firstly, check that the pulley isnt bent,then check that its retaining nut or bolt is tight. If the bearings are worn out then you will need to remove the drum. This involves quite a lot of work so you may consider replacing the machine. If you insist on doing it yourself then go to Halfords and buy a Haynes book of the washing machine. It tells you how to do a complete stripdown and replace the bearings.
fantazum, October 2005