ok, i guess im giving advice?? i didnt see it mentioned at a casual glance is all.
i stripped my slides the other day for some cleaning, and noticed a nasty groove in the "long" gib (adjusty thing).
upon inspection i noticed that;
the dovetails are so small that the adjusting screws are fairly low on the gib.
(i apologise if ive got like a different model maybe, but hey...)
because of their position, and the angle of the gib, they tend to force the bottom IN, and the top OUT. the face of the gib then doesnt even touch the slideway. instead it bears on the lower CORNER of the slide...
i havent actually fixed it properly yet.... my temporary fix was a 2mm TIG rod jammed in the lower corner to hold the gib up... made a huge difference!
4 M4*20 grub screws, 4mm from edge of slide,between the existing holes.
tightened and locked before the main adjusters.
now getting free movement with no binding, no play. it would never adjust properly before... may repeat it on the Y & Z if i ever strip it again