Worn belt, faulty snubber. Washing machine was 'walking' during spin cycle.

Unplugged machine.
Turned off water supply.

Removed front panel.
Pushed in on belt tensioner, removed old belt, replaced with new belt.

Used pry bar to lift the base assembly high enough off the snubber to remove it. Partially propped it with 2x4 wood scraps.

Used bent clothes hangar to remove old snubber ring, to protect my hands.

Replaced snubber, arrow pointing up.
Carefully lowered base assembly.

Replaced front panel.
Turned water back on, plugged back in, washing machine no longer 'walks'.

Remember to check the washer against a level if you moved the machine.