Initial Inspection and Diagnostic Overview
Inspection and VerificationCaution:
^ Do not hold the steering wheel at the stops for an extended amount of time. Damage to the power steering pump can result.
Note:
^ Make the preliminary checks before repairing the steering system:
1. Verify the customer concern by operating the steering system.
2. Inspect Tires
1. Check the tire pressure.
2. Verify that all tires are sized to specification.
3. Check the tires for damage or uneven wear.
3. Belt and Tensioner Check
1. Refer ACCESSORY DRIVE for diagnosis and testing of the accessory drive system.
4. Fluid Level Check
1. Verify that the power steering fluid level is within the appropriate hot or cold range on the dipstick. Add MERCON(R) automatic transaxle fluid (ATF).
5. Air Bleeding
1. Verify that there is no air in the power steering system. Run the engine until it reaches normal operating temperature. Turn the steering wheel to the left and right several times without hitting the stops. If any air bubbles are present, refer to PURGING.
External Leak Check-Typical Power Rack and Pinion Steering Gear
6. External Leak Check
1. With the ignition switch at OFF, wipe off the power steering pump, power steering pressure hose, power steering return hose, power steering fluid cooler and hose assembly and steering gear.
2. With the engine running, turn the steering wheel from stop-to-stop several times. Do not hold steering wheel at stops. Check for leaks. Repair as necessary if leaks are observed.
7. Turning Effort Check
1. Refer to Turning Effort Test.
8. Visually inspect for obvious signs of mechanical damage. Refer to the chart.
Visual Inspection Chart
9. If an obvious cause for an observed or reported malfunction is found, correct the cause (if possible) before proceeding to the next step.
10. If the fault is not visually evident, determine the symptom and proceed to the symptom chart.
Steering System Symptom Definitions Drift/Pull
Pull is a tugging sensation, felt by the hands on the steering wheel, that must be overcome to keep the vehicle going straight.
Drift describes what a vehicle with this condition does with hands off the steering wheel.
^ A vehicle-related drift/pull, on a flat road, can cause a consistent deviation from the straight-ahead path and require constant steering input in the opposite direction to counteract the effect.
^ Drift/pull can be induced by conditions external to the vehicle (i.e., wind, road camber).
Excessive Steering Wheel Play
Excessive steering wheel play is a condition in which there is too much steering wheel movement before the wheels move. A small amount of steering wheel free play is considered normal.
Feedback
Feedback is a roughness felt in the steering wheel when the vehicle is driven over rough pavement.
Hard Steering or Lack of Assist
Hard steering or lack of assist is experienced when the steering wheel effort exceeds specifications. Hard steering can remain constant through the full turn or occur near the end of a turn. It is important to know the difference between hard steering/lack of assist and binding.
Hard steering or lack of assist can result from either hydraulic or mechanical conditions. It is extremely important to know if this concern occurs during driving, during very heavy or static parking maneuvers.
Nibble
Sometimes confused with shimmy, nibble is a condition resulting from tire interaction with various road surfaces and observed by the driver as small rotational oscillations of the steering wheel.
Poor Returnability/Sticky Steering
Poor returnability and sticky steering is used to describe the poor return of the steering wheel to center after a turn or the steering correction is completed.
Shimmy
Shimmy, as observed by the driver, is large, consistent, rotational oscillations of the steering wheel resulting from large, side-to-side (lateral) tire/wheel movements. Shimmy is usually experienced near 64 km/h (40 mph), and can begin or be amplified when the tire contacts pot holes or irregularities in the road surface.
Wander
Wander is the tendency of the vehicle to require frequent, random left and right steering wheel corrections to maintain a straight path down a level road.