Pinpoint Tests

Suspension System

Pinpoint Tests

Pinpoint Test A: Vehicle Drifts/Pulls

This pinpoint test is intended to diagnose the following:

- Unevenly loaded vehicle

- Tire pressure

- Tire forces

- Brake drag

- Incorrect vehicle alignment

- Steering system

PINPOINT TEST A : VEHICLE DRIFTS/PULLS

A1 CHECK FOR UNEVENLY LOADED VEHICLE

- Visually check the vehicle for an uneven loading condition.

Is the vehicle unevenly loaded?

Yes
ADVISE the customer of uneven loading condition.

No
GO to A2.

A2 CHECK THE TIRE PRESSURE

- Check the tire pressures. Refer to the Vehicle Certification (VC) label located on the driver door jamb.

Is the tire pressure OK?

Yes
GO to A3.

No
ADJUST the tire pressures to the specified pressure.

A3 ISOLATE TIRE PULL CONDITION

- Cross the front wheel and tire assemblies from left-to-right. Refer to section Wheels and Tires.

Does the vehicle pull/drift?

Yes
If the vehicle drifts/pulls in the opposite direction, tire forces are causing the drift/pull. REFER to Wheels and Tires to diagnose tire drift/pull. If the vehicle drifts/pulls in the same direction, GO to A4.

No
Tire forces were causing the drift/pull and the concern has been corrected.

A4 CHECK FOR BRAKE DRAG

- Spin all 4 wheel and tire assemblies by hand and check for brake drag.

Do the wheels spin freely?

Yes
GO to A5.

No
REFER to Brakes and Traction Control to diagnose brake drag condition.

A5 CHECK FOR STEERING SYSTEM DRIFT/PULL

- Check the steering system components. to diagnose steering system drift/pull/wander condition.

Is the steering system the cause of the drift/pull?

Yes
REPAIR the steering system as necessary.

No
GO to A6.

A6 CHECK THE WHEEL ALIGNMENT

- NOTE: A 1/4 degree to 1/2 degree side-to-side caster difference is usually sufficient to correct a drift/pull concern.
Using alignment equipment and the manufacturer's instructions, check the wheel alignment.


Is the caster total/split and the camber total/split within specification?

Yes
ADJUST the caster total/split to counteract the drift/pull concern. REFER to General Procedures.

If the concern is vehicle drifts/pulls left, INCREASE the caster total/split toward the upper end of the specification range.

If the concern is vehicle drifts/pulls right, DECREASE the caster total/split toward the lower end of the specification range.

No
ADJUST the camber and caster total/split as close to the nominal specification as possible. REFER to General Procedures.