Steering cluncking could be many things, it's almost impossible to diagnoses by just describing it.
One simple thing you can check is your strut braces. Those things have a tendency to come loose, or just didn't get put back on correctly last time someone had them off.
Make sure check all 3 bolts, centre one is underneath the round cover on the bottom of the windscreen.
I have had alot of cases where it fixes it.