ventilation LAND ROVER DEFENDER 1996 User Guide

54FRONT AXLE AND FINAL DRIVE
2
DESCRIPTION AND OPERATION Lubrication
The differential, swivel pin housing and wheel hubs
are indiviudally lubricated and separated by oil seals
(7) and (8), see J6267A, to prevent oil transfer across
the axle when the vehicle is traversing steep inclines.
The wheel bearings are lubricated with grease and the
swivel housing and differential with oil. On later
vehicles, identified by having only a filler plug in the
swivel housing, grease is used to lubricate the
housing assembly,
Ventilation
Ventilation of the differential is through a plastic pipe
(2) which terminates at a high level in the vehicle axle.
The swivel housings ventilate through axle shaft oil
seals (8) into the differential and the hub bearings
vent via the oil seals into the swivel housing.

FRONT AXLE AND FINAL DRIVE
1
FAULT DIAGNOSIS FAULT DIAGNOSIS
Complaint - Oil leaks
An external leak of lubrication can be caused by a
faulty internal seal. For example, if the seals which
separate the differential from the swivel housings are
faulty and the vehicle is operating or parked on an
embankment, oil may leak across the axle leaving one
swivel with a high level and the opposite swivel and
differential lacking lubrication.
See 'Description and Operation' for illustrations of oil
seal locations.
When investigating leaks or checking oil levels, it is
essential that all the lubrication is drained from any
housing with a high level and that the other levels are
checked.
Swivel oil should be checked for signs of grease
leaking from the hub bearings and oil contamination of
the hub grease.
Check that the axle ventilation system is clear, as a
blockage can cause internal pressure to force oil past
the seals.
If the vehicle is driven in deep water with defective oil
seals, water may contaminate the lubricants and when
checked, give a false impression that the housing has
been overfilled with oil.
Do not assume that a high oil level is due to over
filling or, that a low level is because of an external
leak.

FRONT AXLE AND FINAL DRIVE
1
REPAIR REV: 05/99 FRONT AXLE ASSEMBLY
Service repair no - 54.10.01
Remove
WARNING: Remove and refit of axle
requires a further two persons to steady
axle when lowering or repositioning axle.
1.Support chassis front.
2.Remove road wheels.
3.Support axle weight with hydraulic jack.
4.Remove radius arms to chassis frame nuts.
5.Disconnect steering damper from track rod.
Using a extractor remove track rod links from
swivel pin arms.
6.Remove four nuts and bolts securing radius
arms to axle bracket.
7.Remove radius arms.
8.Remove bolts securing brake hose brackets .
Refit bolts to prevent oil leakage.
9.Remove bolts from brake calipers and tie to one
side.
10.Remove nuts and washers securing shock
absorbers to axle.
11.Disconnect drag link from swivel pin housing
arm.
12.Remove two nuts and bolts securing panhard
rod to axle bracket. Lift rod clear of axle.
13.Mark for reassembly drive shaft flanges.
Remove four nuts and bolts, tie propeller shaft to
one side.
14.Release axle ventilation pipe banjo and lower
axle assembly. Remove road springs.
15.Disconnect anti-roll bar link
See FRONT
SUSPENSION, Repair, Anti-roll bar ball
.
16.Remove axle assembly.
Refit
17.Position axle under vehicle, supporting left side
of axle, and fit anti-roll bar links
See FRONT
SUSPENSION, Repair, Anti-roll bar links
.
18.Fit propeller shaft. Tighten bolts to
47 Nm (35
lbf/ft).
19.Fit panhard rod to axle bracket. Tighten bolts to
88 Nm (65 lbf/ft).
20.Fit drag link to swivel pin arm. Tighten fixings to
40 Nm (30 lbf/ft).
21.Fit shock absorbers to axle.
22.Fit brake calipers. Tighten bolts to
82 Nm (60
lbf/ft).
23.Tighten upper swivel pin bolts to78 Nm (58
lbf/ft).
24.Fit radius arms to axle brackets. Tighten bolts to
197 Nm (145 lbf/ft).
25.Fit steering damper to track rod.
26.Fit radius arms to chassis side member. Tighten
fixings to
197 Nm (145 lbf/ft).
27.Tighten track rod end to40 Nm (30 lbf/ft)and fit
new split pin.
28.Remove chassis supports, fit road wheels and
tighten 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)

76CHASSIS AND BODY
34
REPAIRREV: 05/99 LOWER FASCIA PANEL (HEATER DUCT)
ASSEMBLY
Service repair no - 76.46.05
Remove
1.Disconnect battery.
2.Remove steering wheel
See STEERING,
Repair, Steering wheel
.
3.Remove steering column nacelle
See
STEERING, Repair, Steering column nacelle
.
4.Remove instrument panel
See INSTRUMENTS,
Repair, instrument panel
.
5.Release heater cable at control lever
See
HEATING AND VENTILATION, Repair, Heater
control cable - air distribution
.
6.Remove 2 screws, withdraw switch panel from
lower fascia and disconnect switch multi-plugs.
7.Prise out Land Rover decal and remove screw
securing grab handle to crash pad.
8.Remove lower screw and lift grab handle from
lower fascia panel.
9.On RH drive vehicles only, remove screw
securing LH side of finisher to wiper motor cover.
10.Remove 4 screws and remove both demister
vents from crash pad.
11.Remove 3 screws securing crash pad to fascia
bulkhead.
12.Remove crash pad.
13.Remove radio, if fitted.
14.Remove 2 trim studs securing radio housing to
trim panel. Remove radio housing.

CHASSIS AND BODY
37
REPAIR REV: 05/9947.Connect leads and plugs to auxiliary switches
and clock.
48.Secure switch panel to lower fascia panel and
switch cover.
49.Position radio housing, if applicable, and feed
radio multi- plug, aerial and speaker leads from
switch cover to radio housing.
50.Secure radio housing to trim panel.
51.Fit radio connections and secure radio in
housing.
52.Fit crash pad to fascia bulkhead.
53.Fit demister vents in crash pad.
54.Fit grab handle to lower fascia panel and secure
to crash pad. Refit Land Rover decal.
55.Connect multi-plugs to rear screen, hazard and
interior lamp switches and fit switch panel to
fascia panel.
56.Fit heater control cable
See HEATING AND
VENTILATION, Repair, Heater control cable -
air distribution
.
57.Fit instrument panel
See INSTRUMENTS,
Repair, instrument panel
.
58.Fit steering column nacelle
See STEERING,
Repair, Steering column nacelle
.
59.Fit steering wheel
See STEERING, Repair,
Steering wheel
.
60.Reconnect battery.FRONT UNDERTRAY
Service repair no - 76.11.81 - Front undertray
Service repair no - 76.11.85 - Acoustic pad
Remove
1.Raise vehicle on ramp.
2.Position support under chassis front
crossmember.
3.Lower ramp to give clearance between axle and
undertray.
4.Remove 4 nuts, disconnect propeller shaft from
front axle, and move aside.
5.Remove 2 bolts securing undertray to chassis
front crossmember.
6.Remove nut securing undertray to bump stop
front fixing bolt on both sides.
7.Remove 2 bolts securing sides of undertray to
rear undertray.
8.Pull front undertray forwards to release flanges
from rear undertray.
9.Lower undertray to clear steering box etc. and
manouvre rearwards over axle.
10.Remove front undertray.
11.If necessary, remove 8 fasteners to release
acoustic pad from undertray.

HEATING AND VENTILATION
1
DESCRIPTION AND OPERATION HEATING AND VENTILATION SYSTEM
Description
The heating and ventilation system is standard on all
models. Air conditioning is an optional system which
provides fully integrated climate control for the vehicle
interior.The heater assembly, comprising a matrix housed in a
distribution unit and a variable speed blower motor, is
located on one side of the engine compartment and
attached directly to the fascia bulkhead.
The heating controls are positioned on the outside of
the instrument binnacle and cable linked to
mechanical flaps in the distribution unit.
Heater assembly
1.Heater distribution unit
2.Fixings, heater to fascia bulkhead
3.Heater matrix
4.Blower motor housing
5.Circlip, impeller to blower motor
6.Impeller
7.Resistor unit and harness connector8.Fixings, blower motor mounting plate
9.Mounting plate, blower motor
10.Blower motor
11.Fixings, blower motor to mounting bracket
12.Temperature flap, air flow to heater matrix
13.Air flap, air supply to plenum chamber (heater
duct)

80HEATING AND VENTILATION
2
DESCRIPTION AND OPERATION HEATER OPERATION
The heater matrix (3), located in the distribution unit
(1), see J6341, is connected to the engine cooling
system. As water is circulated continuously through
the matrix, a selection of heated or ambient air is
controlled by two flaps within the distribution unit. The
temperature flap (12) controls the amount of ambient
air to the heater matrix, air being suppliedthrough a ducted vent on top of the vehicle front wing
to the blower motor (volute) housing (4). The blower
motor (10) can be used to boost the air flow into the
distribution unit. The air flap (13) controls the supply of
heated or ambient air from the heater unit into a
plenum chamber integeral with the vehicle fascia. Two
flaps in the plenum chamber (heater duct) distribute
the air flow to either the footwell vents or windscreen
demister vents as shown.
HEATER CONTROLS
1. Temperature control
Move the lever downwards to increase air
temperature or up to decrease air temperature.
2. Air distribution control
Lever fully up - windscreen vents only.
Lever midway - footwell and windscreen vents.
Lever fully down - footwell vents.3. Blower motor fan speed control
Move the lever progressively downwards to increase
fan speed. With the control at '0' the fan is switched
off and the volume of air entering the passenger
compartment is solely dependent on ram air when the
vehicle is moving.

HEATING AND VENTILATION
3
DESCRIPTION AND OPERATION Fresh air vents
Two fresh air vents are fitted in the windscreen frame
and are controlled independently of the vehicle
heating system. Each vent is operated separately.
To open the vents, push the lever to the right and then
down to the required position.

HEATING AND VENTILATION
1
REPAIR HEATER UNIT
Service repair no - 80.20.01
Remove
1.Remove bonnet and disconnect battery.
2.Remove radiator bottom hose at radiator union
and drain cooling system
See COOLING
SYSTEM, Repair, Drain and refill cooling
system
.
3.Slacken clips and remove heater hoses at
heater box unions.
4.Remove outer cable securing clips.
5.Slacken trunnions and remove control cables
from heater vent flap levers.
6.Remove heater wiring harness securing loop.
7.Disconnect harness multi-plug.
8.Remove interior bulkhead trim.
9.Remove lower nuts and bolts securing the
heater unit to the bulkhead.
10.Slacken heater unit upper retaining bolts.
11.Manoeuvre heater unit, complete with blower
motor, clear of air inlet duct and remove from
engine compartment.
12.If existing heater unit is to be refitted, remove
sealing rubber.
For heater matrix removal
See Heater matrix.
For blower motor removal
See Blower motor.
Refit
13.Smear a new heater unit sealing rubber with a
suitable impact adhesive and fit to heater.
14.Manoevre heater unit into position in engine
compartment, fit blower motor to air inlet duct
and locate upper fixing bolts.
15.Loosely fit heater unit lower fixing bolts.
16.Fully tighten upper fixing bolts.
17.Fully tighten lower fixings and refit interior
bulkhead trim.
18.Secure wiring harness and reconnect multi-plug.
19.Fit control cables to vent flap trunnions and
secure with outer cable clips.
20.Connect heater hoses.
21.Fit radiator bottom hose and refill cooling system
See COOLING SYSTEM, Repair, Drain and
refill cooling system
.
22.Fit bonnet and reconnect battery.

80HEATING AND VENTILATION
2
REPAIR BLOWER MOTOR
Service repair no - 80.20.15
Remove
1.Remove heater unit
See Heater unit.
2.Remove 3 nuts securing angled bracket to
heater unit. Pivot bracket to remove from studs.
3.Remove 5 nuts securing blower motor assembly
to volute housing.
4.Disconnect harness connector and remove
blower motor from volute housing.
5.Release circlip and withdraw impeller from motor
shaft.
6.Remove 3 nuts securing blower motor to
mounting plate.
7.Remove blower motor.
8.Examine components for signs of wear and
renew as necessary.
Refit
9.Apply Bostik 1261 adhesive to mating faces of
mounting plate and blower motor.
10.Fit blower motor to mounting plate and secure
with 3 nuts. Ensure rubber mountings are
correctly fitted.
11.Fit impeller to motor shaft and secure with circlip.
12.Position blower motor assembly in volute
housing and secure with 5 nuts. Fit angled
bracket to lower fixing.
13.Reconnect harness plug to resistor harness and
fit angled bracket to heater unit.
14.Fit heater unit
See Heater unit.HEATER MATRIX
Service repair no - 80.20.29
Remove
1.Remove heater unit
See Heater unit.
2.Remove 2 nuts securing angled bracket to
heater unit. Pivot bracket to remove from studs.
3.Remove 14 screws and detach two matrix
retaining plates from heater unit base.
4.Remove 9 screws securing matrix top retaining
plate.
5.Withdraw heater matrix through top of heater
unit casing.