Can anybody tell me if this bar has a small axial play. (5mm) Or does it have a very tight fit between this metal rings, with no axial play in the bushings??
I hope you can understand my question explained in poor english

With your TdV8 the axial length of the anti roll bar varies as the the hydraulic actuator between its' two halves operates. Therefore each half of the bar slides through the chassis mountings to allow for this. The metal rings crimped to the bar each side of the mounting allow this.

If by any chance you are looking for a cause of a knocking noise when going over bumps there is plenty to read here:
http://www.rrsport.co.uk/forum/topic7227.html