Lincoln 2011 Navigator - Manual (Page 270)

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.
Roadside Emergencies
270
2011 Navigator (nav)
Owners Guide, 1st Printing
USA (fus)