2018 4WD Operation Question
 

Looking for some friendly advice, experiences, or helpful hints here. I just recently acquired a new 2018 F-150 XLT SuperCab 3.5 EcoBoost 4WD. My only previous 4WD truck was a 1984 Toyota 4WD with 5-speed manual tranny, manual transfer case, and manual locking hubs, so my new truck is quite a paradigm shift for me in terms of 4WD operation. My model F-150 only has the 2H, 4H, and 4L modes of 4WD and doesn't have the 4A-Automatic selection option.

The 2018 F-150 Owners Manual states that 4H:, "Provides mechanically locked four-wheel drive power to both the front and rear wheels for use in off-road or winter conditions such as deep snow, sand or mud. This mode is not for use on dry pavement." The manual also states, "Do not use 4H or 4L on dry, hard surfaced roads. Doing so can produce excessive noise, increase tire wear and may damage drive components. 4H or 4L modes are only for consistently slippery or loose surfaces."

I live in a section of the mid-South where we experience usually less than 3 months of winter weather, mostly light snow and ice events. Do the guidelines in the owners manual mean that I do not need to engage 4H 4WD unless the road is completely covered by packed snow (road is white and you can't see asphalt underneath) or there is a consistent layer of black ice? As with many areas of the country that have to deal with winter weather, road conditions vary from subdivision and city streets that receive little to no snow removal to Interstate and State Routes that are very well maintained, but may have a layer of slush that has yet to be plowed over to the shoulders. These differing road conditions could and do potentially change every few miles based on roadway type, winter weather treatment, and/or conditions. On a single trip, should I be constantly worried about shifting into and out of 2H to 4H and back to 2H based on the road conditions so as not to cause too much wear on the 4WD drivetrain components or should I just put it in 4H and let her roll?

Thanks in advance for your input and Happy Holidays!

I learned to use 4x4 when you are driving in constantly slick conditions or a place where you'd otherwise get stuck (road is white and you can't see asphalt underneath). The only other time I use 4x4 is for additional brake control when doing straight hill descents.

Otherwise it stays off.

4H does not work like AWD for the reasons the manual states.

In your case, I would have no issues in turning it on and off as deemed necessary per road conditions. That is why a lot of the newer systems are electronic based rather than shifter-based.

Don't use 4wd unless you need the extra traction. If the rear wheels start slipping and spinning, then you need it.

I'm going to offer my advice, which is somewhat different than glc's (but his is quite sound). I put my truck into 4WDH whenever I think the road is slippery, but not necessarily for a rain covered road. (I just slow down a bit to avoid hydroplaning in rain.) But, it the road had a layer of ice or packed snow on it in frequent places, I would use 4WD, and would not wait for a slip to tell me to do so. I also engage it on a Forest Service dirt road in the mountains, because I think it can give me better control on those twisty, often rough surfaces.

But, the Owner's manual is correct in telling you to NOT use it on a paved surface that is dry, because you will be constantly skidding one or more of the wheels as you navigate turns. This can also put strain on the drive systems. What's more, you'll find the steering will feel "squirrely", in that case, which is a clue to turn 4WD off.

- Jack

I like to 'exercise' my 4x4 every now and then... I get stuck in traffic a LOT living in Western Wa, so there are times where I'm going straight ahead and in stop and go traffic on a hwy where the speed limit is 60 mph... If I think about it, I'll pop it into 4H while I'm going straight..

Sure, if there are turns or going more than 35 mph, I don't do it... Duh..

I even use my 4L when backing in my trailer to it's spot next to the house, as it's a steep, gravel driveway and it just backs up easier..

But, that's just what I do and if you don't agree or don't want to do it, that's fine, just don't do it... It's just what works for me and I've not exploded any of the drivetrain and it always works when I do want it to for those 4x4 moments I do get into every once in a while. :)

Good luck!

Mitch

All good advice. Thanks y'all!

The only time you have to be stopped is to go into 4L and then you also need to shift to N. Well, at least for my 13...

You can/should be able to shift to 4H "at any forward speed".. I just choose to keep it at under 35. I've gone faster when it's on snow or gravel or sand many times, but when I "exercise" it on the road, I make sure I'm only going straight.

Good luck!

Mitch

My changing into 4WD is a lot like Mitch just described, but I've done it at around 50 mph with no problems. We recently returned from a trip to the Grand Canyon and on the trip to it, had to drive over snow and ice covered roads on the Colorado Plateau south of Flagstaff. Whenever I saw snow on the road coming up, I simply shifted into 4WD (on a straight patch of road) and then shifted back out when the road was clear. Had no difficulties at all.

- Jack

You can safely shift in and out of 4H at any reasonable speed, that's why they call it "shift on the fly".. It's not possible to shift in and out of 4L unless it's in N and foot is on the brake.

make sure to use the 4 WD system (4 hi and 4 lo) and thoroughly exercise it at least once per month. If you don't you might find that it will not work when you need it.