First I wanto to say thanks to all who have posted about Nissan auto gearboxes. The info has been a real help.
I tow a van and my auto box drops in from 4th to lockup at about 85kph.
I want to avoid this because it overheats the box and I also lose momentum in country with gently rising roads, so I am constantly double tapping the power button to get it to shift back down a notch. Then it goes faster and locks up again.

This makes towing under some circumstances a real drag because I have to keep the speed at 80 kph and if it drifts down a slight hill it speeds up and we do the whole thing again.

Has anyone set up a manual override so it doesn't lock up?

I have some skills. When the auto sparky couldnt do the tps right I fixed it myself

Thanks in advance.

Rick