The big bang...theory?

[Cam]

I've posted this in my build thread as well, but i know my car doesn't really appeal to everyone so posting here for a better chance of a reply...

I've had a mysterious banging in my car for some time, after a looong and expensive search (replacing other parts) I've found the issue..







I am by no means a suspension expert, so I'd like some input on what would cause the upper control arm to do this?? I'd go and buy another and swap it over, but clearly there's a bigger issue??

Thanks in advance..