Aim the headlamps for proper illumination
of the road. Inspect the headlamp aim under the following conditions:
• | When a new headlamp assembly is installed |
• | If service or repairs to the front end area have, or may have,
disturbed the headlamps or the mounting |
Headlamp focus is set when the unit is made. No adjustment for focus
is necessary or possible.
Important: Some state or province and local laws specify requirements for headlamp
aim. Follow those laws.
Horizontal aim is performed by an adjusting screw on the inboard side
of the headlamp assembly. Vertical aim is performed by an adjusting screw
in the upper outboard area. When aiming the headlamps, follow the instructions
below.
Aim Preparation
In order to prepare the vehicle for aiming the headlamps,
perform the following steps:
• | Completely assemble all of the components on the vehicle. |
• | Place the vehicle on a level pad or surface. |
• | Stop all unnecessary operations or work on the vehicle that affects
the vehicle trim. |
• | Rock the vehicle to stabilize the suspension. |
• | Ensure that the fuel level is full. |
• | Ensure that the tires are inflated to the proper pressure. |
• | Ensure that the driver or a similar weight, approximately 165 lbs,
is in the vehicle drivers seat. |
Location
Ensure that the area is
darkened and large enough in order to allow for the vehicle and an additional
7.62 m (25 ft). The distance for this procedure is measured
from the face of the headlamps to the front of the screen. Ensure that
the floor on which the vehicle rests is level with the bottom of the screen.
Compensate for the floor if the floor is not level.
Aiming Screen
If you are using a screen, ensure that the following
criteria is met:
• | The screen is at least 1.52 m (5 ft) high by 3.66 m
(12 ft) wide. |
• | The screen has a matte white surface well shaded from ambient
light. |
• | The screen is properly adjusted to the floor on which the vehicle
stands. |
• | The screen can be aligned parallel with the rear axle of the vehicle. |
Position the screen in order to ensure that a horizontal line will pass
an equal distance midway between the 2 headlamps.
Ensure that the screen provides the following features:
• | Two laterally adjustable vertical tapes |
• | One vertically adjustable horizontal tape |
If a regular commercial aiming screen is not available, use a wall having
a clear uninterrupted area at least 1.83 m (6 ft) high by 3.66 m
(12 ft) wide. Ensure that the surface is finished with a washable
no-gloss white paint.
After the aiming screen is set up and located, paint or tape a reference
line on the floor 7.62 m (25 ft) from the screen. Park the vehicle
with the front of the headlamps directly over the reference line.
Visual Procedure - Alero or Grand Am
- Prepare the vehicle. Refer to Aim Preparation.
- Park the vehicle square
with the screen. Locate the headlamps directly over the reference line.
- Ensure that all the components are in place if other work has
been done on the vehicle.
- Use the following procedure in order to line up the centerline
of the vehicle with the centerline (2, 3) of the aiming screen:
4.1. | Mark the vertical center of the vehicle and the front windows
using tape. |
4.2. | Use these lines as sights in order to line up the centerline of
the vehicle and the screen. |
- Adjust the vertical tapes on the screen to match the vertical
centerline (1) of each lamp. Measure the distance from the centerline
of the vehicle to the centerline of a low beam lamp.
- Adjust the horizontal tapes (2) on the screen to match
the horizontal centerline of the low beam headlamp. Measure the height from
the floor to the center of a low beam.
- Turn on the low beam lamps. Adjust the headlamps in the following manner:
7.1. | The left edge of the high intensity zone on the screen for the
low beams is on the vertical line (5) for each side. |
7.2. | The top edge of the high intensity zone on the screen for the
low beam is on the horizontal line (2) for each side. |
Mechanical Aiming Procedure - Alero
- Alero has a headlamp system
equipped with horizontal and vertical aim indicators. The vertical and horizontal
aim indicators may not fall exactly on the "0" marks
on their scales. The headlamp aiming device is under the hood, near the
headlamps.
- Prepare the vehicle, refer to aim preparation.
- Start with the horizontal aim. Adjustment screws can be turned
with an E8 TORX® socket (or T15 TORX® screwdriver).
Once horizontal aim is adjusted, then adjust the vertical aim.
- Turn the horizontal aiming screw (2) until the indicator
is lined up with zero.
- Turn the vertical aiming screw (3) until the level bubble
is lined up with zero.
- Complete the aiming procedure by using the visual procedure.