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The front radial arm bushing post/bracket that the bushing goes around is cracked on left and right side where it connects to the bus I have welded it before but the cracks are back. what would be causing these stress cracks?

Hey Chart,

Maybe as simple as a defective casting! ??

How is your alignment? Does it stay straight or pull?

You could call Luke at US Coach and ask if he has crossed this path before!

Good Luck
Nick-

It drives straight.

Does it crack in the weldment itself, or beside the weld?  I just went out and looked at my bus, which is the same, the lower radius arm is basically captured on a tube that extends through the post from side to side.  The uppers I couldn't see clearly.  If it broke it's going to have been simple fatigue, most likely, all front end braking loads go through those posts, as well as some suspension control loads and steering loads, but not much of those two.  If it cracked again, put it down to a faulty weld with insufficient penetration or HAZ control.  It's probably just plain mild steel, from the rust I see on mine.  Once something under cyclic loads cracks it's actually quite hard to repair without replacing so I wouldn't feel bad about your welding  :).  Also - where exactly is your crack located?

Brian

Nope not going there never mind. :o