Alignment: Description and Operation
Wheel Alignment AnglesF-Super Duty vehicle caster and camber correction requirements are factory-determined. Adjusters are available to correct a caster/camber measurement that does not meet specification. Before changing the production caster/camber adjuster, thoroughly inspect the suspension system to locate worn or damaged components that may have caused the setting to change.
Camber
Negative and Positive Camber
Negative and Positive Camber:
Camber is the vertical tilt of the wheel when viewed from the front. Camber can be positive or negative and has a direct effect on tire wear.
Caster
Caster and Steering Axis
Caster and Steering Axis:
Caster is the deviation from vertical of an imaginary line drawn through the ball joints when viewed from the side. The caster specifications will give the vehicle the best directional stability characteristics when loaded and driven. The caster setting is not related to tire wear.
Toe
Positive Toe (Toe In)
Positive Toe (Toe In):
Negative Toe (Toe Out)
Negative Toe (Toe Out):
The vehicle toe setting:
^ affects tire wear and directional stability.
^ must be checked after adding aftermarket equipment, such as a snowplow or body.
Ride Height
Front Ride Height Measurement - F-250 and F-350, Rear Wheel Drive (RWD)
Front Ride Height Measurement - F-250 and F-350, Rear Wheel Drive (RWD):
Front Ride Height Measurement - F-250, F-350, Four Wheel Drive (4WD), F-450 and F-550
Front Ride Height Measurement - F-250, F-350, Four Wheel Drive (4WD), F-450 and F-550:
Rear Ride Height Measurement - F-250 and F-350, RWD
Rear Ride Height Measurement - F-250 and F-350, RWD:
Rear Ride Height Measurement - F-250 and F-350, 4WD
Rear Ride Height Measurement - F-250 and F-350, 4WD:
Rear Ride Height Measurement - F-450 and F-550
Rear Ride Height Measurement - F-450 and F-550:
Rear Ride Height Measurement - F-550 with Attitude Improvement Option
Rear Ride Height Measurement - F-550 with Attitude Improvement Option:
Wheel Track
Wheel Track:
Dogtracking
Dogtracking:
Dogtracking is the condition in which the rear axle is not square to the chassis. Heavily crowned roads can give the illusion of dogtracking.
Wander
Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road.
Shimmy
Shimmy, as observed by the driver, is large, consistent, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements.
Shimmy is usually experienced near 64 km/h (40 mph) and can begin or be amplified when the tire contacts pot holes or irregularities in the road surface.
Nibble
Sometimes confused with shimmy, nibble is a condition resulting from tire interaction with various road surfaces and observed by the driver as small rotational oscillations of the steering wheel.
Poor Return/Sticky Steering
Poor return and sticky steering is used to described the poor return of the steering wheel to center after a turn or a steering correction is completed.
Drift/Pull
Pull is a tugging sensation, felt by the hands on the steering wheel, that must be overcome to keep the vehicle going straight.
Drift describes what a vehicle with this condition does with hands off the steering wheel.
^ A vehicle-related drift/pull, on a flat road, will cause a consistent deviation from the straight-ahead path and require constant steering input in the opposite direction to counteract the effect.
^ Drift/pull may be induced by conditions external to the vehicle (for example, wind or road camber).
Poor Groove Feel
Poor groove feel is characterized by little or no buildup of turning effort felt in the steering wheel as the wheel is rocked slowly left and right within very small turns around center or straight-ahead (under 20° of steering wheel turn). Efforts may be said to be "flat on center".
^ In the diagnosis of a driveability problem, it is important to understand the difference between wander and poor groove feel.