Bobcat 320 swing circle noises

Hello all, some weeks ago I bought a used Bobcat 320. I alrady made a big service including changing all oils and filters. Now, after I have used the Bobcat for some hours, I detected a noise comming from the swing circle if I swivel the upper structure to the right. The rattling noise occures when the upper structure gets stopped in a fluent way with the joystick, so if the valve gets closed slowly. If the joystick gets dropped suddenly the whistle noise of the overpressure valve is hearable – this is ok, I think. I recorded a short video. I guess this is the best way to explain the noise: Some more details to the Bobcat 320: Build year : 1999 Operating hours: 35xxh I would be happy to get input where this noise may come from and if I have to fix it soon or if it is ok to fix it next winter. Best regards from Germany Raphael