j2400
My family's mid '60´s BD Kenmore had something like a rubber "stopper" that pressed hard against the right back corner of the tub cover, to hold the entire tub assembly from shaking excessively during spin. At some time after some years of use the washer just seemed to go off balance while spinning any load, no matter if large or small, heavy or light.
After raising the top cover of the washer I discovered that the area of the top cover where this rubber piece pressed against had become somewhat contaminated with powder detergent, which of course "lubricated" the whole area. After some minor disassembly to remove the stopper and its holding wire clamp I thoroughly cleaned the area and the stopper, to free them of any detergent residue.
The washer worked like a charm for many years after that, and from then on I just took the habit of cleaning this area occasionaly. What I did was (without any disassembly or even raising the top of the washer) just moved the whole drum assembly to one side and then to the other, and wiped the whole area where this stopper pressed with a moist cleaning cloth.
I hope this helps,
Emilio