First time towing in mountains

[Telstar]

My 2005 F-350 diesel worked well with tow haul maintaining a safe speed on steep downhills. My new 2018 Ram 3500 is even better with exhaust break. Watch your downhill speed, don’t let your trailer be in control.

[JimMorrell]

Yes! This is normal. The transmission will automatically shift down. I've never had it go from a high gear all the way to 2nd in one shift, but then, I know how it works and "manage" the transmission and gearing according to the terrain. Its a good system, but read up on it and practice. You can do so without the trailer connected.

[rodigio]

thank you all so much for the info and advice.
next time it happens we won't be so totally panicked.
and yes the red line is around 6000 but i was afraid it was going to keep increasing from where we were at 5000.

[rlh1957]

Don't be afraid to touch the brakes to slow and keep it safe and from running away. There is a difference between touching and using the brakes and riding the brakes.
The engine won't go over the redline, they have built in limit sensors that start cutting engine power if it over revved. On an 7% grade downhill you may find some brake use still necessary to stay in the safe zone for speed. Don't let that trailer control you.

[lbrjet]

If 2nd gear held your speed constant then you were in the correct gear. The truck may have startled you, but it did it's job as it was designed to.

[elchilero53]

Perfectly normal. Had a 2014 Tahoe LTZ as a tow vehicle and the first time we took a long trip with it, I had the cruise control set to 40 but turned it off as we were crossing steep mountain passes. As we descended into Ouray, the truck automatically downshifted to maintain 40 mph. I wasn't expecting that and shifted into manual shift to control my speed without using the breaks. This also happens in tow/haul mode after setting the cruise while driving on the flats then disengaging for driving up and down hills; the truck automatically does this. Someone mentioned the truck learning your driving patterns. Maybe. Anyway, your truck is designed to perform the way you described no matter how startling is was for you.

Since this is your first time driving in the mountains, slow down coming to a down-grade. Something that is frequently repeated is don't drive faster on the down-grade than you drove going up when on steep hills or mountain grades. Watch what the truckers are doing and stay off of your brakes. Slow and easy wins the race!

[johnlochbuie]

Do not listen to the guy that said try next time with towing jail turned off leave it on truck was doing what it should do you don't want it in higher gear if not you will be riding brakes all the way down and that is not what you want to do

[madatme]

it's called grade logic, programed in the tcu

[LTnTN]

Once you apply the brake in towing mode, the downshifts will come automatically. All manufacturers have got much more aggressive with the downshifting. I watch TFL Trucks and seen it in action in their videos. Since the ECU’s and transmission controls can calculate what the engine speed will be, it shouldn’t ever put you into a redline condition.

[Lighting546]

Federal law prohibits greater than a 7% grade on the interstate highway system. However, that law does not apply to state, county or U.S. highways (yes, there is a difference). In some states it is illegal to drive down the highway with your 4 way flashers on, Florida is one of those states.

As a general rule, you should go down a hill one gear lower than what you used to go up the hill. In a Ford (gas or diesel powered) truck, select M instead of D and use the +/- buttons on the shifter stalk to change gears, then when you're at the bottom of the grade you can then go back to Drive and let the computer take over until you reach the next large hill you have to crest.

The last time I went up U.S. 19 south in West Virginia I had 45,000 pounds in my trailer, and because the carrier that I was leased to screwed up when they set the governor I wound up having to pull the last 3 miles of the hill in 3rd gear. I was driving a 2006 Peterbilt 379 with a C-15 cat, shortly after that load I traded the truck in for a 2005 Peterbilt 387 with the C-15 cat motor.

With the older truck I didn't have those kinds of problems going up hills or mountains because the governor was not set to limit the max engine rpm, it was set to limit the top speed to 68 mph. Granted Mont Eagle (I-24 outside Chattanooga TN) is not as steep as U.S. 19 is, but I could go up that mountain in 5th or 6th gear at 40-45mph with a 45,000 pound load. The best I could ever do on that mountain with the 2006 Pete was 30-35mph with the same size load in the trailer.

The problem with turning tow/haul mode off while you're going down the road is, when you turn it back on, you have to press the brake pedal a minimum of 3 times before it will reactivate.

If you turn it on before taking it out of Park, it will activate immediately and work the way the engineers designed it to work.

Immediately after I start my F-350 (diesel and factory tune), I turn on the separate engine brake, whether I'm towing or not. I rarely use tow/haul mode as my 5er is less than 11,000 pounds loaded and I don't need the extra torque to get things moving or when going up hills.

As soon as Banks Power has the Derringer tuner for 2016 or older 6.7L powerstrokes available, I am installing it in my truck. since it hooks up to the ODB port it doesn't leave any tracks in the ECM or PCM.

The bumper to bumper portion of the factory warranty is expired so now I'm on the extended 15year / 150,000 mile powertrain warranty that the dealer gave me when I bought the truck 3 years ago. It only has 18,000 miles on it at the present time.

I didn't go on a lot of camping trips with the old 5er, but now that I have a brand new 5er I plan to start going on much more frequent and longer trips so I can start crossing things off of my bucket list and really enjoy my retirement from the rat race known as employment.

[Boz]

Someone probably already mentioned this but my 2016 GMC 2500 has a down grade assist package. It basically engine brakes you if you are trying to brake down a grade. On the Sierra you can turn it off by pressing the tow/haul mode button for three to five seconds. It scared the crap out of me the first time it happened to me too. To my credit I wasn't in the kind of mountains you were in though...

[Thearcher01]

Ford's tow/haul is a little extreme when it comes to downshifting, especially if you touch the brake. I have had to disengage the tow/haul on my F-150 for fear of damaging the transmission or engine because the computer or whatever controls the shifting goes way beyond what I think is safe for downshifting.

[rlh1957]

I don't have to use M on trsnsmission. My 2019 F350 in Tow Mode and Exhaust Brake set to Auto upshifts and down shifts. If you set the cruise it maintains your speed even going downhill. I am always ready to use the -/+ overide and downshift if I don't like the speed or things change. I rarely need to use M. But even in drive the -/+ on shifter still works just like in M.

[Superdutymike]

My 2019 f250 gasser does the same thing but its actully not over revving the engine my tt weighs about 9800lbs