How do you remove rounded off exhaust nuts?

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I'll throw my sheckles in this pot.

 

I know you don't want to hear about how many years ...yada yada yada

 

but I cut my teeth on British cars and their rust beats the tar

out of Roo rust

- many of their bolts are fine thread (no not "T"witworth - those are just on plumbing parts)

and

their nut to stud tolerance is so loose that rust works it's way

deep.

 

First a propane/mapp gas torch ain't gonna cut it!

get a "proper" ox-cetelen blue tip hot wrench.

 

Clean the rust off the exposed stud with a wire brush

(I have a small "toothbrush" size I use, but one on a Dremmel works better)

 

Concentrate

at the junction between the stud and the nut

I use a scratch awl or small bladed screw driver here.

 

reason: if this rust ring is not cleaned off - as soon as the nut turns, it

captures this rust ring under the nut and can gaul it to the point of thread destruction. - WORD.

 

next heat the nut to cherry red - it must be cherry red

Propane/mapp is not hot enough for this.

 

Get your six point on it and turn CLOCKWISE first for an eighth - quarter turn - say what?? That's tighter you say??

 

Yes this act will break the rust ring mentioned earlier.

 

 

Now clean again if ness, reheat and have at it

lefty lucy.

 

BTW: If you hear

a "creaking" noise - stop and reheat.

That is the sound

you will hear before "bing AWchit!!"

if you keep turning said fastener.

 

Hope this helps, but doubt it will.

[idosubaru]

well i got one off, the one that i was focusing on. i attempted to weld a larger nut to it and the weld broke off. but the bolt easily came out after hammering a socket over what was left. turned right out. i suspect the heating from welding probably helped it come out.

 

the next 3 came out with a 6 point socket.

 

now of course i have one left....it won't come out at all. it's tucked in there tight. welded a nut to it, 6 point socket...i'll have to try something else.

[joostvdw]

well i got one off, the one that i was focusing on. i attempted to weld a larger nut to it and the weld broke off. but the bolt easily came out after hammering a socket over what was left. turned right out. i suspect the heating from welding probably helped it come out.

 

the next 3 came out with a 6 point socket.

 

now of course i have one left....it won't come out at all. it's tucked in there tight. welded a nut to it, 6 point socket...i'll have to try something else.

 

tried to weld a round bar to it?

[idosubaru]

actually joost, that was the first thing i did. seemed like the best solution. couldn't get much room to weld based on my skills, my welder, thickness of the rod, limited room, angle to get it up in there...the weld didn't hold and it was being cumbersome. it was sticking down as much as it was out, no way to get close to a 90 degree rod on it for good torque.

 

the newest (and last) monster bolt i have to face is the drivers side tucked in the back by the motor mounts, no way i'll get a good angle or weld back in there...i don't think so anyway, but i'll look again. i think i'm going to drill this one before i mangle the snot out of it like i did the other.

[idosubaru]

tried to weld a round bar to it?

 

well now that the nuts are off and the engine is out i have 4 exhaust studs to remove. they are not friendly. i welded a steel round bar to the existing studs...even with all that heat and cooling...the stud didn't budge, it just sheared off right next to the engine. since the metal is just shearing off even at the engine it's obvious this thing is not coming out.

 

looks like nowhere locally carries left handed titanium bits. i can order, but can only get right hand titanium bits locally.

[daeron]

have you tried a proper stud puller? the type used on the end of a ratchet? you can use the cheap "pipe-wrench action" ones (that is how I think of them anyhow) since the motor is out... you *did* pull this one, or am I wrong on that? Pipe wrench, and try immobilizing it on a sheet of plywood with a pair of 2x4s screwed down hugging the head?

 

I mean, how "apart" is this engine coming, after all? I am just trying to brainstorm ways for you to avoid needing to order the drill bit, thats all.

[idosubaru]

yep, motor is out. i don't think they'll come out with any type of tool or equipment from the remaining stud that's outside the engine. if a welded on rod just sheared the bolt off, even after heating and cooling...the torque to remove the stud is more than the force required to shear it. so i think no matter what, the stud is just going to shear.

 

i'm not sure what stud pullers are, but if they require any threads that's not going to work either. too rusted and weak, the threads just tear up easily...or they really aren't even there. and the first one i've been working on is all mangled. i was putting some serious grunt in it with a large pipe wrench (i think that's what it's called, one of those plumbers tools?)...anyway, it just shredded the metal like a cheese grater once i really put some stank in it. even after grinding all the rust off and getting to clear shiney metal, it still crumbled under the force of the pipe wrench and never turned at all.

 

i'm working on it tonight or tomorrow morning, i'll be trying the drill bits.

[daeron]

well, FWIW i had a post earlier in the thread with some links to the stud pullers.. they dont require threads, per se.. but your comment about the shear strength vs torque required to remove them is still PROBABLY applicable. they wouldnt "eat" the studs quite as easily as a pipe wrench would.. but it is probably irrelevant.

 

Good luck with the drill bits.