I've heard that too and I may be in the same boat. My truck has 135K on it and I am not for sure if the tranny was ever serviced or not. I bought it with 87K on it, so right there is a 48K difference. I want/need to do mine now due to the TC shudder and maybe other problems. Sometimes I think it doesn't shift right and I get odd jerks/surges around 40 mph at 1100-1500 rpm when lightly accelerating. The engine is running fairly good and as far as I can tell the rest of the driveline is in good shape. I guess if it is going out changing the fluid, shouldn't matter that much. I thought about dropping the pan, draining the TC, does adding a Transgo kit and sonnax valves sound like a good idea right now or not? It might help it, it might wipe it out.