I am overhauling my 1996 Camry and as part of that overhaul, I decided to drain the transmission fluid and replace the filter. The car has 131k miles on it, and I bought it new so I do not know whether the fluid has ever been changed or not. Now, I just read a post somewhere else that said if the fluid has been in the vehicle for 80k+ miles, it would be best NOT to change it because the grit in the old fluid is not acting like liquid sandpaper, giving the transmission extra "grip". They said that replacing the fluid with clean fluid could actually cause more harm than good. Did I just make a big mistake?