How would YOU fix this?

Did you take the one off the other side to make sure the tube is oriented correctly? I would remove the known good one and make a simple jig to make certain it's an exact copy. Shouldn't be hard at this point.

gumby (Forum Supporter) said:

Do not weld with a bolt in the tube. It will likely get stuck.

Will this be TIG'd? Is that control arm chromoly?

How do I know if it's chromoly? I'll be honest I never even considered that. It's a pretty thick wall.

I was just going to mig it.

lotusseven7 (Forum Supporter) said:

Did you take the one off the other side to make sure the tube is oriented correctly? I would remove the known good one and make a simple jig to make certain it's an exact copy. Shouldn't be hard at this point.

I'll measure the other side quick too, but before I cut this one up measured and marked the point on the hinge tube where the threaded portion "points".

Really if you boil it down you just need 2 linear measurements and a right angle to place the threaded tube correctly.

APEowner said:

I always weld them empty and run a tap in afterwards.

I think this is correct

In reply to Robbie (Forum Supporter) :

Realistically, that's going to get you pretty durn close.  1mm off this way or that can be taken up with the caster adjustment, if it's even off enough to warrant an adjustment in the first place.

Not sure I'm on board with the don't weld it up with a bolt in it crowd.

It's pretty standard practice when building link suspensions in the off road world, to use a bolt or sacrificial rod end, when welding threaded inserts into the end of a control arm to prevent distortion.

I'd slather some antiseize on the proper size bolt thread it in and weld it up.

Why would this be different?

In reply to bigdaddylee82 :

Size, maybe?  Larger tubes and larger threads less affected?

A bolt in there isn't going to prevent warpage in a physical sense, although maybe it could make it easier for heat to transfer evenly.  (Thinking out loud)

I still wouldn't do it.  And especially with anti seize.  That's nasty to begin with, and it turns into a vile, hateful tar after being heated.

My inclination would be no bolt.  I could see it seizing pretty hard.  If I were doing it I'd just chase it with a tap afterwards.

I wonder if a brass bolt or some other dissimilar material could be used?  Something that would not tend to readily gall.  Not sure about rates of thermal expansion, but that could be a factor as well.

Pure conjecture there.  Aka, I'm speaking out my ass.

bigdaddylee82 said:

Not sure I'm on board with the don't weld it up with a bolt in it crowd.

It's pretty standard practice when building link suspensions in the off road world, to use a bolt or sacrificial rod end, when welding threaded inserts into the end of a control arm to prevent distortion.

I'd slather some antiseize on the proper size bolt thread it in and weld it up.

Why would this be different?

A threaded insert in the end of a tube tends to have a little more meat to it in the welded area than this control arm does.  They're also welded around the circumference so the distortion from shrinkage is pretty consistent whereas the welds in this control arm are elliptical on each side and the distortion is going to be over many more threads.  Also, after having a sacrificial bolt stick in a threaded insert in the end of a tube.  I now weld them empty and run a tap in after.

Weld empty, tap after. APEowner's experience is similar to mine. 

Instead of watching the second half of Monday night football, I decided to get out to the shop and give this a shot.

Here's how I was lining it up. I drew those two marks before I fully removed the original tube. I know sight lines aren't perfect but you can do a pretty darn good job with your eyes. I was also impressed I was even able to take this picture!

Here's welded up. I'm not the best welder in the world, so I work in short beads.

Depaintified:

Repaintified:

All said and done, I think I'm 7 hours into this repair, give or take.

Good deal

I'd send it

Very nice job.  

Nice!  Good Job! 

I just remembered that there was some concern about the material that I had intended to comment on and never did.  Sorry about that.  Had I remembered I would have said that based on the existing welds and the application it's unlikely that it's 4130 but even if it was the new part is mild steel and you could weld it in using the MIG by using short beads to slowly (relatively speaking) bring the temperature up.

Thanks guys, I appreciate the help and feedback through this process. And I am happy with the end results so far!

In reply to APEowner :

My F500 (1994 KBS MK7) has chromoly front control arms, or at least my spares are based on the markings on them (bare metal, never painted).

Apexcarver said:

In reply to APEowner :

My F500 (1994 KBS MK7) has chromoly front control arms, or at least my spares are based on the markings on them (bare metal, never painted).

It's not unheard of