yes it was... my senior colleagues who worked many years for ford and chrysler
of course, they didn't mind up selling a flush service since it paid more service hours
those crappy american gearboxes have no drain plug too... have to drop the sump to drain them, making a big mess
but anyway, the worn out clutch material floating around in the fluid is what gave enough friction in the gearbox to allow those neglected transmissions to still barely work and once they were drained out, there wasn't much left of the clutch packs except to wear out some more then slip