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A-arm welding

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Morris

Morris

Yoda
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I have a practically new a-arm that I will be using to replace a crapped out a-arm. The new a-arm does not have holes drilled for the sway bar. It will be soooooo much easier just to weld the sway bar bracket (or whatever you call that piece) to the a-arm. It also seems like it will be stronger and less likely to crack.

So does this sound like a bad idea?
 
Why not--as long as it is positioned correctly.

I do know, however, bolts are a little more guaranteed. I've had welds break in similar situations. I would install, mark, clamp, and drill.
 
Good golly! Drill the holes!

Don't be a DPO.
 
Awwwwwww. Trevor, I just wanted to know if it was a bad idea. The DPO comment was hitting below the belt.
 
Yes it is a bad idea. What are you going to do when the time comes to replace that A-arm. What if you decide to use a different type sway bar that needs a different mount?

Drill the holes!
 
There you go Morris. Drilling the holes is the way to go. Nice to always have the option to swap out parts and or upgrade!! /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
Morris said:
I have a practically new a-arm that I will be using to replace a crapped out a-arm. The new a-arm does not have holes drilled for the sway bar. It will be soooooo much easier just to weld the sway bar bracket (or whatever you call that piece) to the a-arm. It also seems like it will be stronger and less likely to crack.

So does this sound like a bad idea?
Click to expand...
I would not weld on the a arm, if you get it too hot you might screw up the swivel arm threaded bushings that are silver soldered onto the a arm.
 
I would never weld an A-arm unless I was also going to re-heat-treat it. The weld affected zone will lose its temper and will have a very great possibility of cracking. Am I going overboard? Hap, Frank?
Bill
 
I figured it was prolly a bad idea. That's the number one thing I use you guys for... to stop me from executing my bad ideas.

Anyway, it's all moot. When I put the "new" a-arm next to the old one to mark the position of the bracket, I learned that the new a-arm is about a .5" longer than the old.

I am pretty sure it came off a race car. Anybody know anything about longer a-arms?
 
No weld. Drill and use bolts.

Welding will not affect non-existant "heat treat" but might weaken the A-arm more than the three holes. Too many people assume things are "heat treated" when most things just aren't.

1/2" longer sounds like a few degrees positive camber, right? A few degrees of positive camber is good on race cars, no?
 
Absolutely DO NOT weld the a-arm, at least on a street car. It is illegal in Denmark. It produces h-a-zs Heat Affected Zones, especially in higher alloys, but also in low carbon steel. This is an area around the weld that contains martenzite and is very brittle and will crack, especially when affected with oscillating forces like for example where a sway bar would mount. (fatigue cracks)

Holes on the other hand have nice, relatively large radius roundings. They don't crack so easily.

This is much more pervailant on forged parts like the steering arms, but valid for all high load bearing structures in the suspension, like the A-arm.

https://en.wikipedia.org/wiki/Heat-affected_zone
 
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