Worth doing transmission service @216k
Recently purchased 2003 Toyota Highlander Limited V6 3.0 216.5k for $2500. Just bought it as a second car/beater/hauler. Replaced blown front and rear struts and sway bar links and alignment ($1500). Drove it for about maybe 100+ miles so far and shifts really smooth at city speeds and highway speeds.
For the first time today, I decided to stress the transmission just a bit to get an idea of how it reacts. Pretty much gave it some beans from 45mph-60mph+. Was fine for the first pull and on the second pull decelerating to around 45mph, I experienced transmission shudder for the first time. As if I was driving on rumble strips for about 2-3 seconds. Tried to give it the benefit of the doubt that it was rough patch of pavement but I drove on a familiar road all my life and it was smooth enough to not do that usually.
My question is, should I drain and fill the transmission fluid? Carfax and Toyota portal does not show any history from previous owners. Should I use WS or Maxlife? Should I let it be? Or should I scrap it? I would really love to keep it but would love to have some input. Thank you!