33326767748 ball joint, what does it connect?
 

Hi, I have been told that I need replacement ball joints (33326767748) as well as the wishbones ( I think these are also called control arms)?

I have found the part on real oem but it is not clear on the diagram what the part does, what parts it joins together.

Hope someone can shed some light on it.

Thanks

It connects to the part #1 in that diagram,which is a rear wheel hub,correct me if I am wrong.

http://realoem.com/bmw/diagrams/q/e/230.png

The ball joint connects #1, the wheel carrier, to #15, the swingarm. The outboard side of the swingarm connects to the wheel carrier there and through #4, the integral link. The bolt goes through the tab on the swingarm, then through the ball joint, through the tube of the integral link, then through the other tab on the swingarm. The integral link provides some flex, which allows for a minor amount of rear wheel steering, which is initiated by body lean.

Here's a video shot by one of the guys on mye28.com to show how the dogbones act on the rear subframe; it's a bit exaggerated, as the swingarm wouldn't typically move that far, but it makes for a good demonstration. The e53 is a very different design, but in looking at how things go together, I think the principle is very similar.
e24/28/32/34 rear steering in action - YouTube

Many thanks for that. Hope I notice a difference.