Friends,
Although I try to follow the recommended fluid/filter changes, I've gone over a few times. Real bone headed one was on my 2009 Ram 4500, I completely missed the 30K mile fluid change on the Aisin... it was time for the 60K mile service I figured out what I had done. Had the dealer do the 60K and asked them to look extra close at the condition of the fluid, the filter, and if there was metal in the pan. All checked good. I guess I lucked out, although it's been mentioned before here that folks thought the Aisin might could go longer between fluid changes. And I checked the fluid levels each month, fluid always nice shade of red. Old days, it was a bad sign when red fluid was brown and smelt burnt. Haven't had that experience on any of my vehicles.
On that truck and on this one, I did change axle fluid at 20K mile mark. Fluid didn't look that bad on either one, and both trucks primary and almost only use was pulling heavy trailers. I guess, for the most part, none of the fluids I've ever changed looked particularly bad. And from the days I was doing extend oil drains with Amsoil bypass filter system, I never judged the oil on the appearance, but on the results of the oil analysis.
For all this rant, just saying not doing any extended drains (on purpose) on anything and more or less, that I haven't really been able to assess the quality or wear of the fluids I'm changing.
Cheers, Ron