Aces-n-Eights is right on. I shifted my 2001 Ram just like he said while travelling. To go into 4Lo, you must stop---I always put it in neutral and killed the engine first.
Personal opinions here and possibly out of date:
Assuming you drive the AlCan Highway during the summer, it will be a fairly easy trip.
1. Take note that when you see skid marks on the other lane, slow down. That's often the sign of the unwary going the other way, hitting a frost heave (even in the first half of summer, not fixed yet), and going airborne with their trailer. They will hit the brakes and lock the trailer wheels while in the air and skid when they touch down.
2. If you travel the AlCan in the winter, know that they used to have to close sections of the highway for bigger storms and road damage. Plus plenty of the folks who run the handy gas station/convenience stores every 50 miles or so might be gone for the winter---to Arizona. So carry extra mounted tires and cans of gas/diesel.
3. If you take guns into Canada, understand they have different rules. You can call the Border Guards from home and get the lowdown before you leave. They are not to be messed around with. That caution includes the ones at the Alaska borders.
4. If you take a pet, have the shot records up to date and with you.
5. Best if all human-types have passports, on both border crossings.
It is a
magnificent drive and the people are terrific. The RV parks along the AlCan *used to be* more economical than in Washington, Oregon, and damn-sure than in California.
Happy trails