differential LAND ROVER DISCOVERY 1999 Workshop Manual

CONTENTS
CONTENTS 11
TRANSFER BOX - LT230SE .................................................................... 41-1
DESCRIPTION AND OPERATION
LT230SE transfer box ..................................................................................................................... 41-1
Transfer box cross section .............................................................................................................. 41-2
Main casing components – Vehicles up to 03 model year .............................................................. 41-4
Main casing components – Vehicles from 03 model year ............................................................... 41-5
Differential components – Vehicles up to 03 model year ................................................................ 41-6
Differential components – Vehicles from 03 model year ................................................................. 41-7
Front output housing components – Vehicles up to 03 model year ................................................ 41-8
Front output housing components – Vehicles from 03 model year ................................................. 41-10
Rear output housing components ................................................................................................... 41-12
Description ...................................................................................................................................... 41-13
Operation ........................................................................................................................................ 41-18
ADJUSTMENTS
Cable - selector - differential lock - adjust ...................................................................................... 41-21
Cable - high/low selector ................................................................................................................. 41-21
REPAIRS
Bottom cover - transfer box .......................................................................................................... 41-23
Cable - selector - differential lock .................................................................................................... 41-24
Transfer box - Diesel....................................................................................................................... 41-25
Transfer box - V8 ............................................................................................................................ 41-29
Gasket - rear cover plate ................................................................................................................ 41-33
Switch - differential lock - Up to 03 MY ........................................................................................... 41-34
Cable - high/low selector ................................................................................................................. 41-35
Oil seal - input shaft ...................................................................................................................... 41-36
Seal - front output shaft................................................................................................................... 41-36
Seal - rear output shaft ................................................................................................................... 41-38
Gasket - rear output shaft housing.................................................................................................. 41-39
Solenoid - interlock - Up to 03 MY .................................................................................................. 41-40
Solenoid - interlock - from 03 MY .................................................................................................... 41-40
Sensor - neutral ........................................................................................................................... 41-41
Sensor - oil temperature - If fitted ................................................................................................... 41-41
Switch - high low - warning ........................................................................................................... 41-42
Switch(es) - differential lock warning From 03 MY .......................................................................... 41-42
OVERHAUL
Intermediate gear assembly .......................................................................................................... 41-43
Differential assembly .................................................................................................................... 41-46
Dog clutch - differential lock .......................................................................................................... 41-64
Input gear/bearing .......................................................................................................................... 41-68
Low gear - differential ................................................................................................................... 41-70

CONTENTS
CONTENTS 13
REAR AXLE .............................................................................................. 51-1
DESCRIPTION AND OPERATION
Rear axle component layout ........................................................................................................... 51-1
Description ...................................................................................................................................... 51-2
REPAIRS
Differential - assembly .................................................................................................................... 51-5
Seal - differential pinion ................................................................................................................. 51-7
OVERHAUL
Differential assembly ...................................................................................................................... 51-9
FRONT AXLE............................................................................................ 54-1
DESCRIPTION AND OPERATION
Front axle component layout........................................................................................................... 54-1
Description ...................................................................................................................................... 54-2
REPAIRS
Differential - assembly .................................................................................................................... 54-5
Seal - differential pinion ................................................................................................................ 54-7
Seal - oil - front axle casing ........................................................................................................... 54-9
Constant velocity joint - drive shaft ................................................................................................ 54-11

INTRODUCTION
01-3
Abbreviations and Symbols
A Amperes
AAP Ambient Air Pressure
ABDC After Bottom Dead Centre
ABS Anti-Lock Brake System
ac Alternating current
A/C Air Conditioning
ACE Active Cornering Enhancement
ACEA Association of Constructors of
European Automobiles
AFR Air Fuel Ratio
AP Ambient Pressure
ASC Anti-shunt Control
ATC Air Temperature Control
ATDC After Top Dead Centre
BBDC Before Bottom Dead Centre
BBUS Battery Backed Up Sounder
BCU Body Control Unit
BDC Bottom Dead Centre
bhp Brake Horse Power
BP Boost Pressure
BPP Brake Pedal Position
BS British Standard
BTDC Before Top Dead Centre
C Celsius
CAN Controller Area Network
CD Compact Disc
CDC Centre Differential Control
CDL Central Door Locking
CD - ROM Compact Disc - Read Only
Memory
CFC Chlorofluorocarbon
CHMSL Centre High Mounted Stop Lamp
CKP Crankshaft Position
CLV Calculated Load Value
cm Centimetre
cm
2Square centimetre
cm3Cubic centimetre
CMP Camshaft Position
CPP Clutch Pedal Position
CO Carbon Monoxide
CO
2Carbon Dioxide
CR Common Rail
CVS Canister Vent Solenoid
deg. Degree, angle or temperature
dia. Diameter
DIN Deutsche Industrie Normen
(German Industrial Standards)
dc Direct current
DCV Directional Control Valve
DOHC Double Overhead Camshaft
DTI Dial Test Indicator
DFM Dual Mass Flywheel
DVD Digital Versatile Disc
EACV Electronic Air Control Valve EAT Electronic Automatic
Transmission
EBD Electronic Brake pressure
Distribution
ECD European Community Directive
ECM Engine Control Module
ECT Engine Coolant Temperature
ECU Electronic Control Unit
EDC Electronic Diesel Control
EEPROM Electronic Erasable
Programmable Read Only
Memory
EGR Exhaust Gas Recirculation
EKA Emergency Key Access
EN European Norm
EOBD European On Board Diagnostics
ETC Electronic Traction Control
EUI Electronic Unit Injector
EVAP Evaporative Emission
EVR Electronic Vacuum Regulator
F Fahrenheit
FBH Fuel Burning Heater
FIP Fuel Injection Pump
FTC Fast Throttle Control
g Gramme or Gravity
hHour
hc High compression
HC Hydro Carbons
HDC Hill Descent Control
HDPE High Density Polyethylene
HFS Heated Front Screen
Hg Mercury
HO2S Heated Oxygen Sensor
HMW High Molecular Weight
HRW Heated Rear Window
ht/HT High tension
IACV Idle Air Control Valve
IAT Intake Air Temperature
ICE In-Car Entertainment
i.dia. Internal diameter
IDM Intelligent Driver Module
in3Cubic inch
ILT Inlet Throttle
ISO International Organisation for
Standardisation
k Thousand
kg Kilogramme
km Kilometre
km/h Kilometres per hour
kPa KiloPascal
KS Knock Sensor
lLitre
lbf.in Pounds force inches
lbf/in
2Pounds per square inch
lbf.ft Pounds force feet

GENERAL INFORMATION
03-15
Hose clips
Markings (4) are usually provided on the hose to
indicate the correct clip position. If no markings are
provided, position the clip directly behind the
retaining lip at the end of the stub as shown. Worm
drive clips should be oriented with the crimped side
of the drive housing (5) facing towards the end of the
hose, or the hose may become pinched between the
clip and the stub pipe retaining lip. Worm drive clips
should be tightened to 3 Nm (2 lbf.ft) unless
otherwise stated. Ensure that hose clips do not foul
adjacent components.
Heat protection
Always ensure that heatshields and protective
sheathing are in good condition. Replace if damage
is evident. Particular care must be taken when
routing hoses close to hot engine components, such
as the exhaust manifold and the Exhaust Gas
Recirculation (EGR) pipe. Hoses will relax and
deflect slightly when hot; ensure this movement is
taken into account when routing and securing hoses.
Rolling Road Testing
General
IMPORTANT: Use a four wheel rolling road for
brake testing if possible.
WARNING: Do not attempt to test ABS function
on a rolling road.
Four wheel rolling road
Provided that front and rear rollers are rotating at
identical speeds and that normal workshop safety
standards are applied, there is no speed restriction
during testing except any that may apply to the tyres.
Before testing a vehicle with anti-lock brakes on a
four wheel rolling road, disconnect the ABS
modulator. The ABS function will not work, the ABS
warning light will illuminate. Normal braking will be
available.
Two wheel rolling road
Up to 03MY
ABS will not function on a two wheel rolling road. The
ABS light will illuminate during testing. Normal
braking will be available.
If brake testing on a two wheel rolling road is
necessary, the following precautions should be
taken:
lPropeller shaft to the rear axle is removed.
lNeutral selected in gearbox.
When checking brakes, run engine at idle speed to
maintain servo vacuum.
From 03MY
The differential lock must be engaged for two wheel
rolling road testing. It will also be necessary to
disconnect the propeller shaft from the transfer box
output shaft driving the axle whose wheels are NOT
on the rolling road. Additionally, the ETC system
must be deactivated by either removing the 10 amp
fuse (Number 28, labelled ABS in the main fuse box)
or disconnecting the ABS modulator pump. This
must be done with the ignition OFF ; a fault in the
ABS system may still be recorded.
WARNING; VEHICLES NOT FITTED WITH A
DIFFERENTIAL LOCK MUST NOT BE TESTED
ON A ROLLING ROAD WHERE THE ROLLERS
ARE DRIVEN BY THE VEHICLE.

GENERAL DATA
04-16
Rear axle
Front axle
Type Solid axle casing incorporating a spiral bevel differential and drive
shafts
Reduction ratio 3.538:1
Type Solid axle casing incorporating spiral bevel differential and drive shafts
with constant velocity joints.
Reduction ratio 3.538:1

TORQUE WRENCH SETTINGS
06-11
Transfer box - LT230SE
† New nut must be fitted
* New Patchlok nut must be fitted
+ Apply sealant, Part No. STC 50552 to threads
TORQUE DESCRIPTION METRIC IMPERIAL
High/low selector cable 30 Nm (22 lbf.ft)
Bottom cover plate bolts + 25 Nm (18 lbf.ft)
Transfer box to gearbox bolts - Petrol and diesel + 45 Nm (33 lbf.ft)
Rear cover plate stud nut/bolts + 25 Nm (18 lbf.ft)
Differential lock warning lamp switch locknut - Up to 03 MY 11 Nm (8 lbf.ft)
Differential lock warning lamp switches - 03 MY onwards + 25 Nm (18 lbf.ft)
Drive flange nut 148 Nm (109 lbf.ft)
Output shaft housing bolts + 45 Nm (33 lbf.ft)
Oil temperature sensor - If fitted + 25 Nm (18 lbf.ft)
Inhibitor switch to transfer box 26 Nm (19 lbf.ft)
Intermediate shaft nut † 88 Nm (65 lbf.ft)
Intermediate shaft retaining plate bolt + 25 Nm (18 lbf.ft)
Differential bearing retaining nut * 72 Nm (53 lbf.ft)
Output flange nut 162 Nm (119 lbf.ft)
High/Low selector housing bolts + 25 Nm (18 lbf.ft)
Bearing housing/cover bolts + 25 Nm (18 lbf.ft)
Blanking plug + 25 Nm (18 lbf.ft)
High/Low selector warning lamp switch 25 Nm (18 lbf.ft)
Differential lock selector housing bolts + 25 Nm (18 lbf.ft)
Neutral sensor 25 Nm (18 lbf.ft)
Interlock solenoid bolts - Up to 03 Model Year 10 Nm (7 lbf.ft)

TORQUE WRENCH SETTINGS
06-13
Propeller shafts
Axles
+ Apply sealant, Part No. STC 50552 to bolt threads
TORQUE DESCRIPTION METRIC IMPERIAL
Propeller shaft to transfer gearbox 47 Nm (35 lbf.ft)
Propeller shaft to differential 47 Nm (35 lbf.ft)
Propeller shaft to flexible coupling 76 Nm (56 lbf.ft)
Flexible coupling to differential 76 Nm (56 lbf.ft)
TORQUE DESCRIPTION METRIC IMPERIAL
Front and rear differential to axle bolts + 55 Nm (40 lbf.ft)
Hub to axle bolts100 Nm (74 lbf.ft)
Pinion flange bolt 100 Nm (74 lbf.ft)
Drive shaft nut490 Nm (360 lbf.ft)

LIFTING AND TOWING
08-1
LIFTING AND TOWING
LIFTING
The following instructions must be carried out before
raising the vehicle off the ground.
lUse a solid level ground surface.
lApply hand brake.
lSelect 'P' (Automatic gearbox) or 1st gear
(Manual gearbox) in main gearbox.
lSelect Low range in transfer gearbox.
To avoid damage occurring to the under body
components of the vehicle the following jacking
procedures must be adhered to.
DO NOT POSITION JACKS OR AXLE STANDS
UNDER THE FOLLOWING COMPONENTS:
lBody structure
lBumpers
lFuel lines
lBrake lines
lFront radius arms
lPanhard rod
lSteering linkage
lRear trailing arms
lFuel tank
lEngine sump
lGearbox bell housing
Vehicle jack
The jack provided with the vehicle is only intended for
use in an emergency, for changing a tyre. DO NOT
use the jack for any other purpose. Refer to Owner's
Handbook for vehicle jack location points and
procedure. Never work under a vehicle supported
solely by the vehicle jack.
Hydraulic jack
A hydraulic jack with a minimum 1500 kg, 3,300 lbs
load capacity must be used. Do not commence
work on the underside of the vehicle until
suitable axle stands have been positioned under
the axle.
WARNING: Always chock the wheels when
jacking. The hand brake acts on the
transmission, not the rear wheels, and may be
ineffective when the wheels are off the ground.Raising and supporting the vehicle
Position cup of hydraulic arm under differential
casing (1).The differential casing is not central to
the axle. Care should be taken when raising the
front road wheels off the ground as the rear axle
has less sway stiffness.
Raise vehicle to enable an axle stand to be installed
under left hand axle tube (2).
Position an axle stand under right hand axle tube (4).
Carefully lower jack until vehicle sits securely on both
axle stands, remove jack.
Alternatively, the axle stands can be positioned
under the chassis longitudinals at the front and/or
rear of the vehicle.

CAPACITIES, FLUIDS, LUBRICANTS AND SEALANTS
09-5
Manual
Gearbox -
R380Gate plate bolts STC 50552
Manual
Gearbox -
R380Gear case to
extension housingSTC 4404
Manual
Gearbox -
R380Extension housing
boltsSTC 50552
Manual
Gearbox -
R380Gear change lever
yoke Allen screwSTC 50552
Manual
Gearbox -
R380Gear case to centre
plateSTC 4404
Manual
Gearbox -
R380Detent plugs STC 50552
Manual
Gearbox -
R380Bias spring
adjustment plate
boltsSTC 50552
Transfer Box -
LT230SEBottom cover plate STC 4600
Transfer Box -
LT230SEBottom cover plate
boltsSTC 50552
Transfer Box -
LT230SEFront output
housing core plugSTC 3811
Transfer Box -
LT230SETransfer box to
gear case bolts -
Petrol and Diesel
enginesSTC 50552
Transfer Box -
LT230SETransfer box to
gear case studs -
Petrol and Diesel
enginesSTC 50552
Transfer Box -
LT230SERear cover STC 4600
Transfer Box -
LT230SEDifferential warning
lamp switch(es)STC 50552
Transfer Box -
LT230SEHigh/Low selector
warning lamp
switchSTC 50552
Transfer Box -
LT230SERear output shaft
housingSTC 4600
Transfer Box -
LT230SERear output shaft
housing boltsSTC 50552
Transfer Box -
LT230SEHigh/Low selector
fork set screwSTC 50552
Transfer Box -
LT230SEInterlock solenoid
selector cover - Up
to 03 MYSTC 4600
Transfer Box -
LT230SEInterlock solenoid
circlip - 03 MY
onwardsSTC 50551
Transfer Box -
LT230SENeutral sensor STC 50552
Transfer Box -
LT230SEIntermediate shaft
retaining plate boltSTC 50552Transfer Box -
LT230SESide cover STC 4600
Transfer Box -
LT230SESide cover bolts STC 50552
Transfer Box -
LT230SEDifferential lock
selector shaft
detent plugSTC 50552
Transfer Box -
LT230SEDifferential lock
selector housing
boltsSTC 50552
Transfer Box -
LT230SEFront output shaft
housingSTC 4600
Transfer Box -
LT230SEFront output shaft
housing boltsSTC 50552
Transfer Box -
LT230SEHigh/Low selector
shaft detent plugSTC 50552
Transfer Box -
LT230SEInput gear bearing
housingSTC 4600
Transfer Box -
LT230SERear cover stud nut
and boltSTC 50552
Transfer Box -
LT230SEHigh/Low cross
shaft housingSTC 4600
Transfer Box -
LT230SEHigh/Low cross
shaft housing boltsSTC 50552
Automatic
gearbox -
ZFHP22-24Torque converter
housing to engine
boltsSTC 50553
Rear Axle and
Final DriveDifferential cover to
casingSTC 3811
Rear Axle and
Final DriveDifferential cover to
casing boltsSTC 50552
Front axle Differential cover to
casingSTC 3811
Front axle Differential cover to
casing boltsSTC 50552
Front
suspensionDrive shaft to hub STC 50554
Rear
suspensionDrive shaft to hub STC 50554
Rear
suspensionSLS air compressor
boltsSTC 50552

MAINTENANCE
10-20 PROCEDURES
Front and rear axle
WARNING: Avoid excessive skin contact with
mineral oil. Mineral oils remove the natural fats
from the skin, leading to dryness, irritation and
dermatitis.
Replace oil
1.Place a suitable container beneath differential
housing of axle to be drained.
2.Clean area around oil filler/level and drain
plugs.
3.Remove oil filler/level plug.
4.Remove and discard 'O' ring from oil filler/level
plug.
5.Remove oil drain plug, allow oil to drain.
6. Fit axle drain plug and tighten to 64 Nm (47
lbf.ft).
7.Fill differential housing with recommended oil to
bottom of oil filler/level plug hole.

+ CAPACITIES, FLUIDS,
LUBRICANTS AND SEALANTS,
Lubrication.
8.Lubricate a new 'O' ring with recommended oil
and fit to oil filler/level plug.
9.Fit axle filler/level plug and tighten to 10 Nm (7
lbf.ft).
10.Remove all traces of oil from differential
housing.
Propeller shafts
Lubricate
Rear shaft
1.Clean area around front universal joint grease
nipple.
2.Apply recommended grease to the grease
nipple.

+ CAPACITIES, FLUIDS,
LUBRICANTS AND SEALANTS,
Lubrication.
Front shaft
3.Remove blanking plug adjacent to sliding joint
from propeller shaft.
4.Screw a 1/4in UNF grease nipple into blanking
plug hole.