4x4 Lockers - 4WD Explained

In this video presentation you will see what a 4x4 system is and how it helps with your off-roading.
2H - 2 High
Lets say we are driving our 4x4 and heading off road. We are in 2 high mode and the front axle spins freely while full power is sent to the rear wheels. This is what we use for the city or highway and gives better fuel economy.
Driving in 4WD on DRY PAVEMENT is usually not recommended. In many 4x4 vehicles the transmission box is locked when engaged and this causes friction between front and rear since the rear tires travel less distance than the front tires do.

4H - 4 High
Now the road surface turns into gravel. So -- we engage the 4 high mode.
Shifting into 4 high while driving is usually possible but you should keep a low constant speed and not engage it while the driveline is under strain. Check this out with your particular vehicle manual -- so you don't break anything.

What happens under the body is of course more interesting.
Now the front and rear axles spin at equal speed and power is distributed between the axels.
Using 4 high mode gives your truck the awesome traction needed for the off road.

Standard 4WD sends power to the wheel that has the least traction. So -- lets say that one wheel is on ice and the others are on sturdy ground, the one on the ice will be the wheel rotated!
Because -- now it will start spinning and you will not move at all!

This is when you can lock the transfer case -- sometimes called diff lock.
Now the other axle starts working also and the front wheels - in this case - start moving.
Since the front wheels have traction you get out of the stuck.
Lets say the conditions are getting worse and you engage the 4 low. In 4 low mode the 4x4 is ready for extreme off-road situations, like mud, rockcrawling and heavy snow or sand. The lower transfer case gear ratio gives greatly increased power at the slow speed needed. The role of 4 low is to lessen the strain on the engine and driveline and make control more accurate in low speeds and difficult terrain.

But what happens when one wheel on each axle looses traction?
Then they both start spinning and you are stuck AGAIN!

Lockers
Now having lockers is a must.
Engaging lockers on the differentials makes each pair of wheels turn at the same speed and gets you out.
Lockers are the secret ingredient to successful off-roading.
For most 4x4s - lockers are an aftermarket add-on. And they are really only for the most extreme off-road situations.

When you have active lockers in your front drive, normal steering is highly affected. In fact for a 100% locked front drive turning on hard surface is almost impossible since all wheels are forced to turn at the same speed.
So -- in conclusion.
Get to know your 4x4 and the way the controls work. Test these things before you go on your next off-road adventure.

Head Off Road with your 4x4 and visit us at:

4x4 Lockers - 4WD Explained

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AWD usually uses viscous coupling differential in the center. full-time 4WD uses center diff with H and L range capability

[jasonsong]

generally speaking 4WD usually mean part-time 4WD with a trasfer case in the middle.
if the vehicle has a center diff. then it is AWD or full-time 4WD. however now they have lockable center diff which can turn a AWD into a 4WD. I think the main difference between a 4WD and AWD is if it has a center diff or not.

[samsmall]

some of the terms that you used i.e. diff lock, are usually reserved for front and rear diffs, not centre diff/ transfer case.

AWDs have center differential that's called viscous coupling. which can't be locked or turned on & off. AWD is most similiar to Full-Time FWD from what I've heard. Full-Time FWD basically have a open center diff with high and low range unlike AWDs

[xoffroads]

You can use neutral when being pulled.

[RistaMotorista]

i wonder if ural 4320 and kraz 255b have these lockers

[xoffroads]

Not sure - but I imagine the differential is not locked when the ESP (Electronic Stability Programme) is active.

[prandomable]

never driven a 4WD vehicle before. Do you have to shift to neutral when switching for 2H to 4H?
And the speed must be 55mph or below right otherwise it will not be good for the transfer case?

[jasonsong]

if its a transfer case not a center diff, you cant turn in 4H because it will cause binding.

[servalpha]

I recently bought a calmini 6.5:1DL T-case gears for my zuk. Its due to arrive this week. Do I still need lockers so my zuk can hurdle really rough trails?

[geodezija]

Do you perhaps know, is it possible to make dry pavement turns with the new Ford Ranger in 4H mode, beacuse looking at the Ford catalogue it seems that in combination with ESP each wheel can turn independently??
TNX

[GuyInAChair]

I have often wondered that my self.
In short, with most trucks the transfer case in neutral allows you to be towed, for some distance safely. Long story short, most of the time when being towed, the tires turning, turns the diff, which turns the transmission. But the transmission isn't made to turn that way, so it gets damaged. Putting your transfer case in neutral prevents that.
When is it appropriate? Virtually never. Get a tow truck, don't get your friends to drag you home.

Got a question, isn't it not good to use part-time 4WD on dry pavement because it wears out the transfer case while turning a corner?? Also I know there's stock 4WD vehicle with rear locking diff but not front locking diff... maybe you can get front locking diff as well as a after market product.

[emiliotrainer]

I would like to obtain this video in spanish, it´s very interesting of course, how can i do? thanks from Chile.

[the_original_Bilb_Ono]

i have a question, when is it appropriate use neutral (N - with the 4x4 gear lever)?
it seems to be the same as 2h

[MaxedOut]

Thanks! I've just bought a 4x4 jeep and didn't know shit about the 4x4 mode!

[FranzKrammer]

I avoid the full locking center differentials ...LSD or limited slip differentials are my choice...meaning if just one of your wheels starts spinning, the LSD will turn the other wheel for you to get you going again. Essential for me...an LSD

[BadKarma]

I just got an old land cruiser 95 all time 4 wheel drive'. And if I turn left or right "sharply" it begins to make a click click click sound. Is that normal?

[AftComet]

Good video but damn it, turn off the background music. I want to hear only you.

[MyGTisxHUNTERx]

I have a question regarding my 2012 selverado, in the 4*4 knob (yes U can laugh because its not a lever Sigh) I can see these numbers in the fallowing order: 2H, 4H, N, 4L what does the N stand for? is it the same as the one in the gear box were U put it in Neutral to wait for the traffic light or what?