What is a suspension rod?

A top load washer’s tub hangs from four rods, each with a friction damper that soaks up movement during spin. When the dampers wear, the tub swings freely, the machine bangs against its cabinet and can walk across the floor, and the control keeps adding rinse time trying to rebalance. Rods age together and are sold and replaced as a set of four, fitting one or two leaves the remaining tired rods to fail almost immediately.