2004 GMC Yukon Owner's Manual - Page 119

REVERSE (R): Use this gear to back up. Notice: Shifting to REVERSE (R) while your vehicle is moving forward could damage the transmission. The repairs would not be covered by your warranty. Shift to REVERSE (R) only after your vehicle is stopped. To rock your vehicle back and forth to get out of snow, ice or sand without damaging your transmission, see If You Are Stuck: In Sand, Mud, Ice or Snow on page 4-50. NEUTRAL (N): In this position, your engine doesn't connect with the wheels. To restart when you're already moving, use NEUTRAL (N) only. Also, use NEUTRAL (N) when your two-wheel drive vehicle is being towed. {CAUTION: Shifting into a drive gear while your engine is running at high speed is dangerous. Unless your foot is firmly on the brake pedal, your vehicle could move very rapidly. You could lose control and hit people or objects. Do not shift into a drive gear while your engine is running at high speed. Notice: Shifting out of PARK (P) or NEUTRAL (N) with the engine running at high speed may damage the transmission. The repairs would not be covered by your warranty. Be sure the engine is not running at high speed when shifting your vehicle. 2-25