Headlamp: Adjustments

Headlamp Adjustment

Aerodynamic Headlamp Adjusters










Sealed Beam Headlamp Adjusters










Headlamp Aiming

1. The headlamp aiming procedure depends on what type of beam pattern the headlamp is equipped with. Vehicles may come equipped with visual optical left (VOL), visual optical right (VOR) or SAE only (includes sealed beam type) headlamps. To identify the headlamp beam pattern, look on the headlamp lens. Molded in small letters on the headlamp lens is one of the following:
- SAE

- VOL and SAE

- VOR and SAE

2. Once the headlamp beam pattern is identified, aim the headlamps using one of the following methods as applicable.
- Photometric aimers can aim VOL-, VOR- and SAE-type headlamps only. This is the preferred method of headlamp aiming.

- Visual or screen method aiming can be used to aim VOL-, VOR- and SAE-type headlamps only.

- Mechanical aimers cannot be used with VOR- or VOL-type headlamps. Aerodynamic lamps that can be aimed mechanically have 3 nibs molded into the lens of the lamp.


Photometric Aiming

1. For the photometric aiming procedure, refer to the appropriate photometric headlamp aimer instruction manual.


Screen Method Aiming

All headlamp types

NOTE: Horizontal aim is not necessary for VOL or VOR headlamps.

NOTE: Consult your state vehicle inspection manual for recommended tolerance ranges for visual aiming.

NOTE: The sight shield may need to be positioned or removed for access to the adjusters.

1. Before starting headlamp adjustment:
- check that the vehicle is on level ground.

- check the tire inflation.

- check that no other load is in the vehicle other than a half tank of fuel.

- check that the headlamps are clean.

- check for correct headlamp operation.

- if the vehicle is equipped with air suspension, make sure that the switch is on.

2. NOTE: The vertical wall or screen must be a minimum of 2.4 m (8 ft) wide.

Park the vehicle on a level surface approximately 7.6 m (25 ft) from the vertical wall or screen directly in front of it.





3. NOTE: The center of the lamp is marked either on the lens (circle, crosshair or other mark) or on the bulb shield internal to the lamp (crosshair or other mark).

Mark a horizontal reference line on the vertical wall or screen.

1. Measure the center of the headlamp height to ground and record the measurement.

2. Make a 2.4 m (8 ft) horizontal mark (using masking tape) on the vertical wall or screen at the same distance from the ground as previously recorded.





4. NOTE: This procedure should be done in a dark environment to effectively see the headlamp beam pattern.

Turn on the low beam headlamps to illuminate the wall or screen and open the hood.

5. NOTE: For SAE-type headlamps, the appearance of the beam pattern may vary between vehicles.

On the wall or screen, locate the high intensity area of the beam pattern. Using the adjusting screw, adjust the headlamp until the top edge of the high intensity zone is even with the horizontal reference line.

SAE-type headlamps

6. In addition to the horizontal line marked in Step 3, a pair of vertical lines must be marked at the center line of the headlamps on the wall or screen.

1. Mark the center line of the vehicle on the wall or screen.

2. Measure from the center of the headlamp to the center line of the vehicle.

3. Make two 1.5 m (5 ft) vertical marks (using masking tape) on the wall or screen at the same distance from the vehicle center line as previously recorded.





7. On the wall or screen, locate the high intensity area of the beam pattern. Using the adjusting screw, adjust the headlamp until the left edge of the high intensity zone is even with the vertical and horizontal lines corresponding to the headlamp being adjusted.





VOR-type headlamps

8. NOTE: The appearance of the VOR beam pattern may vary between vehicles.

On the wall or screen, locate the top edge of this high intensity area a distinct horizontal cutoff in the beam pattern. Using the adjusting screw, adjust the headlamp until the top edge of this cutoff is even with the horizontal reference line.





VOL-type headlamps

9. For VOL-type headlamps, locate the distinct cutoff in the left portion of the beam pattern. Using the adjusting screw, adjust the headlamp until the edge of this cutoff is positioned 50.2 mm (2 in) below the horizontal reference line.

1. Horizontal reference line.

2. Top edge of the beam pattern.

3. High intensity zone.






Mechanical Aiming

1. For the mechanical aiming procedure, refer to the appropriate mechanical headlamp aimer instruction manual.