: Headlight Aiming

01-26-06, 10:41 PM
I have a 1998 Catera and recently installed new headlights due to the old ones turning yellow. Does anyone know how to aim them? They are pointing toward the ground. :annoyed: Thanks!

01-27-06, 07:38 AM
I found these from previous posts:

1) Basically, your guide is that graduated cylinder inside the headlight that has a bubble in it. The bubble has to be positioned along the middle line. But then, if the mounting of the headlight itself is not proper, then it is useless. The best way to do it is to park the car in a level area in front of the wall and then aim them. Probably, within ten feet from the wall, if the edge of the middle of the beam is about three inches below the level of the headlights, then it would be fine. I am not saying this is accurate, others might have a different opinion.

2) Guys, I notice someone above mentioning an aiming knob that you "pull turn keft orright...." I iknow it LOOKS like an aiming knob, but it is not. The factory manual says DO NOT TURN THAT KNOB as you will break stuff. There are two socket heqad screws that you access fom the front of the headlight that you turn to aim. I am not at home or I would post the correct aiming instructions. Perhaps someone with access to the Alldata site can cut and past the proper instructions.

has anyone ever posted the correct instructions because I've tried the knob that you pull and nothing happens.

01-27-06, 08:52 AM
There are two different ways to aim the headlamps. One is to use the built in level blulb the other is to use a screen the method used by dealers. The screen method is the most accurate but needs a large area and a screen or a wall that is marked for this particular purpose.

Headlamp Aiming By the Screen Method

Ensure the following conditions are present:

Ensure the area is large enough to accommodate the vehicle plus an additional 7.6 m (25 ft) measured from the face of the head lamps to the front of the visual screen.
Ensure the area is a darkened location.
Ensure floor on which the vehicle rests is flat with the bottom of the screen. Make the necessary compensation if the floor is not level.
Ensure the aiming screen is 1.5 m x 3.7 m (5 ft x 12 ft) . The screen may consist of a vertical wall with a clear uninterrupted area measuring 1.5 m x 3.7 m (5 ft x 12 ft) if a regular commercial aiming screen is not available. Ensure the wall is finished with a washable non-gloss white paint.
Ensure the aiming screen is a matte-white surface.
Ensure the aiming screen is well shaded from the outside light.IMPORTANT : The horizontal line or tape on the screen must be adjusted for each vehicle checked. Vehicles of the same model and year will have different standing height for the headlamps.

Ensure the aiming screen is equipped with the following:
A vertical center line.
Two laterally adjustable vertical tapes.
A vertically adjustable horizontal tape.
Ensure provisions are made for moving the screen so that the screen can align parallel with the rear axle. This allows for a horizontal line drawn perpendicular from the center line of the screen to pass through the center point between the two headlamps.
Ensure to paint a reference line on the floor to identify the proper location of the headlamps, when they are being aimed, once the screen is set in a permanent location.Perform the following steps to prepare the vehicle for checking the beam aim:

Completely assemble all the components on the vehicle.
Ensure the vehicle is at it's normal operating weigh. This includes the spare tire, tools, and any other items normally carried. Additionally, ensure the vehicle fuel load is no less than 1/2 tank.
Check the vehicle tires for correct pressure.
Turn the ignition switch to the ON position.
Activate the Automatic Level Control (ALC) system.
Position the vehicle in the following position:
So it is square with the aiming screen.
So the headlamps are directly over the painted reference line on the floor.
Sight through the center of the rear window and over the hood to locate the vertical line on the aiming screen so that it is in line with the center of the vehicle.
Mark the center of the front window and the center of the rear window with narrow tape to create sights. Use these sights to locate the center of the vehicle.
Move the vehicle or move the screen until the center line of the screen comes into alignment with these two points.
Close the doors.
Rock the vehicle sideways to stabilize the suspension.
Switch the headlamps on to low beam.
Observe the left edge and top edge of the high intensity zone on the screen.
Use the inboard adjusting screw to adjust the horizontal aim if the left edge is more than the following measurements:
More than 102 mm (4 in) RIGHT of straight ahead.
More than 102 mm (4 in) LEFT of straight ahead.
Use the outboard adjusting screw to adjust the vertical aim if the top edge is more than the following measurements:
More than 102 mm (4 in) ABOVE the horizontal line.
More than 102 mm (4 in) BELOW the horizontal line.
An adjusting screw on the upper inboard side of the headlamp is available for horizontal headlamp aim adjustment.
The horizontal aim is preset at the factory. The horizontal aim generally will not require adjustment. Use the screen method to adjust the horizontal aim. Refer to Headlamp Aiming By Screen Method .
A knob located on the back of the headlamp provides a point of reference when adjusting to the left or to the right. This reference knob will not determine the degree of aim. Do not use the reference knob to set the headlamp aim.
An adjusting screw on the upper outboard side of the headlamp is available to set the vertical headlamp aim.
Use the integrated adjustment bubble or use the screen method to set the vertical aim. Refer to Headlamp Aiming By Screen Method . See: Headlamp Aiming By the Screen Method (http://www.alldatadiy.com/alldata/AFI~V6080485~C32314~R0~OD~N/0/56775861/62803304/62803305/62803306/34853741/34867926/34868471/34868577/66480042/66480085)
Adjust the bubble until the bubble is in the middle of the 0 (zero) on the level to set the vertical aim with the integrated bubble.

01-27-06, 04:37 PM
Thanks a million!!!! :)

01-27-06, 08:09 PM
check payable to matthew meyer

01-27-06, 09:22 PM
Checks in the mail! :thumbsup: