I opened up the top and watched it during the spin cycle and the tub is vibrating moving around like crazy.
Front load washer tubs normally gyrate a lot during the spin cycle.
Unfortunately your washer is wobbling excessively--and this causes the entire cabinet to shake/walk/rumble/bang around.
Many of these Samsung-built Maytag front load washers shook uncontrollably on concrete floors even with NO laundry in the tub.
The ONLY alternative that works best for your washer is to buy "ShakeAway Pads".
These are available at Lowes or Home Depot.
The four dense rubber blocks are placed under each leg of the washer---and while this does *not* stop the shaking--it will stop the walking of the washer and reduce the noise of the spin cycle.
I think it is important to keep in mind that although a Technical Service Bulletin was published acknowledging this problem and offering a course of action to remedy the problem--it fell short.
In many brands and types of appliances--Technical Service Bulletins are written almost every month.
About 10 percent of these bulletins fail to adequately resolve a problem with a product.
In some cases 4 or 5 bulletins will be issued for the same problem until a genuine solution has been found.
In the case of the Samsung-built front load washers--Maytag went bankrupt and Whirlpool bought Maytag.
After just two years--the Samung front load washer and the *name* Neptune were discontinued. Everything relating to this washer became moot.
The new Maytag Epic front load washer was introduced. This washer is a Whirlpool Duet with a new name.
Samsung no longer had a reason to keep posting bulletins on the now discontinued model--but *did* have to address the shaking problems in their own brand of washer.
In 2008--the VRT was introduced. This system didn't "make some improvement" with vibration--it KILLED it. No more shakes on wood or concrete floors. It's that good.