@orhan-alison
Hi Orhan, first check in the owners/maintenance manual if it states change or flush. Wipe some dipstick fluid on a white paper towel and if pink like new fluid it's good to change or flush as per above. If it's off colour, say darker but pink is still visible then I would change and not flush. If it's real dark no pink) you could have problems after changing or flushing. If the latter just drive it until it gives up as it will go longer than changing or flushing, hope this helps 🙂

@orhan-alison
well i can tell you i purchased a preowned vehicle with 185,000 miles. but miles dont mean anything when you take care of the vehicle. i highly reccomend changing tranmission oil, DO NOOOOT flush it, that can damage the seals and the seals help you to stop leaks. instead recondition those seals, add atp 205 reseal to recondition those seals. i changed my transmission fluid twice already. i highly reccomend you let it drain overnight, you will be surprise how much more junk and dirt there is inside. take your time take one step at a time. if you have inlet filter also change that every single change. but always use OEM original fluids, and always use oem filters. you will notice the difference in performance right away, my car feels lighter and faster