differential LAND ROVER DISCOVERY 1999 User Guide

MAINTENANCE
PROCEDURES 10-31
Road/roller test
WARNING: Roller test must be restricted to 3
mph (5 km/h). If 2 wheel rolling road is to be used,
disconnect propeller shaft from the transfer box
output shaft driving the axle which is NOT on the
rolling road.
Testing
1. 2 wheel rolling road: Engage differential lock
using a 10 mm open ended spanner on flats
machined on differential lock selector
shaft.Switch on ignition and check that the
differential lock, electronic brake
distribution and hill descent warning lamps
are illuminated.
2.Check for correct operation of starter switch,
ensure engine starts correctly; leave the engine
running.
3.Check for correct operation of starter switch,
ensure engine starts correctly; leave the engine
running.
4.With vehicle stationary, turn steering from lock
to lock. Check for smooth operation and ensure
there is no undue noise from power steering
pump or drive belt.
5.Depress clutch and select all gears in turn,
check for smooth, notch free engagement.6. Check all vehicle systems for correct
operation.
7.Check for unusual engine, gearbox and
suspension noises.
8.Check braking system operation.
9.Check for smooth gear engagement.
10.Check engine performance.
11.Check operation of all instruments and warning
devices where practicable.
12.Where possible, check for correct operation of
hill descent control (HDC) mechanism. This
should not be carried out if excessive journey
time is required.
13.After road/roller test, carry out a final inspection
of vehicle, with vehicle on a ramp.
14.Check all fluid levels and top-up if necessary.
15. 2 wheel rolling road: Ensure differential lock is
disengaged and propeller shaft is connected on
completion of test. Switch on ignition and
check that differential lock, electronic brake
distribution and hill descent warning lamps
are extinguished.

EMISSION CONTROL - V8
17-2-42 DESCRIPTION AND OPERATION
If the piping is broken forward of the purge valve or is not connected, the engine may run rough and fuelling adaptions
will drift. The fault will not be detected by the leak detection diagnostic, but it will be determined by the engine
management ECM through the fuelling adaption diagnostics.
The evaluation of leakage is dependent on the differential pressure between the fuel tank and ambient atmospheric
pressure, the diagnostic is disabled above altitudes of 9500 ft. (2800 m) to avoid false detection of fuel leaks due to
the change in atmospheric pressure at altitude.
Fuel Leak Detection System Operation (positive pressure leak detection type) – NAS only
The EVAP system with positive pressure leak detection capability used on NAS vehicles is similar to the standard
system, but also includes a fuel evaporation leak detection pump with integral solenoid valve. It is capable of detecting
holes in the EVAP system down to 0.5 mm (0.02 in.). The test is carried out at the end of a drive cycle, when the
vehicle is stationary and the ignition switch has been turned off. The ECM maintains an earth supply to the Main relay
to hold it on, so that power can be supplied to the leak detection pump.
First a reference measurement is established by passing the pressurised air through a by-pass circuit containing a
fixed sized restriction. The restriction assimilates a 0.5 mm (0.02 in) hole and the current drawn by the pump motor
during this procedure is recorded for comparison against the value to be obtained in the system test. The purge valve
is held closed, and the reversing valve in the leak detection pump module is not energised while the leak detection
pump is switched on. The pressurised air from the leak detection pump is forced through an orifice while the current
drawn by the pump motor is monitored.
Next the EVAP system diagnostic is performed; the solenoid valve is energised so that it closes off the EVAP system's
vent line to atmosphere, and opens a path for the pressurised air from the leak detection pump to be applied to the
closed EVAP system.
The current drawn by the leak detection pump is monitored and checked against that obtained during the reference
measurement. If the current is less than the reference value, this infers there is a hole in the EVAP system greater
than 0.5 mm (0.02 in) which is allowing the positive air pressure to leak out. If the current drawn by the pump motor
is greater than the value obtained during the reference check, the system is sealed and free from leaks. If an EVAP
system leak is detected, the ECM stores the fault in diagnostic memory and the MIL light on the instrument pack is
illuminated.
On NAS vehicles, the ECM works on a 2 trip cycle before illuminating the MIL. On EU-3 vehicles, the ECM works on
a 3 trip cycle before illuminating the MIL.
Following the test, the solenoid valve is opened to normalise the EVAP system pressure and the system returns to
normal purge operation at the start of the next drive cycle. Possible reasons for an EVAP system leak test failure are
listed below:
lFuel filler not tightened or cap missing.
lSensor or actuator open circuit.
lShort circuit to vehicle supply or ground.
lEither purge or solenoid valve stuck open.
lEither purge or solenoid valve stuck shut.
lBlocked pipe or air filter.
lPiping broken or not connected.
lLoose or leaking connection.
If the piping is broken forward of the purge valve or is not connected, the engine may run rough and fuelling adaptions
will drift. The fault will not be detected by the leak detection test, but will be determined by the engine management
ECM through the fuelling adaption diagnostics. This test can be run from TestBook/T4.

MANUAL GEARBOX - R380
37-12 REPAIRS
Gearbox - V8
$% 37.20.02.99
Remove
1.Release turnbuckles and remove battery cover
and cooling fan cowl.
2.Disconnect battery earth lead.
3.Remove gear lever knob and gear lever trim.
4.Remove clamp bolt and remove gear lever
extension. Apply lubricant to gear lever to aid
removal through grommet.
5.Remove front exhaust pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
6.Drain gearbox oil.

+ MAINTENANCE, PROCEDURES,
Manual gearbox.7.Drain transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
8.Remove 8 bolts securing rear cross member
and remove cross member.
9.Remove 3 nuts securing intermediate silencer
to tail pipe.
10.Release silencer from mounting rubbers,
remove silencer and discard gasket.
11.Mark front propeller shaft to transfer gearbox
and differential flanges.

MANUAL GEARBOX - R380
REPAIRS 37-13
12.Remove 8 nuts securing front propeller shaft to
transfer gearbox and differential.
13.Remove propeller shaft.
14.Repeat above operation for rear propeller
shaft.
15.Remove handbrake drum retaining screw and
remove handbrake drum.
16.Remove 4 bolts from handbrake back plate,
release back plate and tie aside. 17.Remove 2 bolts securing clutch slave cylinder,
collect heat shield, release slave cylinder and
position aside.
18.Fit support plate LRT-99-007 to gearbox jack.
19.Position gearbox jack and support plate to
gearbox and secure with 3 bolts.
20.Support the weight of gearbox, remove nuts
securing gearbox mountings to body.
21.Remove 8 bolts securing mountings to
gearbox, raise gearbox and remove both
mountings.

MANUAL GEARBOX - R380
37-14 REPAIRS
22.Lower gearbox sufficiently to access top of
gearbox.
23.Ensure gear lever is released from grommet
and no wires or pipes are trapped when
gearbox is lowered.
24.Remove clevis pin and 'C' washer securing low
ratio selector cable to lever and release cable
from lever housing.
25.Remove 2 cable ties securing cable to fuel
pipes. 26.Disconnect 2 Lucars from oil temperature
sensor and disconnect reverse lamp switch
multiplug.
27.Remove banjo bolts securing breather pipes
and discard sealing washers.
28.Remove bolt securing breather pipe 'P' clip and
release breather pipes.
29. If fitted: Disconnect 2 Lucars from differential
lock switch, release and disconnect transfer
box neutral sensor multiplug.
30. If fitted: Release harness from 2 retaining
clips.
31.Position container to catch oil spillage

MANUAL GEARBOX - R380
REPAIRS 37-15
32.Remove 3 bolts securing oil cooling pipe
housing to gearbox, release housing and
discard 'O' rings.
33.Using a second jack support the weight of the
engine.
34.Remove 14 bolts securing gearbox to engine.
35.With assistance, remove gearbox from engine.
Refit
1.Clean gearbox to engine mating faces, dowels
and dowel holes.
2.Raise gear gearbox on jack and align to clutch
and engine.
3.Fit bolts securing gearbox to engine and
tighten to 45 Nm (33 lbf.ft).
4.Lubricate and fit new 'O' rings to oil cooling
pipe housing. 5.Position coolant pipe housing, fit bolts and
tighten to 25 Nm (18 lbf.ft).
6. If fitted: Secure harness in retaining clips,
connect Lucars to differential lock warning
switch and multiplug to neutral sensor.
7.Position breather pipes and secure 'P' clip with
bolt.
8.Using new sealing washers fit breather pipe
banjo bolts and tighten to 15 Nm (11 lbf.ft).
9.Connect oil temperature sensor Lucars and
reverse lamp switch multiplug.
10.Position low ratio selector cable to housing and
secure with 'C' washer and clevis pin.
11.Secure cable to fuel pipes with new cable ties.
12.Raise gearbox, ensuring gear change lever is
located in grommet.
13.Fit gearbox mountings and tighten bolts to 85
Nm (63 lbf.ft).
14.Fit nuts to mountings and tighten to 48 Nm (37
lbf.ft).
15.Remove 3 bolts securing support plate to
gearbox.
16.Position clutch slave cylinder and heat shield,
fit bolts and tighten to 25 Nm (18 lbf.ft).
17.Clean handbrake back plate and mating face.
18.Position handbrake back plate, fit bolts and
tighten to 75 Nm (46 lbf.ft).
19.Clean handbrake drum.
20.Fit handbrake drum and tighten retaining
screw.
21.Clean propeller shafts and mating faces.
22.Position propeller shafts, align to marks and
tighten bolts to 47 Nm (35 lbf.ft).
23.Clean exhaust silencer and tail pipe mating
faces.
24.Position silencer and secure on mountings,
using a new gasket align to tail pipe, fit nuts
and tighten to 25 Nm (18 lbf.ft).
25.Position rear cross member, fit bolts and
tighten to 25 Nm (18 lbf.ft).
26.Refill gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Manual gearbox.
27.Refill transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
28.Fit front exhaust pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
29.Fit gear lever extension, fit clamp bolt and
tighten to 25 Nm (18 lbf.ft).
30.Fit gear lever trim and gear change knob.
31.Connect battery earth lead.
32. Fit battery cover and cooling fan cover and
secure fixings.

MANUAL GEARBOX - R380
37-18 REPAIRS
22.Ensure gear lever is released from grommet
and no wires or pipes are trapped when
gearbox is lowered.
23.Remove clevis pin and 'C' washer securing low
ratio selector cable to lever and release cable
from lever housing.
24.Remove 2 cable ties securing cable to fuel
pipes. 25.Disconnect 2 Lucars from oil temperature
sensor and disconnect reverse lamp switch
multiplug.
26.Remove banjo bolts securing breather pipes
and discard sealing washers.
27.Remove bolt securing breather pipe 'P' clip and
release breather pipes.
28. If fitted: Disconnect 2 Lucars from differential
lock switch, release and disconnect transfer
box neutral sensor multiplug. Release harness
from 2 retaining clips.
29.Position container to catch oil spillage
30.Remove 2 bolts securing oil cooling pipe
housing to gearbox, release housing and
discard 'O' rings.
CAUTION: Always fit plugs to open
connections to prevent contamination.
31.Using a second jack support the weight of the
engine.

MANUAL GEARBOX - R380
REPAIRS 37-19
32.Remove 8 bolts securing gearbox to engine.
33.With assistance, remove gearbox from engine.
Refit
1.Clean gearbox to engine mating faces, dowels
and dowel holes.
2.With assistance raise gearbox on jack and
align to clutch and engine.
3.Fit bolts securing gearbox to engine and
tighten to 50 Nm (37 lbf.ft).
4.Clean oil cooling pipe housing mating faces.
5.Lubricate and fit new 'O' rings to oil cooling
pipe housing.
6.Position cooling pipe housing, fit bolts and
tighten to 25 Nm (18 lbf.ft).
7. If fitted: Secure harness in retaining clips,
connect Lucars to differential lock warning
switch and multiplug to transfer box neutral
switch.
8.Position breather pipes and secure 'P' clip with
bolt.
9.Using new sealing washers fit breather pipe
banjo bolts and tighten to 15 Nm (11 lbf.ft).
10.Connect oil temperature sensor Lucars and
reverse lamp switch multiplug.
11.Position low ratio selector cable to housing and
secure with 'C' washer and clevis pin.
12.Secure cable to fuel pipes with new cable ties.
13.Raise gearbox, ensuring gear change lever is
located in grommet.
14.Fit gearbox mountings and tighten bolts to 85
Nm (63 lbf.ft).
15.Fit nuts to gearbox mountings and tighten to 48
Nm (37 lbf.ft).
16.Remove 3 bolts securing support plate to
gearbox. 17.Position clutch slave cylinder and heat shield,
fit bolts and tighten to 25 Nm (18 lbf.ft).
18.Clean handbrake back plate and mating face.
19.Position handbrake back plate, fit bolts and
tighten to 75 Nm (55 lbf.ft).
20.Clean handbrake drum.
21.Fit handbrake drum and tighten retaining
screw.
22.Fit front propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front..
23.Fit rear propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.
24.Clean exhaust silencer and tail pipe mating
faces.
25.Position silencer and secure on mountings,
using a new gasket align to tail pipe, fit nuts
and tighten to 25 Nm (18 lbf.ft).
26.Fit exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - Td5, REPAIRS, Pipe - front.
27.Refit starter motor.

+ CHARGING AND STARTING,
REPAIRS, Starter motor - diesel.
28.Refill gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Manual gearbox.
29.Refill transfer gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
30.Fit gear lever extension, fit clamp bolt and
tighten to 25 Nm (18 lbf.ft).
31.Fit gear lever trim and gear change knob.
32.Connect battery earth lead.
33.Fit cooling fan cowl and battery cover and
secure fixings.

TRANSFER BOX - LT230SE
DESCRIPTION AND OPERATION 41-3
1Rear output housing
2Differential rear bearing
3High range gear and bush
4Main casing
5High/low selector sleeve and hub
6Low range gear
7Differential assembly
8Front output housing
9Differential front bearing
10Selective shim - differential bearing pre-load
11Dog clutch - Differential lock
12Front output flange13Differential lock selector shaft - Differential lock
14Selector fork - Differential lock
15Front output shaft
16Selective spacer - intermediate gear bearing
pre-load
17Mainshaft input gear
18Selective shim - input gear bearing pre-load
19Intermediate shaft
20Intermediate gear cluster
21Rear output shaft
22Rear output flange

TRANSFER BOX - LT230SE
41-6 DESCRIPTION AND OPERATION
Differential components – Vehicles up to
03 model year
1Retaining ring
2Differential carrier - rear half
3Low range gear
4High/low hub
5High/low selector sleeve
6High/low selector shaft
7High/low selector fork
8Setscrew - high/low selector fork
9High range gear
10High range gear bush
11Differential rear bearing
12Bearing outer track13Bearing retaining nut - Patched
14Dished thrust washers
15Planet gears
16Cross shafts
17Sun gears
18Selective thrust washers
19Differential carrier - front half
20Bolt - differential carriers
21Differential front bearings
22Bearing outer track
23Selective shim