I will be doing drain and fills on mine every 30,000 miles. If I were you i would do the same on yours. These trans are pretty good if you keep up on the maintenance for them. You can do it yourself man it is not hard at all. Make sure you buy the toyota world standard fluid which runs a bit over $9 a qt.. Prob buy 4 quarts to do the job. You will use 3.5 of the 4. Look up how to do it on youtube. Plenty of posts on this.