colincagain Posted October 13, 2002 Share Posted October 13, 2002 OK folks - too much omph and not enough plus gas....broken bracket so undid rear bracket (one with the rubber mounting) and the bolt sheared with less than a ml showing outside the skin - cannot grip it to get it out; seat out and only way I can see to get at it is to peel up all the aluminium trim?????? anyone have a smarter idea? what will we find when we can see inside???? All contributions welcome while we calm down and eat roast chicken!!! Thanks Colin Link to comment Share on other sites More sharing options...
EFA Posted October 13, 2002 Share Posted October 13, 2002 Drill and stud extractor is the way to go. Fat Arn Visit the K2 RUM website See the Lotus Seven Club 4 Counties Area Website here Link to comment Share on other sites More sharing options...
scooby dooby doo Posted October 13, 2002 Share Posted October 13, 2002 there are many horror stories with stud extractors. If you do use one make sure its a very good one. else it will also shear and break and you'll be left with a very hard thing thats a nightmare to drill out. HOOPY Membership Number 4136 R706KGU Link to comment Share on other sites More sharing options...
Ronbo Posted October 13, 2002 Share Posted October 13, 2002 I agree with what the others have said about the stud extractor. That bracket must be a weak spot, as mine also broke about 6 months ago (rubber separated from the metal). Had to drive about 2 miles home holding the muffler at the heat shield with my left hand. Thankfully I have a LHD car! Link to comment Share on other sites More sharing options...
AMMO Posted October 13, 2002 Share Posted October 13, 2002 I would not use a stud extractor either. They are rubbish. Never have and never will own one. They will undo something that is loose if the head has sheared of due to overtightening. If the head of the bolt sheared off because the bolt is seized you can bet that the extractor will break as it is quite brittle. The only way to then get a broken stud extractor out is by spark erosion. Big pain in the bottom. I would drill it out. Dot punch the bolt and drill a pilot hole around 4 mm then for 5/16" UNF use something like a 6.5 or 7 mm drill. If you get it central enough you can sometimes re-tap and pick up un the old threads. You can also re-grind your drill so that it cuts anti-clockwise. Sometimes what happens is that with the heat the drill will actually unwind the broken bolt. To be realistic this vary rarely happens. If you screw it up and you go off-centre and you end up with a crescent section of bolt in the hole you can usually get this out with a variety of punches or chisels. You then have to drill and helicoil to restore the thread. Or drill and tap one size bigger (yuk). I have done lots of broken exhaust studs over the years and have developed a knack for doing this. If you take it steady and have someone line the drill up for you you should be OK. Make sure your drills are sharp. Good luck. AMMO Link to comment Share on other sites More sharing options...
Big Brother Posted October 13, 2002 Share Posted October 13, 2002 If the worst comes to the absolute worst - drill out the remains of the stud and keep going, drilling through the inner skin into the car. You can then use a normal bolt to hold the bracket with a nut securing it inside the car (down the side of the seat and out of sight) Last resort but effective Steve Se7en-Up! Less is more! Link to comment Share on other sites More sharing options...
colincagain Posted October 13, 2002 Author Share Posted October 13, 2002 hmmmm...thanks all...no one seems to think peeling up the aluminium trim is very smart .....shame as I have 10 rivet heads drilled off already....what is actually inside (then dinner was ready) ...is it a captured nut??? sounds like I should put the skin back and go for the nut and bolt solution if necessary... Link to comment Share on other sites More sharing options...
colincagain Posted October 13, 2002 Author Share Posted October 13, 2002 is there any risk of drilling through the chassis tube ???? or is the captive nut(??) in a lug above the chassis?? Link to comment Share on other sites More sharing options...
Andrew Walker Posted October 15, 2002 Share Posted October 15, 2002 Colin, are you the Colin Chapman in Latin America 🤔 Link to comment Share on other sites More sharing options...
c7heh Posted October 15, 2002 Share Posted October 15, 2002 I have just sheared an exhaust stud (wrong torque nos in the build manual (VX1.6))...tried mole grips, tried to file a flat on the 10 mm sticking out - still no luck, and have now ordered stud pullers from Frost's (at great expense). I over did the torque on the stud to 25lb foot - should have been 15lb foot on a 8mm nut ... Should I just have a go and hope with the stud pullers......or is there any prep I can do that will reduce the risk of a second shear - but this time flush with the head! Link to comment Share on other sites More sharing options...
elie boone Posted October 15, 2002 Share Posted October 15, 2002 First, always use grease on bolts witch have to go in a nut witch is welded to the chassis. If you suspect a bolt that will be difficult to undo because of rust try this : loosen the bolt 90° then turn it back 45° loosen again 90° then back 45° until u feel that it will undo easely this way you reduce the risk of breaking a rusty bolt. Link to comment Share on other sites More sharing options...
Paul McKenzie Posted October 15, 2002 Share Posted October 15, 2002 IMHO broken stud extraction is incredibly difficult unless you have the very best top quality tools and drills. If you're near the NW this guy can sort any problem: http://www.kevinmosshelicoiling.co.uk/ Paul Link to comment Share on other sites More sharing options...
Chelspeed Posted October 15, 2002 Share Posted October 15, 2002 All of these threaded bits, exhaust mount, seatbelt mounts, petty strut mount, roll cage mounts are the same. Arch make all of these mounts by taking a length (30mm or so) of threaded tube and brazing it inside or to the outside of one the chassis tubes. For the exhaust mount it's brazed inside the square tube which forms the bottom of the chassis. So yes it's open ended, yes you can drill right though it but thats not too elegant is it? OK for last resort though. Don't shear off a seat belt mount though, drill that out and the nut ends up on the outside, not big or clever..... I've got a photo of my chassis at Arch last winter after bead blasting and before powder coating and you can clearly see the seatbelt mounting tube and exhaust mount, they're very close. Drop me an email address if you want a copy. Link to comment Share on other sites More sharing options...
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