Correct front wheel alignment is essential for proper steering control, tyre life and vehicle stability. Alignment consists of three primary factors: caster, camber and toe-in. Inspection and adjustment of these settings must be performed carefully using proper alignment equipment and procedures.
Because incorrect alignment can be caused by worn or damaged suspension components, a preliminary inspection of the front suspension and steering system must always be completed before attempting alignment adjustments.
Preliminary Front End Inspection
Front wheel alignment should not be checked or adjusted until a thorough inspection has been made for front-end malfunction, damage or wear.
Begin by checking the air pressure in all four tyres to ensure they are inflated to the specified pressure.
Raise the vehicle using the lower suspension arms, placing the jack directly beneath the reinforced section of the arm. This allows proper inspection of suspension components.
Shake each front wheel and check the front suspension ball joints and mounting points for looseness, wear or damage. Inspect the brake backing plate mountings and tighten all loose bolts and nuts to the specified torque. Replace any worn parts discovered during the inspection.
Next inspect the steering gear mountings and steering linkage connections for looseness or damage. Tighten all mountings to specification and replace any worn or bent linkage components.
Check the front wheel bearings for excessive free play. If any looseness is detected, adjust the bearings to eliminate the play or replace worn bearings.
Spin each front wheel and inspect for wheel balance or run-out problems. Correct any imbalance before proceeding with alignment adjustments.
Finally check the shock absorbers for proper operation. Faulty shock absorbers can prevent the vehicle from settling at the correct ride height and may affect alignment measurements.
Front Wheel Alignment Inspection
Front wheel alignment inspection must be carried out using accurate alignment equipment installed according to the manufacturer's instructions.
When portable equipment is used, ensure that the vehicle is positioned on a level floor before beginning measurements.
Drive the vehicle forward far enough to establish the straight-ahead position of the front wheels, then mark the relationship between the steering wheel hub and the steering column collar. The steering wheel should not be adjusted during inspection. If the wheels are turned during testing, the marks should be aligned again to restore the straight-ahead position.
After alignment equipment has been installed, inspect all alignment factors except toe-out on turns, which should only be checked after caster, camber and toe-in have been adjusted to specification.
Caster
Caster is the angle formed between the true vertical line and the centreline through the upper and lower ball joints.
The specified caster angle for the Falcon XK is 0° to 1°, with 0° preferred. The maximum difference between the caster angle of the two front wheels should not exceed ½°.
Correct caster ensures directional stability and proper steering return after turning.
Camber
Camber is the angle between the vertical line and the centreline of the wheel and tyre.
The specified camber angle is 0° to 1° positive. The maximum allowable difference between the camber angles of the two front wheels should not exceed ½°. A camber setting of 0° on both wheels is preferred.
Incorrect camber can cause uneven tyre wear and steering instability.
Toe-In
Toe-in is measured with the front wheels in the straight-ahead position.
It is determined by measuring the distance between the front edges of the tyres and the rear edges of the tyres. Toe-in is the difference between these measurements.
Correct toe-in for the Falcon XK is 5/32 inch to 7/32 inch, with 5/32 inch preferred.
Proper toe-in helps maintain directional stability and prevents irregular tyre wear.
Toe-Out on Turns
After caster, camber and toe-in have been adjusted correctly, the toe-out on turns should be checked.
When the outside wheel is turned inward 20 degrees, the inside wheel should turn outward approximately 20¾ degrees.
If this angle is incorrect, the spindle arm on the inside wheel may be bent and should be replaced.
Front Wheel Alignment Adjustments
After alignment measurements have been completed, necessary adjustments can be made. Alignment should never be corrected by bending suspension or steering components.
Caster and Camber Adjustments
Caster and camber are adjusted by adding or removing shims between the inner shaft of the front suspension upper arm and the vehicle body.
Both adjustments can be performed simultaneously by loosening the two bolts that secure the inner shaft to the body.
After the correct number of shims has been installed or removed, tighten the bolts to 65–90 foot-pounds torque.
Adjustment shims are available in 1/32-inch and 1/8-inch thicknesses.
Caster Adjustment
Caster is adjusted by installing or removing shims at the front or rear mounting bolts.
Removing shims from the front bolt or adding shims to the rear bolt will move the upper ball joint forward. Removing shims from the rear bolt or adding shims to the front bolt will move the upper ball joint rearward.
A 1/8-inch change in shim thickness at either bolt will change caster approximately ½ degree.
The difference between shim stacks at the two bolts should not exceed 1/16 inch.
Camber Adjustment
Camber is adjusted by installing or removing equal thickness shims at both mounting bolts.
Removing equal shims at both bolts moves the upper ball joint inward. Adding equal shims moves the ball joint outward.
A 1/16-inch change in shim thickness at both bolts will change camber approximately ⅓ degree. The total shim stack thickness at each bolt should not exceed 5/16 inch.
Toe-In and Steering Wheel Alignment
After caster and camber adjustments have been completed, toe-in must be set and the steering wheel aligned.
Ensure the steering wheel is in its normal straight-ahead position. If the wheel spokes are not centered, they can be corrected during toe-in adjustment.
Loosen the two clamp bolts on each spindle connecting rod sleeve, then adjust the sleeve to lengthen or shorten the rod until correct toe-in is obtained.
If the steering wheel spokes are correctly positioned, adjust both rods equally. This ensures proper steering wheel alignment while maintaining correct toe-in.
After adjustment, tighten the clamp bolts securely.
Safety, Copyright and Source Notice
Safety Disclaimer
Working on motor vehicles involves mechanical, electrical and chemical hazards. Always ensure the vehicle is safely supported, the engine is switched off when appropriate, and suitable safety equipment such as gloves and eye protection is used. If you are unsure about any repair or maintenance procedure, consult a qualified mechanic before attempting the work.
Source
Information compiled from period factory shop manual.
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