Section 54 (Wheel Alignment Specifications & Procedures): Adjustments: Caster
WARNING: This page is about a different car, the 1983 Jeep Scrambler, 1983 Jeep CJ7, and 1983 Jeep CJ5. However, it is still accessible from the selected car via links, so may be relevant.
Correct caster is preset at factory to 6° for CJ and Scrambler models, and 4° for all other models. Adjustment is made by inserting shim between spring and axle.
To increase caster, insert thick portion of shim toward rear of vehicle. To decrease caster, insert thick portion of shim toward front of vehicle.