Automatic Transmission - 100k plus miles --Service trans ????

Just picked up a 98 formula auto with just over 100k miles. Car was well taken care of and very clean. Trans works fine and drove fine on the 1200 mile ride home from FL to ma. The trans fluid smells pretty nasty and was probably never changed. This car is bone stock and will be my daily driver. I will not thrash it - its just a commuter car w 2.73 gears that I will be driving 100 mi a day on the hwy.

I plan on changing the fluid and filter. No flush or anything crazy. I have been told numerous times not to do this with an older unservieced trans but cant see how leaving burnt fluid in there can be a good thing.

Would love to hear from the trans builders thoughts on this.
thanks
Ted

If the atf is past the "burgundy color", I would not change. The detergents in the new atf are enacted with the heat of the trans. They can wash away varnish, loosen metal chips and grit to float in the atf and scratch surfaces or stick valves or solenoids and cause havock. From new, the atf should be changed every 25-30,000 miles with normal driving. I've always recommended changing high stalled, or cars that are "played with" twice per year as most people are really hard on their stuff. At the first sign of a problem, address the trans immediately.