either the drum bearing has seized or broken up,or the clutch spring has broken, you first need to remove the clutch, once off check the condition of the spring ( if you can pull the shoes apart by hand you will need to replace the spring ) if the cluth is ok, pull the drum away from the crankshaft, check the bearing condition, this component is only available as a complete drum and bearing.
Husqvarna man, November 2009
