2011 Ford F450 Super Duty Crew Cab Owner Guide 4th Printing - Page 280

Driving 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). • 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 19 mph (30 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 (ELD) For vehicles equipped with an electronic shift 4WD system: Pull the knob on the 4WD control indicator light toward you. The will display in the instrument cluster. 280 2011 F-250/350/450/550 (f23) Owners Guide, 4th Printing USA (fus)