Would you trust a MIG weld to hold a pitman arm together?

I recently converted my 59 El Camino to power steering from manual with a 605 steering box. The box I got was supposed to work with my stock manual pitman arm and center link, but for some reason my stock pitman arm was not lining up correctly and was too long. So to make a long story short my only solution was to take a one inch section out of the pitman arm and weld it back together. A buddy of mine used a MIG welder to weld it together. Its been a few days Ive been driving it now and so far so good. BUT a few of my other buddies say that its dangerous and I should have gas or arch welded it and that the MIG weld wont hold up. Coincidently there is an article in the current Car Kulture Deluxe about making your own custom pitman arm and using a MIG welder. Im a little worried and confused, whaddya guys think??

 

I would be fine with it if I welded it. I have no idea how good a welder your buddy is.

 

He's gone to school for it and has done it for quite some time.

 

I would not question the welding process, but rather the person who did it.
Mig welding is ok, with the right technique.

 

I'd say as long as it was a powerful machine and he penetrated the **** out of it you'd be ok. If it fails just hit the brakes, hopefully their 100%.

 

they are pretty thick if it was me i would tig it what kind of amps is his mig??

 

Welding is the act of melting metal together, regaurdless of the process.

If done right, any type of weld should be as strong as another. But that being said, Tig and O/A welding (Heli-Arch too?) are generally thought of as stronger welds... That's mainly because you have more control of the penetration with those processes.

So if your buddy is a really good Mig welder (with a top-notch machine), it might hold up.

The thing is, a welded pitman arm just doesn't give me warm fuzzys period. Any chance you could find a unmolested, heavy forged one that would work?

 

a friend of mine migs 'em but he's got an industrial mig.
heats 'em up, welds it, throws it in a bucket of floor dry (dry sand would work too) for a couple of days.
notice the "days" part....

he's NEVER had a problem and he's done a bunch.....

and has beeen said, how good is the guy welding?...

 

btw, i've got a leftover pitman from flaming river, 5 1/2-6" long with a 1" drop.
would that work for ya?
pm me with an e-mail addy and i'll send some pics iffn you want...

 

I'm in the camp with those that say it's more dependent on the base material, the filler material, and the welder rather than the welding process. Remember, also, a weld is a casting; forgings generally have better mechanical properties.

 

Good call...

Also this is a big heavy car with power steering... I don't think you want to cheap-out on arguably the most important part of you car... Next to the gas pedal.

 

I know a lot of people who weld them different ways, but i would seriously try to find an uncut and welded one if possible .A good friend of mine had the pitman arm nut come off of his 40 recently at about 65 mph.He went across the median on the freeway in the mud to the oncoming side before he got it stopped and nearly hit a semi.He said he saw his life flash before eyes,so think about it.

 

If done with good welding techniques and an experienced weldor it should be no problem. A stepped joint or slashed joint would be better than a straight cut.

Frank

 

Ahhh....NOPE! Sorry it isn't that simple. Gas welding just is NOT as strong as TIG welding - different process = different results.

You're gonna have to 'splain the difference between Tig and HeliArc because the last time I looked that was the same process. HeliArc simply being the outdated reference to the process - simply because in the beginning the shielding gas was Helium - where today there are several additional choices.

If I remember my welding cl*** days right - O/A was the weakest method - as direct result of the "lesser" quality shielding envelope.


For the origional post...... MIG is a rather dangerous process as it is easy to get a good looking weld and still have it substandard. I would venture to say if he ground on the welds at all - toss it!!

Otherwise post a pic - maybe some of the welding guru's can post their thoughts.

 

MIG is NOT as strong of a weld as TIG. Stop and think about the processes involved in each, as well as the properties and characteristics of metal, and it becomes clear.

TIG is a slower process, involves a longer and hotter arc, ultimately bringing the piece to a higher temp over a more extended period of time. Of course, the user's ability to visually make adjustments in wire feed and current generally make for a sturdier weld.

MIG is faster, but involves a much more rapid heating and cooling of the metal, which often shocks the molecular structure of the piece and causes it to be more brittle.

Regardless of the process, I would pre heat the piece with an O/A torch, allowing it to get up to temperature over a few minutes, then TIG it with a hot arc and ensure good penetration, then with the O/A torch, continue to hold a flame on it to allow it to come back down to a lower temp gradually. Allowing the metal to "normalize" minimizes the shock done to the molecular structure of the piece, and can help eliminate heat affected zones, which are the areas directly around the weld which are subjected to the highest heat and are damaged from the weld itself. When a weld fails, it is often not the weld, but the area immediately around it.

Also, cast parts are never great to weld, as there are inhernet impurities in the metal from the casting process, which contaminate the weld and weaken it. forged/billet metals are always easier to weld largely for this reason.

Check into local fabrication shops to see if anyone does heat treating. It might be worth a few bucks to have your custom piece heat treated to ensure the strength you need on such a crucial component

 

Well my concern wasnt my buds welding skill, its the type of weld, as most of you know welding can be very technical,unfortunately im not that great of a welder and obviously dont know too much about the different processes of it. So, the last thing I wanted to do is practice on a pitman arm. I think im going to take it off, inspect it closely and maybe have it arch welded so I feel safer, not shure yet. I appreciate all the info so far!

 

sounds like you got the box mounted in the wrong place somehow? should not affect the length of the pitman arm if you put the 605 box in the same place the stock box was.

 

I did, there is only one way the box goes on with the bracket I got. The only possibility of why I think it wasnt lining up is the fact there has been 2 coils snipped out of the springs. But even then I thought it should still line up, im confused.

 

I have done several dozen pitman arms over the years, MIG welded with no problem. I raced and built IMCA modified circle track cars that used '64-'72 Chevelle front clips, and the power steering pitman arms were very hard to find, so I would shorten the '70-'81 Camaro/Firebird arms to the Chevelle length. With at least a 200 amp machine, and a nice beveling of the pieces, there will not be a problem.

 

are your pitman arm and idler arm the same length now? take some pics of your car up on a lift if you can.

 

I've done some destructive testing on my own MIG and Arc welding on s**** forgings.- 50s Ford Truck axle. Used blade hydralics on an 850 Case dozer to break the samples.. The worst was a good looking high heat weld on cold metal with a MIG.. The side next to the weld was crystalized.. The best was arc fillit welding on a forging, heated black hot and slow cooled.. Bent -No break-- Well almost no break.. Broke my hand releasing the axle from the rig.. Had built up some spring tension I didn't expect..PA

 

was your box off a wreaked car?
i've seen twisted shafts on some that wern't obvious... and the splines wouldn't come close to where they needed to be without a box replacement...

 

Nope the box is brand new,thanks anyway.

 

Take it off the car and get it magnafluxed. That will show you whether the weld has good penetration.

 

what makes you so sure the bracket was properly designed? gotta beware of the parts you buy, some of them are just made or designed wrong. or they fit a different year car just right, and someone ***umed they would also fit your car, but they don't.

 

Thats possible but I doubt it.

 

if done properly no weld is stronger than another...NOTE: IF DONE PROPERLY!!!

 

I like chicken

 

huh....I'd think that if I had to modify the pitman arm that is supposed to work as is, then the "kit" might not be designed properly.

 

I wholeheartedly...disagree. Sorry.

Especially when it comes to suspension parts. You would be amazed at the metallurgy behind the different welding methods/materials. TIG/MIG/GAS...they all have their strengths/downfalls, escpecially depending on the material being welded.

In this case...with suspension stuff...I dunno. I wouldn't feel safe based on what he's described.

And for the record, I prefer Beef.