I have a Kenmore washer 70 Series Heavy Duty Plus model #110.82372120 serial #C62035883 purchased in 1986. The inner tub is stuck and will not spin. The belt is ok, the spin solenoid is functioning, the lid switch works, the pump works, Agitation is working. What would cause the tub to stick? I can move the tub about a half turn in either direction but it takes a bit of force, and beyond that it is stuck good. Can you help?