Head bolt snapped off
Discussion
Is it sheared off flush with or even inside the block? I would think about replacing all of them. Are they bolts that are not supposed be reused?
Given the collateral damage of buggering up the removal of the broken bit you may wish to bring the block to a machine shop. Having said that the lack of tension on the broken bit might make it easier to remove than you might think. Try drilling into the head of the loose bit to see how hard it is.
Given the collateral damage of buggering up the removal of the broken bit you may wish to bring the block to a machine shop. Having said that the lack of tension on the broken bit might make it easier to remove than you might think. Try drilling into the head of the loose bit to see how hard it is.
There are few ways to try and sort this and the "easyout" option (reverse thread extractor) would be one of the last in my list as they aren't great unless you splash out on professional quality ones. You just end up drilling the hole, wind in the extractor and then the extractor snaps off leaving a lovely hardened steel insert in the middle of the broken bolt. Been there, done that and the T-shirt is not nice. If the stud is flush with the this is often the only way to get them out though.
Some suggestions (all assuming there is some of the stud above the block surface):
Stud extractor (although I have yet to find a decent one).
Irwin make a nice set of bolt extractors, worth their weight in gold.
As mentioned you can weld a nut onto the top of the remaining stud, often just the act of grinding the stud flat and welding onto the end of the stud loosens it due to the heat and the "burning" of the high resistance corroded threads.
Cut a slot in the top of the stud to take a screwdriver. Again the heat and vibration from the cutting action can help loosen it. Use a screwdriver bit in a ratchet to give more torque. It may seem mad but if it won't undo try tightening it slightly, you just need to break the corrosion, once moved in either direction it should undo. You could also try an impact screwdriver (depending on what the block is made from).
If this doesn't work and you have the room without burning anything try heating the block around the stud so it expands loosening the stud, just use an ordinary blow lamp and don't go mad.
I have yet to have a bolt, broken or otherwise defeat me, heat works 99.9% of the time and is often the kindest option rather than forcing something and chewing it up or striping threads.
Some suggestions (all assuming there is some of the stud above the block surface):
Stud extractor (although I have yet to find a decent one).
Irwin make a nice set of bolt extractors, worth their weight in gold.
As mentioned you can weld a nut onto the top of the remaining stud, often just the act of grinding the stud flat and welding onto the end of the stud loosens it due to the heat and the "burning" of the high resistance corroded threads.
Cut a slot in the top of the stud to take a screwdriver. Again the heat and vibration from the cutting action can help loosen it. Use a screwdriver bit in a ratchet to give more torque. It may seem mad but if it won't undo try tightening it slightly, you just need to break the corrosion, once moved in either direction it should undo. You could also try an impact screwdriver (depending on what the block is made from).
If this doesn't work and you have the room without burning anything try heating the block around the stud so it expands loosening the stud, just use an ordinary blow lamp and don't go mad.
I have yet to have a bolt, broken or otherwise defeat me, heat works 99.9% of the time and is often the kindest option rather than forcing something and chewing it up or striping threads.
MPETT said:
the torx ridges have sheeted off leaving the flange oh the head therefore retaining the head. I'll try drilling as grinding may damage the head and access is tight!
Missed this bit.If that's the case I would drill out the flange, just concentrate on getting the head off to start with instead of removing the bolt. With the head out of the way you will have more of the bolt to grapple with.
I think it is fair to say I had a bad night last night! I was so angry with myself I couldn't find the an appropriate swear word. Firstly I fitted my gearbox to the engine and in doing so accodentlu trapped the chain I was using to lift the engine and broke off a gearbox mount/engine lifting point
it's repairable but what a stupid thing to do! Then tried to remove the bolt by welding a nut onto it. 3rd time lucky! Unfortunatley another bolts head sheeted off again and this one will not weld. It's almost like it is negativley charge and won't take the weld! I'm going to get a auto mobile welder round and let him sort it. Grrr thinks can only get better!
it's repairable but what a stupid thing to do! Then tried to remove the bolt by welding a nut onto it. 3rd time lucky! Unfortunatley another bolts head sheeted off again and this one will not weld. It's almost like it is negativley charge and won't take the weld! I'm going to get a auto mobile welder round and let him sort it. Grrr thinks can only get better!Those bolts must be pretty crappy quality, I've never had a torx type bolt fail in any way, and that includes the head bolts on an old Opel that I had to use a length of scaffolding on a breaker bar to shift!!
Unlucky on trapping that chain, I think most of us have damaged something by doing something silly at one point or another.
Whilst it is really, really annoying, best to take the view that if it only resulted in damage to what you're working on and not missing fingers or worse, then it isn't too bad really!!
Take a day or two off, chill and then have another go..
Unlucky on trapping that chain, I think most of us have damaged something by doing something silly at one point or another.
Whilst it is really, really annoying, best to take the view that if it only resulted in damage to what you're working on and not missing fingers or worse, then it isn't too bad really!!
Take a day or two off, chill and then have another go..
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