when you say “damaged” what exactly do you mean?
do you mean for example “the printer was dropped so that the frame was bent into a parallelogram”?
because the symptoms you’re describing - two bearings binding to the z-rod - tend to suggest that the frame is bent into a parallelogram, when looked at from the front.
how is it possible to deduce that?
well, if the frame is bent into a left-to-right parallelogram then the z-rods will no longer be upright: they too, just like the frame sides will also be at an angle.
the x-rods will still be dead level (horizontal).
meaning that whilst the z-holders are designed for a right-angle, the ACTUAL angle the z and x rods will be at will NOT be 90 degrees.
what THAT will do is cause the exact type of side-loading on the z-rod bearings that you are describing.
first check that the frame sis actually “true”. you can do that very very easily by measuring across the two diagonals of each face, try to get sub-millimetre accuracy on the measurements, as best you can.
so, let us know if the frame is properly square, ok? it would also help to take photos of the frame and post them here so that the damage can be properly assessed.