I took the bed off my machine to get lapped and ground in preparation for a new indexing plate. I inadvertently rotated the ball screw too much and the nuts came a apart. I put back together did a preload so there is slight drag while turning the ball screw however, while there is no axial play, when I reverse directions, the ball screw will turn more easily for a small amount before “feeling” the drag again in opposite direction.

Basically, when reversing direction, should the ball screw rotate easily for a small amount before picking up the drag I. The opposite direction?

Is this normal or should I replace the nuts?