First of all ensure feet adjusted and level floor.
Put it on a cycle without clothes and ensure all the water is drained at a reasonable rate and if not concentrate on the filter, hoses or pump for blockages.
If o.k then when complete open the door and turn the drum by hand ensuring free rotation (sometimes you get garments lodged between the inner and outer drum that float when water enters the machine and cause havoc with drum speed/torque) and move it around for play. If it feels too slack then check the concrete block, springs and dampers.
Hope this helps.
sparky, February 2006