Ok got the ballnut greased, divided all the balls into three groups with even amount in each and put them in the three circuits, making sure everything is nice and tidy. Carefully used a piece of ali tubing which came with the ballnut, to secure the balls in place ie. slid the ballnut over the tube making sure not to knock any balls out. Pressed the tube against the ballscrew and 'screwed' the ballnut on. It ran fine but I could hear some rattling in the ball nut like before (as if there's a ball stuck in an unused circuit), so I took the ballnut off by unscrewing into the tubing and removed the tubing carefully to inspect. Found nothing, all where it should be, so again I made sure all the balls are pressed against the races, put the tubing back in, screwed the ballnut onto the ballscrew and same thing, rattling and the ballnut stops on its own when you spin it.

Any ideas what it can be? I'm almost sure the balls are where they should be and I've seen this before when I had all balls in the ballnut. If I leave 3 or so out, it runs smooth.

Regards,
dsc.