Wheel Alignment Measurement Front
Steering and vibration complaints are not always the result
of improper alignment. Another possibility is tire lead due to worn or improperly
manufactured tires. Lead is the vehicle deviation from a straight path on
a level road without pressure on the steering wheel. Refer to
Wheel Alignment Specifications
in Tires and Wheels
in order to determine if the vehicle has a tire lead problem. Before you make
any adjustment affecting wheel alignment, perform the following inspections
in order to ensure correct alignment readings and adjustments.
| • | Inspect all of the tires for proper inflation pressures. |
| • | Inspect that all of the tires are of the recommended size. |
| • | Inspect that all of the tires have about the same tread wear. |
| • | Inspect the wheel bearings for proper adjustment. Correct if necessary. |
| • | Inspect the following components. If the components are loose,
correct the components before you adjust the wheel alignment: |
| • | Inspect the vehicle trim height. If the vehicle trim height is
out of limits make the necessary corrections before adjusting the wheel alignment.
Refer to
Trim Height Specifications
. |
| • | Verify that the steering gear is not loose at the frame. |
| • | Inspect the lower control arms for loose bushings. |
| • | Inspect the stabilizer shafts for loose or missing parts. |
| • | Inspect for leaking or worn out shock absorbers. |
| • | Inspect the remaining suspension and steering components for damage.
Replace all of the worn parts prior to adjusting the wheel alignment. |
| • | Inspect the vehicle for stability. The fuel tank should be full
or the vehicle should have compensating ballast. |
Consideration must be given to excess loads, such as tool boxes, sample
cases, etc. If these items are normally carried in the vehicle, the items
should remain in the vehicle during alignment adjustments. Consideration should
also be given to the condition of the equipment being used to adjust alignment.
Be sure to follow the equipment manufacturer's instructions. Regardless of
the equipment used to adjust alignment, the vehicle must be on a level surface,
both front-to-rear and side-to-side.
Satisfactory vehicle operation may occur over a wide range
of alignment settings. If settings vary beyond the specifications, correct
the alignment angles.
Perform the following steps to measure the wheel alignment angles:
- Install the alignment equipment according to the manufacturer's
instructions.
- Jounce the front bumpers and the rear bumpers lightly 3 times
in order to normalize the suspension prior to measuring the angles.
- Measure the alignment angles.
- Record the readings. If adjustments are required, perform the
adjustments in the following order:
Wheel Alignment Measurement Rear Wheel Alignment
Rear Wheel Alignment
Toe angle is the only adjustment that you can make to the rear wheels.
Refer to
Wheel Alignment Specifications
for proper alignment specifications.
