freightliner 108SD, Driver Manual

Page: 177 / 192

Preliminary Checks
Before checking or adjusting the headlight aim, com-
plete the following inspection:
•
Check that the hood is closed and latched.
•
Remove any large amounts of mud or ice from
the underside of the fenders.
•
Check the springs for sagging or broken
leaves.
•
Check the suspension for proper functioning of
the leveling mechanism. On cabs with air sus-
pensions, make sure that the height is properly
adjusted.
•
Check for damage to the hood and hinge as-
sembly. Repair as necessary.
•
With the vehicle unloaded, check that the tires
are inflated to the recommended air pressure.
•
Clean the headlight lenses. Use a soft cloth
with mild, non-caustic soap or detergent, and
water.
Checking Headlight Aim
1. Park the vehicle on a level surface, 25 ft (7.6 m)
away from, and perpendicular to, a vertical
screen or wall. Shut down the engine and set the
parking brake. Chock the tires.
2. On each headlight, find the bulb center behind
the headlight lens.
3.
Measure the distance from the ground to the
center of each headlight bulb (
Fig. 23.1 , Item A).
Note those distances.
4. On the screen or wall, mark the locations of each
headlight bulb center using the distances found
in step 3. See
Fig. 23.1 , Items 2 and 3.
5. Turn on the low-beam headlights.
6. Check the vertical adjustment of the low beams.
The center of each beam projection should fall
on or near the marks made during step 4. See
Fig. 23.2 .
f545850 10/27/2011
B
B
1
2
3
25 ft (7.6 m)
A
A
A. Measure the distance from the ground to the center of each headlight bulb.
B. Mark where the center of each headlight projection should appear.
1.
Screen or Wall
2. Center of Right-Hand Headlight Projection
3. Center of Left-Hand Headlight Projection
Fig. 23.1, Headlight Aiming Screen/Wall
Headlight Aiming
23.1