* Part-time 4WD: These systems typically require you to be in neutral (N) or stopped to engage 4WD. Driving with part-time 4WD engaged on dry pavement can damage the drivetrain.
* Full-time 4WD: These systems can usually be engaged while moving, but often only at low speeds. The specific speed limit varies by vehicle. Check your owner's manual.
* Automatic 4WD: These systems automatically engage 4WD when needed, based on wheel slip. You don't manually select a gear to engage them.
Always consult your owner's manual for the specific instructions for your truck's 4WD system. This is crucial to avoid damaging your vehicle.