You can do this and I believe Ford even recommends doing it for a few miles every so often to get the lubrication moved around.

You may get a little extra noise up front. But no it isn't a problem to do so.


-bn

 

Actually now that I think about it. If this is the ESOF system the hubs should function as a backup to that system. Meaning you lock the hubs manually if the ESOF system fails. At least that is the way I understand it to work. May not work this way on early vehicles.

-bn

 

I leave the hubs locked during the fall and winter. For our trucks, its not a big deal - the only difference you might see is a slight drop in gas mileage due to the increase drag of locked hubs. The only reason I unlock them every few months is just to move the internals so they dont 'freeze' in place.

 

You can get auto hubs, but a lot of people convert back to manual. It's kind of "It's not a Jeep" thing! LOL

Keeping the hubs locked is fine except that it decreases mileage a slight amount and will wear the front diff gears/u-joints unnecessarily. My suggestion is to keep them locked when you are needing to pop in and out of 4WD often and unlock them when you are on long road trips.

 

The "extra wear" thing is 99% BS. If you're not putting any torque through them then they're not wearing measurably.

 

Yo,
"...Manual Hub OPERATING INSTRUCTIONS: ONLY use fingers to turn dials. DO NOT USE PLIERS. Set the hublock dials to “FREE” and transfer case to 2-high for all driving that does not require four wheel drive. To engage four wheel drive set the hublock dials to “LOCK” and set the transfer case to 4-high or 4-low. Return the transfer case to 2-high before disengaging hublocks. Do not drive on hard surface roads in 4-wheel rive because it can cause drive train damage. Do not move the vehicle if the hubs are anywhere between “FREE” and “LOCK” or it will damage the hublocks. Driving with only one hublock engaged can cause drive train damage. Driving with the hublocks in ”FREE’’ and transfer case in 4-low can cause drive train damage. To ensure lubrication of the front axle, engage hublocks for a minimum of one mile monthly..." Source: by Warn®
&
SERVICING INSTRUCTIONS: Service at the same interval as wheel bearings. Clean and lightly grease
internal working surfaces.
Source: by Warn®
Ford specifies XG-1-C Motorcraft® Premium Long-Life Grease

 

It also messes with steering alittle

 

Gives you a little more versatility for various conditions and usage. It's a Bronco... not a Jeep.
You can convert to auto-lock, as Scoop said... if you feel the need to make it more like something else you're used too.
I prefer manual hubs... but I've never owned a push button 4x either. :shrug

I did have a Heep CJ once the had a hydro-switch on the dash though. :toothless

 

Because it turns the front drivetrain while you drive, which puts more wear on components and reduces fuel efficiency and on road performance. Most jeeps just spin the front drivetrain the whole time. If you look at them going down the road the front U joints are spinning the whole time. Makes it quick to get in 4wd, also means you're up shits creek if something happens to the front drivetrain. I've seen jeeps get towed because something in the front diff let go, that won't happen with a Bronco.

I lock mine when I go offroading, I only unlock them when I'm ready to go home or have to drive at high speeds on pavement.

Actually now that I think about it. If this is the ESOF system the hubs should function as a backup to that system. Meaning you lock the hubs manually if the ESOF system fails. At least that is the way I understand it to work. May not work this way on early vehicles.
No, that's not how it works.
-bn

The "extra wear" thing is 99% BS. If you're not putting any torque through them then they're not wearing measurably.

That's the theory all the new cars that have cv axles up front. The trailblazer developed a vibration from one of the axle shafts that hardly ever had torque on it. Also wore a nice groove in the disconnect gear.

 

That's the theory all the new cars that have cv axles up front. The trailblazer developed a vibration from one of the axle shafts that hardly ever had torque on it. Also wore a nice groove in the disconnect gear.

I see a lot more wear from infrequent use on trucks like ours (mostly in the form of lubrication not getting places it should, moisture getting places it shouldn't and corrosion) than over use from parts spinning without load on newer vehicles.

Literally every front (including drive shaft) U joint I've pulled has been in un-reusable shape (so that's probably around 20 or so). They all have worn spots from where they sit and the needle bearings are packed with rust everywhere else. Occasionally there's a hint of grease in them.

Literally every rear drive shaft U joint I've pulled (8 or so) except one has been reusable.

If disconnecting the second drive axle at the hubs was worth it in the long run every OEM would do it for the +1 mpg it offers.

 

To answer your original question, basically you have two pieces to the equation.

The transfer case connects the output from the transmission to the front axle. When it's in 2WD, power is only sent to the rear. When it's in 4WD, it spins the front driveshaft, which turns the front axles.

The hubs connect the axles to the hubs/wheels. If they're locked, when the axles spin, they make contact with the hub and turn your wheels. If they're not locked, and it's in 4WD, there's no connection so the axles will still spin, but not turn the hubs.

On the flip side, if the hubs are locked and you're in 2WD, the hubs turning will spin the axles, spin the front differential, and the front driveshaft, but there'll be no connection with the transmission/transfer case. This is where the use of unlocking them comes in as that's a bit of parasitic drag to be spinning all that stuff when you're not using it. It doesn't hurt anything, but there's no point in making the engine turn it all when you don't need to.

However, if you leave them locked all the time, you're really only decreasing your performance/mpg slightly due to the drag, and not much else.

 

No they wouldn't, for the same reason the OP started this thread.

Vehicles are designed to appeal to "the Masses", and are designed accordingly. Fooling with manual hubs is not something "the Masses" want to do. Auto hubs where an attempt around that, but had seriously poor reliability. From a sales and warranty pov, it's better to just let the front end spin and loose an mpg or two to parasitic drag.

This. They also aren't concerned with long term (100k+) reliability.They don't care if you need 2 new CV axles and a $500 disconnect for the front end of a 2wd vehicle at 140k, by then you're out of a warranty and they have their money. People are vain, they want instant gratification and they want it now. They aren't looking at the potential costs and problems that may occur down the road and the automakers therefore aren't going to worry about that. Its the reason "Lifetime fill" fluids have become a thing. It's why major engine work on a modern car often requires removal of the body. If you really think long term functionality and well being of the vehicle is the major concern for automakers you're kidding yourself. Priority #1 is to satisfy the masses seeking instant gratification.


As far as Parasitic drag most modern cars do have a way to disconnect part of the front drivetrain. Usually what they do is disconnect the axle on one side of the diff. The axles and spider gears still spin but the carrier won't which reduces the parasitic drag enough that any remaining is negligable. However this setup requires that all the front end components be in good working order and still causes some wear. If you get a leak in the front diff and don't notice the spider gears will run dry and grenade, same if a boot splits on the axle and throws all the grease out.
I've seen some new heavier duty trucks that have selectable hubs but instead of locked and unlocked they have auto and locked. There are benefits to disconnecting the entire front drivetrain at the hubs but for most vehicles the automaker chooses to please the consumer rather than worry about that.

 

Usually what they do is disconnect the axle on one side of the diff. The axles and spider gears still spin but the carrier won't which reduces the parasitic drag enough that any remaining is negligable. However this setup requires that all the front end components be in good working order and still causes some wear.

This called C.A.D.S. (Central Axle Disconnect System) It's a Chrysler thing, Ford doesn't use it and to my Knowledge neither does GM. The only disconnect in my 2006 F-150s front is at the Transfer Case. The entire front end spins the whole time.

I've seen some new heavier duty trucks that have selectable hubs but instead of locked and unlocked they have auto and locked.

That's How Super Duty's are. I dont know a whole lot about that system, but I would bet it's so when the Auto hub fails (They always Fail Open) you can still force the hub to lock.... But dont quote me on that :toothless

 

The hubs are basically switches; on and off position.
The 4WD lever is also an on and off switch.

The hubs lock the wheels to the front axles, on or off
The 4WD lever locks the transfer case to the front driveshaft, on or off

The hubs can be locked and the 4WD not be active because the 4WD lever is still in 2WD, just like the 4WD lever can be in 4WD and the the front hubs unlocked, which also means there is no 4WD connection to drive the front wheels.

When the hubs are locked the connection to the front axles is made, which causes the differential to turn which spins the front driveshaft, it doesn't mean you're actually in 4WD because you haven't completed the connection from the front wheel to the transfer case by putting it in 4WD.

Only when the hubs are locked AND the transfer case selector in 4WD are you actually "locked" into 4WD.

 

This called C.A.D.S. (Central Axle Disconnect System) It's a Chrysler thing, Ford doesn't use it and to my Knowledge neither does GM. The only disconnect in my 2006 F-150s front is at the Transfer Case. The entire front end spins the whole time.

The GMT 360 platform (trailblazer, envoy) uses it.

The Fullsize GM trucks also have a similar setup built into the front diff.

That's How Super Duty's are. I dont know a whole lot about that system, but I would bet it's so when the Auto hub fails (They always Fail Open) you can still force the hub to lock.... But dont quote me on that :toothless

I was under the impression that it was to keep them from disengaging when you change direction.

 

The GMT 360 platform (trailblazer, envoy) uses it.
The Fullsize GM trucks also have a similar setup built into the front diff.

I guess that shows how little I know about modern GM stuff.

I was under the impression that it was to keep them from disengaging when you change direction.

This could also very well be the case, or at least part of it.
:thumbup