PS–The trans dipstick was marked “ATF+4”, and in doing some Googling on the subject, I found this excerpt from a Chrysler TSB about the ATF+4 fluid:
"FLUID COLOR
Mopar ATF+4® has exceptional durability. However, the red dye used in
ATF+4® is not permanent; as the fluid ages it may become darker or appear
brown in color. ATF+4® also has a unique odor that may change with age.
With ATF+4® fluid, color and odor are no longer indicators of fluid
condition and do not necessarily support a fluid change."
Whatever that means. (I think they’re trying to say that brown fluid isn’t necessarily bad, but who really knows…)