Welded control arm

today I was changing both of my curved lower control arms and both outter tie rod ends. The first side went smooth but once I jacked up the second side I found this....





That right. My control arm has one bolt welded on.

My question is can I drill this out safely? I cannot find anything online that says whats behind that hole. I already have the drill and tap ready just need to know how deep I can go.

I appologize for the poor quality of pictures. My cell was all I had handy.

The two bolts holding that arm are different sizes. From the picture, it looks like the smaller of the two. From what i can remember its about 2 inches, but maybe somebody who has their control arm unbolted can verify this.

Your best bet is to just cafefully drill the welded part until the arm is free, then use an extractor rather than damaging the original threads.

It is in fact the shorter one. Cuz I already removed the other one and it is longer. I plan on grinding the weld off to remove the arm. But if the remainder of the bolt is siezed I will have no choice but to drill.

Why not just take the bolt off on the otherwise an measure it?

Maybe my question wasnt clear enought. I know the size of bolt I need. Im just concerned with what is behind that hole. I want to know that I wont mess anything up when my drill breaks through the end of the siezed bolt.

Your going to find drilling through weld, into a hardened suspension bolt to be nearly impossible without fairly substantial tools (speed controlled drill, lots of good quality bits with an understanding how to sharpen them etc). Even well prepared, the odds are your going to get a bit sideways and chew up the arm, and or the body.

On a centered mill, I wind up crooked now and again. Doing it upside down under a car? Miserable for sure.

I wouldn't start this project without having backup transportation.

There's a pretty good chance what's happend is someone's got the bolt stuck going in, or out, and snapped the head of the bolt off, and filled whatever hole remained with weld. Those bolts in particular tend to get somewhat eaten by rust in the shank area. It's probably not removable even once the arms out of the way.

The weld could be 50 thou thick, or 2" of poured in rod/wire. It's also really not a terribly safe situation as it stands.

Under the arm, behind the 'hole' in the body is a semi captured nut. As there is a good chance there's a entirely un-repairable bolt stuck in, your options are probably going to wind up cutting a hole in the body to get in behind that nut so you can remove, and replace it.

And if your going that far, it might be easier just to slip a cut-off wheel between the arm and body to try and clip the bolt entirely and shift the effort into replacing that nut instead of trying to drill the weld off.

Miserable luck, anti-seize any remaining hardware once it's fixed so hopefully it won't happen in the future

Paul

Thanks for the advice Paul. But I was a lot luckier than I thought I would be. I took an angle grinder to the welds and ground it flush. Then took a pry bar to it and it came off fairly easy and to my supprise I found the rest of the bolt. I ground 2 flats on the bolt and and clamped the living hell out it with vise grips and I was able to screw it out. Of course with a little help of WD40.
I also replaces the bolts on both sides with new ones.

I was very prepared for drilling. I have a nice set of solid carbide drills that I "borrowed" from work; along with a tap and an air drill.

Holy crap that's damned lucky, and, a little scary. If you were able to 'grind off' the weld and the arm down down, it was really hanging on by very little.

Congratulations though, you probably just saved yourself a pile of work

Paul