oil change LAND ROVER DISCOVERY 1999 Workshop Manual

CONTENTS
10 CONTENTS
MANUAL GEARBOX - R380 .................................................................... 37-1
DESCRIPTION AND OPERATION
R380 gearbox ................................................................................................................................. 37-1
Gearbox casings, gear change and oil pump ................................................................................ 37-2
Selector shaft and forks, synchromesh assemblies and gear train ............................................... 37-4
R380 gearbox cross section ........................................................................................................... 37-6
Description ...................................................................................................................................... 37-7
Operation ........................................................................................................................................ 37-8
ADJUSTMENTS
Spring - gear lever bias .................................................................................................................. 37-9
REPAIRS
Housing - gear selector .................................................................................................................. 37-11
Gearbox - V8 .................................................................................................................................. 37-12
Gearbox - Diesel ............................................................................................................................. 37-16
Seal - gearbox mainshaft ............................................................................................................... 37-20
Seal - input shaft ............................................................................................................................ 37-21
Cooler - oil - gearbox - Diesel ......................................................................................................... 37-23
Cooler - oil - gearbox - V8............................................................................................................... 37-24
Switch - Reverse light ................................................................................................................... 37-25
OVERHAUL
Shaft - output ................................................................................................................................. 37-27
Synchroniser - gearbox - set ......................................................................................................... 37-32
Fork - set - selector shaft .............................................................................................................. 37-34
Shaft - gearbox - input .................................................................................................................. 37-35
Extension - gearbox rear ............................................................................................................... 37-38
Pump - gearbox oil ......................................................................................................................... 37-41
Filter - gearbox oil ......................................................................................................................... 37-41
Gear - 5th gear set ........................................................................................................................ 37-42
Synchronizer assembly - 5th/reverse ........................................................................................... 37-43
5th gear - layshaft ......................................................................................................................... 37-44
Bearing - layshaft rear support ..................................................................................................... 37-46
Bearing - output shaft rear support ............................................................................................... 37-47
Shaft - reverse idler ...................................................................................................................... 37-48
Housing - gear selector mechanism ............................................................................................. 37-50
Lever - gear change ...................................................................................................................... 37-51
Housing - clutch ............................................................................................................................ 37-52
Cover - front ................................................................................................................................... 37-53

GENERAL INFORMATION
03-6
General Fitting Instructions
Component removal
Whenever possible, clean components and
surrounding area before removal.
lBlank off openings exposed by component
removal.
lImmediately seal fuel, oil or hydraulic lines when
apertures are exposed; use plastic caps or
plugs to prevent loss of fluid and ingress of dirt.
lClose the open ends of oilways exposed by
component removal with tapered hardwood
plugs or conspicuous plastic plugs.
lImmediately a component is removed, place it in
a suitable container; use a separate container
for each component and its associated parts.
lClean bench and provide marking materials,
labels and containers before dismantling a
component.
Dismantling
Observe scrupulous cleanliness when dismantling
components, particularly when brake, fuel or
hydraulic system parts are being worked on. A
particle of dirt or a cloth fragment could cause a
serious malfunction if trapped in these systems.
lBlow out all tapped holes, crevices, oilways and
fluid passages with an air line. Ensure that any
'O' rings used for sealing are correctly replaced
or renewed, if disturbed during the process.
lUse marking ink to identify mating parts and
ensure correct reassembly. Do not use a centre
punch or scriber to mark parts, they could
initiate cracks or distortion in marked
components.
lWire together mating parts where necessary to
prevent accidental interchange (e.g. roller
bearing components).
lWire labels on to all parts which are to be
renewed, and to parts requiring further
inspection before being passed for reassembly;
place these parts in separate containers from
those containing parts for rebuild.
lDo not discard a part due for renewal until after
comparing it with a new part, to ensure that its
correct replacement has been obtained.Cleaning components
Always use the recommended cleaning agent or
equivalent. Ensure that adequate ventilation is
provided when volatile degreasing agents are being
used. Do not use degreasing equipment for
components containing items which could be
damaged by the use of this process.
General inspection
All components should be inspected for wear or
damage before being reassembled.
lNever inspect a component for wear or
dimensional check unless it is absolutely clean;
a slight smear of grease can conceal an
incipient failure.
lWhen a component is to be checked
dimensionally against recommended values,
use the appropriate measuring equipment
(surface plates, micrometers, dial gauges etc.).
Ensure the measuring equipment is calibrated
and in good serviceable condition.
lReject a component if its dimensions are
outside the specified tolerances, or if it appears
to be damaged.
lA part may be refitted if its critical dimension is
exactly to its tolerance limit and it appears to be
in satisfactory condition. Use 'Plastigauge' 12
Type PG-1 for checking bearing surface
clearances.

TORQUE WRENCH SETTINGS
06-10
Manual gearbox - R380
+ Apply sealant, Part No. STC 50552 to threads
TORQUE DESCRIPTION METRIC IMPERIAL
Bias spring adjustment plate bolts + 25 Nm (18 lbf.ft)
Gearbox to engine bolts 45 Nm (33 lbf.ft)
Coolant pipe housing bolts 25 Nm (18 lbf.ft)
Breather pipe banjo bolt 15 Nm (11 lbf.ft)
Gear lever extension clamp bolt 25 Nm (18 lbf.ft)
Gearbox mounting bolts 85 Nm (63 lbf.ft)
Gearbox mounting nuts 48 Nm (37 lbf.ft)
Seal housing bolts 18 Nm (13 lbf.ft)
Bearing sleeve bolts 25 Nm (18 lbf.ft)
Fork bolt7 Nm (5.2 lbf.ft)
Reverse light switch 24 Nm (18 lbf.ft)
Extension housing bolts + 25 Nm (18 lbf.ft)
Gear selector housing bolts + 25 Nm (18 lbf.ft)
Oil pump to housing Torx screws 6 Nm (4.4 lbf.ft)
Gear change lever yoke Allen screw + 25 Nm (18 lbf.ft)
5th gear stake nut 350 Nm (258 lbf.ft)
Spool retainer bolts 8 Nm (6 lbf.ft)
Centre plate detent spring and ball Torx screw 25 Nm (18 lbf.ft)
Selector lever to housing bolts + 25 Nm (18 lbf.ft)
Clutch \ Bell housing bolts 73 Nm (54 lbf.ft)

CAPACITIES, FLUIDS, LUBRICANTS AND SEALANTS
09-1
CAPACITIES, FLUIDS, LUBRICANTS AND SEALANTS
Capacities
The following capacities are only an approximation of
the amount of fluid required to fill the respective
system.
Capacities - UK EURO ROWCapacities - NAS
Refrigerant - A/C system
Component Metric Units
Fuel tank 95 litres
Engine - Td5:
⇒ Engine oil and filter change 7.2 litres
⇒ Fill from dry 8.2 litres
Engine - V8 with oil cooler:
⇒Engine oil and filter change 6.27 litres
⇒Engine oil refill from dry: 7 litres
Engine - V8 without oil cooler:
⇒Engine oil and filter change 5.8 litres
⇒ Engine oil refill from dry 6.5 litres
Manual gearbox without oil cooler:
⇒ Refill 2.3 litres
⇒ Fill from dry 2.6 litres
Manual gearbox with oil cooler:
⇒ Refill 2.8 litres
⇒ Fill from dry 3.1 litres
Automatic gearbox fill from dry 9.7 litres
Transfer box:
⇒ Refill 2.0 litres
⇒ Fill from dry 2.3 litres
Front and rear axle:
⇒ Refill 1.6 litres
⇒ Fill from dry 1.7 litres
Cooling system - Td5 Engine:
⇒ Refill 8 litres
⇒ Fill from dry 13 litres
Cooling system - V8 Engine:
⇒ Refill 12 litres
⇒ Fill from dry 13 litres
Component US Units
Fuel tank 25.5 gal
Engine - V8 with oil cooler:
⇒ Engine oil and filter change 6.6 qt
⇒ Engine oil refill from dry 7.4 qt
Engine - V8 without oil cooler:
⇒ Engine oil and filter change 6.1 qt
⇒ Engine oil refill from dry 6.9 qt
Automatic gearbox fill from dry
19.7 pt
Transfer box:
⇒ Refill 4.1 pt
⇒ Fill from dry 4.8 pt
Front and rear axle:
⇒ Refill 3.4 pt
⇒ Fill from dry 3.6 pt
Cooling system - V8 Engine:
⇒ Refill 24.2 pt
⇒ Fill from dry 26.2 pt
⇒Front A/C 700 ± 25 g
⇒Front/rear A/C 900 ± 25 g

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-43
Secondary Air Injection System
Operation
When the engine is started, the engine control module checks the engine coolant temperature and if it is below 55°
C, the ECM grounds the electrical connection to the coil of the secondary air injection (SAI) pump relay.
A 12V battery supply is fed to the inertia switch via fuse 13 in the engine compartment fusebox. When the inertia
switch contacts are closed, the feed passes through the switch and is connected to the coil of the Main relay. An earth
connection from the Main relay coil is connected to the ECM. When the ECM completes the earth path, the coil
energises and closes the contacts of the Main relay.
The Main and Secondary Air Injection (SAI) pump relays are located in the engine compartment fusebox. When the
contacts of the Main relay are closed, a 12V battery supply is fed to the coil of the SAI pump relay. An earth connection
from the coil of the SAI pump relay is connected to the ECM. When the ECM completes the earth path, the coil
energises and closes the contacts of the SAI pump relay to supply 12V to the SAI pump via fusible link 2 in the engine
compartment fusebox. The SAI pump starts to operate, and will continue to do so until the ECM switches off the earth
connection to the coil of the SAI pump relay.
The SAI pump remains operational for a period determined by the ECM and depends on the starting temperature of
the engine, or for a maximum operation period determined by the ECM if the target engine coolant temperature has
not been reached in the usual time.
When the contacts of the main relay are closed, a 12V battery supply is fed to the SAI solenoid valve via Fuse 2 in
the engine compartment fusebox.
The ECM grounds the electrical connection to the SAI vacuum solenoid valve at the same time as it switches on the
SAI pump motor. When the SAI vacuum solenoid valve is energised, a vacuum is provided to the operation control
ports on both of the vacuum operated SAI control valves at the exhaust manifolds. The control vacuum is sourced
from the intake manifold depression and routed to the SAI control valves via a vacuum reservoir and the SAI vacuum
solenoid valve.
The vacuum reservoir is included in the vacuum supply circuit to prevent vacuum fluctuations caused by changes in
the intake manifold depression affecting the operation of the SAI control valves.
When a vacuum is applied to the control ports of the SAI control valves, the valves open to allow pressurised air from
the SAI pump to pass through to the exhaust ports in the cylinder heads for combustion.
When the ECM has determined that the SAI pump has operated for the desired duration, it switches off the earth paths
to the SAI pump relay and the SAI vacuum solenoid valve. With the SAI vacuum solenoid valve de-energised, the
valve closes, cutting off the vacuum supply to the SAI control valves. The SAI control valves close immediately and
completely to prevent any further pressurised air from the SAI pump entering the exhaust manifolds.
The engine coolant temperature sensor incurs a time lag in respect of detecting a change in temperature and the SAI
pump automatically enters a 'soak period' between operations to prevent the SAI pump overheating. The ECM also
compares the switch off and start up temperatures, to determine whether it is necessary to operate the SAI pump.
This prevents the pump running repeatedly and overheating on repeat starts.
Other factors which may prevent or stop SAI pump operation include the prevailing engine speed / load conditions.

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-51
Conditions
The ECM calculates ignition timing using input from the following:
lCKP sensor.
lKnock sensors (KS).
lMAF sensor.
lTP sensor (idle only).
lECT sensor.
Function
At engine start up, the ECM sets ignition timing dependent on ECT information and starting rev/min from the CKP. As
the running characteristics of the engine change, the ignition timing changes. The ECM compares the CKP signal to
stored values in its memory, and if necessary advances or retards the spark via the ignition coils.
Ignition timing is used by the ECM for knock control.
Knock control
The ECM uses active knock control to prevent possible engine damage due to pre-ignition. This is achieved by
converting engine block noise into a suitable electrical signal that can be processed by the ECM. A major contributing
factor to engine 'knock' is fuel quality, the ECM can function satisfactorily on 91 RON fuel as well as the 95 RON fuel
that it is calibrated for.
Conditions
The ECM knock control system operates as follows:
lHot running engine.
l91 or 95 RON fuel.
Function
The ECM knock control uses two sensors located one between the centre two cylinders of each bank. The knock
sensors consist of piezo ceramic crystals that oscillate to create a voltage signal. During pre-ignition, the frequency
of crystal oscillation increases which alters the signal output to the ECM.
If the knock sensors detect pre-ignition in any of the cylinders, the ECM retards the ignition timing by 3° for that
particular cylinder. If this action stops the engine knock, the ignition timing is restored to its previous figure in
increments of 0.75°. If this action does not stop engine knock then the ECM retards the ignition timing a further 3° up
to a maximum of -15° and then restores it by 0.75° and so on until the engine knock is eliminated.
The ECM also counteracts engine knock at high intake air temperatures by retarding the ignition as above. The ECM
uses the IAT signal to determine air temperature.
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.

MANUAL GEARBOX - R380
37-2 DESCRIPTION AND OPERATION
Gearbox casings, gear change and oil
pump

MANUAL GEARBOX - R380
DESCRIPTION AND OPERATION 37-3
1Front cover
2Input shaft oil seal
3Oil filler/level plug
4Sealing washer
5Oil drain plug
6Gear case
7Interlock spool retainer, bolt and 'O' ring
8Centre plate
9Locating dowels
10Selector plug, detent balls and spring
11Splash shield and retaining bolt
12Extension housing
13Gate plate and retaining bolt
14Interlock spool retainer, retaining bolt and 'O'
ring – if fitted – extension housing
15Inhibitor cam spring
16Inhibitor cam
17Reverse inhibitor shaft
18Output shaft oil seal
19Oil seal collar
20Oil pump and retaining bolt
21'O' ring
22Reverse lamp switch23Oil by-pass block - UK and European models
24Bolt - oil by-pass block
25'O' ring - oil by-pass block
26Thermostat and housing - non UK and non
European models
27'O' ring - thermostat housing
28Bolt - thermostat housing
29Oil pick-up pipe
30Oil filter
31Oil pick-up ring
32Rubber gaiter
33Cable tie
34Upper gear lever
35Clamp bolt
36Bias springs
37Bolts and washers - bias adjusting plate and
housing
38Bias adjusting plate
39Lower gear lever and ball
40Railko bush
41Oil seal
42Gear change housing

MANUAL GEARBOX - R380
37-6 DESCRIPTION AND OPERATION
R380 gearbox cross section
1Input shaft
2Breather
3Input shaft 4th gear
4Selector shaft
53rd/4th selector fork
6Output shaft 3rd gear
7Output shaft 2nd gear
81st/2nd selector fork
9Output shaft 1st gear
10Selective shims - output shaft and layshaft end-
float
11Selective shim - reverse gear idler shaft end-
float
125th/reverse selector fork
13Selector yoke14Gear change assembly
15Railko bush
16Output shaft 5th gear
17Output shaft oil seal
18Output shaft
19Oil pump
205th/reverse gear synchromesh assembly
21Output shaft reverse gear
22Centre plate
23Oil filter
241st/2nd synchromesh assembly
25Layshaft
263rd/4th gear synchromesh assembly
27Input shaft oil seal

MANUAL GEARBOX - R380
DESCRIPTION AND OPERATION 37-7
Description
General
The R380 all synchromesh gearbox has five forward speeds and reverse and is mounted in line with the engine. The
clutch bell housing is bolted to the front of the gearbox and the transfer box is mounted at the rear.
Gearbox casings
Gearbox casings consist of a front cover, gearcase, centre plate and extension housing. All casings with the exception
of the front cover are located to each other by dowels and sealed. Gearbox filler/level and drain plugs are located in
the gearcase.
Reverse lamp switch
A reverse lamp switch is inserted into the extension housing. Selection of reverse gear will close the switch allowing
current from fuse 25 to flow through the switch to illuminate the reverse lamps. The switch also provides a feed to the
BCU and the electrochromic automatic interior mirror - if fitted; the mirror moving from the dimmed position if
applicable.
Gearchange assembly
The gearchange assembly is bolted to the top of the gearcase, the upper gear lever being attached to the lower gear
lever by means of a clamp bolt. The lower gear lever ball is housed in a Railko bush inserted in the gear change
housing, the end of the lever locating in the selector yoke which is attached to the end of the selector shaft. Bias
springs provide a positive return of the gear lever to the neutral position with selection of 1st/2nd and 5th/reverse gears
being against bias spring pressure. Spring loaded detent balls fitted in the centre plate locate in grooves in the selector
shaft to provide positive gear and neutral selection.
Lubrication
Lubrication is by an oil pump located in the extension housing and driven by the layshaft with additional lubrication
being provided by splash. The pump directs oil via a filter and internal drillings in the output shaft to lubricate the
components. On non UK and non European models, provision for oil cooling is by means of a thermostat housed in
a cover bolted to the side of the extension housing. The cover incorporates tappings for connections to an oil cooler.
On UK and European models, the thermostat and cover are replaced by an oil by-pass block.
Internal pressures produced within the gearbox are vented to atmosphere via a plastic breather pipe. The pipe is
attached to the extension housing and is routed across the top of the gearcase and secured at the open end by a clip
attached to the engine cylinder block.
Selector shaft and forks
Selector forks for 1st/2nd, 3rd/4th and 5th/reverse gears are located on a single selector shaft; the 1st/2nd and 3rd/
4th selector forks are inside the main gearcase whilst the 5th/reverse selector fork is inside the extension housing.
Each of the selector forks locates inside its corresponding synchromesh hub.
Synchromesh assemblies
Each synchromesh assembly is located on the output shaft adjacent to its corresponding gears and comprises a
synchromesh ring, hub, slippers and sleeve. The hubs and slippers are retained in the sleeves by means of spring
clips. 1st/2nd and 3rd synchromesh assemblies are fitted with double synchromesh rings whilst 4th, 5th and reverse
assemblies are fitted with single rings.
The gear train
The gear train comprises an input shaft, output shaft, layshaft and reverse idler shaft together with their appropriate
gears and synchromesh assemblies.
The gear train input shaft, output shaft and layshaft are supported by taper roller bearings with all gears on the input
and output shafts running on caged needle roller bearings. Layshaft gears are integral with the shaft with the
exception of reverse/5th gears which are splined to the shaft and retained with a nut. 1st, 2nd, 3rd and 4th gears are
shot peened to improve durability. The reverse idler shaft and gear are supported in the centre plate by a caged
needle roller bearing. End-float of the output shaft and layshaft is controlled by selective shims located in the centre
plate whilst reverse idler shaft end-float is controlled by a selective shim located behind reverse gear.