New to electronic 4x4 - educate me

[Kliferd The Big Red Truck]

Learned to drive on a ‘95 F-150 with manual hubs and fully manual 4x4 (dad didn’t want any of the new electronic stuff). My last 2 trucks were RWD.

1. I read I should engage 4H monthly/quarterly on a drive home from work to “exercise it”. Seems logical.

2. Do I need to periodically engage 4L and crawl around some? Good idea?

3. 4H doesn’t appear to turn off with key cycle. If I don’t put it back in 2H will it stay in 4x4 “forever”?

I live at the beach so short of going in the sand in the OBX, 4H won’t be used much. We typically get one good 6-10” snow event a season.

 

[donmatteo]

1. Only if you want your 4X4 system to explode on dry pavement.
Ford explicitly prohibits using 4H or 4L on dry, hard-surface roads because it can increase tire wear and damage drivetrain components. Use a suitable loose-gravel or dirt surface instead. A straight road is not an exception to Ford’s warning.


2. No. A straightforward check is to stop on suitable loose ground, hold the brake, put the transmission in Neutral—not Park—select 4L, and wait for confirmation. Then select Drive and move slowly. To exit, stop, return the transmission to Neutral, select 4H or 2H, and wait for the shift to finish. Ford’s actual requirement for shifting into or out of 4L is 3 mph or less, with the transmission in Neutral; stopping satisfies that requirement.

3. It does not reset - The 2023+ Super Duty manual specifically explains that even when the driving program returns to Normal, the four-wheel-drive setting can remain as selected during the previous ignition cycle. “Normal” drive mode does not necessarily mean “2H.”

AUTO on the front hub dials does not mean automatic all-wheel drive. It allows the hubs to operate automatically with the selectable 4WD system. Ford says to leave both hubs in AUTO for normal operation; the manual LOCK position is available if automatic engagement fails. Both hubs should be in the same position.

Make occasional 4H/4L checks on an appropriate surface, especially before anticipated use, rather than adding a dry-pavement “exercise” commute. And make selecting 2H afterward part of the routine.

I'd recommend reading the owners manual......twice in your case.

 

[Kliferd The Big Red Truck]

That seems utterly reterded… when it snows here you go between cleared pavement snow covered side roads. Never heard of a 4X4 system you can’t use on asphalt.

Sure I can’t to excessively tight turns or figure 8s.

My dad’s F150 auto shits to 4H when you put it in sport mode.

 

[donmatteo]

That seems utterly reterded… when it snows here you go between cleared pavement snow covered side roads. Never heard of a 4X4 system you can’t use on asphalt.

DRY asphalt. I literally said....DRY.

"Ford explicitly prohibits using 4H or 4L on dry, hard-surface roads because it can increase tire wear and damage drivetrain components. Use a suitable loose-gravel or dirt surface instead. A straight road is not an exception to Ford’s warning."


You said "1. I read I should engage 4H monthly/quarterly on a drive home from work to “exercise it”. Seems logical."

Monthly or quarterly indicates DRY roads at times....unless you live in snow 365 days a year.

 

[donmatteo]

My dad’s F150 auto shits to 4H when you put it in sport mode.

No...It shifts into 4A. Not 4H.

There is a huge difference between 4A and 4H.

Super duties DO NOT HAVE 4A

 

[RS90]

Shifting into 4H while driving on a straight dry road isn't going to hurt anything. If you start trying to turn you will bind up the drive line and that isn't great for it but its also not going to cause it to explode. Just make sure you dont have your rear tires spinning faster than the fronts when you do it. Ideally you should be off the throttle completely and coasting for a few seconds before hitting the button.

Every winter I use 4H driving on snow covered roads and usually forget to turn it off when pulling into a plowed parking lot. Some how my trucks have survived for the last 20 years without problems. Ive also shift in and out of 4h well above thr maximum speeds fird recommends.

Yes you should shift it a couple times out of season just to keep things moving and verify the hubs still lock automatically.

 

[Kliferd The Big Red Truck]

Does the truck not automatically prohibit you from shifting over the recommended speeds?

Also, I don’t understand what you guys are talking about the driveline binding when the trimmer specifically has unlimited slip front differential

 

[MrFancypants]

I always use 4H when driving forward onto ramps (on pavement). This helps pinch the ramps rather than push them. You aren’t going to shrapnel your transfer case if you use 4H on dry pavement. Ford just knows the average moron doesn’t think how these systems work and it is safer to just “put it in the manual”. I guarantee you there are idiots that leave it in 4H all the time assuming it is 4A!

Of course turning on pavement is bad but it also doesn’t cause immediate damage. You will hear the drivetrain chatter and that is your indication you are doing something stupid. Use common sense and use 4WD when you actually have a traction issue.

Testing it monthly is more for assurance that it will work when you need it. If you don’t test it frequently that doesn’t mean it will fail on you. It is not a super complicated system.

 

[donmatteo]

Does the truck not automatically prohibit you from shifting over the recommended speeds?

Also, I don’t understand what you guys are talking about the driveline binding when the trimmer specifically has unlimited slip front differential

Unlimited slip?

you mean limited I hope.

 

[donmatteo]

I guarantee you there are idiots that leave it in 4H all the time assuming it is 4A!

This is what I think the OP's issue is. He's comparing a super duty that has 4H and 4L with his dad's F150 that has 4A.

 

[RS90]

Does the truck not automatically prohibit you from shifting over the recommended speeds?

Also, I don’t understand what you guys are talking about the driveline binding when the trimmer specifically has unlimited slip front differential

Yes you have a limited slip up front and either open or locked in the rear depending on if you hit the locker button.

The transfer case doesn't have a differential gearset in it though so it can't allow the front or rear to spin at different speeds. When you turn on 4H/4L the front and rear must spin at the same speed. This wont happen in a turn because the rear is going travel a slightly shorter distance than the front.

You can try it easily enough. Go find a parking lot and put the truck in 4H. Now slowly move forward at idle and start turning. The truck will eventually stop moving in its own as the front and rear bind up. You can give it a little gas and eventually you'll feel/gear one of your tires slip as the truck moves.

I use my 4wd all the time at home because I park all of my trailer in grass. usually when I pull back into the gravel driveway the truck will get enough traction to start binding up until I remember to turn it off.

 

[Kliferd The Big Red Truck]

I get it now… don’t realize it would have enough difference to be an issue. No viscous coupling in the transfer case.

 

[Kliferd The Big Red Truck]

So how do these trucks do rock crawling on firm hard rock? I have to imagine the systems have some robust tolerances.

 

[Donnie With A Dee]

So how do these trucks do rock crawling on firm hard rock? I have to imagine the systems have some robust tolerances.

You're literally creeping up and over rocks in rock crawl mode in four low. There's wheel slip involved as it goes up and over rocks. Very minimal. I find rock crawl mode useful when in riverbeds.

 

[HeavyAssault]

Given some of the possibilities of using 4H that one can encounter the use of the ESOF (Electronic Shift On the Fly) can be done at higher speeds but with some real caution. As the way the hubs engage the front stub shafts you can have some serious noise if the hubs don't align properly. One thing is to not be on the pedal applying power, so to allow the hubs to mesh properly to the front stub shafts.
As far as using 4H "offroad" make sure it's engaged BEFORE you get stuck. That way the hubs are rotating properly to align and lock in.
The "LOCK" position is there just in case there's a system problem or you are already stuck with the wheels not able to be rotating.

Just ask questions if you want to learn more. That's what we are all here for.

 

[Godzilla/Tremornator]

my option & explanation for what it's worth

the engagement exercise is to insure the hubs engage when needed. the driving in 4x4 (H or L) isn't an issue I've ever heard of, if the hubs engage.

the 2nd reason for the manual hubs is not just if the hubs won't engage in auto. on long stretches of acceleration vacuum is lost. the hubs can possibly lose vacuum & disengage if in this situation. manual engagement prevents this situation also.

i engage my hubs weekly. just cause. i don't worry about driving in 4x4 for any substantial time. just enough to insure the hubs engage

straight driving in 4x4 will not damage anything. turning is where the stress occurs.

when turning the front tires travel on a larger circumference than the rear tires. the rear tires tend to push the front tires. this is what causes the truck to not turn well in 4x4 mode. (H or L) this is also the binding others speak of. at speed & dry pavement you run the risk of tearing stuff up. whether it's a diff or transfer case or both. damage isn't certain but it is very possible & should be avoided.

just a slightly different take on it.

as previously stated, any further questions share & maybe we all learn more

 

[Apples]

A straight road is not an exception to Ford’s warning.

straight driving in 4x4 will not damage anything. turning is where the stress occurs

This.

I have owned my SD Tremor for 15 months and have at least once per month before Moab's trails last week exercised my truck's 4WD in both 4H and 4L and with Warn Premium Manual hubs engaged.

I just don't turn the steering wheels when doing so in very large aerospace business community parking lots on Saturday mornings when returning home from the local cars-N-coffee meets.

Truck worked perfectly in Moab last week, and we were waaaaaaay out there for 12 hours last Saturday. My favorite Mexican restaurant was just about to close when I stopped after 9:30PM on the way back into town. Chicken enchiladas w/ a side o' frijoles never tasted so good.

 

[ramv]

Extended 4WD use on roads that are dryish will lead to additional driveshaft and Ujoint wear. Cycling one a month while driving (I try to be on dirt) will help lubricate the front differential and cycle everything so reducing any risk of sticking.

It’s interesting on slick rock in Moab , specifically Hells Revenge, how much rubber is left on trails (due to the binding 4WD causing tire slipping)

 

[HeavyAssault]

the 2nd reason for the manual hubs is not just if the hubs won't engage in auto. on long stretches of acceleration vacuum is lost. the hubs can possibly lose vacuum & disengage if in this situation. manual engagement prevents this situation also.

Is this a gasser thing??? Never heard or read of anyone giving this as an issue with ESOF.

 

[Phillbo]

You said "1. I read I should engage 4H monthly/quarterly on a drive home from work to “exercise it”. Seems logical."

Monthly or quarterly indicates DRY roads at times....unless you live in snow 365 days a year.

What if he works at the end of a long dirt road.