I have a trusty Impreza knocking noise when driving that I just can't find and its now driving me mad!

The noise occurs when steering, generally a right hand corner but sometimes a occasional knock can be heard going left.

CV joints have been checked and seem solid

Steering rack checked and seems solid.

Springs on coilovers seem fine (they are pretty new) Top mounts ok too.

ARB droplinks again are new as they are aftermarket and no play can be found.



The only thing I can find wrong is if I grab the drivers side drive shaft and pull/push it up and down it makes a slight knock where it locates into the gearbox....?

 

Any ideas to throw at this.......