Ten year old whirlpool washing machine

My whirlpool washer is ten years and one month old. During the spin cycle, the tub wobbles out of control. I have check and adjusted the load, and it is not simply a matter of balance of the load. I know there are three springs that attach the tub to the mount. (If that's the proper word) Is it possible that those three springs have metal fatigue? There is a triangular plate between the tub and the mount. I can see no place where it should be attached to anything. Is it a floating piece??

Thanks very much for your time. Sincerely, Val