E30 stuck broken bolt but i mean stuck!!

[Obito22]

So I was removing the subframe on my E30 to swap it out for a reinforced subframe and everything went well except for one small thing, the subframe mounting bolts , to be specific the one next to the sway bar mount broke. The broken bolt is inside the metal so I can’t welt a nut to it because the space is very limited, I already tired a left handed drill bit , bolt extractor but it just ended up breaking the tip inside the hole I drilled , and I tried to weld the other half of the bolt on to see if that would somehow work but I couldn’t even do that because the opening is just too small . I have tried everything I even made sure to torch it but nothing is working, what’s making it difficult is that the bolt flange is inside and not flush . At this point I don’t know what to do , should I just cut that little square of metal out and weld in a “new” from my part out E30 or possibly even just drilling a hole the same size and make the opening bigger for a bigger bolt but I know that’s not right but I’m stuck I’ve tried everything!

any ideas or suggestions, has anyone faced the same problem?

[82eye]

i've drilled out bolts before and ran a tap to clear the threads. finnicky work and it can make things worse if it goes wrong. you have to drill it in stages and take it to the threads, then pick the edge of the bolt remains from the threads. that bolt is actually inside a sleeve in the frame.

[moatilliatta]

Flux core welder may not help. You might be able to find socket that will fit in the hole, put the square drive in towards the broken bolt and try to use shielded gas welder to fill weld the inside of the hex into broken stud.. Then use a Allen key hex driver to loosen the socket that is welded to the stud. Possibly 3/8 drive 19MM one that gives your some error room for filling the square up with weld to the stud.

[Obito22]

That actually sounds like a good idea with the socket the other way around I’ll probably try that and if not I’ll probably have to try what 82eye said

[gone002]

heat is your friend...get a torch and heat the bich up!

[Obito22]

gone002 how long would I be heating for ? lol

[Bimmermaven]

you have some melted metal lying around...use a drill about 1/8 inch (3 mm) larger than the bolt diameter to clean it up.

then get some copper pipe with OD similar to bolt. use this as a sleeve and weld inside the pipe. once you've filled the pipe....above surface of frame, put a nut on top and weld it. spray nut and welded stud with water too cool and shrink relative to frame. box wrench to work it back and forth.

watch video first for general idea.

https://m.youtube.com/watch?v=-8N0y0jVAng

[varg]

I have never been successful welding to a broken bolt with my fluxcore welder, and I hope I don't have to try it again with my TIG. I am not a certified welder or anything, but it seems to me that with the bolt down in a hole the flux core is working against you, vaporizing an causing the metal to spew everywhere and not penetrate. If you do short pulses at higher amperage followed by cleaning you may get a better weld. Good luck.

[hopeful]

i've drilled out bolts before and ran a tap to clear the threads. finnicky work and it can make things worse if it goes wrong. you have to drill it in stages and take it to the threads, then pick the edge of the bolt remains from the threads. that bolt is actually inside a sleeve in the frame.

Every broken bolt usually has 1 of the many different ways to extract a broken bolt that are more suitable and likely to have a higher chance of success. In my opinion, in this scenario, this is it. Difficult, requires some skill and multiples of that in patience but I don't see a different way forward.

In hindsight, I should have just liked his post.

[Aleman]

I broke this same bolt on the front subframe. Rookie mistake - I got a long-ass breaker bar and started pulling with everything I had. Bolt head snapped off, ugh! After screwing around with a dozen back-out tools, ended up taking the car to my local indie shop. They drilled it out and put in a new bolt. Lesson learned: Use an impact wrench on stuck bolts vs. brute pulling force. Thinking back on it, some of the back-out tools would have probably also worked better with an impact wrench.

[gone002]

gone002 how long would I be heating for ? lol

not that long. the two dissimilar metals cool at different rates. after being heat they almost undo them selves. id say dont get it cherry hot. but when u spit on it , it should sizzle.....lol

[82eye]

you have some melted metal lying around...use a drill about 1/8 inch (3 mm) larger than the bolt diameter to clean it up.

then get some copper pipe with OD similar to bolt. use this as a sleeve and weld inside the pipe. once you've filled the pipe....above surface of frame, put a nut on top and weld it. spray nut and welded stud with water too cool and shrink relative to frame. box wrench to work it back and forth.

watch video first for general idea.

https://m.youtube.com/watch?v=-8N0y0jVAng

i like this but it probably won't work so well as the bolt is upside down.

[Bimmermaven]

<<the bolt is upside down>>

"Welders do it in all positions."

[82eye]

<<the bolt is upside down>>

"Welders do it in all positions."

shielding gas is heavier than air and would drop complicating the pre-gas. copper isn't magnetic and a piece of copper pipe would not stay in that position upside down. i'd honestly try tape it lol. the tape would burn off but i could probably get enough in there to have it hold. i do know how to weld. welding upside down sucks no matter what.