Hope someone can shine some light on this and help me out its driving me nuts!

4x4 Cossie knocking coming from passenger side rear. Just replaced beam bushes with solids and diff mount with poly bush noise still there. When going round a left hand bend and the weight is on the right it sounds like something I loose and a tapping type knock. Drop the rear seat and you can hear it quite loud.
Also open the boot and rock the car from side to side and I can hear it in the rear arch but cannot work out where it's coming from.

Help fellas!