FORD 2015 F-550 v.1 - Manual (Page 163)

LIMITED SLIP DIFFERENTIAL
This axle provides added traction on
slippery surfaces, particularly when one
wheel is on a poor traction surface. Under
normal conditions, the limited-slip axle
functions like a standard rear axle. The axle
may exhibit a slight noise or vibration
during tight turns with low vehicle speed.
This is normal behavior and indicates the
axle is working.
ELECTRONIC LOCKING
DIFFERENTIAL
Note: The electronic locking differential is
for off-road use only and is not for use on
dry pavement. Using the electronic locking
differential on dry pavement will result in
increased tire wear, noise and vibration.
The electronic locking differential is a
device housed in the rear axle that allows
both rear wheels to turn at the same
speed. The electronic locking differential
can provide additional traction should your
vehicle become stuck. You can activate
the differential electronically and shift it
on the fly within the differential operating
speed range. The differential is for use in
mud, rocks, sand, or any off-road condition
where you need maximum traction. It is
not for use on dry pavement.
The following conditions will affect the
electronic locking differential:
• On 2WD vehicles and 4WD vehicles in
2H (4X2) or 4H (4X4 High), the ELD
will not engage if the vehicle speed is
above 20 mph (32 km/h).
• On 2WD vehicles and 4WD vehicles in
2H (4X2) or 4H (4X4 High), the ELD
will automatically disengage at speeds
above 25 mph (40 km/h) and will
automatically reengage at speeds
below 20 mph (32 km/h).
• On 4WD vehicles in 4L (4X4 Low), the
ELD can be engaged at any speed and
will not automatically disengage.
Activating the Electronic Locking
Differential
(If Equipped)
Note: Do not use electronic locking
differential on dry, hard surfaced roads.
Doing so will produce excessive noise,
vibration and increase tire wear.
Note: If the electronic locking differential
has difficulty disengaging, release the
accelerator pedal and turn the steering
wheel in the opposite direction while rolling.
For vehicles equipped with an
electronic shift 4WD system
E172924
Pull the 4WD control knob toward you.
160
Super Duty (), enUSA
Rear Axle