What is the difference between Full-Time 4WD and Part-Time 4WD systems? Full-Time 4WD systems utilize a center differential, which enables the front and rear driveshafts to turn at different speeds, thereby allowing engagement on dry surfaces for normal driving conditions. A Part-Time system does not employ a center differential and locks the front and rear driveshafts together. With a Part-Time system, 2WD mode should be used during normal driving conditions and 4WD mode is to be used only when off-road or on wet or slippery surfaces.
Why can't you use Part-Time 4WD on dry surfaces? Part-Time 4WD systems effectively lock the front and rear driveshafts together, forming a single driving unit that does not allow for differential action between the front and rear driveshafts. Driveline noise and binding (Crow Hop) may occur when operated excessively on dry surfaces or in turns. This binding can lead to heat buildup and early part failure.
Why does "Crow Hop" occur? When a vehicle turns, each wheel rotates on a different radius to the turning circle, thus traveling at different distances and speeds. If the vehicle's front and rear axles are locked together and are turning on dry surfaces, the difference in wheel speed sometimes results in driveline binding that is released with a "bang" or vehicle "shudder" when one of the tires loses traction.
How long can I drive in 4WD High Range? Shifting into 4WD High Range can be made with the vehicle stopped or in motion. If the vehicle is in motion, shifts can be made up to 55 mph (88km/h).
How long can I drive in 4WD High Range? With a Part-Time system, prolonged driving in 4WD High Range is recommended only for wet, loose, or slippery road surfaces. With a Full-Time system, you need not worry about switching to 2WD mode when road surfaces improve.
How fast can I drive in 4WD High Range? You should not go faster than road conditions permit.
What is 4WD Low Range? 4WD Low Range is a mode specifically designed for temporary use when additional traction and maximum pulling power is desired. Front and rear driveshafts are locked together and engine power is sent through another set of gears to multiply torque. Avoid attempting to engage or disengage Low Range with the vehicle moving faster than 2 to 3 mph (3 to 5 km/h) and do not use this mode for normal driving.
Can I shift into 4WD Low Range at any speed? No. With the vehicle rolling at 2 to 3 mph (3 to 5 km/h), shift an automatic transmission to Neutral or depress the clutch pedal on a manual transmission. While the vehicle is coasting at to 3 mph (3 to 5 km/h), shift the transfer case lever firmly through Neutral and into the Low Range position.
How fast can I drive in 4WD Low Range? Do not exceed 25 mph (40 km/h).
Can I shift into 4WD Low Range when stopped? Shifting into or out of 4WD Low Range is possible with the vehicle completely stopped, however, difficulty may occur due to the teeth of the gears not being properly aligned. Several attempts may be required for clutch teeth alignment and shift completion to occur. The preferred method is with the vehicle rolling at 2 to 3 mph (3 to 5 km/h). Avoid attempting to engage or disengage 4 Low Range with the vehicle moving faster than 2 to 3 mph (3 to 5 km/h).
What if I never use the Selec-Terrain™ switch? In Auto mode, the vehicle will automatically select the correct drive system for the condition it senses.
Does the vehicle need to be parked or moving to operate the Quadra-Lift™ suspension or the Selec-Terrain™ system? The vehicle can be in either Park or moving to operate the Quadra-Lift™ air suspension or Selec-Terrain™ settings. When the vehicle is moving, the driver can manually select the appropriate height setting of the Quadra-Lift™ system or have the vehicle select the optimal setting automatically. Drivers can also use the Selec-Terrain™ control dial to optimize drivetrain and brake control systems for a specific terrain. There are speed thresholds for the various Quadra-Lift™ height settings. For instance, the driver can make the request for Park mode at speeds below 12 mph. The system begins lowering to Park height when the vehicle speed is below 6 mph. This feature ensures that Park height is achieved prior to exiting the vehicle. Off-road heights are also speed limited on the upper end to maintain ride comfort objectives.