The answer to the title question is, it varies. "On what?" you may ask. Numerous factors can affect the number of miles between each transmission fluid change, and the first deciding factor(s) is your car's make/model/age.
To physically inspect your transmission fluid, you have to determine if your car even has a dipstick for it. It is usually located somewhere under the hood, but you can look in the owner's manual if you can't find it. Keep in mind; some newer models will not have this tool. Our shop has a dipstick or other devices to monitor the levels on vehicles without the transmission dipstick. Your owner's manual will also list your vehicle's maintenance schedule, so it will tell you when you need to service your transmission fluid.
In some cases, newer maintenance schedules will not mention transmission fluid changes, so owners are often left clueless about it. Even in this situation, it is still a good idea to have a professional check the fluid at a particular checkpoint. For older vehicles with higher mileage, a lot of dirt and filth may have built up in the transmission fluid, and a professional may advise skipping the fluid change as these particles have already adhered to the seal.
If you decide to change the fluid, it's better to go with a fluid flush than a change with a machine. This service will ensure the paths of the fluid are cleaned as well. Furthermore, most automotive shops have one fluid changing machine, so cross-contamination can take place. You can avoid the possible damaging effects of this by simply getting a flush instead.
If you think you may be due for a transmission fluid service, we invite you to give Tom's Auto Center a call or visit soon!