I've been a Dodge/Ram owner ('95 and '05) for 22 years and I'm jumping into the Ford family with a '17 F350 Supercab Longbed XLT due to land 12/26. (from reading some threads Ford won't come close to making this date?)
Anyway, I downloaded the owners manual to get a jump learning how to operate all of this technology. I ordered the floor shifter for 4x4 for the reliability. I was reading in the manual that you cannot drive the truck in 4L OR 4H with the hubs open (unlocked) as this may cause damage. (it states this for the manual shifter or for the electronic shift as well) and it is best to shift from 2H to 4H at 3mph or less (manual shifter only). Did I make a mistake my ordering the manual shifter?
Now I have owned 4WD vehicles my whole life and have always been able to shift between 2H and 4H on the fly on the highway. Also, on my 05 Dodge I added manual locking hubs and it was safe to drive in 4L without locking the hubs. That way you could drive steep grades on pavement in 4L without actually being in 4WD. This was a very nice feature especially when towing my toy hauler up a winding dirt road or menuvering it in a parking area on pavement.
Does anyone know the truth on how Ford's locking hubs / 4H /2H work without guessing or just giving an opionion.
I'm finally admitting....Ford has Ram beat now!!! I'm glad to be part of the team.

 

My Ford is a 2001 and like you I drive the steep mountain forest roads in 4x4 L, just to keep from cooking the brakes. I have manual Warn hubs.

Haven't tried to shift H to L while moving... guess someone else can answer that question

 

The manual tells you not to run it in 4L or 4H with the hubs disengaged. I've seen people on here talk about doing it, but I probably won't. When I am in the mountains (which is fairly rare) I've always found downshifting to be fine, on the couple occasions I wanted a lower gear (I was in a 2WD truck) I also wanted 4WD.

But, to answer your question, the manual tells you not to run it in 4L with the hubs disengaged on the manual shifter.

 

Don't do that. You need to be stopped with the vehicle in neutral.

 

I have the shift of the fly, which comes with the AUTO hubs. My only choices on the actual hubs are Auto and Locked. So when I use 4 Low, it engages the hubs as well. I too would like the ability to use the low range gears, without 4x4 engaged.

So either way, you end up in the same predicament.

 

you can shift from 2 hi to 4 hi at speed.


To go from 2hi or 4 hi to 4lo, stop, shift trans to N and then move the transfer case to 4 lo.


You can leave the hubs in the locked position if desired and just run 2hi till needed.


You can also unlock the hubs (free position) and use 4 lo for low speed like controlling the slow movement of trailers and such.

 

Just lock your hubs in ahead of time and you can shift into 4hi at any speed. You could drive with the hubs locked in for the life of the vehicle but there will be a slight loss of mileage due to the extra rotating parts and there will be more wear and tear on the 4wd parts.

I've never tried driving in 4lo with the hubs unlocked.

 

I have the manual hubs with manual transfer case and I have been shifting from 2hi to 4hi at highway speeds no problem. We've debated the ESOF 4wd and most prefer the electric but I'm with you I like the reliability of manual

 

Same here, you won't find me in any "ESOF not working" thread". Anyway, just got back from a Holiday trip over the pass, I shifted into 4hi at hwy speeds just like I have on all of my past SD's. No problem at all.

 

BINGO.

I have ran my work truck like this for 120,000 hard miles and never had a problem. With manual shift you also have manual hubs

 

You need to be good at matching the RPMs to the low range speed. Extremely difficult with an automatic, moderately difficult with a standard transmission, a thing of the past for the super duty. It is like shifting a non syncro transmission, you need to double clutch.

As far as the comments about not running in 4L without the hubs turned in the conventional wisdom is the distribution of torque. Using 4L simply as a speed control when hitching trailers or other slow motion operation of the vehicle in my opinion is perfectly ok. Trying to pull a stump out of the ground or move a bulldozer or pull the space shuttle without distribution the torque to the front and rear wheel is a recipe for a broken driveshaft or worse. Even with the hubs locked I broke both yokes in the front axle once trying to pull a stuck concrete truck out on a jobsite using 4L when I had reasonable traction at all 4 wheels. Too much torque for just 2WD

 

Rasalas, I pretty sure you gave me my answer. I too believe Ford says not to run 4L with unlocked hubs due to torque management as well. If your not careful it would be too much torque going to just one axle. Maybe I can get this verified one day so when I'm pulling or menuvering my toy hauler in 4L with unlocked hubs I won't be so paranoid about doing some other type of damage. Also, I figured you could shift from 2H to 4H at speeds because you can in any other manual shifting 4WD truck I have ever known of. I just needed to hear it. I am now happy once again that I ordered the manual shifting as with the electronic shift you are now relying on not only the electric shift in the transfer case but also the electric shift of the hubs. Too much to go wrong.
I can't understand why Ford would have auto and lock on the electric hubs? Why not just auto? Just in case they fail?

 

Yeah, I know that, but if a person doesn't know whether or not you can shift to 4L from 4H 'on the fly', then it's best not to try to explain the procedure you mentioned to that person.

 

I personally am not interested in shifting from 4H to 4L on the fly, just 2H to 4H and back. It sounds dangerous trying this.

 

Torque? I had a 2004 CC with 5.4 gas for work. A wrecker was trying to pull a truck that got stuck. Well the wrecker got stuck as he pulled himself off the pavement. So I was going to pull the wrecker back onto the pavement and anchor him. Hooked a good chain (wreckers tow chain) to the wrecker. I put it in 4L and started to pull. That 5.4 did not even appear to strain but I knew I was pulling then POW BANG. That chain popped and flew back at the wrecker hitting it. Lesson learned.