Knocking from car

[cartoonwally]

Hey guys,

I believe this has been addressed before but i forget where i saw the information. When i'm sitting at lights on a slight downhill with my foot on the brake, and then take my foot off the brake (with the clutch still in) and start rolling i get some loud knocks from the back which then goes away...

I'm not too sure what its coming from, and what i need to replace to fix it... and how?

The car is a VY S1 SS Ute Manual.

Any help is greatly appreciated!

[cartoonwally]

No ideas on this one? I get the feelings its coming from the diff..?