Sheared a bolt...
Discussion
Hi all,
Just taking the interior apart so that I can replace the carpets and I've come up against some resistance on the seatbelt bolts. I've got all off but one but annoyingly I managed to shear off the last one after it put up a huge fight. The offending bolt is on the passenger side down on the door sill (the bottom left anchor). I've looked under the car and it appears to bolt straight into the outrigger so I can't get to it from the other side. I'm not sure how I should go about removing it though. There isn't really enough thread left to attach a nut so as far as I can work out, the only way to get it out would be to drill it. Is this correct? If so, whats the best way of approaching it? Is it just a case of drilling bigger and bigger holes into the bolt until it can be collapsed? And would I be able to do it or would I be better off taking it to a professional being that it is a pretty important bolt?!
Just taking the interior apart so that I can replace the carpets and I've come up against some resistance on the seatbelt bolts. I've got all off but one but annoyingly I managed to shear off the last one after it put up a huge fight. The offending bolt is on the passenger side down on the door sill (the bottom left anchor). I've looked under the car and it appears to bolt straight into the outrigger so I can't get to it from the other side. I'm not sure how I should go about removing it though. There isn't really enough thread left to attach a nut so as far as I can work out, the only way to get it out would be to drill it. Is this correct? If so, whats the best way of approaching it? Is it just a case of drilling bigger and bigger holes into the bolt until it can be collapsed? And would I be able to do it or would I be better off taking it to a professional being that it is a pretty important bolt?!
Before going too far and doing any more harm I'd see if a local engineering shop can get it out with a spark eroder. Some may suggest using tapered extractors but they are hardened and will most likely exacerbate the situation in this case if you're not expert at using them.
The reason I suggest this approach is that the thread is obviously seized along the length of the thread and it will be very tight. It's already proved it can shear 7/16" of HT steel!
The reason I suggest this approach is that the thread is obviously seized along the length of the thread and it will be very tight. It's already proved it can shear 7/16" of HT steel!
Thanks guys, sounds like an engineering shop would be my best bet then. I'll give them a ring tomorrow and see if they can help. Yeah it is a rather big bolt so I'm surprise I was able to shear it in the first place! The other side had a fair bit of rust and stuff in it so it's probably siezed quite far up the thread. Bugger 
The seat belt anchors were the ones I was most afraid of when I took the body off. The other body bolts could be ground off from the underneath but if one of those goes it's goodbye Vienna.
Top tip for removing them, plenty of penetrating oil first then only turn them a fraction of a turn at a time then back them of as if you were tapping a thread. After each turn wait a short while. By waiting you prevent heat building up and the bolt expanding in the thread.
Invest in a 7/16th UNF first tap when you eventually get them out and run the thread through.
Top tip for removing them, plenty of penetrating oil first then only turn them a fraction of a turn at a time then back them of as if you were tapping a thread. After each turn wait a short while. By waiting you prevent heat building up and the bolt expanding in the thread.
Invest in a 7/16th UNF first tap when you eventually get them out and run the thread through.
Tried the penetrating oil and couldn't get the bolt to move at all. I started with a 1/2 inch driver socket which I couldn't move, so I went on to use a breaker bar which worked on the other side a treat but on the passenger side it just sheared the bolt with relative ease despite my best efforts to be gentle. I'll certainly clean up the threads and use some copper slip before putting it all back though...
HRG said:
The seat belt anchors were the ones I was most afraid of when I took the body off. The other body bolts could be ground off from the underneath but if one of those goes it's goodbye Vienna.
Top tip for removing them, plenty of penetrating oil first then only turn them a fraction of a turn at a time then back them of as if you were tapping a thread. After each turn wait a short while. By waiting you prevent heat building up and the bolt expanding in the thread.
Invest in a 7/16th UNF first tap when you eventually get them out and run the thread through.
Mmmm Copperslip!!!!!!!!!!!!Top tip for removing them, plenty of penetrating oil first then only turn them a fraction of a turn at a time then back them of as if you were tapping a thread. After each turn wait a short while. By waiting you prevent heat building up and the bolt expanding in the thread.
Invest in a 7/16th UNF first tap when you eventually get them out and run the thread through.
Can you get a nut welded on, the weld can be done inside the nut, so if there is any thread sticking out it should be achievable. The heat also helps break the 'threadlock'..
Dave
Quite possibly, there are about 2 threads sticking out so when I pull the carpet off there should be a bit more still to get a nut on and hopefully weld it in place. Its very close to the fibreglass though, would welding be safe to do that close? At any rate though I'll get the local engineering place to have a look at it as I really don't have the tools or the skill to do it and I don't want to end up making it worse!
Too late now for Nick but I'd always approach a fastener like that with plenty of penetrating fluid and then a measured attempt to tighten slightly before undoing. I've got lower seatbelt bolt that looks less than fantastic mysef so the proof will be in the pudding soon,
The welded nut technique seems favourite to remedy this one though. Good luck
The welded nut technique seems favourite to remedy this one though. Good luck
Cheers Gary, I should have been more careful really. It's such a fat bolt that I didn't really think about shearing it since the other one also took a lot of force to move but came out ok. If I were doing it again I would have probably tried some more penetrating fluid, a few taps of the hammer and maybe even some shock freeze spray I have from other difficult bolts along with a bit of working both ways with the socket. But nevermind hindsight is a wonderful thing!
Is yours running properly yet mate?
Is yours running properly yet mate?
thenick said:
Is yours running properly yet mate?
Properly? You mean at all! lolTonight's adventure in auto-frustration was establishing I had aligned the TW as I originally thought (thereby removing one possible reason for its current non-cooperation), finding and fixing a dodgy joint on the crank sensor plug pins (I'm hoping that's the culprit) and also having to fix a coolant leak into the passenger footwell that helpfully followed my slackening and retightening after rotating one of the heater circuit hoseclips to save the loom chafing where it runs against it....didn't think the runes were in favour of me pressing the button tonight so I'm gonna surprise the bugger first thing tomorrow morning when its unaware
HRG said:
Johno said:
'Easy out' . . . best option.
The devils spawn (for the reason above) IMO.
if its sheared the bolt already it will eat the easyout for breakfast,just out curiosity i tried both mine a while back in preparation for new carpets,the offside bolt is seized,i give it a squirt everytime i have it on the lift,cant bring myself to try it again yet
good luck,the welding a nut to the broken piece works well(does on exhaust manifolds in the workshop)
thenick said:
..there are about 2 threads sticking out so when I pull the carpet off there should be a bit more still to get a nut on and hopefully weld it in place. Its very close to the fibreglass though, would welding be safe to do that close?
Pity the usual plus1's didn't attempt to answer your question...When the carpet comes off, you may also find foam underneath that can be peeled away, you may well be able to get the complete nut on.
There is a sleeve/spacer between the thread & fibreglass IIRC which should dissipate the heat well enough, unless they turn up with a oxy/acet. lance
The nut should also shroud the heat as long as the weld is done on the end of the exposed thread IYSWIM.I'd give the spacer and the stub a damned good tap with punch & lump hammer before you start. I am told it is better to try & turn it out whilst hot & reweld if necessary, rather than allow the weld to cool it seems the heat on the seizure is a better attribute than the strength of the weld.
Dave
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