Programmer or transmission hacks?

Hi All. I just finished pulling a 5500lb RV across Wyoming’s 6000-8000 foot elevation I80 into a 20mph headwind and want to know if there’s anything that can be done to force the transmission to actually obey the manual shift selector, or if there are other ways of making the transmission upshift and/or keeping it from downshifting so easily? Specifically.. I’d like it to be quicker out of 4th and more reluctant to drop into it in the first place.
Overall it did fantastic, it pulled steep hills really well at 60mph grunting in 4th, but it refuses to do the same thing in 5th into wind, which makes wind a far bigger nemesis than hills :/

 

5th into the wind you dont have the torque to maintain speed. Thats normal

 

I actually prefer the way my truck tows in S4. It seems to behave more predictably and to respond the way I expect it to. In S5 or D, it will downshift for the tiniest little incline. On bigger hills, it won't downshift at all, it will just lug until I'm going to slow that I have to downshift for safety. At that point, it will pick up so much speed that I end up going way faster at the top of the hill than I was at the bottom, which is not what I want from a fuel economy standpoint. Now the only time I shift to S5 is on long flat sections when I want my gas gauge to drop a little slower.

 

S4+TH and let that 5.7 roar!

Too add some here. 5th and 6th gears are over drive gears and shouldn't really be used for towing large loads. These gears when towing are more likely to continue slipping the torque converter versus locking it up.

That can cause higher transmission temps, lower efficiency delivering power to the wheels and potentially lower fuel economy versus just staying in 4th gear which is 1:1.

Also, the power band for our trucks is 4500rpm and up. So keeping RPM up will give you the power you need at a moments notice for passing, pushing up a hill, etc.

 

Unless you regear and tune, you’re much better off to simply tow in 4th gear. You won’t hurt a thing, including mileage.