how can i fix my hoover600 m washing machine?

Our hoover washing machine is around 3 yrs old and has been going good but it has started leaving the clothes quite damp when it spin,s .The machine sound,s like it,s out of balance but it,s not and the spin speed sound,s slower.Is there any filters that could be blocked or maybe the drive belt is the problem.Any help would be appriciated.