Lincoln 2009 Navigator Owner's Manual page 302

Roadside Emergencies
WARNING: When one of the rear wheels is off the ground, the
transmission alone will not prevent the vehicle from moving or
slipping off the jack, even if the transmission is in P (Park). To prevent
the vehicle from moving when you change the tire, be sure that the
parking brake is set and the block the wheels (both front or both rear)
on the opposite end of the vehicle from the wheel being changed. If on
a grade, block both opposite wheels on the downward side of the hill.
If the vehicle slips off the jack, someone could be seriously injured.
• Front
• Rear
WARNING: Turn off the running boards (if equipped) before
jacking or placing any object under the vehicle. Never place your
hand between the extended running board and the vehicle. A moving
running board may cause injury.
302
2009 Navigator (nav)
Owners Guide, 2nd Printing
USA (fus)