Personally, I have never seen a transmission fail due to a flush or known anyone that did. It can happen though if the truck has a LOT of miles on it and it has been really abused/ignored. There are a lot of opinions on changing fluid-period, but I think a flush should be done every 75,000 miles myself. OK to do a simple pan drop and filter change say, every 25,000 miles or every 2 years to keep the crud out of the system as much as possible(the magnet will have a lot on it) but still, the system needs a total cleaning at least ONCE if you plan to get 200+miles out of it. If you tow I think even more often, say 50K. If a transmission is ignored TOO long it gets dependant on the crud inside for friction on the clutch plates. The material wears away faster than it should and the particles in the fluid can help maintain some friction (a lousy way to do it) and when finally done a flush can cause slippage, not due to the change itself, but the clutch material is gone. If done wrong you can have seals blow, but have not seen this personally. 97K is not that many miles. Get is flushed and new filter and pan cleaning. I have flushed ALL my family's vehicles (five including my father's old Olds) and their mileage when done was 64K, 102K,140K, 110K, and 160K with no problems. Four I did myself, one (the old lady's Dodge) I had a good shop do. the trucks at my work were done all around 90-100K. AOK.