forget the additives, there only good for a car your about to sell to make the tranny seem better than it really is, and does not last long and wont actually fix anything, all it really does anyways is swell the rubber parts to stop leaks on old worn out trannys, and help worn out apply pistons to seal up, but again it only lasts for a short time and after that things will be worse then you started with, a good simple fluid change and filter replacement is about the best you can do, mercon 5 i beleive is what your ax4s was "upgraded" to, i remember seeing a service buliten about it.