How to Adjust the Headlights on a GMC Yukonby Ziggy Thomas
GMC Yukons have their headlights adjusted before leaving the factory. But if you damage the headlights, you might have to adjust again them to ensure the proper aim. The low-beam headlight is used to analyze the adjustment. When the low-beam headlight is adjusted correctly, the high-beam headlights will follow suit. Adjusting the headlights on a GMC Yukon is a simple project that should take less than 30 minutes.
Maneuver your Yukon so that it is perpendicular to a light-colored wall, about 25 feet away, with the headlights facing the wall. Make sure the tires are properly inflated and the area between your vehicle and the wall is flat.
Open the hood of your Yukon. The aim dot is in the center of the low-beam headlight. It is used to aim the lights.
Measure the distance from the ground to the aim dot using the tape measure. Mark the wall the same distance, measured from the ground up. Tape a horizontal line at this height, the width of your vehicle.
Cover one headlight with a piece of cardboard or other light-proof material. Turn the lights on.
Locate the headlight aiming screws. They are in the engine compartment near the headlights. Adjust the headlight aiming screws with an E8 Torx socket. Turn them clockwise to raise the light or counterclockwise to lower it.
Adjust the headlight so the top of the light beam stops at the bottom edge of the horizontal line on the wall.
Repeat Steps 4 to 6 with the other headlight if needed.