How to: Aim Headlights

John Baxter | May 01, 2012

Light your path

Properly aiming your headlamps can improve night vision and reduce the risk of blinding oncoming drivers. When a fix is needed, a dealer charges about a half-hour of labor to use a headlight focusing machine. While that’s not unreasonable, on some trucks you can do it yourself by simply turning screws.

Late-model trucks have headlamp assemblies that are integrated with the hood. They use an aiming process called visual optical aim, and will have either VOL or VOR marked on their lenses. A dealer can use an electronic device to focus headlights by aligning the beam with certain markings.

Sometimes a misdirected beam is caused by an imbalance on the truck. Before working on the lights, take these steps to assure that the truck body is as level as it should be, then check to see if the beams are still off:

• Fill tires to correct pressure.

• Ensure air suspension is operating and at optimum spec for ride height.

• Fill the fuel tank.

• Have someone in the driver’s seat.

• Ensure that hood bushings are not too worn. Wear is indicated by flexing up and down or rocking when opening or closing the hood.

This 2013 Peterbilt has a headlight vertical adjustment near the rear of its lens that can be adjusted with a Torx screwdriver. There’s no horizontal adjustment.

• Ensure the hood is adjusted for proper alignment on both sides. Bolts can be loosened and the position of the hood on the brackets adjusted, if necessary.

• Ensure that the rubber pads on the cowl and corresponding cups in the hood are in good condition.






Many lamps must be adjusted from under the hood. On this International, the under-hood vertical adjustment is above the lamp, and the horizontal to the right. The screws have hex heads.

Assisting with this article were Ryan Nosia, service manager; George Torres, technician; and Billy Tornetta, body shop manager of GL Sayre Peterbilt/International in Conshohocken, Pa. Brad Van Riper, a senior vice president at Truck-Lite, also assisted.

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