1995 LAND ROVER DISCOVERY power steering

STEERING
3
FAULT DIAGNOSIS STEERING DAMPER
The power steering system, as well as reducing the
effort required to manoeuvre the vehicle when
parking, also helps to dampen any deflections of the
road wheels, being transmitted back to the steering
wheel.
When operating the vehicle off road, the road wheels
are often deflected by ruts and boulders causing the
steering wheel to turn left and right. This phenomenon
is known as 'steering kickback'. To subdue the effects
of 'steering kickback', a hydraulic damper is fitted in
the steering linkage between the track rod and the
differential casing. The damper, which offers the same
resistance in extension and compression, is sealed for
life.
Steering damper check
Check the condition operation of the hydraulic
steering damper as follows:
Check procedure
1.Inspect damper for casing damage or leaks.
2.Clamp one end of the damper horizontally in a
vice using soft jaws. Compress and extend the
unit by hand. Resistance should be equal in both
directions.
3.If it is felt that the unit is outside acceptable
limits, fit a new steering damperSTEERING FAULTS
Symptom:-
Excessive kickback through steering wheel - when
driven on rough terrain.
1.Is the steering damper in good working order?
See Steering Damper
NO - Renew unit.See Repair, Steering
Damper
YES - Continue.
2.Is there any looseness or free play in the
steering ball joints and linkage?
YES -
See Steering Linkage Inspect
NO - Continue.
3.Is there any looseness or worn bushes in front
suspension?
YES -
See FRONT SUSPENSION, Repair,
Radius Arm
NOTE: When replacing suspension bushes
ALL bushes and fixings must be replaced.
NO - Continue.
4.Is the steering exceptionally light/sensitive when
driven on good road surface?
YES - See fault symptom -Steering
excessively light/sensitive and
freeplay at steering wheel.
NO - Suspect axle swivel resistance.
5.Check the resistance of the axle swivels.
See
FRONT AXLE AND FINAL DRIVE, Overhaul,
Front Stub Axle, Constant Velocity Joint and
Swivel Pin Housing Non ABS See FRONT
AXLE AND FINAL DRIVE, Overhaul, Front
Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS

57STEERING
4
FAULT DIAGNOSIS Symptom:-
Fluid leaks from steering box seals.
CAUTION: The steering wheel must not be
held on full lock for more than 30 seconds
in one minute, as this may overheat the
fluid and cause damage to the oil seals.
1.Check fluid level.
See Repair, Power Steering
Fluid Reservoir
Check fluid pressure.See Power Steering
System - Test
2.Is pressure high?
YES - Renew pump.
See Repair, Power
steering Pump
If oil seal leaks persist after renewing the
pump.
See Overhaul, Power Steering
Box
NO -See Overhaul, Power Steering Box
Symptom:-
Insufficient power assistance - castor return
action normal.
1.Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
YES - Continue.
2.Is fluid level correct?
NO - Check fluid level
See Repair, Power
Steering Fluid Reservoir
YES - Check system for air locks.See Repair,
Power Steering System - Bleed
3.Is pressure correct?
NO - Check fluid pressure.
See Power
Steering System - Test
If pressure is not correct after bleeding
the system, renew pump.
See Repair,
Power Steering Pump
YES -See Overhaul, Power Steering Box
Symptom:-
Steering heavy - stiff, poor castor return action.
1.Are tyres correct type and pressure?
NO -
See GENERAL SPECIFICATION DATA,
Information, Wheels and Tyres
YES - Check universal joints for seizure and
correct alignment.
See Repair, Lower
Steering Shaft and Universal Joints
Check power steering box adjustments.
See Overhaul, Power Steering Box
2.Is the power assistance satisfactory?
NO - See fault symptomInsufficient
assistance, (castor return action
normal).
YES - Disconnect drag link from drop arm and
check steering column and box for
stiffness.
See Repair, Drag Link and
Drag Link Ends
3.Is the steering stiff with the drag link
disconnected?
NO - Check steering ball joints for seizure and
axle swivels lubrication and resistance.
See Repair, Drag Link and Drag Link
Ends See FRONT AXLE AND FINAL
DRIVE, Overhaul, Front Stub Axle,
Constant Velocity Joint and Swivel Pin
Housing Non ABS See FRONT AXLE
AND FINAL DRIVE, Overhaul, Front
Stub Axle, Constant Velocity Joint and
Swivel Pin Housing ABS
YES - Disconnect the lower steering shaft and
check the column and box for stiffness.
See Repair, Lower Steering Shaft and
Universal Joints
4.Is the steering column stiff to turn when
disconnected from the box?
NO - Remove and overhaul box.
See
Overhaul, Power Steering Box
YES - Adjust steering column.See Stiff
Steering Checklist

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

57STEERING
8
FAULT DIAGNOSIS 4. DIRECTIONAL STABILITY
From 1. GENERAL STEERING:
1.Is directional stability concern when vehicle is
towing?
YES - Check towing/vehicle loading parameters
in Owner's Handbook.
NO - go to 3.
2.Is problem resolved?
YES - end
NO - continue.
3.Check condition of rear trailing link/chassis
bushes.
4.Is problem resolved?
YES - end
NO - continue.
5.Check condition of front and rear shock
absorbers. If in doubt change units in pairs, side
to side.
6.Is problem resolved?
YES - end
NO - continue.
7.Check steering damper.
See Steering Damper
8.Is problem resolved?
YES - end
NO - continue.
9.Check wheel balance
10.Is problem resolved?
YES - end
NO - contact local technical office.POWER STEERING FLUID LEAKS
1.Is fluid level correct?
YES - go to 3.
NO - Refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Is problem resolved?
YES - end
NO - continue.
3.Are hoses or joints leaking? Check on full lock
with engine at 2000 rev/min.
YES - loosen and retorque joints.
NO - go to 6.
4.Does leak remain?
YES - change PAS pipe.
NO - end.
5.Does leak remain?
YES - suspect seal in component. Check and
replace as necessary.
NO - end.
6.Is oil escaping from filler cap?
YES - bleed system.
See Repair, Power
Steering System - Bleed
NO - go to 8.
7.Is oil still escaping from filler cap?
YES - go back to 1.
NO - end.
8.Is oil leaking from PAS pump?
YES - go to 10.
NO - continue.
9.Is oil leaking from PAS box?
YES - go to 10.
NO - end.
10.Clean unit, add tracer dye to system. Retest
11.Is oil still leaking?
YES - establish leak point. Repair or replace
unit as necessary.
NO - end.

STEERING
9
FAULT DIAGNOSIS POWER STEERING SYSTEM - EXCESSIVE NOISE
1.Is fluid level correct?
YES - go to 3.
NO - Refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Is problem resolved?
YES - end
NO - continue.
3.Is pressure hose from pump to box touching
body in a hard foul condition?
YES - reroute hose away from body.
NO - go to 5.
4.Does noise remain?
YES - continue.
NO - end.
5.Is noise a whistle or hiss on full lock?
YES - noise is not a fault unless excessive.
Compare with other vehicles
NO - go to 8.
6.Is noise excessive?
YES - continue.
NO - end.
7.Change steering box and/or pump.
8.Is noise a squeal on full lock?
YES - check/reset drive belt tension.
See
ENGINE, Repair, Drive Belt
NO - go to 10.
9.Does squeal remain?
YES - drive belt contaminated, change belt.
NO - end.
10.Is noise a continuous moan?
YES - bleed PAS system.
See Repair, Power
Steering System - Bleed
NO - go to 13.
11.Does moan remain?
YES - do figure 8 manoeuvres.
NO - end.
12.Does moan remain?
YES - continue
NO - end.13.Is noise an intermittent "grunt"?
YES -
See Power Steering System - Grunt
NO - continue.
14.Is it a clunking noise?
YES - reset drive belt tension.
See ENGINE,
Repair, Drive Belt
NO - contact local technical office.
15.Does noise remain?
YES - Suspect suspension or drive train.
NO - end.
POWER STEERING SYSTEM - GRUNT
Steering box grunts intermittently when turning
from lock to lock:
1.Is fluid level correct?
YES - go to 3.
NO - refill or drain to correct level. Bleed
system, check for leaks.
See Repair,
Power Steering System - Bleed
2.Does grunt remain?
YES - continue
NO - end.
3.Is correct low pressure hose ANR 3152, steering
box to reservoir fitted?
YES - go to 5.
NO - Fit correct hose.
4.Does grunt remain?
YES - continue
NO - end.
5.Purge box by doing figure 8 manoeuvres e.g. on
car park, followed by 10 minutes normal road
use.
6.Does grunt remain?
YES - Contact local technical office
NO - end.

57STEERING
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FAULT DIAGNOSIS Steering column alignment
1.Place vehicle on level ground. Measure the
angle of lower steering shaft using a Pernumeter
placed on the shaft between the universal joints.
The angle should measure a minimum of 12Ê.
2.If necessary, realign the shaft. Release the five
fixings securing the steering column. Position
column as required. Tighten the fixings evenly,
27 Nm.
3.Loosen the three screws securing lower steering
column shroud to upper shroud ensure lower
shroud is clipped to upper shroud. Reposition
shroud, tighten screws.
4.Recheck steering column angle.
Steering box adjustment
1.Check steering box adjustment.
See
Adjustment, Power Steering Box
Steering damper check
1.Check condition of steering damper
See
Steering Damper
VISUAL CHECK AND BASIC ADJUSTMENTS
NOTE: It is important that the following
instructions are carried out in the
sequence shown and the results recorded.
1.Road springs - check that road springs are
correctly seated and are to correct specification
for vehicle. For spring specification.
See
GENERAL SPECIFICATION DATA,
Information, Road Springs Data
2.Ride height - measure trim height from wheel
centre to wheelarch eyebrow. Record results on
data sheet.
3.Check/top up power steering fluid
See Repair,
Power Steering Fluid Reservoir
4.Check tension and condition of drive belt.See
ENGINE, Repair, Drive Belt
5.Track rod/drag link - check condition of track rod,
drag link and ball joints.
See Repair, Drag Link
and Drag Link Ends
If either component is damaged, check operation
of steering damper and steering box for
smoothness. Replace all damaged or worn
components that impair the operation of the
steering system.
6.Suspension bushes - examine all steering and
suspension bushes for signs of wear and
deterioration. Also check all fixings for torque
relaxation. Tighten to correct torque value.
See
FRONT SUSPENSION, Specifications, torque,
Torque Values
7.Oil leaks - check front and rear axle hubs for
leak and repair as necessary.
8.Brake system - check brake system for leaks,
pipe condition, pad wear/contamination, disc
wear/condition and ABS sensors for correct
fitting.
9.Hub end float - check movement in the hubs by
rocking the wheels.
10.Check front wheel alignment. Vehicles displaying
a tendency to veer more than considered
allowable, it is permissible to set the front track
to parallel.
11.Having completed all the above checks and
adjustments, road test vehicle.
See Road Test
Procedure
Attempting to reproduce the symptoms
established earlier. If symptoms still exist refer to
relevant Diagnostic Chart.

STEERING
1
ADJUSTMENT POWER STEERING BOX
Service repair no - 57.10.13
WARNING: Adjustments of steering box
should not be required while in warranty
period. If box is stiff or tight and within
warranty, it must be returned to manufacturer. No
attempt must be made to introduce backlash.
1.Apply park brake, select 'P' in automatic
transmission and chock wheels. Support chassis
front on axle stands.
2.Remove engine undertray.
3.Disconnect drag link from steering drop arm.
4.Check torque to turn.
See Fault diagnosis,
Stiff Steering Checklist
5.Centralise steering box.See Centralise
Steering Box
NOTE: Only check for no backlash when
steering box is in central position.
NOTE: If steering wheel is not straight, it
should be repositioned.
See Repair,
Steering Wheel
The adjustment of the steering box ensures
any preload or end float present on centre is
removed.
6.The adjustment is obtained by rocking the drop
arm about centre whilst an assistant slowly
tightens the steering box adjuster screw.
7.Tighten the locknut when all backlash has been
removed.
8.Repeat the check for backlash. If backlash exists
loosen locknut and repeat adjustment
procedure.
9.Turn steering wheel lock to lock and check no
tightness exists.
10.Ensure front wheels are aligned and in straight
ahead position.
See Front Wheel Alignment
11.Adjust drag link 924 mm between ball joint
centres.
12.Connect drag link. Tighten to
40 Nm.
13.Lower vehicle to ground level and remove
chocks.
14.Road test vehicle.
See Fault diagnosis, Road
Test Procedure
NOTE: If steering wheel is not in straight
ahead position when vehicle is travelling
in a straight line, drag link length is
incorrect and is pushing drop arm away from
central position.
Drag link adjust
15.Right hand drive vehicles - if steering wheel is to
right, drag link is too long. If steering wheel is to
left drag link is too short.
Left hand drive vehicles - if steering wheel is to
right, drag link is too short. If steering wheel is to
left drag link is too long.
16.Adjust drag link until steering wheel points
straight ahead when vehicle is travelling in a
straight line.
CENTRALISE STEERING BOX
1.To centralise the box, insert a suitable peg (hole
size 8.06 mm) into the rear of the drop arm and
into the steering box casing to enable rapid and
accurate setting on centre.

STEERING
3
ADJUSTMENT FRONT WHEEL ALIGNMENT
Service repair no - 57.65.01
Checking Toe-out dimensions
NOTE: No Adjustment is provided for
castor, camber or swivel pin inclinations.
1.Set vehicle on level ground with road wheels
positioned straight ahead.
2.Push vehicle back and forwards to settle linkage.
3.Measure toe-out at horizontal centre-line of
wheels.
4.Check tightness of clamp bolt fixings. Tighten to
14 Nm.
Adjust
5.Loosen adjuster sleeve clamp.
6.Rotate adjuster to lengthen or shorten track rod.
7.Check toe-out setting as instructions 1 to 4.
When toe-out is correct, tap steering linkage ball
joint, in directions of arrows shown, to maximum
of their travel. This ensures full unrestricted
working travel.
8.Tighten clamp bolts to
14 Nm.
POWER STEERING PUMP DRIVE BELT
Service repair no - 57.20.01
Adjust
NOTE: For details of drive belt adjust
procedure
See ENGINE, Repair, Drive
Belt