Checking Procedure

To restore the vehicle to a level condition at the fender wheel lip openings, use the following procedure to check and correct service leans with differences in excess of 0.5" (12.7 mm) side-to-side.





1. Confirm that the vehicle is assembled with the proper front spring codes. Refer to the following Front Spring Chart.


2. Place the vehicle on a level surface and check tire pressures to ensure that the left front/right front and left rear/right rear are identical.

3. With the engine OFF, but the ignition in the ON position and the driver's door open, proceed as follows:

a. Load the rear bumper until the air suspension compressor cycles for at least 30 seconds.

b. Close the driver's door and let the vehicle vent to the "Top of Trim" position (approximately 10 seconds).

c. If the air suspension does not function properly, perform service diagnostics as outlined in the 1991 Lincoln Town Car Shop Manual, Section 14-40.

Figure 1:

4. Equalize the suspension by shaking the vehicle side-to-side from the "B" pillar joint before taking wheel lip measurements, Figure 1.

5. Determine the difference in the front and rear wheel lip measurements by subtracting the left side measurement from the right hand side at both the front and rear locations.

NOTE: THE FENDER WHEEL LIP MEASUREMENT IS THE VERTICAL DISTANCE FROM THE FENDER WHEEL LIP TO THE GROUND WHILE PASSING THROUGH THE CENTER OF THE WHEEL, FIGURE 1.





6. Use the following Spring Selection Chart to select the correct spring three letter code and/or shim combination.





The following Front Spring Load Chart provides information about the 410 lbs/in rate springs which are specifically released for the 1991 Lincoln Town Car.

CAUTION: DO NOT USE ANY OTHER SPRINGS THAN THOSE SPECIFIED.


7. Install the appropriate shim pack and/or spring combination per the Shop Manual procedures. Eliminate the potential of suspension noise by taping the shims and spring insulator to the flat end of the front spring. On reinstallation of the spring(s), ensure that...

a. There is proper orientation of the spring tail in the lower control arm assembly.

b. All disrupted fasteners are returned to the recommended torque settings.

8. Test drive the vehicle about two miles over a moderate road surface to settle the suspension befor re-evaluating it for body lean. Revent the air suspension prior to making lean measurements.

NOTE: WHEEL LIP AND BUMPER SHOULD NOT EXCEED 29.5" (749.3 MM) AND 16.0" (406.4 MM) RESPECTIVELY AFTER CORRECTIVE ACTIONS HAVE BEEN COMPLETED.

9. If this procedure does not reduce the lean to acceptable levels of 0.5" (12.7 mm), the following body/frame shimming procedure should be performed to further reduce the vehicle lean condition.