2009 Hummer H3T Owner's Manual - Page 192

4-10 Driving Your Vehicle Notice: If the vehicle's axle is locked while driving on pavement, the drivetrain could be damaged. Repairs would not be covered by the vehicle warranty. Do not use the locking axle on pavement. If four-wheel drive is needed when traveling on pavement, use only 4HI. 5. Wait for the light in the button to stop flashing and remain illuminated to show that the front axle is locked. Notice: If you try to lock the axle while the vehicle is stuck and the tires are spinning, the vehicle's drivetrain could be damaged. The repairs would not be covered by the vehicle warranty. Always lock the axle before attempting situations and/or navigating terrain which could possibly cause the vehicle to become stuck. Locking axles will be disengaged when the wheel speed is greater than 40 mph (64 km/h), if the vehicle's battery is low and/or the transfer case is shifted out of 4LO Lock mode. Steering Tips It is important to take curves at a reasonable speed. Traction in a curve depends on the condition of the tires and the road surface, the angle at which the curve is banked, and vehicle speed. While in a curve, speed is the one factor that can be controlled. If there is a need to reduce speed, do it before entering the curve, while the front wheels are straight. Try to adjust the speed so you can drive through the curve. Maintain a reasonable, steady speed. Wait to accelerate until out of the curve, and then accelerate gently into the straightaway. Steering Power Steering If power steering assist is lost because the engine stops or the system is not functioning, the vehicle can be steered but it will take more effort.