2009 Dodge Durango Owner Manual - Page 302

300 STARTING AND OPERATING WARNING! Always engage the parking brake when powering down the vehicle if the ؆SVC 4WD Warning Light" is illuminated. Not engaging the parking brake may allow the vehicle to roll, which may cause personal injury. NOTE: Do not attempt to make a shift while only the front or rear wheels are spinning. The NV 244 Generation II transfer case is not equipped with a synchronizer and therefore the front and rear driveshaft speeds must be equal for the shift to take place. Shifting while only the front or rear wheels are spinning can cause damage to the transfer case. When operating your vehicle in 4WD LOW, the engine speed is approximately three times that of the 4WD or 4WD LOCK positions at a given road speed. Take care not to overspeed the engine and do not exceed 25 mph (40 km/h). Proper operation of four-wheel drive vehicles depends on tires of equal size, type and circumference on each wheel. Any difference in tire size can cause damage to the transfer case. Because four-wheel drive provides improved traction, there is a tendency to exceed safe turning and stopping speeds. Do not go faster than road conditions permit.