GMC 2008 Savana Van Owner's Manual page 328

10. Lower the vehicle by turning the jack handle
counterclockwise. Lower the jack completely.
CAUTION:
{
Wheel nuts that are not tight can work loose. If
all the nuts on a wheel come off, the wheel can
come off the vehicle, causing a crash. All
wheel nuts must be properly tightened. Follow
the rules in this section to be sure they are.
5-88
CAUTION:
{
If wheel studs are damaged, they can break. If
all the studs on a wheel broke, the wheel could
come off and cause a crash. If any stud is
damaged because of a loose-running wheel, it
could be that all of the studs are damaged. To
be sure, replace all studs on the wheel. If the
stud holes in a wheel have become larger, the
wheel could collapse in operation. Replace any
wheel if its stud holes have become larger or
distorted in any way. Inspect hubs and
hub-piloted wheels for damage. Because of
loose running wheels, piloting pad damage
may occur and require replacement of the
entire hub, for proper centering of the wheels.
When replacing studs, hubs, wheel nuts or
wheels, be sure to use GM original
equipment parts.