I have a Tree J325 that has been having some Z axis issues - I took the side cover off to inspect the z axis ball screw and there was a plastic ring on the screw.Attachment 461466 I'm thinking it comes from the gap near the top.
To the heart of the question is this part available to replace? I am going to do a round of maintenance that will include new balls for all the lead screws but is there anything else required?
Does anyone have a mechanical diagram of the z axis ball screw?