Help needed - broken bolt in transmission housing

[pjb]

Folks, I've got a bolt sheared off in the transmission housing . How can I get this out???
Seems like easy-outs are the way to go, but I'm worried I'll stuff it up (never used them before).
Anyone got any advice?

[pjb]

PS: it's M10 x 25

[kbushnz]

Don't think you have much of a choice...

[T-Boon]

try an easy out, hopefully she`ll come out, othertwisee you will have to drill it out, and likeley retap it.

[benorange]

if it close to surface you could get a pice of 6mm flat bar and drill a 7mmish hole in it at one end then put hole over bolt and weld it to it leave to cool then turn it out.

[LR90NZ]

First make up a drilling guide that just fits into the hole with a small hole centred that you drill through to ensure you stay centred on the bolt.
Then use the easiout

[Crash bandicoot]

hold an m10 nut over it and fill the center with weld using a mig and a high heat it will help to expand the bolt. as it cools and contracts put a socket on the nut and undo., the weld wont stick to aluminium. but doesn't mean it wont melt it also so be careful.

[pruggerdore]

hold an m10 nut over it and fill the center with weld using a mig and a high heat it will help to expand the bolt. as it cools and contracts put a socket on the nut and undo., the weld wont stick to aluminium. but doesn't mean it wont melt it also so be careful.

this one be me. if the bolt broke trying to undo it? then an easy out wont want to know about it. if you broke it tightening it say I am a twit lol (we all been there ) but an eaziout may do it.

[Tarmac]

eazy outs are shit, find someone with a tig, it is similar to the common mig a washer on trick taken a step further.... you can put the tig tip out around 20mm and turn the gas up a bit if its going into a "pocket" the gas will stay where you point it build up the broken stud until proud then stick a bit of 6mm scrap or whatever is lying round,allow to cool, gently work with a nutfkr. If it breaks off stick it back on . The built up heat in the ally housing will cause it to expand ever so slightly more than the steel stud, will also burn off any locktite if its around

[Sadam_Husain]

x3 on the easy outs being shit if the bolt was tight enough to snap then it usually means you'll end up with a broken easy out snaped off in there as well , give it a quick go by all means but dont snap the easy out off then try the mig/tig method or drill most of the bolt out and clean the hole up with a 10mm tap

[Tarmac]

Nooo!!!!! stickin to my guns on this one. VERY few broken bolts are better off being attacked with an easy out first, this example is the best case for tig-ing up the head, ally housing / steel stud. Getting heat into it is the key. "If" it dosnt work you can drill it out and try those things I fkn hate and refuse to use it may take a few goes

I have also had conversations about left hand drills, the theory being if/when you drill close enough then the bit will bite and "wind out" the remaining thread. I have drilled out broken bolts that wernt blind and once they get thin enough the drill bites and winds it out of the thread ( so you end up with a thin sleeve of thread on the drill bit. Hope this makes sense to the grammer police

[slide]

Probably a big consideration re removal is to why bolt snapped.
If it got bound real tight in thread, then drill and tap is probably your only option...

Drilling hole through broken bolt/ stud can help to relieve tension and help make removal possible.
Heat will help heaps to due to alloys greater expansion than the steel stud.
Try easyout with caution- snapping one will leave you without a paddle up that creek....
I've never seen a broken stud that lefthand drills will remove that an easyout won't....

Sometimes winding stud in further, then oversize drilling or retapping initial thread section can get rid of damaged section allowing stud to wind out.
But depend on what tools you've got, and why it broke/how tight it is...
Cheers,
Nath

[Tarmac]

Probably a big consideration re removal is to why bolt snapped.
If it got bound real tight in thread, then drill and tap is probably your only option...

Drilling hole through broken bolt/ stud can help to relieve tension and help make removal possible.
Heat will help heaps to due to alloys greater expansion than the steel stud.
Try easyout with caution- snapping one will leave you without a paddle up that creek....
I've never seen a broken stud that lefthand drills will remove that an easyout won't....

Sometimes winding stud in further, then oversize drilling or retapping initial thread section can get rid of damaged section allowing stud to wind out.
But depend on what tools you've got, and why it broke/how tight it is...
Cheers,
Nath

Nup, tig up the head, if you were in CHCH I wld do it for free to show how well it works. May snap a few times, I wind out and in to free it up.. done this many times.

James

Also I havnt seen left hand drills, let alone used them but going by my exp I believe they wld be worth a try. Where did you get your LH drill bits to compare to eazyouts

[mudlva]

cant remember the crowds name but a engineering co in great south rd penrose sell them and all sorts of drills cutters taps and dies

very cool place to browse in but hard on the wallet

[pjb]

Thanks for the feedback fellas.

Not sure on the history of this bolt. Was replacing the trans mount, and discovered the bracket that bolts to the trans housing had one bolt missing completely, and the remaining one partially undone and seized! Took surprisingly little effort to break it off, so I'm guessing it had probably received quite a bit of damage from the bracket knocking around on it.

I don't have a welder handy, or any decent welding skills, so I've drilled out the stud ready for a #4 extractor. At least now I can get penetrating oil to both ends of the thread.

I've had the torch on it (for ages), but my torch is too feeble to get the stud anywhere near glowing - the housing gobbles up all the heat. Might try and find me something a bit more potent.

[slide]

Also I havnt seen left hand drills, let alone used them but going by my exp I believe they wld be worth a try. Where did you get your LH drill bits to compare to eazyouts

Wurth is where we got ours, seen them advertised in sulco catalogue too.
Stud has to be pretty free for them to work. Tig would be great idea. I don't have tig, but will mig on a nut if theres enough left outside of surface.

Not sure on the history of this bolt. Was replacing the trans mount, and discovered the bracket that bolts to the trans housing had one bolt missing completely, and the remaining one partially undone and seized! Took surprisingly little effort to break it off, so I'm guessing it had probably received quite a bit of damage from the bracket knocking around on it.

Sounds like it might have had a lot of load on it, and caused bolt thread to seize. Be prepared for a rethread job..

so I've drilled out the stud ready for a #4 extractor. At least now I can get penetrating oil to both ends of the thread.

That will help. And leave it to soak as long as you can.

my torch is too feeble to get the stud anywhere near glowing - the housing gobbles up all the heat.

You don't want stud glowing. Try get heat into housing and leave bolt cold. (cold bolt=small bolt, warm housing = large thread hole) Also heat will destroy edge of easyout.
Try not to hammer easyout in very hard also, as the taper potentially will expand stud, making thread jamb harder...
Worst come to worst, fit helicoil or tap out to a larger size

Nath

[T-Boon]

Howto !

A wild snapped stud appears:


Clinton uses 'Weld-a-nut' attack.


It's super effective:

[pjb]

Well, I've torqued an extractor as much as I dare - no movement. Not really surprised. Looks like the bolt might have bent inside the aluminium boss - the surface of the boss is slightly deformed.

Next up: drill out to the threads, finish with a dremel, then tap threads.

[Sadam_Husain]

Well, I've torqued an extractor as much as I dare - no movement. Not really surprised. Looks like the bolt might have bent inside the aluminium boss - the surface of the boss is slightly deformed.

Next up: drill out to the threads, finish with a dremel, then tap threads.

before you go drilling anything out oversize try drilling your M10 bolt out to 8.5-9.0mm drill size and see if you can get a M10 tap in there I usually find that cleans the remaining bolt out and your left with the origional thread.... got to get your drilling well centred though

[pjb]

A couple of hours with a carbide burr on the dremel and I was able to pick the threads out. Good result.

[Tarmac]

GD sht you got it in the end . coincidently we are adapting an old diezel to an older box at wk for a yacht aux. the bell had a broken mounting bolt in it and the other 3 were rusty. Tig it up to some 8mm plate let it cool over smoko and work it out with a 15" adjustable.