FORCE4x4.COM
Where world class
performance speaks for itself
Ain't no poser
If you are impressed by cheap plastic and fake wood, the Gurkha is
not the vehicle for you. 
If you want
unrelenting world class performance, you have few options other than
the Gurkha.
Links
Gallery
Click here to see pictures of the vehicles.
What is so great about differential locks?
For those who are unfamiliar with the differential, it is the big spherical "thing" in the back of your car sitting between your two rear wheels (in case of rear wheel drive).
Before highlighting the power of differential locks, one needs to understand the purpose of the differential gear mechanism. It is not an exaggeration to say that the automobile revolution would not have happened if the differential had not been invented. When you are driving straight ahead, both your left and right wheels are spinning at the same speed. But when you take a left turn, your right wheels must travel a longer distance than your left wheel.
In short, without the differential you cannot steer your car on dry pavement. It allows one wheel to spin faster or slower with respect to the other wheel, thus allowing the vehicle to turn.
This is all well and good, but the differential also has a bad quality. It transmits power to the wheel that has the least resistance (grip). In layman's terms, when this happens, you get what is called as wheel spin, where you step on the accelerator pedal, one wheel just keeps on spinning and your vehicle does not move.
See picture below where the right rear wheel is spinning but the vehicle is not moving anywhere.
If you go off road, you are bound to go into terrain that will cause wheel spin. Once you get wheel spin in both the front and rear axle of your 4 wheel drive, you cease to move. It is a bad situation to be in, especially if you are stuck deep inside the jungle. There is no easy way to get out of it UNLESS YOU HAVE DIFF LOCKS.
A differential locker is a simple device that when activated, simply negates the functioning of the differential gear mechanism. Once the differential is locked, power is transmitted equally to both the wheels immaterial of whether it is spinning or not.
See picture below where a vehicle with locked differentials is able to make it through the same ditch without any problems. Once you cross the hazard you just unlock your differential and drive on like a normal vehicle!!!
The basic mechanism of the diff-lock is shown in the schematic below. When activated, it locks one of the half shafts to the differential gear housing, thereby negating the differential action.
