ifit4x4
by Piet van Heerde
iplan4x4
itour4x4
idiff4x4
How does a differential work
The following video is the best explanation of how a differential actually works
Different Differential configurations
Old school standard 4x4 with hubs:
In the old school standard 4x4 setup you would have a front and rear differential in your vehicle. You would also have a central transfer case, that drives these differentials and you would have the freewheeling hubs on the front wheels.
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In normal driving the transfer case only drives the rear differential. When you engage the 4x4 lever inside the vehicle, the central transfer case, supplies both the front and rear differentials with equal power and speed. As if the center differential is locked.
To reduce wear and strain, the front axle have been fitted with freewheeling hubs. This is the final engagement to get power to the front wheels. Now you have four wheel drive.
All wheel drive: (permanent 4x4)
In this setup you would have a differential in the central transfer case as well. This is in order for the front and rear differentials that is turning at different speeds when cornering to match up. Especially on a hard surface that can cause windup in your axles. This is a very safe drive setup as all wheels will receive equal power, but if one wheel is slipping, all the power will go there.
Center differential lock:
The center differential lock is to overcome that problem of all power going to one wheel. You will thus lock the center differential as if a solid axle with same power to go to the respective front and rear differentials and thus more wheels will receive equal power, but if two wheels are slipping, one in front and one in the rear, you are still stuck.
Limited slip differential:
Some vehicles are fitted with a limited slip differential, mostly in the rear differential. This would mean that some of the power will be transferred to the slipping wheel in order to get unstuck. This could also be achieved by engaging the handbrake to an extend but you need to have experience with that.
Differential lock:
A Differential lock is where you can lock both wheels on the same axle. This will have both wheels turning at the same speed and receiving the same power. It is very helpful in off-road conditions where traction is lost and all the power goes to one spinning wheel with the least resistance. You can have a differential lock on your rear or front differential but normally on the rear first and then on the front.
It is important to know that you can not drive with the differential locked, as soon as your are out of the obstacle you must switch it off. If not switched off or disengaged you will have windup of you axle and could lead to serious damage.
Traction control:
Traction control is an electronic system that is designed to assist with getting the best traction. Essentially what it does is it works with your brakes and whenever there is a wheel slipping or spinning, the system will apply a brake to that wheel. Hereby it changes the power going to the spinning wheel and transferring the power to the wheel that has traction. Personally I do not like that system as it requires a wheel to spin before anything happens.