Front Alignment - Specifications/Procedures

Article No.
92-25-11

Dec. 2, 1992

^ SUSPENSION - FRONT - 1993 ALIGNMENT SETTINGS

^ SUSPENSION - FRONT ALIGNMENT SERVICE PROCEDURES - 1993 VEHICLES



LIGHT TRUCK:
1993 AEROSTAR, BRONCO, ECONOLINE, EXPLORER, F-150-350 SERIES, F-47, RANGER



ISSUE:
Front end alignment on the subject light trucks may occasionally require adjustment. Information about the service parts available to provide the adjustments and service setting objectives is featured in this TSB article.

ACTION:
If the Light Truck Service Manual diagnostics indicate the need for front alignment adjustment, use the following caster/camber adjustment parts and alignment specifications to make the adjustment.






The Front End Alignment Settings Chart, Figure 1, provides optimum alignment settings and recommended allowable ranges for light truck alignments. The ranges given in this chart are only recommended guidelines within which most customers would not indicate concern with vehicle alignment.



NOTE:
WHEN SERVICE MANUAL DIAGNOSTICS INDICATE THAT AN ALIGNMENT ADJUSTMENT MAY BE REQUIRED TO RESOLVE THE CUSTOMER CONCERN, THEN ALL OF THE VEHICLE'S ALIGNMENT PARAMETERS SHOULD BE SET TO THEIR OPTIMUM VALUES TO ASSURE CUSTOMER SATISFACTION.





If Light Truck Service Manual Diagnostics indicate the need for a front alignment adjustment, use the optimum alignment settings and caster/camber adjustment parts list, Figure 2. Refer to the appropriate 1993 Light Truck Service Manual for service details.

Be sure that the following required vehicle conditions are met before checking alignment.

^ No driver and/or passenger in vehicle

^ Full fluids

^ All tires set to specified pressure

^ All tire sizes comparable to original equipment

^ Vehicle configured to normal operated conditions (Not to exceed Maximum GAWR, Maximum Rear GAWR, and/or Maximum GVW)

DEFINITIONS

CAMBER AVERAGE is defined as LH camber plus RH camber divided by 2 (LH Camber + RH Camber)/2.

Vehicles set to this specification, as measured with the vehicle loaded to normal loading conditions will result in optimum tire wear.

CASTER AVERAGE is defined as LH caster plus RH caster divided by 2 (LH Caster + RH Caster)/2.

These are not recommended values for settings. They are only maximum and minimum limitations. Vehicles outside these limits may exhibit the following concerns.

^ Vehicles which exceed the maximum caster value may result in shimmy concerns.

^ Vehicles operated below the minimum caster value may wander and have poor steering returnability concerns.

CAMBER SPLIT is defined as LH camber minus RH camber (LH camber - RH camber).



CASTER SPLIT is defined as LH caster minus RH caster (LH caster - RH caster).

NOTE:
VEHICLES WITH AVERAGE CASTER AND/OR CAMBER SIGNIFICANTLY OUT OF SPECIFIED RANGES MAY HAVE A RIDE HEIGHT OUT OF NORMAL OPERATING RANGE. NORMAL SERVICE PROCEDURES MAY NOT PROVIDE ADEQUATE ADJUSTMENT TO BRING THE ALIGNMENT TO THE PREFERRED SPECIFICATION. IF RIDE HEIGHT APPEARS TO BE AN ISSUE, INVESTIGATE AS FOLLOWS:

Front ride height can be below specification if the front loading exceeds the rated capacity listed on the certification label.

a. Weigh the front end and compare to the certification label to determine if an overloaded condition exists.

b. If overloaded, adjust weight to bring the vehicle back into compliance with the published weight limits or rerate the front suspension within guidelines of the Body Builder's Layouts Book.

Front ride height can be abnormally high on lightly loaded vehicles equipped with heavy duty front suspension options or maximum FGAWR options.

c. Compare the ride height of the frame-to-ground guidelines at the wheel centers published in the Body Builder's Layouts Book.

d. Adjust loading as required or revise the front suspension rating within the guidelines in the Body Builder's Layouts Book.








The 1993 Model - Alignment Service Parts Usage Chart, Figure 2, provides correct parts usage for each type of vehicle. Select the appropriate parts group from this chart and use the Caster/Camber Parts Information Chart, Figure 3, to order the parts required.





Part Number/Name Chart





Warranty, Operation, Description