vibration

[RGuzz]

There is the annoying steering vibration getting worse. The g60's are
fine, rotors turned, wheels and tires balanced, a little clunking but my
audi mechanic of over 20 years says  only minimal bushing play ( didn't
specify). He says tie rods, ball joints okay. There is a clunk while
turning the steering wheel and i wonder if some of this is related to
play in the box, which i gather is not uncommon. The steering wheel
itself, and it's springs were recently spruced up without much change.
Most suspension parts are at roughly 50k miles.  The vibration really
feels like it's in the steering column, like a bum dampner only there
isn't one i'm told.
Any ideas? Thanks,
Rich
226k.