1. Worn suspension rods (a common cause)
What it is: The 4 suspension rods that support the inner tub lose damping ability. Washer shakes hard during spin, walks across the floor, throws UL once vibration crosses threshold. Often presents first on small loads where balance is harder to maintain.
Fix: Replace all 4 OEM Whirlpool suspension rods as a set (mixing old and new rods re-creates the imbalance).
Typical all-in: $185–$285 all-in