either the motor is loose, or the belt is stretched, i would be looking at the former, disconnect the m/c from the electricity, you need to get underneath the m/c, i assume there is water still in it so lean it against the worktop, have an assistant to hold it for you, the motor is held by two bolts, 1 is fixed the other is in a slot, loosen the bolts and then use something to force the motor away from the drum, hold it in place and then tighten the bolts, alternatively, remove belt from motor pulley and move motor away from drum, tighten up and then turn drum and belt to get it back on pulley.
WS, May 2009