Initial Inspection and Diagnostic Overview

1. Road test.
- Verify the customer's concern by performing a road test on a smooth road.
2. Inspect tires.
- Check the tire pressure with all normal loads in the vehicle and the tires cold. For additional information, refer to the Vehicle Certification (VC) label.
- Verify that all tires are sized to specification.
Drift describes what a vehicle with this condition does with hands off the steering wheel.
- Drift/pull may be induced by conditions external to the vehicle (i.e., wind, road camber).

Poor Groove Feel
Poor groove feel is characterized by little or no buildup of turning effort felt in the steering wheel as the wheel is rocked slowly left and right within very small turns around center or straight-ahead (under 20 degrees of steering wheel turn). Efforts may be said to be "flat on center."

- Under 20 degrees of turn, most of the turning effort that builds up comes from the mesh of gear teeth in the steering gear. In this range, the steering wheel is not yet turned enough to feel the effort from the self-aligning forces at the road wheel or tire patch.
- In the diagnosis of a handling problem, it is important to understand the difference between wander and poor groove feel.
- Inspect the tires for incorrect wear and damage.
3. Inspect chassis and underbody.
- Remove any excessive accumulation of mud, dirt or road deposits from the chassis and underbody.
4. Inspect for aftermarket equipment.
- Check for aftermarket changes to the steering, suspension, wheel and tire components (such as competition, heavy duty, etc.) The specifications do not apply to vehicles equipped with aftermarket equipment.
5. Inspect shock absorbers.
All vehicles are equipped with gas-pressurized hydraulic shock absorbers. These shock absorbers are not adjustable or refillable and cannot be repaired.
- Oil Leak: A light film of oil (weepage) on the upper portion of the shock absorber is permissible and is a result or correct shock lubrication. Weepage is a condition in which a film of oil accumulates on the thin tube (body) and is normally noticed due to the collection of dust in this area. If shock absorbers exhibit this weepage condition, they are functional units and new shock absorbers should not be installed. Leakage is a condition in which the entire shock absorber body is covered with oil and the oil will drip from the shock absorber onto the pavement. If condition exists:
- Make sure fluid observed is not from sources other than the shock absorber.
- Install a new shock absorber, if necessary.
- Vehicle Sag: Many times new shock absorbers are installed in an effort to solve a vehicle sag concern. Shock absorbers by design are hydraulic damping units only and, unlike suspension springs, do not support any suspension loads. Therefore, installing a new shock absorber will not correct a vehicle sag concern.





- Installment in Pairs: In the past it was recommended that new shock absorbers be installed in pairs if one unit became unrepairable. New shock absorbers no longer need to be installed in pairs when only one unit is not repairable.
6. If an obvious cause for an observed or reported condition is found, correct the cause (if possible) before proceeding to the next step.
7. If the fault is not visually evident, determine the symptom and proceed to the symptom chart. Symptom Related Diagnostic Procedures