Just two things related to this to consider:

Those same FAQ's have a very simple tranny flush procedure that basically requires two common hand tools, a one gallon milk jug, 3/8" tubing and 3-4 gallons of ATF. It is without a doubt the best thing you can do for your transmission other than change a radiator that is more than 10 years old.

The transmission coolers on these cars are in the (US) passenger's side radiator end cap. If your radiator says the brand is "Blackstone" or just Volvo on it...seriously consider changing it. Newer Volvo radiators are marked as Valeo and the Nissen's is considered equally good by most. If the tiny o-ring connection in that radiator tank fails, your transmission will fill with coolant and it is toast. This is one of the few things that can kill a AW7X transmission before about 350k miles.