I hsve a 2006 F250 6.0, 261k. I’ve put 60k on it and am now to the point where I’m supposed to change the transmission fluid. However, I’ve been told if it’s never been changed before, then leave it be. I have no idea if the fluid has ever been changed by the previous owners. It’s doesnt smell burnt, fluid level is fine, etc. Should i change it or leave it be?