300Tdi Discovery
STEERING
5
FAULT DIAGNOSIS
Symptom :-
Steering excessively light/sensitive. Excessive
freeplay at steering wheel.
1. Are steering box adjustments correct?
NO -
See Adjustment, Power Steering Box
WARNING: Adjustments of steering box
should not be required while in warranty
period. If box is within warranty, it must be
returned to manufacturer. No attempt must be
made to introduce backlash.
YES - Suspect worn panhard rod or radius arm
bushes Check condition of ball joints and
the lower steering column shaft universal
joints for wear.
See Repair, Lower
Steering Shaft and Universal Joints
Symptom :-
Steering vibration, road wheel shimmy - wobble.
Vibration through the steering linkage powerful
enough to induce high frequency oscillation of the
steering wheel, is generally caused by out of balance
road wheels. However there are a number of other
possible causes of this symptom which if severe, may
be described as shimmy or wobble. Regardless of the
terminology used by the owner/driver to describe the
symptoms, the following diagnostic checks should be
carried out in the order presented.
1. Check the tyres and balance of the road wheels.
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres See
WHEELS AND TYRES, Fault diagnosis, Fault
- Symptoms See WHEELS AND TYRES,
Repair, Wheel Balancing
2. Check the steering hydraulic damper function.
See Steering Damper
3. Check steering column universal joints for wear
and correct alignment.
See Repair, Lower
Steering Shaft and Universal Joints
4. Check steering linkage ball joints for wear,
correct alignment and security, including steering
box and tie rod.
See Steering Linkage Inspect
5. Check all front suspension rubbers for wear.
Check all fixing torques, including radius arm
bushes, panhard rod and anti-roll [sway] bar.
See FRONT SUSPENSION, Repair, Panhard
Rod See FRONT SUSPENSION, Repair,
Radius Arm See FRONT SUSPENSION,
Repair, Anti-Roll[Sway] Bar Assembly See
FRONT SUSPENSION, Repair, Front Shock
Absorber
6. Fit new radius arm bushes using NTC 6860. Fit
harmonic damper if vehicle has air suspension.
Fit new nuts, bolts and washers.
7. Coil spring vehicles only - If problem persists
fit damper kit STC 241 (2 off front) and STC
1474 (2 off rear). Road test vehicle.
8. Check the power steering box adjustments and
operation.
See Overhaul, Power Steering Box
9. Check the hub bearing end floats and determine
the condition of the hub bearings. As applicable.
See FRONT AXLE AND FINAL DRIVE, Repair,
Front Hub Assembly
10. Check the resistance and condition of the
swivels.
See FRONT AXLE AND FINAL
DRIVE, Description and operation,
Description
If problem is not diagnosed: Repeat
checks starting at 1.
11. Carry out a full steering geometry check.
See
INTRODUCTION, Information, Steering
