'99 S70 T5 auto trans, with approx 42K miles. Twice today while accelerating --not sharply, & not enough throttle to kick down--the trans hung up to 70+ before shifting, and there was a noticeable THUD when it did. Query: Time to tow in under warranty, or are we just looking at a flush and refill? Sticky switch or valve somewhere? Just got in off the road, and no time yet to check the color of the fluid. Usually shifts into top gear at 60, so smoothly you have to watch the tach to know it's shifted. 100 miles to nearest surly dealer; all suggestions welcome.