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
12
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
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
57STEERING
6
REPAIR Refit
6.Position reservoir, connect feed and return
hoses and tighten clamps to
3 Nm.
7.Fit reservoir in clamp, tighten clamp bolt.
8.Fill reservoir to 'MAX' mark on dipstick with
power steering fluid.
See LUBRICANTS,
FLUIDS AND CAPACITIES, Information,
Recommended Lubricants and Fluids
9.Fit undertray.
10.Bleed power steering system.
See Power
Steering System - Bleed
POWER STEERING PUMP DRIVE BELT
Service repair no - 57.20.02
NOTE: For details of drive belt remove and
refit.
See ENGINE, Repair, Drive Belt
POWER STEERING PUMP - V8i
Service repair no - 57.20.14
NOTE: The power steering pump is not
serviceable. Fit new pump if worn or
damaged.
Remove
1.Disconnect battery negative lead.
2.Remove drive belt from steering pump.
See
ENGINE, Repair, Drive Belt
3.Remove undertray.
4.Remove fan blades and viscous coupling.
See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
5.Position drain tin beneath steering pump.
6.Using a 9 mm Allen key to restrain steering
pump pulley, remove 3 bolts securing pulley to
pump; remove pulley.
STEERING
7
REPAIR 7.Loosen clamp securing reservoir hose to
steering pump; disconnect hose.
8.Disconnect high pressure pipe from steering
pump.
CAUTION: Plug the connections.
9.Release ht lead from clip
10.Remove 3 bolts securing steering pump.
Remove pump and recover engine lifting
bracket.
NOTE:Do not carry out further
dismantling if component is removed for
access only.
11.Remove 5 bolts securing front mounting plate.
12.Fit front mounting plate to replacement steering
pump. Tighten bolts to
9 Nm.
Refit
13.Position steering pump and engine lifting plate,
fit bolts. Tighten to
35 Nm.Secure ht lead in
clip.
14.Connect high pressure pipe to steering pump,
tighten union to
20 Nm.
15.Connect reservoir hose to steering pump.
Tighten clamp to
3 Nm.
16.Position pulley to pump, coat threads of bolts
with Loctite 242.
17.Restrain pulley using a 9 mm Allen key, fit bolts.
Tighten to
10 Nm.
18.Fit drive belt.See ENGINE, Repair, Drive Belt
19.Fit fan blades and viscous coupling.See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
20.Fit undertray.
21.Reconnect battery negative lead.
22.Bleed power steering system.
See Power
Steering System - Bleed
POWER STEERING PUMP - Tdi
Service repair no - 57.20.14
Remove
1.Remove fan blades and viscous coupling.
See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
2.Restrain steering pump pulley, loosen but do not
remove 3 bolts securing pulley.
3.Remove drive belt.
See ENGINE, Repair,
Drive Belt
4.Remove 3 bolts securing steering pump pulley,
remove pulley.
5.Remove undertray.
6.Position drain tin beneath steering pump.
57STEERING
8
REPAIR 7.Loosen clamp securing reservoir hose to
steering pump, disconnect hose.
8.Disconnect high pressure pipe from steering
pump.
CAUTION: Plug the connections.
9.Remove 4 bolts securing steering pump to
mounting bracket, remove pump.
NOTE:Do not carry out further
dismantling if component is removed for
access only.
10.Remove 3 bolts securing mounting plate to
pump, remove plate.
11.Fit mounting plate to replacement steering
pump. Tighten bolts to
9 Nm.
Refit
12.Position steering pump, fit 3 bolts. Tighten to
35
Nm.
13.Connect high pressure pipe to steering pump.
Tighten to
20 Nm.
14.Connect reservoir hose to steering pump.
Tighten clamp to
3 Nm.
15.Position pulley to steering pump, coat threads of
bolts with Loctite 242; fit but do not fully tighten 3
bolts.
16.Fit drive belt.
See ENGINE, Repair, Drive Belt
17.Restrain steering pump pulley, tighten bolts to10
Nm.
18.Fit fan blades and viscous coupling.See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
19.Fit undertray.
20.Bleed power steering system.
See Power
Steering System - Bleed
WHEELS AND TYRES
1
REPAIR GENERAL INFORMATION
WARNING: This is a multi- purpose vehicle
with wheels and tyres designed for both
on and off road usage. Only use wheels
and tyres specified for use on the vehicle.
The vehicle is equipped with tubeless 'S','T' or 'H'
rated radial ply tyres as standard equipment. The
tyres are of European metric size and must not be
confused with the "P" size metric tyres available in
North America.
Vehicle wheel sets, including spare wheel, must be
fitted with the same make and type of tyre to the
correct specification and tread pattern. Under no
circumstances must cross-ply or bias-belted tyres be
used.
For tyre specification and pressures.
See GENERAL
SPECIFICATION DATA, Information, Wheels and
Tyres
Alloy Wheels
Tubeless tyres are mounted on 7.0 inch wide by 16
inch diameter cast aluminium alloy wheels.The
surface has a paint finish covered with a clear
polyurethane lacquer. Care must be taken when
handling the wheel to avoid scratching or chipping the
finish.
The alloy wheel rim is of the asymmetric hump
type incorporating a safety hump to improve
location of the tyre bead in its seat. If difficulty is
experienced in fitting tyres to this type of rim.
See
Tyre Fitting
WARNING: Do not fit an inner tube to an
alloy wheel.
Steel wheels
Tubeless tyres are mounted on 7.0 inch wide by 16
inch diameter steel wheels.TYRE INSPECTION
Inspect tyres at weekly intervals to obtain maximum
tyre life and performance and to ensure compliance
with legal requirements. Check for signs of incorrect
inflation and uneven wear, which may indicate a need
for balancing or front wheel alignment.
See Fault
diagnosis, Tyre Wear Chart
if the tyres have
abnormal or uneven wear patterns.
Check tyres at least weekly for cuts, abrasions, bulges
and for objects embedded in the tread. More frequent
inspections are recommended when the vehicle is
regularly used in off road conditions.
To assist tyre inspection, tread wear indicators are
moulded into the bottom of the tread grooves, as
shown in the illustration below.
When the tread has worn to a remaining depth of 1.6
mm the indicators appear at the surface as bars which
connect the tread pattern across the width of the tread
as shown in the illustration below.
75SUPPLEMENTARY RESTRAINT SYSTEM
2
DESCRIPTION AND OPERATION OPERATION
The airbag supplementary restraint system (SRS) is a
safety device which, when used in conjunction with
the seat belt, is designed to protect the driver and
front passenger.
Two different SRS systems are fitted to Discovery.
The Distributed SRS which has two crash sensors
located in the engine compartment on the chassis
longitudinals and the Single Point Sensing (SPS) SRS
which has a single crash sensor located in the Airbag
diagnostic control unit.
The change from distributed SRS to SPS SRS
occurred at VINs198222and528977.
Distributed SRS
In the event of a frontal impact, when the airbag
diagnostic control unit and one of the airbag crash
sensors senses the impact, the diagnostic control unit
fires igniters. This in turn ignites tablets of sodium
azide which generate a large amount of Nitrogen gas
leading to airbag inflation in approximately 30
milli-seconds.SPS SRS
In the event of a frontal impact, when the airbag
diagnostic control unit senses the impact, the
diagnostic control unit fires igniters. This in turn ignites
tablets of sodium azide which generate a large
amount of Nitrogen gas leading to airbag inflation in
approximately 30 milli-seconds.
All Models
When fully deployed the airbag offers additional
protection to the front seat occupant. As an occupant
moves into the airbag it immediately discharges the
gas to provide progressive occupant deceleration and
reduce risk of injuries. The whole process is
completed in approximately 0.3 seconds.
WARNING: All the airbag system
components, including the wiring harness,
MUST be renewed after the airbags have
deployed.