[Angelcma]

What I did confirm was that the actual clunk of the steering rack is indeed this piece. The metal to metal contact does not seem to be the pinion or rack tooth smashing.

Clunking sound of steering rack comes from this exact piece smashing with the casing of the rack with the rack rod, tightening this thrust piece will reduce the sound but steering feel at the wheel will become muted and hard.
I will buy some grease and apply it to the trust piece to verify of sound reduces.