Yeah, this sounds familiar. It's happened 3 times this year to the washing machines in my apartment building, which are unfortunately located right outside the wall of my rooms. So when the machine goes berserk, I hear the banging immediately. And then I have to explain to the landlord how someone ELSE broke the washer.
Apparently the spindle that drives the rotation gets bent from being overloaded with an imbalanced load, it gradually gets worse because the spin cycle puts more force on the spindle, bending it further.
I always see the repairman taking the machine apart and working underneath it where the motor drives the spindle. I suspect my landlord got screwed buying cheap commercial washers that were guaranteed to need continuous repairs. Anyway, you'll need a repairman to fix this, and they'll certainly be well familiar with this sort of problem, it's quite common. I don't pay the repair bills but it looked like a fairly quick repair (as these things go).
Once it's repaired, avoid overloading the washer, or it will just happen again. Your clothes get cleaner in a smaller load anyway.
P.S. Yes, I do pay far too much attention to my laundering.