I would oil all moving parts first of all with WD40, if it was recently serviced you should not need to oil it and you should not need to adjust anything if it was done properly, you need to get into the side of the machine to adjust the belt if you have to but it will be unlikely that is the problem.
If you have a two piece body machine it is not very likely the parts inside were oiled.
drivewithken
June 2010