Towing through mountains

We have a 15 Ram dually with Aisan transmission and use tow/haul and the exhaust brake. We installed and Edge monitor so we can look at transmission temp/EGTs and a bunch of different things. Rarely do we have to use the brakes when going down a grade. With the "manual" shifting and exhaust brake, we feel well in control.

I'm surprised nobody mentioned keeping an eye on EGT's and trans temp and Tach. Of course I have an OLD 1999 7.3 F550. I choose to keep it in the 7.3 sweet spot of 2200 to 2500 rpms. EGT around 1300 degrees or so. Only a 4 speed auto. on a 6 or 7% grade this = a speed of 35 to 45MPH.
Pulling a 20K# loaded toy hauler.
Not sure any of this applies to the new 6.7 which has way way more torque then my 7.3. I would still recommend keeping an eye on temps.

If you have a new model F350, you should have both Tow/Haul function and Engine Braking. I pull a 16k lb 5ver with a 2016 F350 DRW. I will pull most grades at 65mph unless I (unintentionally) get behind a slow moving vehicle.

I will usually start any significant grade selecting 5th (but still in cruise), to attempt quicker converter lockup. (At this point I am unsure if the converter locks in 5th or 4th on the 2016 transmission). It is rare that I will see an automatic downshift into 4th.

For descent, I will set my cruise at 55mph, and the combination of tow/haul and exhaust brake always holds me to within 5 mph (sometimes climbing to 60 prior to applying increased hold back) of 55mph.

If you Google the song, you'll find a pretty good Youtube video (Gopro ?) of a drive down the pass accompanied by the song. The song lyrics are absolutely hilarious.

^Lol
All the geezers on here and only one comment about CW MCCall, one of Colorados finest??
I remember listening to CW as a kid when it first came out. You got a copy on me pig pen cmon?

I have a 2013 F350 diesel dually pulling a 36 ft fiver. I will assume we are talking about non-interstate highways in states west Nebraska.

I always ALWAYS use Tow/Haul mode when I am hitched up. There is no reason not to.

Going uphill, I turn off cruise control and I don't necessarily try to maintain my normal level ground cruising speed. At best you will burn diesel at an alarming rate for absolutely no gain. Do not be in a hurry when going up or down. If the trans starts shifting down to 5th and then back up, I will generally just lock out 6th. Or 5th and 6th, etc. I usually only run about 60 mph anyway so the revs can start dropping off early in 6th and that's when I lock out 6th. I don't let the revs drop below 1500 going uphill in any gear. I don't mash the pedal in 5th just to maintain higher speed either. If revs start dropping I'll just lock out 5th and motor on in 4th. I shift down early in all gears to pick up some revs if I know it's going to get steeper. I don't use Manual mode much but might start experimenting with it. I suspect it might offer a few advantages.

Going down. I go over the crest and start down in a lower gear at slower speed. The general rule is to go down in the same gear you used coming up. I lock out the top 2-3 gears at the top. If needed, I will use the brakes to knock off 5-10 mph but you do not want to use the brakes very much. That's why it's important to start over the top at a slower speed in lower gears. Notice how the truckers do it. They don't start down going at 55 mph. I would never use cruise control going down and ALWAYS make sure that Tow/Haul is on.

** I drove it this way going both up and DOWN Wolf Creek Pass and did not hit the feed store in downtown Pagosa Springs.

Seriously, let the truck do what it wants/needs going up the hills. You'll find the sweet spot for speed/rpms pretty quick.
Going down, start slow until you know how much, how fast you can run down hill with your load. And as said above, when you need to use the service brakes, use them firmly and briefly to get down below your threshold speed and then get off them. Give em time to cool before hittin them again. Don't ride them.

Listen to CW McCall, "Wolf Creek Pass". Don't crash into the side of the feed store in downtown Pagosa Springs!

I leave it in drive with tow/haul on. The Ford engineers have it figured out just fine. The only time I ever use manual is cruising on an interstate, with rolling hills, to prevent downhill downshifting when moderate speed gain is OK.

I have a F350 6.7 towing a 35' 5er and have never used manual shift. I just press the throttle and let the truck decide where it needs to be. Works fine going up Colorado mountain passes.