2005 Mercedes G-Class Owner's Manual - Page 157

Controls in detail Differential locks A few words about differentials and differential locks When a vehicle negotiates a turn, wheels on the outside of the curve must travel farther and rotate faster than the inside wheels. The differential, the operation of a set of gears that allows the powered wheels in a vehicle to turn at different speeds, makes this essential function possible. The drawback is that the differential also sends most of the engine's power to the wheel with the least load or strain on it. For example, if one of a vehicle's powered wheels sits on a patch of snow and spins because there is no traction, all of the engine's power will go to that wheel because the power will take the path of least resistance. Meanwhile, the opposite wheel, sitting on dry pavement where it could get enough grip to start the vehicle moving, sits idle because it receives no power. The Electronic Traction System (ETS) addresses this problem and provides for good control and steering ability by automatically slowing the slipping wheel and thus increasing the power to the other non-slipping drive wheels to get the vehicle moving. The ESP and ETS in this vehicle feature such intelligent limited-slip differential technology, ideally suited for on-road and light off-road driving. Transfer case position LOW ( page 154) also enhances off-road driving capabilities ( page 223). More extreme off-road conditions may call for another solution, engaging a differential lock or preventing the differential from operating altogether. As part of its standard equipment, this vehicle comes with three differential locks: front, transfer case (center) and rear. Each can be engaged simply by pushing dashboard-mounted buttons in sequential order (center, rear, front) ( page 158). When the transfer case (center) differential is locked, half of the engine's power is automatically distributed to the front wheels and half to the rear wheels. When the rear differential is locked, power going to the rear wheels is equally distributed, so that both rear wheels turn at the same speed and torque. When the front differential is locked, all four wheels now turn with equal power and torque. Please be aware that engaging the differential locks will significantly reduce the steering ability of the vehicle. For your safety and the safety of others and to prevent damage to the vehicle, the differential locks must not be engaged when driving on paved roads. It is important to understand that during on-road/paved driving, differentials are absolutely necessary for providing the essential control and steering ability of the vehicle. The differential locks, therefore, must not be engaged when driving on paved roads and should only be used to the extent necessary to negotiate off-road conditions which cannot be handled by the systems (automatic 4-ETS, the ESP, manual switch position "LOW" of transfer case) this vehicle comes equipped with. 157