30, 2009 I had similar on an oil pump. Heat it a few times. WD40 it a lot. Cut a slot in one side of the head or nick the head enough so a flat screwdriver can sit in the nick and then hit the driver to push the bolt anticlockwise. Repeat the process. Picture 1 shows the oil pump drive and the holes for the new screws. Picture 2 shows the bolts above the removed oilpump. Picture 3 shows new Allen bolts installed. Link to comment Share on other sites More sharing options...
Russell James Posted July 4, 2009 Share Posted July 4, 2009 I would be cautious about drilling any "hexagon headed screw" alen key bolt/ screw as most are hardened. best of luck. Russell James Link to comment Share on other sites More sharing options...
sausage-fingers Posted July 5, 2009 Share Posted July 5, 2009 being a mechanical technician I come across this problem alot. One trick that always works for me is to find a decent quality stubby star bit that fits into a socket so you can use a ratchet. Find a star bit that is very slightly larger than the allen and drive it in with a hammer. The teeth on the star will cut themselves some grip and with gentle but firm pressure, the allen bolt will come out. Secondly, a trick with hex heads is if possible, heat the head until it is cherry red, then let it cool naturally, it will then sail out. Its OK spraying it with WD or whatever, but it takes a long time for the oil to penetrate, if at all, and applying heat and WD wont do alot other than make lots of nice smoke and smells ! You can drill bolts easily if you use a cobolt drill. Most bolts are only 8.8 and not the HT 9.6 or 10.2's unless it is engine mounts, engine internals, brake mountings or other stress areas. Even HT Bolts can be drilled if done correctly with the correct speed and pressure, but dont use an old drill bit as a blunt bit will just wear into the bolt and cause unnesessary heat. Another method is to put a good centre pop in the centre of the bolt head or inside the allen head. The focussed energy of the centre punch can sometimes loosen the bolt concerned. If this fails, at least you have a centre pop ready to drill and easy out. Hope this helps Link to comment Share on other sites More sharing options...
mike1949 Posted July 5, 2009 Share Posted July 5, 2009 being a mechanical technician I come across this problem alot. One trick that always works for me is to find a decent quality stubby star bit that fits into a socket so you can use a ratchet. Find a star bit that is very slightly larger than the allen and drive it in with a hammer. The teeth on the star will cut themselves some grip and with gentle but firm pressure, the allen bolt will come out. Hope this helps What is a stubby star bit? I've heard of heating the head to cherry red, but then cooling it with water straight away rather than letting it cool naturally? Link to comment Share on other sites More sharing options...
sausage-fingers Posted July 5, 2009 Share Posted July 5, 2009 What is a stubby star bit? I've heard of heating the head to cherry red, but then cooling it with water straight away rather than letting it cool naturally? Here you go - star bits: If you cool the bolt immediately after heating, you can run the risk of making it brittle, making it easier to snap, which creates another slight headache. If you heat and then allow to cool slowly, you are effectively Annealing the bolt, or tempering it, making it slightly tougher. Link to comment Share on other sites More sharing options...
qtws Posted July 24, 2009 Share Posted July 24, 2009 Steel allen headed bolt into alloy. You get galvanic (?) corrosion, and they stick like crazy - you WILL ruin the bolt head. I generally take a hex bit, put it in the bolt head, and hit it a couple of times with a big hammer. This cracks the corrosion that will be preventing the bolt from turning. Bolt then comes out easily, I have found. HTH, Nigel Link to comment Share on other sites More sharing options...
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