Buick 2008 Lucerne Owner's Manual page 355

3. Turn the jack handle counterclockwise to lower the
jack lift head until it fits under the vehicle.
Turn the jack handle clockwise to raise the jack
lift head.
CAUTION:
{
Raising your vehicle with the jack improperly
positioned can damage the vehicle and even
make the vehicle fall. To help avoid personal
injury and vehicle damage, be sure to fit the
jack lift head into the proper location before
raising the vehicle.
Notice: If you position the jack under the rocker
molding and attempt to raise the vehicle, you could
break the molding and/or cause other damage to
your vehicle. Always position the jack so that when
the jack head is raised, it will fit firmly in the
notch located inboard from the rocker molding.
4. Put the jack into the flange in the frame which is
located near each wheel well. The flanges are
accessible through openings in the plastic trim at
the bottom of the vehicle. The front opening is about
8 inches (20 cm) back from the front wheel well.
The rear opening is about 3 inches (8 cm) forward
from the rear wheel well.
5. Position the jack and raise the jack head until it fits
firmly on the ridge in the vehicle's frame nearest the
flat tire. Do not raise the vehicle yet.
5-87