1996 LAND ROVER DEFENDER lock

57STEERING
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DESCRIPTION AND OPERATION Rotary valve misaligned
Demand for assistance (Valve misaligned)
When the steering wheel and input shaft is turned,
steering resistance transmitted to the worm causes
the torsion bar to be twisted and the valve ports to be
misaligned for a right or left turn. The misalignment of
the valve ports directs all fluid pressure A to one side
of the piston only and allows displaced fluid B on the
other side.
When demanding maximum assistance, any
excessive fluid output from the pump due to high
pump speed, will circulate through the regulator valve
located in the pump unit, causing the temperature of
the fluid and the pump to rise rapidly.CAUTION: To avoid excessive fluid
temperatures which could damage the oil
seals, the steering must not be held on full
lock for more than 30 seconds in one minute.
Only when the steering wheel, and the demand for
assistance, is released, will the torsion bar return the
valve to neutral, allowing the fluid to circulate through
the reservoir where it is cooled.
In the unlikely event of mechanical failure of the
torsion bar, a coarse splined connection (7) between
the input shaft and worm, ensures steering control is
maintained sufficient to allow the vehicle to be
recovered.

STEERING
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FAULT DIAGNOSIS INSUFFICIENT POWER ASSISTANCE
1.Is fluid level correct?
YES - go to 3.
NO - Fill/bleed sytem
2.Is problem a leak?
YES - Diagnose
See Power Steering Fluid
Leaks
.
NO - continue
3.Is drive belt tension correct?
YES - go to 5.
NO - Is drive belt worn or contaminated with oil?
See ELECTRICAL, Repair, Auxiliary drive
belt
.
4.Is problem resolved?
YES - end
NO - continue
5.Carry out pressure test at idle and 1000 rev/min.
See Power Steering System - Test.
6.Is correct pressure achieved?
YES - steering box defective
Not at any speed go to 9.
Not at idle go to 7.
7.Is idle speed correct?
YES-Goto8.
NO - Correct idle speed -
See ENGINE TUNING
DATA, Information, 300 Tdi Engine
.
8.Is problem resolved?
YES - end
NO - go to 9.
9.Bypass steering box using adaptor tap
LRT-57-001
10.Is correct pressure obtained?
YES - defective steering box
NO - defective steering pump
CAUTION: Do not hold steering wheel on
full lock for more than 30 seconds in any
one minute to avoid overheating fluid and
possibly damaging seals.
NOTE: 1. Excessive pressure in the
system is almost always caused by a
faulty relief valve in the PAS pump.
NOTE: 2. Insufficient pressure in the
system is usually caused by low fluid level
or PAS pump drive belt slip, or one of the
following: PAS system leaks, faulty PAS pump
relief valve, fault in steering box valve and worm
assembly, leak at piston in steering box, worn
components in PAS pump or box.

57STEERING
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FAULT DIAGNOSIS POWER STEERING SYSTEM - TEST
NOTE: If steering lacks power assistance.
Check pressure of hydraulic pump before
fitting new components. Use fault
diagnosis chart to assist in tracing faults.
A. Steering box.
B. Steering pump.
C. Existing hose, steering box to pump.
D. HoseLRT-57-030.
E. Test adaptorLRT-57-001.
F. Pressure gaugeLRT-57-005.
G. Thread adaptorLRT-57-004.
H. Thread adaptorLRT-57-022.Procedure
1.A hydraulic pressure gauge and test adaptor is
used to test power steering system. This gauge
is able to measure 140 kgf/cm
2. The maximum
power steering system pressure is 77 kgf/cm2.
2.Under certain fault conditions of the hydraulic
pump it is possible to obtain pressures up to 105
kgf/cm
2. It is important to realise that pressure on
gauge is same pressure being exerted upon
steering wheel. When testing, turn steering
wheel gradually while reading pressure gauge.
3.Check and maintain maximum fluid level of
reservoir.
4.Examine power steering units and connections
for leaks. All leaks must be rectified before
attempting to test the system.
5.Check steering pump drive belt tension and
renew belt if necessary,
See ELECTRICAL,
Repair, Auxiliary drive Belt
.
6.Assemble test equipment and fit to vehicle, as
shown in RR3959M.
7.Open tap of adaptor.
8.Bleed system, take care not to overload
pressure gauge.
9.With system in good condition, pressures should
be:
(A) Steering wheel held on full lock and engine
running at 1,000 rev/min, 70 to 77 kgf/cm
2.
(B) Steering wheel held on full lock and engine
idling, 28 kgf/cm
2.
Checks should be carried out on both full lock
positions.
CAUTION: Do not maintain this pressure
for more than 30 seconds in any one
minute to avoid overheating fluid and
possibly damaging seals.
10.Release steering wheel and with engine idling.
Pressure should read below 7 kgf/cm
2.
11.If pressures differ to those given a fault exists.
12.To determine if fault is steering box or pump.
Close adaptor tap for a maximum five seconds.
13.If gauge does not register specified pressure,
pump is faulty.
14.Fit a new pump, bleed system and repeat test. If
low pressure or a substantial imbalance exists,
fault is in steering box valve and worm
assembly.

57STEERING
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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 INTRODUCTION, 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
.
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
.

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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 necessary, 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
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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 - route 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 drive belt tension and remove belt if
necessary
See ELECTRICAL, Repair,
Auxiliary 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 - check drive belt tension and renew belt if
necessary
See ELECTRICAL, Repair,
Auxiliary 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, 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.

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FAULT DIAGNOSISREV: 05/99 VISUAL AND SAFETY CHECKS
WARNING: Before taking vehicle out on
the public highway for road test, it is
important that the following basic visual
checks are carried out to ensure that the vehicle
complies with legal requirements.
Tyres and wheel rims
1.Check and adjust tyre pressures
See
GENERAL SPECIFICATION DATA,
Information, Tyre Pressures
.
Note that this information refers to standard tyres
fitted as original equipment.
2.Check condition of tyres. Inspect for signs of
uneven wear, damage and feathering. Check
tread depth.
3.Ensure that the tyre make, type and general
condition are common across each axle.
4.Check wheel rims for signs of damage and
excessive run out.
5.Carry out road test
See Road Test Procedure
.
ROAD TEST PROCEDURE
General steering/handling problems can usually be
classified into one of the categories listed and ARE
GENERALLY RELATED TO THE AGE, CONDITION
AND USE OF THE VEHICLE.
WARNING: Ensure that all road tests are
conducted by suitably qualified drivers in
a safe and legal manner, and where local
traffic conditions allow.
1.Carry out visual and safety checks
See Visual
and Safety Checks
.
Confirm general nature of complaint with customer,
simulating where possible the conditions under which
the problem occurs. Carry out following road test
procedure to establish the problem.2.Steering load assessment - drive at 16 km/h (10
mph). Put 90°turn input into steering wheel,
check self centering. The self centering should
be equal on each lock but not necessarily return
to exactly straight ahead without assistance from
the driver.
3.Steering assessment - drive at 64 km/h (40 mph)
on a staight FLAT road (no camber), check for
steering veer. The vehicle should follow a
straight path with NO tendency to follow a
curved path. If vehicle veers towards the kerb,
vehicle may be 'camber sensitive'. A small
amount of veer in direction of camber is
acceptable.
4.Directional stability assessment - drive at 112
km/h (70 mph) or maximum legal speed on a
straight flat road. Carry out a normal lane
change. Vehicle should quickly settle into a new
straight path.
5.Braking assessment (medium effort) - drive at 96
km/h (60 mph) on a straight flat road. Apply
steady medium braking effort, noting any
tendency to veer. Carry out brake test three
times, if a veer is consistently noted carry out a
braking efficiency test on a rolling road.
6.Braking assessment (full effort) - drive at 96
km/h (60 mph) on a straight flat road. Apply full
braking effort, noting any tendency to veer. Carry
out brake test three times, if a veer is
consistently noted carry out a braking efficiency
test on a rolling road.
If the symptom described by the customer is stiff
steering or steering niggle, carry out stiff steering
procedure
See Stiff Steering Checklist.
If not, proceed with basic checks and adjustments
See Visual Check and Basic Adjustments.

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FAULT DIAGNOSIS STIFF STEERING CHECKLIST
NOTE: Having completed visual checks
and steering assessment and confirmed
that vehicle steering load is incorrect carry
out the following procedure in order shown.
Steering wheel 'torque to turn' loads
1.Raise vehicle so both front wheels free.
2.With engine off, centralise steering wheel, and
remove steering wheel decal. Using torque
wrench on column nut, check torque required to
turn the steering wheel one turn in each
direction.
3.Record readings obtained in each direction.
Reading should be
4.40 Nm (3.5 lbf/ft).
NOTE: If figures are in excess of that
specified carry out steering box tie bar
reset below. If figures are as specified
See
Visual Check and Basic Adjustments
.
Steering box tie bar reset
1.Loosen the tie bar fixings one complete turn.
2.Drive vehicle carefully a short distance (within
the dealership) applying full lock in both
directions in order to settle steering components.
Drive vehicle over speed bumps and include
harsh braking if possible.
WARNING: Do not drive on public
highway.
3.Near end of operation 2. ensure vehicle is driven
in a straight line on level ground and halted.
4.Tighten panhard rod mounting arm nut to
110
Nm (81 lbf/ft).
5.Tighten the 2 fixings, tie bar to steering box, to
81 Nm (60 lbf/ft).
6.Recheck steering wheel torque to turn. If torque
reading is still greater than specified, carry out
steering shaft universal joint lubrication.Lower steering shaft universal joint lubrication
1.Check lower steering shaft is correctly phased
See Repair, Lower Steering Shaft and
Universal Joints
.
2.Lubricate universal joints with an anti-seizure
type penetrating spray. Work the joints to ensure
full penetration of the spray by driving vehicle
and steering from lock to lock.
3.If steering stiffness still persists carry out swivel
pin preload setting.
Swivel pin preload setting
1.The swivel pin preload setting must be checked
and set
See FRONT AXLE AND FINAL DRIVE,
Overhaul, Front Stub Axle, Constant Velocity
Joint and Swivel Pin Housing
.
Note that a pull load of 1.16 - 1.46 kg is required
after the axle shaft and swivel housing seal have
been removed.
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
.