You are indeed titled to your opinion, however the fact is you do not need it to change it more than recommended intervals. 'Fresh' everything is always nice, but they do get your wallet rather light and does nothing to extend the life of your torque converter. What does affect it, is the neglect of changing the ATF at warranted intervals or improper ATF (formulation) aka non-Honda specified ATF. Newer Honda transmissions are sensitive to these than the older ones.
As long as the ATF is experiencing normal driving conditions, it is fine to change it at the MM intervals. If the conditions warrant, extreme cold, extreme hot, or frequent towing (not really applicable to an Odyssey), you may want to change often. As long as the ATF does not experience extreme high temps, its shear strength is intact with the modifiers alive and well. I have a 230K+ Ridgeline (2010) and used to tow a 3500lb trailer about 40+ times a year for 6 years averaging 27K mi/yr. I average around 18K miles a year now and the ATF gets changed at warranted intervals. Mine uses the same DW1 that many Honda/Acura vehicles use on their transmission and I have no shifting or abnormal issues. Though the transmissions are apples and oranges, what I am expressing is the MM procedural followup.
It is possible.
9spd ATF change >>
9-spd ATF change. The drain bolt is similar to many other Honda drain bolts that are recessed 6-point socket style than typical 'bolt' and is located on the bottom of the transmission housing. The fill bolt is located to the right of the 'park lock shaft on top of the transmission housing. 9spd uses Type 2 fluid. Level check hole is by the outboard axle.
10spd ATF change >>>> The fill bolt is a traditional bolt in the front of the transmission (next to the TCM) Though it (92800-20000) is labelled as a drain bolt in the parts catalog, it is actually a fill bolt. The drain bolt is the magnetic drain bolt, used in 1992+ Hondas and seems to be located on the bellhousing side (by TC). The fluid is a Type 3.1.
There is no 'dipstick' on these transmissions as they use a method similar to the transfer case and rear diff fluid level/quantity method. You have a level check bolt that needs to overflow and that tells you that the transmission has adequate fluid. Granted the vehicle is level. This is the method, per FSM, I have to use on the Ridgeline to fill the rear diff and transfer case.
How many miles on the Ody? What service code did you get?
