Tack Welding Ball Joints - Best Approach?

[abboq]

Hello. Nearing 200,000 miles on my truck, I needed new ball joints all the way around. Three installed perfectly, but my left upper ball joint wants to pop out. That ball joint's upper control arm's flange is bent, possibly from the removal of the stock ball joint. They were horribly corroded and took a lot of pressure to remove. The ball joint is popping out because the bent flange isn't gripping it well enough.

I don't want to buy a new control arm; they're too expensive. Instead, I want to tack weld the ball joint into the existing arm to hold it in place. The trouble is that I'm no welding expert, and what little experience I have was learned a long time ago. A friend of mine offered to loan me his little ARC welder.

My question is: Would we be able to tack that ball joint to the upper control arm with the ARC welder? Or, do I need to get ahold of a MIG welder?

There's a ninety degree angle where the arm and the joint's lip meet, and I just need to run a couple of beads around it. Obviously, I need a fairly strong joint.

Thanks in advance for any help ya'll can provide.

[astroracer]

Don't do it... The amount of heat you throw into the joint will have a bad affect on the hardened components in the ball joint. The seat especially.
You can pick up a good used arm at a 'yard for fairly cheap. This fix just isn't worth the danger you will be putting yourself, your passengers and anybody on the road next to you into...

[abboq]

I've checked the local yards twice this weekend, and they didn't have any suitable donors. Ordering an arm from a parts supplier will cost me roughly $300.

I appreciate your safety concerns, astroracer, but many vehicles come from the factory with ball joints tack welded in place. And, as far as heat issues, many mechanics remove ball joints without a press by heating the surrounding control arms with a torch until they are red hot and popping the joints out with a hammer (I didn't use this particular method, I used a huge ball joint press). Both Haynes and Chilton manuals outline these methods as being perfectly acceptable.

You're welcome to disagree with me. I'm not trying to argue, but I don't think three tack welds are going to weaken the upper control arm on my truck.

[mike@af]

The hardening is a few millimeters deep. When heated with an Oxytorch this does tamper with the hardening because it is rearranging molecules. A tack weld isnt going to hold it. It would need a full bead around.

How good at welding are you? Can you get a deep enough penetration all the way around? You said you have little experience, and an arc welder. To get good arc welds you have to have mastered it because they are inconsistent and often change penetration. I'd MIG weld it if I had to. Being that you dont have much experience either get a new part, or have an experienced welder weld it.

[TheSilentChamber]

Dont weld it, its a bad idea. Look around online and find you a control arm, should be able to pick one up on ebay cheep.

[abboq]

Well, I called a very trusted local mechanic today, and he welded the joint for $30 (he used a MIG welder). He wasn't surprised I had a ball joint popping. I was only able to get two joints made by Moog. The other two I had to go to Autozone for, and my mechanic informed me that they weren't nearly the quality of Moog.

I'm relieved to have this project done. And I'm glad I didn't try to relearn welding and finish this project in the same day. I'll get back to welding when I can take it at my own pace without the pressure of finishing a work vehicle.

Thank you all for your help and your expertise. I really appreciate it.

[curtis73]

If you do it properly, there is no heat intrusion into the joint itself. I make it a habit to tack in my press-fit ball joints, but I'm not sure what kind of truck you have. All of the ones I've tacked were GM and they have a generous flange.