2008 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 142

Shifting Out of Four-Wheel-Drive Low To shift from Four-Wheel-Drive Low to Four-Wheel-Drive High, AUTO or Two-Wheel-Drive High, your vehicle must be stopped or moving less than 3 mph (5 km/h) with the transmission in NEUTRAL (N) and the ignition in RUN. The preferred method for shifting out of Four-Wheel-Drive Low is to have your vehicle moving 1 to 2 mph (1.6 to 3.2 km/h). Turn the knob to the Four-Wheel-Drive High, AUTO or Two-Wheel-Drive High position. You must wait for the Four-Wheel-Drive High, AUTO or Two-Wheel-Drive High indicator light to stop flashing and remain on before shifting your transmission into gear. Notice: Shifting the transmission into gear before the requested mode indicator light has stopped flashing could damage the transfer case. To help avoid damaging your vehicle, always wait for the mode indicator lights to stop flashing before shifting the transmission into gear. It is typical for your vehicle to exhibit significant engagement noise and bump when shifting between Four-Wheel-Drive Low and Four-Wheel-Drive High ranges or from NEUTRAL with the engine running. If the knob is turned to the Four-Wheel-Drive High, AUTO, or Two-Wheel-Drive High switch position when your vehicle is in gear and/or moving, the Four-Wheel-Drive High, AUTO or Two-Wheel-Drive High indicator light will flash for 30 seconds but will not complete the shift unless your vehicle is moving less than 3 mph (5 km/h) and the transmission is in NEUTRAL (N). 2-48