sam_canton wrote:Thank you, for the manual of ML360, there is mark of lubricantion, while for the PD400, no such mark and indicated low speed 6000 hours and high speed for 1800 hours to get specialist to maintain it......I am afraid I can not keep the precise if I remove the bearings...
I understand your concern with replacing precision bearings. They are easily harmed by those who don't have experience in their installation. I also share your concern about setting the proper preload, so they perform to standards that are acceptable.
You may find that you can use the machine "as is" and it will serve you well enough, even for many years. I think that I'd recommend you try the spindle to see if it runs quietly, and if it runs true (using a tenths indicator if you have one). If you find the machine has issues, you can always do the necessary repairs as required, and that may not happen for many years.
Sorry I'm not more help, but I have very limited experience in the way of machine repairs.
Harold