Wheel Alignment Measurement

Measuring Wheel Alignment

Steering and vibration complaints are not always the result of improper alignment. One possible cause is wheel and tire imbalance. Another possibility is tire lead due to worn or improperly manufactured tires. Lead/pull is defined as follows: At a constant highway speed on a typical straight road, lead/pull is the amount of effort required at the steering wheel to maintain the vehicle's straight path. Lead is the vehicle deviation from a straight path on a level road without pressure on the steering wheel. Refer to Radial Tire Lead/Pull Correction in order to determine if the vehicle has a tire lead problem.

Before performing any adjustment affecting wheel alignment, perform the following inspections and adjustments in order to ensure correct alignment readings:

^ Inspect the tires for the proper inflation and irregular tire wear. Refer to Label - Vehicle Certification, Tire Place Card, Anti-Theft and Service Parts ID and Tire Diagnosis - Irregular or Premature Wear.
^ Inspect the runout of the wheels and the tires.
^ Inspect the wheel bearings for backlash and excessive play. Refer to Wheel Bearings Diagnosis. Wheel Bearings Diagnosis
^ Inspect the ball joints and tie rod ends for looseness or wear.
^ Inspect the control arms and stabilizer shaft for looseness or wear.
^ Inspect the steering gear for looseness at the frame. Refer to Fastener Tightening Specifications.
^ Inspect the struts/shock absorbers for wear, leaks, and any noticeable noises. Refer to Struts or Shock Absorbers Testing - On Vehicle. Struts or Shock Absorbers Testing - On Vehicle
^ Inspect the vehicle trim height.
^ Inspect the steering wheel for excessive drag or poor return due to stiff or rusted linkage or suspension components.
^ Inspect the fuel level. The fuel tank should be full or the vehicle should have a compensating load added.

Give consideration to excess loads, such as tool boxes, sample cases, etc. If normally carried in the vehicle, these items should remain in the vehicle during alignment adjustments. Give consideration also to the condition of the equipment being used for the alignment. Follow the equipment manufacturer's instructions.

Satisfactory vehicle operation may occur over a wide range of alignment settings. However, if the setting exceeds the service allowable specifications, correct the alignment to the service preferred specifications. Refer to Wheel Alignment Specifications.

Perform the following steps in order to measure the front and rear alignment angles:

1. Install the alignment equipment according to the manufacturer's instructions.
2. Jounce the front and the rear bumpers 3 times prior to checking the wheel alignment.
3. Measure the alignment angles and record the readings.

Important: When performing adjustments to vehicles requiring a 4-wheel alignment, set the rear wheel alignment angles first in order to obtain proper front alignment angles.

4. Adjust alignment angles to vehicle specification, if necessary. Refer to Wheel Alignment Specifications.

Front Camber Adjustment

Removal Procedure

1. Raise the vehicle and provide suitable support. refer to Vehicle Lifting.
2. Remove the tire and wheel assemblies from the front and the rear axles.
3. Remove the strut from the vehicle.
4. Place the strut in a vise and file the hole lateral - oblong. Compare the appearance of the holes before filing (2) with after filing (3).
5. File the lower strut-to-knuckle attaching hole for a front camber adjustment.

Installation Procedure

Notice: Refer to Fastener Notice in Service Precautions.

1. Install the strut to the vehicle.

Tighten the strut-to-knuckle nuts as far as to allow movement of the knuckle.

2. Install the tire and wheel assemblies.
3. Adjust the camber (1).

Tighten the strut-to-knuckle nuts to 120 N.m (89 lb ft).

4. Lower the vehicle.

Front Toe Adjustment

1. Remove the small seal clamp from the inner tie rod boot.
2. Position the steering wheel in the straight ahead position.
3. Loosen the hex nut on the tie rod (2). Turn the tie rod shaft (1) in order to obtain the proper toe angle. Refer to Wheel Alignment Specifications.
4. Confirm the number of threads showing on each tie rod end is nearly equal.

Notice: Refer to Fastener Notice in Service Precautions.

5. Confirm that the tie rod ends (3) are square before you tighten the lock nuts (2).

Tighten the jam nut at the tie rod ends to 68 N.m (50 lb ft).

Important: Ensure the seals do not twist.

6. Install the seal clamps.

Rear Camber Adjustment

Removal Procedure

1. Raise the vehicle and provide suitable support. refer to Vehicle Lifting.
2. Remove the tire and wheel assemblies.
3. Remove the strut from the vehicle.
4. Place the strut in a vise and file the upper strut-to-knuckle hole lateral (oblong). Compare the appearance of the holes before filing (2) with after filing (3).

Installation Procedure

1. Loosen the jam nut at the rear wheel spindle rod (rear).

2. Adjust the toe to the proper setting by turning the adjusting nut. Refer to Wheel Alignment Specifications.

Notice: Refer to Fastener Notice in Service Precautions.

3. Tighten the hex nuts on the rear wheel spindle rod (rear).

Tighten the rear wheel spindle tie rod end jam nut to 68 N.m (50 lb ft).