Had transmission flushed on my 2001 4Runner which has c. 125,000 miles. Now transmission seems to make a whirring or whinning sound. The whines changes pitch as RPMs increase/decrease. There is no odor or any other indication of problem or change in performance. Trans fluid is on the mark. Any idea what is source of whine?
Take it back to whoever did the flush and have them run a diagnostic check. Too many possibilities to provide any advice.
Twotone