1995 LAND ROVER DISCOVERY electrical

ZF
7
REPAIR Accessories removal/fitting
If fitting a replacement transmission assembly to the
vehicle, remove the following items from the existing
assembly and fit to the replacement.
CAUTION: It is important to remove the
spacer from the extension shaft and fit
onto the replacement unit.
50.Breather pipe union and washers from main
gearbox.
51.Breather pipe, union and washers from transfer
gearbox.
52.Main gearbox selector lever.
53.RH mounting bracket assembly.
54.Oil cooler pipe unions.
55.Fit blanks to all apertures where unions have
been removed and blank off pipe ends.
Refit
1.Fit transmission to cradle and hoist.
2.Locate hoist under vehicle and remove torque
convertor retaining strap.
3.Ensure low range gear is engaged.
4.Apply approved sealant to bell housing face.
5.Carefully raise assembly, align bell housing with
flywheel housing and bring mating faces
together.
6.Fit nuts and bolts to secure transmission to
engine.
7.Locate electrical wiring and breather pipes to
position.
8.Secure kick down cable clip to bell housing.
9.Raise hoist sufficiently to take weight.
10.Remove block and jack from engine sump.
11.Fit filler/dipstick tube to gearbox sump and
secure bracket to bell housing.
12.Apply Loctite to torque convertor bolts
13.Working through starter aperture refit the four
torque convertor to flexible drive securing bolts,
rotating crankshaft to gain access to bolt
locations.
14.Refit starter and heatshield.
15.Secure breather pipes and harness with ties.
16.Fit left hand mounting bracket assembly to
gearbox.
17.Raise transmission and support with a suitable
ramp [hoist] jack.
18.Remove two bolts securing transmission to
cradle, lower hoist and remove from under
vehicle.
19.Apply Loctite to above bolts and fit to transfer
gearbox input bearing support plate.
20.Fit chassis cross member.21.Secure gearbox mounting brackets to chassis
cross member.
22.Remove ramp [hoist] jack.
23.Connect electrical leads to differential lock
switch.
24.Connect inhibitor switch multi-plug.
25.Connect selector cable to lever on side of
gearbox.
26.Connect oil cooler pipes to gearbox and secure
retaining bracket to gearbox sump.
27.Secure silencer to chassis and refit exhaust front
pipe.
28.Refit front propeller shaft to transfer gearbox.
29.Refit rear propeller shaft.
See PROPELLER
SHAFTS, Overhaul, Flexible Coupling
30.Connect speedometer cable to transfer gearbox.
31.Refill transfer gearbox with correct grade of
lubricating oil.
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information,
Recommended Lubricants and Fluids
32.Lower ramp [hoist] to ground level.
33.Reconnect turbo-charger hose to inter-cooler.
34.Reconnect top hose to radiator.
35.Refill cooling system with correct mixture of
coolant.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
36.Reconnect kick down cable to fuel injection
pump.
37.Secure breather pipe clip to rear of cylinder
head.
38.Engage harness with clips along top of
bulkhead.
39.On left hand drive vehicles only, connect
multi-plug to top of brake fluid reservoir.
40.Refit insulation pad to rocker cover and inlet
manifold, secure with oil filler cap.
41.Refit gaiter and knob to transfer gear lever.
42.Select high range gear.
43.Reconnect battery terminals.
44.Refill main gearbox with correct grade of
lubricating oil.
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information,
Recommended Lubricants and Fluids

44AUTOMATIC GEARBOX
22
REPAIR
13.Place end-float gauge LST111 onto pump
housing and check that axial play is between
0.2-0.4 mm. Replace existing washer, situated at
rear of intermediate plate, with suitable washer
to give required end-float.
NOTE: If damage is apparent to bolts they
should be replaced.
14.Refit torque converter into housing using torque
converter handles 18G1501. Check dimension
converter fixing boss to converter housing face is
50 mm. This shows converter is properly seated
in housing.
15.Refit gearbox/transfer box assembly.
See
LT230T Transfer Gearbox
GEAR SELECTOR-INTERLOCK
For remove and refit of gear selector interlock.
See
ELECTRICAL, Repair, Gear Selector-Interlock

FRONT AXLE AND FINAL DRIVE
1
DESCRIPTION AND OPERATION DESCRIPTION
The welded steel front axle casing houses a separate
spiral bevel type differential unit, which is off set to the
right of the vehicle centre line. The differential unit
drives the front wheels via the axle shafts and
constant velocity joints which are totally enclosed in
the spherical and swivel housings.
The front axles fitted with ABS brakes or non ABS
brakes are of the same construction except for
different top swivel pins in the swivel housing and a
sensor on the constant velocity joint.
Front axle - ABS
The front wheels are pivoted on taper roller bearings
19 at the bottom of the swivel housing and a 'Rialco
bush' 25 at the top. The top swivel pin also houses the
ABS pickup (electrical connection) as shown in the
main illustration, J5367.
Front axle - non ABS
The front wheels are pivoted on tape roller bearings at
the top (see insert) and bottom of the swivel housing.
The wheel hubs on all axles are supported by two
taper bearings and driven by drive flanges which are
splined to the one piece, stub shaft/constant velocity
joint.
Lubrication
The differential, swivel pin housing and wheel hubs
are indiviudally lubricated and separated by oil seals 7
and 8 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.
Ventilation
Ventilation of the differential is through a plastic pipe 2
which terminates at a high level in the vehicle on both
ABS and non ABS axles. The swivel housings
ventilate through axle shaft oil seals 8 into the
differential and the hub bearings vent via the oil seals
into swivel housing.

54FRONT AXLE AND FINAL DRIVE
2
DESCRIPTION AND OPERATION
Front axle
1. Axle casing
2. Ventilation pipe
3. Axle shaft
4. Wheel studs and hub
5. Stub axle
6. Wheel bearings (2)
7. Inner and outer hub seals
8. Axle shaft seal
9. Hub lock plate, thrust washer and nuts (2)
10. Brake disc
11. Drive flange
12. Shim washer and circlip
13. Dust cap14. Constant velocity joint/shaft
15. Thrust collar for CV joint
16. Roller bearing
17. Spacer
18. Circlip
19. Bottom swivel taper bearing
20. Top and bottom swivel pins
21. Spherical housing, seal and retainer
22. Swivel housing
23. Constant velocity shaft seal
24. ABS pickup (electrical connection)
25. 'Rialco' bush ABS

BRAKES
3
DESCRIPTION AND OPERATION Description of components
1. ABS Modulator unit
To provide the ABS function a Modulator is positioned
within the system between the master cylinder and the
calipers. On both LHD and RHD vehicles it is sited on
the left inner wing [fender]. The Modulator has 8
solenoid valves, 2 for each wheel, 2 expanders and a
recirculation pump. It is non serviceable.
2. Servo/master cylinder
Actuation of the system is provided by a combined
master cylinder and servo assembly attached to the
pedal box, this provides pressure to opposed piston
calipers at each brake pad Twin piston at the front
axle, single piston at the rear.
3. Pressure reducing valve
To maintain the braking balance, pressure to the rear
axle is regulated by a Pressure Reducing Valve (PRV)
This PRV is of the failure bypass type, allowing full
system pressure to the rear axle in the event of a front
circuit failure. It is sited on the left inner wing [fender].
4. Electronic control unit - ECU
ABS control is provided by an electronic control unit
which is positioned on the passenger side of the
vehicle behind the dash panel/glove box.
The ECU, which is non-serviceable, is connected to
the ABS harness by a 35 way connector. non
serviceable.
The ECU continually monitors the brake system,
providing diagnostics in the event of a system
malfunction. Details of how to access the ECU
diagnostics are provided in the Electrical
Troubleshooting Manual.
5.& 6. Front and rear sensors/exciter rings - 4 off
A sensor is sited at each wheel, sensing a 60 tooth
exciter ring. When vehicle is in motion inductive
sensors send signals to ECU. Front exciter ring is
fitted to outside diameter of constant velocity joint
inside each front hub assembly. The rear exciter ring
is bolted to the rear of each brake disc bell.7. Diagnostic plug connection
A diagnostic plug is located behind the dash. To the
left of the steering column on LHD vehicles. To the
right of the steering column on RHD vehicles. It is a 5
way blue connector.
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual.
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment
ANTI-LOCK BRAKE SYSTEM - ABS
Manufactured by WABCO
Introduction
The purpose of ABS is to prevent vehicle wheels
locking during brake application, thus maintaining
vehicle steerability and stability. This allows vehicle to
be steered whilst brakes are applied, even under
emergency conditions, and to avoid obstacles where
there is sufficient space to redirect the vehicle.
WARNING: ABS is an aid to retaining
steering control and stability while
braking.
·ABS cannot defy the natural laws of physics
acting on the vehicle.
·ABS will not prevent accidents resulting from
excessive cornering speeds, following
another vehicle too closely or aquaplaning,
i.e. where a layer of water prevents adequate
contact between tyre and road surface.
·The additional control provided by ABS must
never be exploited in a dangerous or
reckless manner which could jeopardise the
safety of driver or other road users.
·The fitting of ABS does not imply that the
vehicle will always stop in a shorter stopping
distance.

70BRAKES
4
DESCRIPTION AND OPERATION System description
The brake system consists of dual hydraulic circuits in
a front - rear split. That is individual circuits to front
and rear axles.
Wheelspeed signals are provided by the fitting of
exciter rings to axles and speed sensors.
An ABS stop light switch is fitted to provide a braking
signal to the ECU as well as operate the stop lights.
Electrical wiring is provided as necessary with system
relays and fuses. Discovery Electrical Troubleshooting
Manual gives the location and wiring circuits of these
components.
Visual warning of system malfunction is provided via a
warning light in the instrument panel.
Hydraulic circuit ABS
Key
A = Primary hydraulic circuit
B = Secondary hydraulic circuit
C = Pressure reducing valve
D = ABS ModulatorABS System operation
During normal braking the feel of the brake pedal on
vehicles equipped with ABS will be the same as that
on non ABS vehicles. During ABS cycling the driver
will experience feedback in the form of a pulsating
brake pedal and solenoid/pump motor noise from the
Modulator.
The system is fully automatic in operation both on and
off road, and will only act when the ECU detects that
ABS cycling is necessary. The ECU continually
monitors the operation of the system.
When starting the ABS system will go through a series
of self checks, including a check of the solenoid
valves/pump motor.
WARNING LIGHT
The warning light will be on during the self check
(1.3-2 secs). If no faults are stored in the memory the
light goes out for 0.5sec,then comes on again. It will
then remain on until the vehicle is driven faster than 7
kph/5mph. This is the only time that the light will be on
without indicating a problem.
Any faults detected by the ECU will cause the warning
light to illuminate indicating that the vehicle may not
have full ABS control.

BRAKES
5
DESCRIPTION AND OPERATION BRAKE PIPE LAYOUT ABS
Left hand drive shown. On right hand drive vehicles the master cylinder and servo unit only move
position.
KEY
1. Connector double elbow
2. Rear left brake
3. Modulator to rear left brake
4. Modulator to master cylinder
5. Modulator to pressure reducing valve upper
6. Electrical connection
7. Modulator unit
8. Nut, mounting bush and cup
9. Modulator to front left brake
10. Front left brake
11. Electrical connection12. Modulator to front right brake
13. Modulator to pressure reducing valve lower
14. Master cylinder to pressure reducing valve lower
15. Front right brake
16. Bolt
17. Pressure reducing valve
18. Modulator to pressure reducing valve upper
19. Master cylinder
20. Servo unit
21. Modulator to rear right brake
22. Rear right brake

BRAKES
1
FAULT DIAGNOSIS ABS FAULT DIAGNOSIS
If a fault has occurred, or has been identified by ECU
self diagnostic function and ABS warning light is
illuminated. The system and components must be
checked to locate and rectify fault, using Testbook
diagnostics.
NOTE: If warning lamp has indicated a
fault in system, and no fault code has been
stored in memory, cause of fault is:
a) Failure in electrical supply
b) Bad ECU ground
c) Faulty warning light relay
d) ECU not connected
Before commencing fault diagnosis procedure
following items must be checked:
1.Inspect all exposed cables for damage or
abrasion.
2.Check ground on ABS system.
3.Battery - state of charge.
4.Check hub end-float.
5.All ABS fuses and electrical connections.
Fault rectification
1.Complete harness should be replaced if faults
are found in wiring harness.
2.DO NOT use unspecified cables or connectors,
as this could jeopardise safe function of ABS.
3.DO NOT attempt to open sealed 35 way
connector to ECU.FAULT DIAGNOSIS PROCEDURE
NOTE: If ABS warning light illuminates due
to large sensor air gap, fault will be
retained by the ECU memory. Where wheel
sensors have been pushed fully home prior to
test, The ECU will indicate a fault that has been
rectified.
NOTE: After any steering adjustment,
bearing replacement/adjustment, brake
disc replacement: Check hub end-float and
sensor clearance.
RELAYS AND FUSES ABS
The location and identification of ABS electrical relays
are given in the Electrical Troubleshooting Manual
For location and identification of ABS electrical fuses.
See ELECTRICAL, Repair, Fuse Box - Interioror.
See ELECTRICAL, Repair, Fuse Box - Engine
Compartment