2002 Mercedes G-Class Owner's Manual - Page 254

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 allow the powered wheels in a vehicle to turn a different speeds, provides for this essential function. 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 gets 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. The position "LOW" of the transfer case (see pages 247and 226) also enhances off-road driving capabilities. More extreme off-road conditions may call for another cure which is to engage a differential lock, preventing the differential from operating altogether. This vehicle offers as standard equipment three differential locks: front, transfer case (center), and rear. Each can be engaged simply by pushing a dashboard-mounted button (see pages 253 and 254 for engaging differential locks). 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 steering ability of the vehicle. Driving systems Instruments and controls Operation Driving 251 Instrument cluster display Practical hints Car care Technical data Index