I have the same problem with my model, 80 series. Sears diagnosis - timer. For an 11+ yr old washer, not worth it. Before I start shopping I am going to try replacing the knob.
Under $20 and returnable (timer is electrical and therefore not). I made this mistake with the dryer and ended up with a timer I did not need and could not return.
Good luck
NotDiyDiva
February 2005