Buick 2010 Lacrosse Owner's Manual page 355

If a tire goes flat, avoid further tire
and wheel damage by driving slowly
to a level place. Turn on the hazard
warning flashers. See
Changing a tire can be
dangerous. The vehicle can slip
off the jack and roll over or fall on
you or other people. You and they
could be badly injured or even
killed. Find a level place to
change your tire. To help prevent
the vehicle from moving:
1. Set the parking brake firmly.
2. Put an automatic
transmission shift lever in
P (Park), or shift a manual
transmission to 1 (First) or
R (Reverse).
3. Turn off the engine and do
not restart while the vehicle
.
is raised.
4. Do not allow passengers to
remain in the vehicle.
To be certain the vehicle will not
move, put blocks at the front and
rear of the tire farthest away from
the one being changed. That
would be the tire on the other
side, at the opposite end of the
vehicle.
When the vehicle has a flat tire (B),
use the following example as a
guide to assist you in the placement
of wheel blocks (A).
(Continued)
A. Wheel Block
B. Flat Tire
The following information explains
how to repair or change a tire.