LAND ROVER DISCOVERY 2002 Workshop Manual

CLUTCH - TD5
33-1-10 DESCRIPTION AND OPERATION
Operation
Hydraulic operation
Refer to illustration.

+ CLUTCH - Td5, DESCRIPTION AND OPERATION, Hydraulic operation.
When the clutch pedal is depressed, the master cylinder piston is pushed into the master cylinder. The movement of
the piston pressurises the fluid in the master cylinder, forcing the pressurised fluid into the hydraulic feed pipe to the
slave cylinder. The hydraulic pressure is felt at the slave cylinder piston which moves under the hydraulic force
applied, pushing the clutch release lever via the piston rod.
When the clutch pedal is released, the force applied to the release lever by the fingers of the diaphragm, moves the
release lever, which pushes the slave cylinder piston into the cylinder. The displaced hydraulic fluid is pushed up the
hydraulic feed pipe and returns to the master cylinder.
Mechanism operation
When the clutch pedal is depressed, hydraulic pressure extends the piston and rod in the slave cylinder. The
extension of the piston pushes the rod against the outer end of the release lever which pivots around the ball spigot.
The inner end of the release lever pivots towards the engine applying pressure to the release bearing. The release
bearing slides along the release bearing sleeve and pushes on the fingers of the diaphragm. The diaphragm pivots
around the chamfered rivets in the cover. As the diaphragm is deflected, it removes pressure from the pressure plate.
The pressure plate moves away from the drive plate assisted by the three leaf springs.
The removal of force from the pressure plate on the drive plate reduces the friction between the dual mass flywheel,
drive plate and pressure plate. The drive plate slips between the flywheel and the pressure plate preventing rotary
movement being transferred from the flywheel and pressure plate to the primary driveshaft.
When the clutch pedal is released, hydraulic force is removed from the piston in the slave cylinder. This allows the
fingers of the diaphragm to push the release bearing along the release bearing sleeve. The movement of the release
bearing moves the release lever which pivots on the ball spigot, pushing the piston and rod back into the slave
cylinder.
The removal of pressure from the release bearing on the diaphragm, causes the diaphragm to pivot around the
chamfered rivets in the cover. The force applied to the pressure plate from the diaphragm overcomes the force of the
leaf springs and the pressure plate moves towards the drive plate and flywheel.
The pressure plate applies pressure to the drive plate which is pushed against the flywheel. As the clutch pedal is
progressively released, the friction between the drive plate, flywheel and pressure plate increases. The increase in
friction transfers the rotary movement of the flywheel and pressure plate to the drive plate, which in turn starts to rotate
the primary drive shaft. When the clutch pedal is released fully, the force applied by the diaphragm to the pressure
plate forces the drive plate onto the flywheel with no slippage.

CLUTCH - TD5
ADJUSTMENTS 33-1-11
ADJUST ME NTS
Clutch hydraulic system - bleed
$% 33.15.01
CAUTION: Ensure the fluid in the reservoir is
maintained between the minimum and maximum
levels throughout the bleed procedure using new
brake fluid.
CAUTION: Brake fluid will damage paint finished
surfaces. If spilled, immediately remove fluid and
clean area with water.
Bleeding
1.Top up reservoir.
2.Raise the front of the vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
3.Connect tube to bleed screw on clutch slave
cylinder and submerge free end in a clear
container containing brake fluid.
4.Loosen bleed screw, then apply steady
pressure to the clutch pedal, depressing it
through its full stroke. Allow the pedal to return
unassisted.5.Repeat the procedure until a flow of clean, air-
free fluid is purged into the container.
6.Hold the pedal to the floor and tighten the
clutch bleed screw to 9 Nm (7 lbf.ft).
7.Check and top up reservoir.
CAUTION: Never re-use fluid that has been
bled from the system.
8.Remove stands and lower the vehicle.

CLUTCH - TD5
33-1-12 ADJUSTMENTS

CLUTCH - TD5
REPAIRS 33-1-13
REPAIRS
Clutch assembly
$% 33.10.01
Remove
1.Remove gearbox assembly.

+ MANUAL GEARBOX - R380,
REPAIRS, Gearbox - Diesel.
2.Restrain flywheel.
3.Working in diagonal sequence, progressively
loosen 6 nuts securing clutch cover to flywheel.
4.Remove clutch cover and clutch plate.
5.Renew all worn or damaged components.Refit
1.Clean clutch cover and flywheel mating faces
and spigot bush in end of crankshaft.
2.Position clutch plate to flywheel with 'gearbox
side' facing towards gearbox.
3.Position tool LRT-12-152 through drive plate
into spigot bearing in crankshaft.
4.Fit clutch cover and locate on dowels.
5.Fit clutch cover nuts and progressively tighten
in diagonal sequence to 25 Nm (18 lbf.ft).
6.Fit gearbox assembly.

+ MANUAL GEARBOX - R380,
REPAIRS, Gearbox - Diesel.

CLUTCH - TD5
33-1-14 REPAIRS
Master cylinder
$% 33.20.01
CAUTION: Brake fluid will damage paint finished
surfaces. If spilled, immediately remove fluid and
clean area with water.
Remove
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Release spring clip securing clutch pedal
clevis pin and remove pin from push rod and
clutch pedal.
3.Position container to catch spillage. Disconnect
hydraulic pipe from clutch master cylinder.
CAUTION: Always fit plugs to open
connections to prevent contamination.4.Release clip and remove connecting hose from
clutch master cylinder.
5.Remove 2 bolts securing clutch master
cylinder to pedal box and remove clutch master
cylinder.
Refit
1.Clean master cylinder and pedal box mating
faces.
2.Position clutch master cylinder to pedal box, fit
bolts and tighten to 25 Nm (18 lbf.ft).
3.Position clevis pin to push-rod and clutch pedal
and secure with spring clip.
4.Fit connecting hose to brake master cylinder
and tighten clip.
5.Position hydraulic pipe and tighten union to 18
Nm (13 lbf.ft).
6.Bleed clutch.

+ CLUTCH - Td5, ADJUSTMENTS,
Clutch hydraulic system - bleed.
7.Remove stand(s) and lower vehicle.

CLUTCH - TD5
REPAIRS 33-1-15
Bearing and lever - clutch release
$% 33.25.12
Remove
1.Remove gearbox assembly.

+ MANUAL GEARBOX - R380,
REPAIRS, Gearbox - Diesel.
2.Remove retaining peg and remove release
bearing.
3.Remove bolt securing clutch release lever.
Remove retaining clip and clutch release lever.
Refit
1.Clean clutch release lever.
2.Examine clutch release lever pivot points for
wear.
3.Apply a smear of Molybdenum disulphide
grease to clutch release lever pivot points.
4.Fit retaining clip ensuring it locates over
release bearing pivot point washer, fit bolt and
tighten to 8 Nm (6 lbf.ft).
5.Clean release bearing and bearing sleeve
mating faces.
6.Apply a smear of Molybdenum disulphide
grease to release bearing sleeve.
7.Fit release bearing and secure with retaining
peg.
8.Fit gearbox assembly.

+ MANUAL GEARBOX - R380,
REPAIRS, Gearbox - Diesel.
Slave cylinder
$% 33.35.01
Remove
1.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Position container to catch spillage.
3.Disconnect hydraulic pipe from slave cylinder.
CAUTION: Always fit plugs to open
connections to prevent contamination.
4.Remove 2 bolts securing slave cylinder to
gearbox housing and collect heat shield.
5.Withdraw slave cylinder from gearbox housing
and push rod.
Refit
1.Clean ends of pipes, gearbox housing and
slave cylinder mating faces.
2.Lubricate end of push rod with Molybdenum
disulphide grease.
3.Locate slave cylinder to push rod and gearbox
housing.
4.Position heatshield. Fit bolts securing slave
cylinder and tighten to 25 Nm (18 lbf.ft).
5.Connect hydraulic pipe to slave cylinder.
6.Bleed clutch system.

+ CLUTCH - Td5, ADJUSTMENTS,
Clutch hydraulic system - bleed.
7.Remove stand(s) and lower vehicle.

CLUTCH - TD5
33-1-16 REPAIRS

CLUTCH - V8
DESCRIPTION AND OPERATION 33-2-1
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CLUTCH - V8 DESCRIPTION AND OPERAT ION

CLUTCH - V8
33-2-2 DESCRIPTION AND OPERATION
Clutch components

CLUTCH - V8
DESCRIPTION AND OPERATION 33-2-3
1Brake/clutch reservoir
2Connecting hose
3Bolt 2 off
4Master cylinder
5Clutch pedal
6Gearbox housing
7Primary driveshaft
8Bolt 2 off
9Slave cylinder
10Bleed nipple
11Pressure plate
12Drive plate
13Flywheel
14Metal hydraulic pipes
15Ball spigot
16Clutch release bearing sleeve
17Bolt 2 off
18Pivot washer
19Release lever
20Release bearing
21Retaining clip
22Bolt
23Bolt