myredracer wrote:
We can't turn OD on or off, unlike our old 2000 F150.
Our transmission doesn't seem to hunt. I use tow/haul nearly all the time when towing and it seems to select the appropriate gear at the appropriate time just fine. When I was going up the 10% grade at 50-55 mph, it was running nicely at 4,000 - 4,500 rpm and stayed in the same gear.
It also downshifts nicely when in T/H when slowing down going downhill.
I hear people saying they lock out their transmissions all the time and it seemed like a basic and simple thing to do. I thought maybe you just flicked the right switch or pushed the right button like when switching in an out of T/H mode. I don't seem to have any better idea of understanding "locking out" from the above posts and maybe it's something I don't need to know or worry about.
If the transmission isn't hunting, let the tow/haul do it's thing. It does eliminate most of the issues compared to older transmissions by itself.
Just so you understand:
Hunting doesn't typically happen while on a long steady climb. In that case even the older transmissions will downshift until the engine can hold a steady speed and it will stay there, which is what you want.
Hunting happens when you have lots of up and down sections closely spaced. When you start up a hill, the transmission downshifts to get better torque at the wheels but as soon as you crest the hill with less torque needed at the wheels, the transmission shifts to a higher gear.
In hilly terrain (it doesn't have to be high altitude or even paticularly steep), you can have the transmission shifting all the time and that is hard on the transmission.
Again, if the transmission is holding a steady gear and the engine isn't lugging, you generally don't need to worry about it.