Most likely a bent suspension rod. Very difficult to detect with a visual inspection while installed, especially the back right suspension rod. If the rod is even slightly bent, the tub will bang violently during the spin cycle (last 12 minutes) regardless of the size of the load. The washer will then display a UL code and attempt repeatedly to redistribute the load by adding water, agitating, which will not help. You can attempt to manually redistribute the wet clothes, but that is frustrating.
Good news. It is a $60 repair (including shipping and taxes) and you can easily do it yourself with a replacement suspension rod kit, a putty knife, a piece of tape and a piece of paper towel. For a novice, it will take about 15 minutes, if you are an experienced DIY, easily done in under 10 min. Go to the Repairclinic.com
video on YouTube to see how it is done.
Would recommend doing this troubleshooting step first.
Attached is a photo of the damaged suspension rod. You will notice the bottom one in the picture is noticeably bent when viewed from the side. This deformation is hard to see when it is installed.
Not included in the Repairclinic video is the plastic retaining clip on the right rear rod that holds a water tube. Pretty self explanatory and easy to remove/reinstall once you see it. If you are having a difficult time lifting the upper hook and seating it in the plastic suspension ball, slide a large Phillips head screwdriver through the hook and use it like a handle. Slide the suspension ball slot onto the shaft of the rod and lower the hook. When it is aligned, simply slide the screwdriver out laterally and the hook will seat in the suspension ball.
Hope this helps.