I'm not really sure... I replaced mine when I did my shocks/springs for the hell of it, but my old ones looked fine to me, very little difference.
It's basically a giant rubberized 'mount' with a bearing race and those three threaded pins.... I guess if there was a weak point it would be those pins?
I suppose if there was somehow some play between the mount and the nut on the shock piston, you'd hear it at some point?
are you hearing a banging or something?