I flushed my fluid after 25K of beating the piss out my trans and Blackstone said the fluid still had another 20-21K on it. And John Wood just laughed at me as he charged me the $224 for the Swepco racing fluid I run. He said I had thrown away perfectly good fluid. I think I learned a little from that lesson. Test first then change, not the other way around. Oh yah, and listen to the pros.....