How can I fix my unbalanced Kenmore Washing Maching Model 110.92429600?

during the spin cycle, the washing machine vibrates terribly and has to be stopped while the clothes are still very wet. If the pads between the base and the tub are worn, could it cause such vibration? What is the procedure for balancing the tub? Could the problem be that one or more of the springs are not as strong as they should be? Do they sometime need to be replaced? Is it possible to balance the tub by bending the brackets which the springs are attached to?