Axle support - fatigue cracks

Fritzie

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Hello BMW Freunden,

Today I discovered some fatigue cracks in my front axle support. I discovered the cracks by visual inspection. After that I did some magnetic particle testing. Still the crack appears.

I believe that after all those year the forces due to braking activities, the reaction force will eventually cause fatigue cracking at that area.

So I TIG welded the crack and added some extra weld deposit in the corner.

Please find attached pictures.

Maybe it helps you with your restorations.

Fritzie
 

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I found cracks in this area as well. some low around the control arm connection, others high likely due to the stiff sway bar forces. I TIG welded the cracks and also added additional metal at the top where the sway bar bushing attaches. I went a little overboard.
20211118-rounded edges.jpg
 
Spare rear axle restoration which I bought long ago. After the chemical cleaning and light sand blasting I visual detected a “nice” crack. And some small one on the bracket for the differential. Changed the topic name to Fatigue Cracks
 

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Here in Germany, a car is not longer street legal when welding on the axle frames.

And with that long crack, I would replace the frame, legal or not.

Breiti
 
Here in Germany, a car is not longer street legal when welding on the axle frames.

And with that long crack, I would replace the frame, legal or not.

Breiti
Interesting; (and also my curious nature) How could they see it if you just weld the crack and grind it smooth?
Then after paint or power coat it's all just flat.
 
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You would have to know the right person to scarf and weld that crack correctly which would include a sort of “heat treating”. Otherwise it will just come right back.
 
Interesting; (and also my curious nature) How could they see it if you just weld the crack and grind it smooth?
Then after against or power coat it's all just flat.
Not to sound reckless, but that seems like a repairable condition. Careful prep, welding, heat treatment. Could be "like new" again. Maybe even stronger. I guess I am pretty "shade tree" with that comment. :D
 
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