Symptom Related Diagnostic Procedures

General Diagnostic Table (Part 1):

General Diagnostic Table (Part 2):

INSPECTION

NOISE AND VIBRATION

Important: Don't keep the relief valve operated over 5 seconds at any time or inner parts of the oil pump may be damaged due to rapid increase of fluid temperature.

Note:
^ Grinding noise may be heard immediately after the engine start in extremely cold condition. In this case, if the noise goes off during warm-up there is no abnormal function in the system. This is due to the fluid characteristic in extremely cold condition.
^ Oil pump makes whine or growl noise slightly due to its mechanism. Even if the noise can be heard when steering wheel is turned at stand still there is no abnormal function in the system provided that the noise eliminates when the vehicle is running.
^ When turning the steering wheel with service brake and/or parking brake applied, the noise is generated by creaking between disk and pads. However this does not indicate abnormal function in system.
^ There may be a little vibration around the steering devices when turning steering wheel at standstill, even though the component parts have no defects.














Hydraulic systems are likely to generate this kind of vibration as well as working noise and fluid noise because of combined conditions, i.e., road surface and tire surface, engine speed and turning speed of steering wheel, fluid temperature and braking condition.
This phenomena does not indicate there is some abnormal function in the system.
The vibration can be known when steering wheel is turned repeatedly at various speeds from slow to rapid step by step with parking brake applied on concrete road and in "D" range for AT model.

MEASUREMENT OF STEERING EFFORT
CHECK STEERING EFFORT.
Stop the vehicle on a concrete road.
Start the engine.
Idle the engine.
Install the spring scale on the steering wheel.
Pull the spring scale at an right angle to steering wheel, and measure both right and left steering wheel effort.

Note: When turning the steering more quickly than necessary from a direction to the other direction at an engine speed over 2,000 rpm, steering effort may be heavy. This is caused by flow characteristic of oil pump and is not a problem.

Is the steering effort less than 31.4 N (3.2 kgf, 7.1 lb)?
YES
Go to next step
NO
Adjust the backlash.

CHECK STEERING EFFORT.
Stop the engine.
Pull the spring scale at an right angle to the steering wheel, and measure both right and left steering wheel effort.
Is the steering effort less than 294.2 N (30 kgf, 66.2 lb)?
YES
Go to next step
NO
Perform adjustment.

CHECK STEERING WHEEL EFFORT.
Remove the universal joint. Measure the steering wheel effort.
Is the maximum steering effort less than 2.26 N (0.23 kgf, 0.51 lb)?
YES
Go to next step
NO
Check, adjust and replace if necessary.

CHECK STEERING WHEEL EFFORT.
Measure the steering wheel effort.
Is the difference of steering effort between clockwise and counterclockwise less than 20% ?
YES
Go to next step
NO

CHECK UNIVERSAL JOINT.
Measure the swing torque of the joint (yoke of steering column side).
Is the swing torque less than 7.3 N (0.74 kgf, 1.64 lb)?
YES
Go to next step
NO
Replace with new one.

CHECK UNIVERSAL JOINT.
Measure the swing torque of the joint (yoke of gearbox side).
Is the swing torque less than 3.8 N (0.39 kgf, 0.86 lb)?
YES
Go to next step
NO
Replace with new one.

CHECK FRONT WHEEL.
Check the front wheel.
Are the front wheels for unsteady revolution or rattling and brake for dragging?
YES
Inspect, readjust and replace if necessary.
NO
Go to next step

CHECK TIE-ROD ENDS.
Remove the tie-rod ends.
Are the tie-rod ends of suspension for unsteady revolution or rattling?
YES
Inspect and replace if necessary.
NO
Go to next step

CHECK BALL JOINT.
Remove the ball joint.
Are the ball joints of suspension for unsteady revolution or rattling?
YES
Inspect and replace if necessary.
NO
Go to next step

CHECK GEARBOX.
Measure the rotating of gearbox.
Is the rotating resistance of gear box less than 10.5 N (1.1 kgf, 2.4 lb)? Is the difference between clockwise and counterclockwise 20%?
YES
Go to next step
NO
Readjust the backlash, and if ineffective, replace the faulty parts.

CHECK GEARBOX.
Measure the sliding of gearbox.
Is the sliding resistance of gear box less than 400 N (41 kgf, 90 lb)? Is the difference between right and left 20% ?
YES
Steering effort is normal.
NO
Readjust the backlash, and if ineffective, replace the faulty parts.