I don't know how many miles are on the car, but if you do have to replace the hub as psfred suggest you may have to do (This is why I would first try running a tap), I would consider replacing the wheel bearing. You have to remove the hub to do this anyway.

I have a replacement bearing to put in myself. I'm not looking forward to the job.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)