Since breaking a left front a arm I have dropped the axle out twice now without popping a ball cup. I replaced the arm with a old one I had new in package from my b44.1 could it be that the new arms are stiffer with the reinforced webbing on the arm. Or just bad luck don't remember having too much trouble with old car. I will get the new arms when available but since its the same part # it's not that easy.