2008 GMC Yukon Owner's Manual - Page 139

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 ON/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 Four-Wheel Drive Low indicator light has stopped flashing could damage the transfer case. To help avoid damaging your vehicle, always wait for the Four-Wheel Drive Low indicator light to stop flashing before shifting the transmission into gear. The vehicle may have significant engagement noise and bump when shifting between Four-Wheel Drive Low and Four-Wheel Drive High ranges or from NEUTRAL while the engine is 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). Shifting into NEUTRAL To shift the transfer case to NEUTRAL do the following: 1. Make sure the vehicle is parked so that it will not roll. 2. Set the parking brake and apply the regular brake pedal. See Parking Brake on page 2-43 for more information. 3. Start the vehicle or turn the ignition to ON/RUN. 4. Put the transmission in NEUTRAL (N). 5. Shift the transfer case to Two-Wheel Drive High. 6. Turn the transfer case dial clockwise to NEUTRAL till it stops and hold it for 10 seconds. Then slowly release the dial to the four low position. The NEUTRAL light will come on when the transfer case shift to NEUTRAL is complete. 2-41