I have abit of dilemma;
Purchased cheap C7 screw with SFE ball nut; (please kindly read on); after a run it sometimes makes a noise.

Ball nut was making a like a crunchy type noise when table it was mounted on was viberating. Stopped table from viberting and the noise went. It is not practical for me. As if balls were juddering.

I need better system. I cannot get double ball nut because of the pitchsize. They dont do a DFU in my size.

What do you suggest is the best of the below actions please:

1) get 2 single ball nuts and use a spacer in between

2) I have been offered SFS ball nut but its the same length as mine. 47mm.They say its more precision but same number of balls cant see that working.

3) get a C5 screw, dont mind because 3 times of $30 I can just about manage. Can ya trust sellers from ebay selling you a C5 that might be a C7; can you see a difference

4) I don't even mind paying for a ground screw. In fact thats what I want from far east of course but I don't know where to look. Seems like rolled are more popular.