1996 LAND ROVER DEFENDER air condition

MANIFOLD AND EXHAUST SYSTEM
1
DESCRIPTION AND OPERATION MANIFOLDS AND EXHAUST SYSTEM
Description
The exhaust systems fitted on all models with the
300Tdi engine comprise three sections; front pipe
assembly, intermediate silencer assembly, and tail
pipe and silencer assembly. All sections, including
silencers, are manufactured from luminised steel to
give the system a durable working life under all
conditions. Special clamps are provided to ensureleak proof jointing between the various sections,
which are supported by flexible rubber mountings.
Catalytic convertor
When fitted, the catalytic converter is integral with the
front pipe assembly, which also incorporates a flexible
joint. The catalyst forms part of the engine emission
control that can also include an EGR valve system
See FUEL SYSTEM, Repair, EGR valve
Exhaust system - 90
1.Gasket
2.Front pipe
3.Front pipe with catalytic converter
4.Front mounting bracket
5.Intermediate silencer6.Intermediate mounting brackets
7.Tail pipe silencer*
8.Tail pipe silencer mounting
9.Tail pipe mounting
* Deleted on later models

33CLUTCH
2
FAULT DIAGNOSIS FAULT/SYMPTOM CHART
Symptoms
Slip Spin/Drag Judder/Fierce Fault Item
* * * Worn or oil on clutch linings 2
* * * Mechanical damage45678
* * Distorted clutch plate 2
* Failed or air in hydraulic system 12 13
* * Primary shaft tight fit in crankshaft bush 15 17
* Clutch splines sticking 2 15
* Weak clutch plate springs or insecure/worn
engine/gearbox mountings6
* Insecure/worn propeller shafts
* Insecure/worn suspension components/rubber
bushes
The items refered to in this chart relate to the clutch components shown in J6270 and J6271.See Description
and operation, Description
CLUTCH NOISE - MECHANICAL FAULTS
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox input/primary shaft bearings
See MANUAL GEARBOX, Fault diagnosis,
R380 gearbox
.
Noise from clutch or gearbox in neutral, which
changes tone or becomes worse when the clutch
is depressed.
Suspect worn release bearing.
Knocking/rattling from clutch or gearbox in
neutral, which is reduced or disappears when the
clutch is depressed.
Suspect worn/weak release lever retainer or
clutch unit.
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox fault
See MANUAL
GEARBOX, Fault diagnosis, R380 gearbox
.HYDRAULIC FAULTS
Unable to dis-engage clutch, little or no pedal
resistance.
1.Check condition, specification and level of fluid.
2.Check pipes and cylinders for leaks.
3.Check that air vent in reservoir lid is clear.
Suspect faulty master cylinder if no fluid leaks
present
See Repair, Master cylinder.
Spongy pedal operation
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect air in fluid
See Repair, Bleed
hydraulic system
.
Clutch is difficult to dis-engage and/or does not
immediately re-engage when pedal is released.
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect pedal pivot, master cylinder or slave
cylinder seizure
See Repair, Master cylinder.

41TRANSFER GEARBOX
2
FAULT DIAGNOSIS OIL LEAKS
Verify that oil leak is from transfer box and not main
gearbox before proceeding with checks.
Prior to road test
1.Check oil level in transfer box is correct.
2.Check tightness of level and drain plugs.
3.Check breather system for blockage. To validate
system pipe must be removed, inspected,
rectified as necessary and refitted.
4.Remove all traces of oil from exterior of transfer
box.
Take vehicle for short road test.
5.Identify source of leaks and rectify as follows.
Front or rear output seal leaking:-
1.Drain oil and remove leaking output flange.
2.Inspect seal track on flange for surface damage.
If damaged renew component.
3.Remove and discard oil seal.
4.Inspect seal locating bore and remove any sharp
edges which may damage new oil seal.
5.Fit new seal.
6.Fit output flange and all other parts.
7.Add oil to correct level into gearbox
See
SECTION 10, Maintenance, Under vehicle
maintenance
.
Cover plate sealant leaking.
1.Drain oil and remove leaking cover plate.
2.Remove all traces of joint sealant from both joint
faces.
3.Degrease all components and apply a thin film of
Hylomar sealant, to both joint faces.
4.Apply thread sealant to bolts which come into
contact with gearbox oil.
5.Refit cover plate.
CAUTION: Care must be taken not to
overtighten fixings.Leak between main and transfer gearboxes.
1.Site vehicle onto a ramp .
2.Select neutral in transfer box and select 4th gear
in main gearbox.
3.Run engine at 2000 rpm with clutch/drive
engaged.
4.Observe joint between main and transfer boxes.
5.If oil leak is found establish if it is gear oil.
6.If so, leak is originating from transfer box.
7.Check two inner (main/transfer) bolts are oil
tight, as these holes are tapped into main
transfer case.
8.Remove transfer box to inspect mainshaft collar
seal track condition, and front face of transfer
case for porosity
See Repair, Transfer
gearbox
.
9.If these areas require servicing, transfer gearbox
input seal must also be renewed.
CAUTION: Avoid damaging new seal lip
and ensure seal is fitted flush with
machined face. Also ensure new seal is
not damaged when refitting transfer gearbox.
10.If red ATF type oil is seen leaking during
workshop test, investigate main gearbox for
cause of leak.
Detent plug or electrical switch leaks.
1.Detent plugs and electrical switches do not
usually leak. It must be noted that they fit into
open tapped holes in transfer case and therefore
should be considered when looking for source of
leak.

FRONT AXLE AND FINAL DRIVE
3
REPAIR REV: 05/99 Refit
11.Clean stub axle and drive shaft and fit hub
assembly to axle.
12.Fit spacing washer.
13.Fit hub adjusting nut. Tighten to
50 Nm (37
lbf/ft).
Ensure hub is free to rotate with no
bearing play.
14.Back off adjusting nut 90°and tighten to
10 Nm
(7 lbf/ft).
15.Fit a new lock washer.
16.Fit locknut. Tighten to
50 Nm (37 lbf/ft).
17.Tab over lock washer to secure adjusting nut
and locknut.
18.Fit a new joint washer to driving member and fit
member to hub. Tighten bolts to
65 Nm (48
lbf/ft).
19.Fit original drive shaft shim and secure with a
circlip.
20.To check drive shaft end play, mount a dial
gauge using bracketLRT-99-503and rest pin in
a loaded condition on end of drive shaft.
21.Fit a suitable bolt to threaded end of drive shaft.
Move drive shaft in and out noting dial gauge
reading. End play should be between 0,08 to
0,25 mm.
22.If end play requires adjustment, remove circlip,
measure shim thickness and fit an appropriate
shim to give required end-play.
23.Remove bolt from drive shaft, fit circlip and dust
cap.
24.Fit brake disc shield and brake caliper. Tighten
fixings to
82 Nm (60 lbf/ft).
25.Bleed brake systemSee BRAKES, Repair,
Brake system bleed
.
26.Fit road wheel, remove axle stands and tighten
road wheel nuts to correct torque:
Alloy wheels -
130 Nm (96 lbf/ft)
Steel wheels -100 Nm (80 lbf/ft)
Heavy duty wheels -170 Nm (125 lbf/ft)
27.Operate footbrake to locate brake pads before
driving vehicle.

57STEERING
2
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.

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
.

STEERING
5
FAULT DIAGNOSIS REV: 05/99 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 bar
See
FRONT SUSPENSION, Repair, Panhard Rod
,
See FRONT SUSPENSION, Repair, Radius
Arm
,See FRONT SUSPENSION, Repair,
Anti-Roll Bar
,See FRONT SUSPENSION,
Repair, Front Shock Absorber
.
6.Fit new radius arm bushes using NTC 6781. Fit
new nuts, bolts and washers.
7.If problem persists fit damper kit STC 288 - 90,
STC 290 - 110/130 (2 off front) and STC 289 -
90, STC 291 - 110 levelled, STC 292 - 110
unlevelled, STC 293 - 130 (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
GENERAL SPECIFICATION DATA,
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 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.