FORD 2012 F-550 v.1 - Manual (Page 287)

• Some noise is normal during operation. If excessive, check for low
power steering pump fluid level before seeking service by your dealer.
• Heavy or uneven efforts may be caused by low power steering fluid.
Check for low power steering pump fluid level before seeking service
by your dealer.
• Do not fill the power steering pump reservoir above the MAX mark on
the reservoir, as this may result in leaks from the reservoir.
If the power steering system breaks down (or if the engine is turned
off), you can steer the vehicle manually, but it takes more effort.
If the steering wanders or pulls, check for:
• an improperly inflated tire
• uneven tire wear
• loose or worn suspension components
• loose or worn steering components
• improper steering alignment
If any steering components are serviced or replaced, install new
fasteners (many are coated with thread adhesive or have prevailing
torque features which may not be re-used). Never re-use a bolt or nut.
Torque fasteners to specifications in Workshop Manual.
A high crown in the road or high crosswinds may also make the steering
seem to wander/pull.
ELECTRONIC LOCKING DIFFERENTIAL (ELD) (IF EQUIPPED)
The electronic locking differential (ELD) is a device housed in the rear
axle which allows both rear wheels to turn at the same speed. It provides
added traction on slippery and/or off road surfaces, particularly when
one wheel is on a poor traction surface. The ELD may be locked or
unlocked by the vehicle operator and can be engaged or disengaged on
the fly. When the axle is unlocked it will function like a standard rear
axle. When the axle is locked it will not allow the rear wheels to rotate
at different speeds when turning. It is not recommended for use on good
traction surfaces such as dry pavement. Doing so may result in abnormal
driving behavior and noise while cornering and excessive tire wear.
The ELD is affected by the following conditions of your vehicle:
• On 2WD vehicles and 4WD vehicles in 2H (4X2) or 4H (4X4 High),
the ELD will not engage if the vehicle speed is above 25 mph
(40 km/h).
Driving
287
2012 F-250/350/450/550 (f23)
Owners Guide, 1st Printing
USA (fus)