Pitman Arm

[Tim...Ok]

I'm not sure why I'm even asking this since so many things on these vehicles are home built..But one thing I'm not totally comfortable with for some reason is my Pitman arm..the steering box I'm using is off of an early 50's Chevy pickup, but i needed to shorten the pitman by about 2 inches..I cut it,tacked it back together for mockup, but haven't brought myself to weld it yet..I've got a 220 miller mig (250X) running .035 wire and I've probably ran it 3000+ hrs..never been scared of a welding job, but this one is buggin me for some reason..If anybody has welded one, a little encouragement would be appreciated..I think I need to just weld it, clean it up and get on with my life

thanks,
Tim

 

[Old Iron]

If it's a cast iron pitman arm you need to bevel the ends quite a ways back and almost all the way through then arc weld it with a rod designed for cast [
I've done a lot of spindle steering arms and all kinds of cast, never had a problem and it's not hard to do
If you're not comfortable with arc and cast take it to someone who is and see how they do it then you will know, that's how I learned 44 yrs ago
This is a place where you might not get a second chance to fix a mistake

Jim

 

[BigIrish]

I always thought pitman arms were forged steel - at least the Ford ones were.

If it makes you feel better, you could always weld it up, then weld a sleeve of tubing around it. I did that on a drag link I had to shorten. I did feel alot better about it after that.

 

[Tim...Ok]

I always thought pitman arms were forged steel - at least the Ford ones were.

If it makes you feel better, you could always weld it up, then weld a sleeve of tubing around it. I did that on a drag link I had to shorten. I did feel alot better about it after that.

I cut it on the chop saw and from what I can remember, it seemed like steel rather than cast iron..I thought about welding a "gusset" on the back side more or less out of sight..

 

[Torch]

cast iron has more carbon in larger formations than in steel which is why its harder to weld. if the carbon flakes align uniformly it is white cast which breaks on a line. if carbon flake is scattered it is grey cast which fractues out in a spder web of many cracks. low carbon cast iron is actually cast steel and while the grain hasnt been compressed and aligned with the shape of the product by forging, it is still steel. all welds must be ground back for penetration or you only have a surface weld.


preheat and after welding cover with sand to force a slow cool. read up on hydrogen embrittlement and temper. if in doubt after welding get an xray inspection of the part.

 

[donsrods]

The one on my 27 is a shorted and modified 56 Ford pickup arm. It originally had that ball socket end on it and I wanted a tie rod end, so I took it to an extremely good welder that used to have a shop here years ago and he tapered both cutoff ends and built that area back up with mig welding. When I got it back from him it was as if there was never any welding done there and I sent it right off and had it chromed. It has been on the car for over 20 years with no problems at all.

If the welder knows his stuff and uses the proper machine it will be fine, but there is no way I would trust my welding on something so important. One thing you might consider doing is preheating both halves with a torch then welding it. We find we get deeper, stronger welds on thick stuff if we heat it cherry red first with a torch and then the welder bites into the metal better. Just a thought.


Don

 

[rainman]

Take a good hard look at the spindle arms on the spindles!!
There usually not nearly as significant in size as the pitman arm!
They are subjected to basicly the same stress as the pitman!!
Does that make you feel better?

 

[Old Iron]

Honestly, I've never really considered what a pitman arm was made out of.
I've only replaced two from a wreck. So I learned something today, thanks

Jim

 

[Tim...Ok]

Thanks for the replies fellas, I do feel more comfy about it now..I had already beveled it out to probably 3/4" wide before I tacked it.. I"m gonna heat it cherry red and go for it..I'll make sure and post pics in my build thread when I get it done..

thanks again,
Tim

 

[Ricks Garage]

I shorted my 50 Chevy truck pitman arm. However I used my arc welder. The arm is STEEL. I beveled the edges and laid down LAYERS of weld. I cleaned and sandblasted each layer to removed any slag. I did not gussset it or add any bracing. I did hit it with a sledge hammer to test it. There are no pin holes or marks were it was welded after it was finished ground.

 

[Tim...Ok]

I shorted my 50 Chevy truck pitman arm. However I used my arc welder. The arm is STEEL. I beveled the edges and laid down LAYERS of weld. I cleaned and sandblasted each layer to removed any slag. I did not gussset it or add any bracing. I did hit it with a sledge hammer to test it. There are no pin holes or marks were it was welded after it was finished ground.

Thanks Rick, same steering box, same pitman..Thats helps alot, I feel a lot more confident knowing that same arm has been welded with good results..

thanks again,
Tim

 

[Willowbilly3]

I think almost every piece of my steering and axle have been modified and welded. Even my tie rod but I did slide a piece inside of it at the juncture. On the pitman/steering arms you want to bevel them back so you have a solid place where it is welded, not a butt joint with any gap left inside. Also remember that a lot of the strength is in the surface. I always weld enough extra so I can grind down the welds and finish it with the flap wheel disc on the grinder to almost a mirror finish. If you leave any edges of welds or undercuts the joint will be compromised.
If you do it right you shouldn't need any ugly stuff like sleeves or gussets.
Also, and this is a point of opinion, I never weld structural things that are safety related using a wire feed. I use only a good DC stick welder with 7018 rod. Professional welders I know follow the same practice and tell me the wire feed welds are more brittle.

 

[Torch]

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http://www.weldingtipsandtricks.com/tillman-welding-gloves-tigfinger.html

http://www.thefabricator.com/

one of (my) authorities on welds

http://www.weldreality.com/default2.htm

 

[Torch]

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