Lincoln Electric 2004 Town Car Owner's Manual page 189

Do not rock the vehicle if the engine is not at normal operating
temperature or damage to the transmission may occur.
Do not rock the vehicle for more than a minute or damage to the
transmission and tires may occur, or the engine may overheat.
TRACTION-LOK AXLE (IF EQUIPPED)
This axle provides added traction on slippery surfaces, particularly when
one wheel is on a poor traction surface. Under normal conditions, the
Traction-Lok axle functions like a standard rear axle.
REVERSE SENSING SYSTEM
The extended rear park aid system sounds a tone to warn the driver of
obstacles near the rear bumper when the R (Reverse) gear is selected.
To help avoid personal injury, please read and understand the
limitations of the extended rear park assist system as contained
in this section. The park assist is only an aid for some (generally large
and fixed) objects when moving in reverse on a flat surface at "parking
speeds". Inclement weather may also affect the function of the RSS;
this may include reduced performance or a false activation.
To help avoid personal injury, always use caution when in R
(Reverse) and when using the extended rear park aid.
This system is not designed to prevent contact with small or
moving objects. The system is designed to provide a warning to
assist the driver in detecting objects to avoid damaging the vehicle.
The system may not detect smaller objects, particularly those close to
the ground.
Certain add-on devices such as large trailer hitches, bike or
surfboard racks and any device that may block the normal
detection zone of the extended rear park aid system may create false
beeps.
The system will assist the driver in detecting certain objects while the
vehicle slowly moves in reverse at speeds less than 10 km/h (6 mph).
The system is not effective at speeds greater than 10 km/h (6 mph) and
may not detect certain angular or moving objects.
2004 Town Car (tow)
Owners Guide (post-2002-fmt)
USA English (fus)
Driving
189