Some adjustments are made to set up the way the parts fit when building it. They can be readjusted during a service.
When in different speeds, some "members" are drive, some are driven, and some are held, some freewheel. some items are applied, some exhaust, these can have selective parts that complete the installation. There are no user serviceable parts on a transmission. If you touch one, its on you.
Any flash update that could be so indicated by shift programming should only be done by the dealer till its out of warranty.
Then you can go make a treehouse out of it if you want to bad enough.
Automatics use the same set of gears for all ratios? Really?
What the hell are you on about? You can't get different ratios without changing the whole gear set. If it's a 4 speed transmission it will always be a 4 speed. You can't just add a gear without essentially re fabricating the entire transmission.
The car's computer has nothing to do with the gear sets which determines gear ratios.
Altering the shift control software? Not a good plan. Very likely to make the car undriveable, or dangerous, or a brick.
Since they only use the same set of gears for all ratios, can you tune them or adjust them from 4 speed to 5 or 6 speed for example? Changing the computer that does the work?
