root Posted November 17, 2009 Share Posted November 17, 2009 Hi guys I have been changing the silencer & snapped the lower stud & have tried everything I can think of ( penetrating oil soak / heating around the stud with both oxy & propane /waxing / tapping to shock threads & no way will it budge with vice grips & I dont think easy outs will work I think its Bottomed ? ! There is less than centimetre of the stud sticking out so im thinking of filing it flat & drilling it out to completely then retapping, so what I would like to know is the best way to carry on like what drill size to start & what stages of sizes should I use the stud is only 5mm with a 2cm thread length with about 1cm left in the head so this is the maximum i can go in . Have any members done this any input would be greatly appreciated before I get started & drop another dangling spherical vital bit of my anatomy creers root Link to comment Share on other sites More sharing options...
KirriePete Posted November 17, 2009 Share Posted November 17, 2009 Been there, done that on Wee Arfur the XBR just a while ago. One step-by-step (with piccies) coming up: Before: It's best if you can take the head off so you can get a good angle with the drill - drilling in while squashed by the front wheel is never going to be fun. Cut the stud as flush to the head as possible (I used a Dremel with disc cutter), but leave a little bit sticking up so you can grab it later (if Lady Luck is on your side), then centre punch the top as near the middle as you can: Start drilling with a 2 or 2.5 mm drill bit, use lots of lubricant and take it steady. If you know the depth you need, mark the drill with some white insulting tape, so you know when to stop. Once the small drill has done it's work, swap with the next size up - I went 2,3,4,5,6 then 6.8 for an M8 stud: You'll probably find when you get to the 4 or 5mm drill that the remains of the thread will start to collapse in, you can get some tweezers/needle nose pliers and unwind it like a spring, if you're really lucky. If not, take it to 5mm then run a tap down to recut the thread - again, use lots of lube and take it steady - even if you do unwind the remains, it's a good idea to clean up the thread with a tap anyway, just be gentle. A quarter turn then back off, then another quarter and back off and so on is the way to go with taps (unless you're fond of trying to remove snapped off hardened steel from the hole). You should end up with: Then grab your new studs, give them a wipe-over with some copper grease and run them in: Seemples! Link to comment Share on other sites More sharing options...
ddrdsm Posted November 17, 2009 Share Posted November 17, 2009 Hi Another solution would be to drill the stud as described but try a reverse thread stud extractor first - normally as the extractor gets a grip it will start to turn the stud as it's taper increases in the drilled hole. Worth a try - eliminates staged drilling and re-tapping etc. Link to comment Share on other sites More sharing options...
root Posted November 17, 2009 Author Share Posted November 17, 2009 Been there, done that on Wee Arfur the XBR just a while ago. One step-by-step (with piccies) coming up: Before: It's best if you can take the head off so you can get a good angle with the drill - drilling in while squashed by the front wheel is never going to be fun. Cut the stud as flush to the head as possible (I used a Dremel with disc cutter), but leave a little bit sticking up so you can grab it later (if Lady Luck is on your side), then centre punch the top as near the middle as you can: Start drilling with a 2 or 2.5 mm drill bit, use lots of lubricant and take it steady. If you know the depth you need, mark the drill with some white insulting tape, so you know when to stop. Once the small drill has done it's work, swap with the next size up - I went 2,3,4,5,6 then 6.8 for an M8 stud: You'll probably find when you get to the 4 or 5mm drill that the remains of the thread will start to collapse in, you can get some tweezers/needle nose pliers and unwind it like a spring, if you're really lucky. If not, take it to 5mm then run a tap down to recut the thread - again, use lots of lube and take it steady - even if you do unwind the remains, it's a good idea to clean up the thread with a tap anyway, just be gentle. A quarter turn then back off, then another quarter and back off and so on is the way to go with taps (unless you're fond of trying to remove snapped off hardened steel from the hole). You should end up with: Then grab your new studs, give them a wipe-over with some copper grease and run them in: Seemples! Link to comment Share on other sites More sharing options...
root Posted November 17, 2009 Author Share Posted November 17, 2009 Cheers KP your pics very reassuring & well done on an excellent job ( hope my attempt is as good ? ) & im sure will be helpful to others I have tried a test run today on a same type these are only 5 mil studs in the vice & got through the length I need to do in about 4 hours with 2mil hss titanium coated bits & wd 40 lol ! I'll get cobalt drill bits & cutting oil before I try for real but leaving engine in with both wheels off & front end raised to a comfy sitting hight will take pics ive heard lager is a good coolant ? Thanks again cos I realy think easy out extractors are a good thing for certain jobs where the bolt isn't to tight & this one IS when they snap in the drill hole its double bad news ( very brittle ) CHEERS ROOT 3 days later success with the drilling method did it in the frame but would advise for easier access especialy with the tapping removing engine or head on this bike thanks for all the tips guys Link to comment Share on other sites More sharing options...
Moderator drewpy Posted November 17, 2009 Moderator Share Posted November 17, 2009 easier than the above, weld a large nut using an arc welder. the process turns the stud orange with the heat and when it cools, use a socket to unscrew. you can even do this in situ. I have done this on a few bikes and a classic car where the stud was flush in the ally head!! drewps Link to comment Share on other sites More sharing options...
ddrdsm Posted November 17, 2009 Share Posted November 17, 2009 Hi Again Don't tink it will snap - more likely the stud will wear which means you no worse off - try soaking in Plus Gas overnight. Link to comment Share on other sites More sharing options...
KirriePete Posted November 17, 2009 Share Posted November 17, 2009 Smaller bolt sizes and EZ-outs are never a good mix (for me, anyway) - as the taper moves in, the stud swells to accomodate it and gets forced further into the thread, which is why they have a reputation for snapping off. Larger stud sizes (M10 and up) suffer proportionately less from the swelling, so EZ-outs are a good option. Welding nuts on is an excellent option as long as (1) there's enough sticking up to weld onto, (2) you've got access to welding kit and (3) you know how to weld (or can wave a beer at someone who does). I can drill straight, but every time I've tried welding in the past .... no, it's too horrible to contemplate! Good luck with doing it (whichever option 'it' is) in situ, root - pics of the lager-cooled drilling rig would be good. You're welcome. Link to comment Share on other sites More sharing options...
root Posted November 17, 2009 Author Share Posted November 17, 2009 THANK You guys these are all great great solutions & will all work one way or another but as I said I soaked it for a few days used the heat & got a good purchase with the vice grips I dont think I would get any more torque with ez extractor & it was going nowhere , The same with nut welding on a 5mil stud if it snaps again flush there will be nothing to grab hold of after drilling plus I can't weld ! Also if it has bottomed wich I think it has there is the added friction of the stud end against the bottom of the thread well so ive found out its better to refit with a washer to stop this happenimg again & copper grease , So ive ordered cobalt drills & going with that I think I may take the lump out & do it on the bench but not taking the head off I dont like to disturb them + gasket prices ! These tips will help more than me out & are greatly recieved will let you know how I make out wish me luck & cheers again root Link to comment Share on other sites More sharing options...
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