2002 LAND ROVER DISCOVERY transmission oil

CONTENTS
CONTENTS 13
Cooler - fluid - V8 ........................................................................................................................... 44-46
Valve body assembly ..................................................................................................................... 44-47
Seal - valve body ........................................................................................................................... 44-49
Pressure regulator ......................................................................................................................... 44-50
Lock-up solenoid valve (MV 3) ....................................................................................................... 44-51
Solenoids - shift control valves (MV 1 & 2) .................................................................................... 44-51
Harness - solenoid valves .............................................................................................................. 44-52
Electronic control unit - automatic transmission .............................................................................. 44-53
PROPELLER SHAFTS ............................................................................. 47-1
DESCRIPTION AND OPERATION
Propeller shaft component layout ................................................................................................... 47-1
Description ...................................................................................................................................... 47-2
REPAIRS
Propeller shaft - front ..................................................................................................................... 47-5
Propeller shaft - rear ...................................................................................................................... 47-5
Flexible coupling ............................................................................................................................ 47-6
OVERHAUL
Propeller shaft ................................................................................................................................. 47-7
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
STEERING ................................................................................................ 57-1
DESCRIPTION AND OPERATION

TORQUE WRENCH SETTINGS
06-2
Engine Td5
TORQUE DESCRIPTION METRIC IMPERIAL
ACE pump bolts25 Nm (18 lbf.ft)
A/C compressor bolts 25 Nm (18 lbf.ft)
Alternator support bracket to cylinder head bolts 25 Nm (18 lbf.ft)
Alternator/vacuum pump oil feed pipe union 10 Nm (7 lbf.ft)
Camshaft cover to camshaft carrier bolts 10 Nm (7 lbf.ft)
Camshaft sprocket to camshaft bolts 37 Nm (27 lbf.ft)
Centrifuge cover bolts 10 Nm (7 lbf.ft)
Centrifuge oil drain pipe to sump bolts (or nuts) 10 Nm (7 lbf.ft)
Centrifuge to oil drain pipe bolts 10 Nm (7 lbf.ft)
Centrifuge to oil cooler housing bolts 25 Nm (18 lbf.ft)
CKP sensor bolt10 Nm (7 lbf.ft)
Coolant pipe bolt50 Nm (37 lbf.ft)
Connecting rod bolts, then a further 80°20 Nm (15 lbf.ft)
Crankshaft pulley bolt 460 Nm (340 lbf.ft)
Crankshaft pulley TV damper bolts 80 Nm (59 lbf.ft)
Crankshaft rear oil seal housing bolts 10 Nm (7 lbf.ft)
Cylinder head bolts initial tighten 30 Nm (22 lbf.ft)
Cylinder head bolts final tighten, then a further 90°, then a further 180° and finally a
further 45°65 Nm (48 lbf.ft)
Dipstick tube to camshaft carrier bolt 10 Nm (7 lbf.ft)
Drive plate (automatic transmission) to crankshaft bolts 115 Nm (85 lbf.ft)
EGR pipe clamp to cylinder head bolt - if fitted 25 Nm (18 lbf.ft)
EGR pipe Allen screws 10 Nm (7 lbf.ft)
Engine mounting (front) to cylinder block bolts 48 Nm (35 lbf.ft)
Engine mounting (front) to chassis nuts 85 Nm (63 lbf.ft)
Engine mounting bracket (rear, LH & RH) to gearbox bolts 85 Nm (63 lbf.ft)
Engine mounting bracket (rear, LH & RH) nuts 45 Nm (33 lbf.ft)
Flywheel to crankshaft (manual transmission) bolts, then a further 90°40 Nm (30 lbf.ft)
Front crossmember bolts 26 Nm (20 lbf.ft)
Fuel connector block bolts 25 Nm (18 lbf.ft)
Fuel cooler to inlet manifold bolts 25 Nm (18 lbf.ft)
Gearbox housing to engine bolts 50 Nm (37 lbf.ft)
Heater pipe to cylinder head bolts 25 Nm (18 lbf.ft)
Main bearing cap bolts then a further 90°33 Nm (24 lbf.ft)
Oil cooler housing to cylinder block bolts 25 Nm (18 lbf.ft)
Oil cooler pipe clip bolts 10 Nm (7 lbf.ft)
Oil filter adaptor housing to oil cooler housing bolts 25 Nm (18 lbf.ft)
Oil pick-up strainer screws 10 Nm (7 lbf.ft)
Oil pressure switch 15 Nm (11 lbf.ft)
Oil pump drive sprocket bolt 25 Nm (18 lbf.ft)
Oil pump pressure relief valve plug 25 Nm (18 lbf.ft)
Oil pump and stiffener assembly to cylinder block bolts 13 Nm (10 lbf.ft)
Oil sump to cylinder block bolts 25 Nm (18 lbf.ft)
Oil sump to gearbox bell housing bolts 13 Nm (10 lbf.ft)
PAS pump bracket bolts 27 Nm (20 lbf.ft)
PAS pump pulley bolts 27 Nm (20 lbf.ft)
Rocker arm adjusting screw locknuts 16 Nm (12 lbf.ft)

TORQUE WRENCH SETTINGS
06-3
Rocker shaft bolts 32 Nm (24 lbf. ft)
Timing chain adjustable guide bolt 25 Nm (18 lbf.ft)
Timing chain cover bolts 27 Nm (20 lbf.ft)
Timing chain cover to cylinder block stud 7 Nm (5.2 lbf.ft)
Timing chain fixed guide retaining pin 25 Nm (18 lbf.ft)
Timing chain cover to cylinder head nut and bolt 25 Nm (18 lbf.ft)
Timing chain fixed guide (M6) bolt 10 Nm (7 lbf.ft)
Timing chain fixed guide (M10) bolt 45 Nm (33 lbf.ft)
Timing chain lubrication jet bolt 10 Nm (7 lbf.ft)
Timing chain tensioner 45 Nm (33 lbf.ft)
Torque converter to drive plate (automatic transmission) bolts 50 Nm (37 lbf.ft)
Turbocharger heatshield bolts 10 Nm (7 lbf.ft)
Turbocharger oil feed pipe banjo bolt 25 Nm (18 lbf.ft)
Turbocharger to exhaust manifold nuts 30 Nm (22 lbf.ft)
Vacuum pump oil feed pipe to cylinder head union 10 Nm (7 lbf.ft)
Viscous fan nut45 Nm (33 lbf.ft)
Fuel spill return pipe unions - if fitted 20 Nm (15 lbf.ft)TORQUE DESCRIPTION METRIC IMPERIAL

EMISSION CONTROL - V8
17-2-10 DESCRIPTION AND OPERATION
A spiral oil separator is located in the stub pipe to the ventilation hose on the right hand cylinder head rocker cover,
where oil is separated and returned to the cylinder head. The rubber ventilation hose from the right hand rocker cover
is routed to a port on the right hand side of the inlet manifold plenum chamber where the returned gases mix with the
fresh inlet air passing through the throttle butterfly valve. The stub pipe on the left hand rocker cover does not contain
an oil separator, and the ventilation hose is routed to the throttle body housing at the air inlet side of the butterfly valve.
The ventilation hoses are attached to the stub pipe by metal band clamps.
Exhaust emission control system
The fuel injection system provides accurately metered quantities of fuel to the combustion chambers to ensure the
most efficient air to fuel ratio under all operating conditions. A further improvement to combustion is made by
measuring the oxygen content of the exhaust gases to enable the quantity of fuel injected to be varied in accordance
with the prevailing engine operation and ambient conditions; any unsatisfactory composition of the exhaust gas is
then corrected by adjustments made to the fuelling by the ECM.
The main components of the exhaust emission system are two catalytic converters which are an integral part of the
front exhaust pipe assembly. The catalytic converters are included in the system to reduce the emission to
atmosphere of carbon monoxide (CO), oxides of nitrogen (NO
x) and hydrocarbons (HC). The active constituents of
the catalytic converters are platinum (Pt), palladium (PD) and rhodium (Rh). Catalytic converters for NAS low
emission vehicles (LEVs) from 2000MY have active constituents of palladium and rhodium only. The correct
functioning of the converters is dependent upon close control of the oxygen concentration in the exhaust gas entering
the catalyst.
The two catalytic converters are shaped differently to allow sufficient clearance between the body and transmission,
but they remain functionally identical since they have the same volume and use the same active constituents.
The basic control loop comprises the engine (controlled system), the heated oxygen sensors (measuring elements),
the engine management ECM (control) and the injectors and ignition (actuators). Other factors also influence the
calculations of the ECM, such as air flow, air intake temperature and throttle position. Additionally, special driving
conditions are compensated for, such as starting, acceleration, deceleration, overrun and full load.
The reliability of the ignition system is critical for efficient catalytic converter operation, since misfiring will lead to
irreparable damage of the catalytic converter due to the overheating that occurs when unburned combustion gases
are burnt inside it.
CAUTION: If the engine is misfiring, it should be shut down immediately and the cause rectified. Failure to do
so will result in irreparable damage to the catalytic converter.
CAUTION: Ensure the exhaust system is free from leaks. Exhaust gas leaks upstream of the catalytic
converter could cause internal damage to the catalytic converter.
CAUTION: Serious damage to the engine may occur if a lower octane number fuel than recommended is used.
Serious damage to the catalytic converter and oxygen sensors will occur if leaded fuel is used.
Air : fuel ratio
The theoretical ideal air:fuel ratio to ensure complete combustion and minimise emissions in a spark-ignition engine
is 14.7:1 and is referred to as the stoichiometric ratio.
The excess air factor is denoted by the Lambda symbol
λ, and is used to indicate how far the air:fuel mixture ratio
deviates from the theoretical optimum during any particular operating condition.
lWhen
λ = 1, the air to fuel ratio corresponds to the theoretical optimum of 14.7:1 and is the desired condition for
minimising emissions.
lWhen
λ > 1, (i.e. λ = 1.05 to λ = 1.3) there is excess air available (lean mixture) and lower fuel consumption can
be attained at the cost of reduced performance. For mixtures above
λ = 1.3, the mixture ceases to be ignitable.
lWhen
λ < 1, (i.e. λ = 0.85 to λ = 0.95) there is an air deficiency (rich mixture) and maximum output is available,
but fuel economy is impaired.
The engine management system used with V8 engines operates in a narrower control range about the stoichiometric
ideal between
λ = 0.97 to 1.03 using closed-loop control techniques. When the engine is warmed up and operating
under normal conditions, it is essential to maintain
λ close to the ideal (λ = 1) to ensure the effective treatment of
exhaust gases by the three-way catalytic converters installed in the downpipes from each exhaust manifold.

ENGINE MANAGEMENT SYSTEM - V8
18-2-46 DESCRIPTION AND OPERATION
Idle speed control
The ECM regulates the engine speed at idling. The ECM uses the idle air control valve (IACV) to compensate for the
idle speed drop that occurs when the engine is placed under greater load than usual. When the throttle is in the rest
position i.e. it has not been pressed, the majority of intake air that the engine consumes comes from the idle air control
valve.
IACV control idle speed
Conditions in which the ECM operates the IACV control idle speed is as follows:
lIf any automatic transmission gears other than P or N are selected.
lIf air conditioning is switched on.
lIf cooling fans are switched on.
lAny electrical loads activated by the driver.
Function
The idle air control valve utilises two coils that use opposing pulse width modulated (PWM) signals to control the
position of a rotary valve. If one of the circuits that supplies the PWM signal fails, the ECM closes down the remaining
signal preventing the idle air control valve from working at its maximum/ minimum setting. If this should occur, the idle
air control valve assumes a default idle position at which the engine idle speed is raised to 1200 rev/min with no load
placed on the engine.
Evaporative emission control
Due to increasing legislation, all new vehicles must be able to limit evaporative emissions (fuel vapour) from the fuel
tank.
The ECM controls the emission control system using the following components:
lEVAP canister.
lPurge valve.
lCanister vent solenoid (CVS) valve – (NAS vehicles with vacuum type EVAP system leak detection capability
only)
lFuel tank pressure sensor – (NAS vehicles with vacuum type EVAP system leak detection capability only)
lFuel leak detection pump – (NAS vehicles with positive pressure type EVAP system leak detection capability
only)
lInterconnecting pipe work.
Refer to Emissions section for operating conditions of evaporative emission systems.

+ EMISSION CONTROL - V8, DESCRIPTION AND OPERATION, Evaporative emission control operation.
On-Board Diagnostics (OBD) - North American Specification vehicles only
The ECM monitors performance of the engine for misfires, catalyst efficiency, exhaust leaks and evaporative control
loss. If a fault occurs, the ECM stores the relevant fault code and warns the driver of component failure by illuminating
the Malfunction Indicator Light in the instrument pack.
On vehicles fitted with automatic gearbox, the ECM combines with the Electronic Automatic Transmission (EAT) ECU
to provide the OBD strategy.
Conditions
If the OBD function of the ECM flags a fault during its operation, it falls into one of the following categories:
lmin = minimum value of the signal exceeded.
lmax = maximum value of the signal exceeded.
lsignal = signal not present.
lplaus = an implausible condition has been diagnosed.

AUTOMATIC GEARBOX - ZF4HP22 - 24
DESCRIPTION AND OPERATION 44-1
AUTOMATIC GE ARBOX - ZF4HP22 - 24 DESCRIPTION AND OPERAT ION
Automatic gearbox component layout
1Selector lever assembly
2Gearbox
3Electronic automatic transmission ECU
4Selector position switch
5Oil cooler
6Fluid lines
7Breather tube
8Selector cable

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-4 DESCRIPTION AND OPERATION
Description
General
The automatic gearbox is a four speed unit with electronic control of gear selection, shift quality and torque converter
lock-up. Selections on the selector lever assembly are transmitted to the gearbox by a selector cable. A gear position
switch on the gearbox transmits the gear selection to an Electronic Automatic Transmission (EAT) ECU, which
outputs the appropriate control signals to an electro-hydraulic valve block in the gearbox. A mode switch enables the
driver to change the control mode of the EAT ECU. The EAT ECU operates warning lamps in the instrument pack to
indicate the control mode and system status.
The gearbox features a pressure lubrication system and is cooled by pumping the lubricant through an oil cooler.
On NAS market vehicles from 03 model year, the ZF 4HP24 transmission unit is introduced for use with the 4.6 litre
V8 engine. This transmission is required to accomodate the increased power output of the larger engine. The ZF
4HP22 transmission remains in use on vehicles with Td5 and 4.0 litre V8 engines.
Both transmission units are of similar construction, with the ZF 4HP24 unit being 15 mm longer than the 4HP22 unit
to accomodate a larger fluid pump. The operation of both transmission units is the same.
Selector lever assembly

AUTOMATIC GEARBOX - ZF4HP22 - 24
DESCRIPTION AND OPERATION 44-13
Oil cooler
1Inlet connection
2Fixing bracket
3Outlet connection
4Fixing bracket
5Temperature sensor
Transmission fluid from the gearbox is circulated through a cooler attached to the front of the radiator. Quick release
connectors on the transmission fluid lines attach to connections on each end tank of the cooler. A temperature sensor
on the RH end tank provides the instrument pack with an input of transmission fluid temperature. If the temperature
exceeds a preset limit, the instrument pack illuminates the transmission temperature warning lamp. The warning lamp
remains illuminated until the temperature of the fluid returns within limits.
EAT ECU
The EAT ECU operates the solenoid valves in the gearbox to provide automatic control of gear shifts and torque
converter lock-up. The EAT ECU is attached to a protective bracket which is secured to the cabin floor below the LH
front seat. A 55 pin connector links the EAT ECU to the vehicle wiring.
Software in the EAT ECU monitors hard wired inputs and exchanges information with the ECM on a Controller Area
Network (CAN) bus to determine gear shift and torque converter lock-up requirements. Resultant control signals are
then output to the gearbox solenoid valves.