Cadillac 1998 Seville Owner's Manual page 313

For the vertical adjustment, state inspection stations
generally will allow a reading of plus 0.76 degrees or
minus 0.76 degrees from the center of the bubble.
It is recommended that the upper limit not exceed plus
0.4 degrees from the center of the bubble. Other drivers
may flash their high beams at you if your adjustment is
much above plus 0.4 degrees.
If you find that
the
headlamp aiming needs adjustment,
follow these steps:
Adjustment screws can be turned with an E8 Torx@
socket or T15 Torx screwdriver.
I l l
1. Locate the vertical
aiming screw (B) that is
directly behind the
headlamp assembly.
2. Turn the vertical aiming screw until the bubble
inside the level (A) is centered at zero (0).
3. Now check the
horizontal aim (C) and
adjust it as necessary.
The horizontal aiming
device is located on the
inboard side of each
lamp. Turn the horizontal
aiming screw (D) until
the screw aligns with the
zero (0).
4.
Recheck the vertical aim level (A) to make sure it is
still correct after the horizontal aim adjustment.
Re-adjust as necessary.
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