1995 LAND ROVER DISCOVERY Workshop Manual

MANIFOLD AND EXHAUST SYSTEM
9
REPAIR MANIFOLD CHAMBER GASKET - Mpi
Service repair no - 30.15.37
Remove
1.Disconnect battery negative lead.
2.Position absorbent cloth around fuel pipe to fuel
rail union. Loosen union to relieve pressure.
Re-tighten union.
3.Release clip and remove air cleaner to throttle
housing hose.
4.Disconnect stepper motor and throttle
potentiometer multiplugs.
5.Release clip and disconnect breather hose from
throttle housing.
6.Release throttle cable from abutment bracket.
7.Release throttle cable from cam. Remove
coolant bypass hose from throttle housing.
8.Disconnect fuel temperature sensor multiplug.
9.Release clip and disconnect brake servo hose
from manifold.

30MANIFOLD AND EXHAUST SYSTEM
10
REPAIR 10.Release clip and disconnect breather hose from
manifold.
11.Release 2 bolts securing camshaft cover
brackets to manifold.
12.Disconnect 4 vacuum hoses from manifold.
13.Remove 6 bolts securing manifold chamber to
lower manifold.
14.Remove manifold chamber and collect gaskets.
Refit
NOTE: For torque values.See
Specifications, torque, Torque Values
15.Ensure mating faces of manifold chamber and
lower manifold are clean.
16.Fit a new gasket, position manifold chamber to
lower manifold.
17.Fit bolts, tighten to the correct torque.
18.Connect vacuum hoses to manifold.
19.Position camshaft cover brackets to manifold,
secure with bolts.
20.Connect breather hose and brake servo hose to
manifold, secure with clips.
21.Connect multiplug to fuel temperature sensor.
22.Connect breather hose to throttle housing and
secure with clip.
23.Connect throttle cable to cam and secure to
abutment bracket.
24.Connect coolant bypass hose to throttle housing.
25.Connect stepper motor and throttle
potentiometer multiplugs.
26.Connect air cleaner hose to throttle housing and
secure with clip.
27.Reconnect battery negative lead.
28.Adjust throttle cable.

MANIFOLD AND EXHAUST SYSTEM
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
MANIFOLDS AND EXHAUSTS - Mpi
Inlet manifold nuts and bolts 25......................................................................
Fuel pipe to fuel rail 10....................................................................................
Exhaust manifold nuts 45................................................................................
Exhaust frontpipe to manifold 10....................................................................
Exhaust downpipe to silencer box 30.............................................................
Manifold chamber gasket 10...........................................................................

CLUTCH
1
DESCRIPTION AND OPERATION DESCRIPTION
The clutch unit fitted with the manual transmission,
comprises a single dry plate friction disc and
diaphragm spring clutch unit, secured to the engine
flywheel.OPERATION
The unit is operated hydraulically by the clutch master
cylinder 12 and a slave cylinder 13 attached to the
transmission bell housing.
1. Crankshaft and flywheel
2. Friction plate
3. Clutch cover
4. Diaphragm spring
5. Pressure plate
6. Fulcrum posts (9) for diaphragm spring
7. Bearing rings (2) for diaphragm spring
8. Retraction links and bolts (3) for pressure plate
9. Release bearing
10. Release lever11. Release lever pivot post
12. Master cylinder
13. Slave cylinder
14. Master cylinder pedal pushrod
15. Primary shaft and taper bearing (in gearbox)
16. Gearbox front cover
17. Primary shaft flywheel bush
18. Pedal pivot and return spring
19. Hydraulic damper (Diesel only)

33CLUTCH
2
DESCRIPTION AND OPERATION When the clutch pedal is depressed, hydraulic fluid
transmits the movement via the slave cylinder, release
lever 10, bearing 9, to the inner fingers of the
diaphragm spring 4.
The diaphragm spring 4 pivots on the bearing rings 7
and fulcrum posts 6 causing the pressure plate 5 to
release the clamping force on the friction plate and
linings 2.As the the clamping force is removed from the friction
plate 2, the plate slides on the splines of the primary
shaft 15 and takes up a neutral position between the
flywheel 1 and the pressure plate 5 , thus breaking the
drive between the engine and the gearbox.
NOTE: Diesel engined vehicles have an
hydraulic damper 19 fitted into the system.
The damper contains a steel diaphragm
which absorbs slight hydraulic pulses caused by
cyclic variations of the diesel engine crankshaft at
low rpm.

CLUTCH
1
FAULT DIAGNOSIS CLUTCH ASSEMBLY CONDITIONS
For the clutch to operate correctly as described and
illustrated in the "Description and Operation", it is
important the following conditions are satisfied:-
A. The primary shaft 15 must be free in the
crankshaft spigot bush 17.
B. The friction plate 2 must be able to slide easily
on the splines on the primary shaft 15, to a
position where it does not contact either the
flywheel or the pressure plate.
C. The friction plate must not be distorted or the
linings contaminated with oil, which may cause it
to stick or continue to run in contact with the
flywheel or pressure plate.
A number of faults can develop in the operation of the
clutch for a variety of reasons and although most
faults are due to normal wear at high mileage,
problems can also occur if the unit has been renewed
by an unskilled operator.
Recognising and diagnosing a particular clutch fault is
therefore of paramount importance in ensuring, that
the problem is rectified at the first attempt.
Problems which develop in the clutch are as follows:-
A. Clutch spin/drag
B. Clutch slip
C. Clutch judder/fierceCLUTCH SPIN - DRAG
Symptoms
Clutch spin is that, with engine running and clutch
pedal depressed, the gears cannot be immediately
engaged without making a grinding noise. This
indicates the clutch is not making a clean break.
However, if the clutch pedal is held depressed for
several seconds the friction plate will eventually break
free from the engine and the gear will engage silently.
Clutch spin as it becomes more severe develops into
clutch drag, making the silent engagement of a gear
impossible, regardless of how long the pedal is held
depressed.
CLUTCH SLIP
Symptoms
Clutch slip is most evident climbing a hill or when the
vehicle is moving off from stationary with a heavy
load. As the clutch is released slip occurs between the
engine and the transmission, allowing the engine
speed to increase without a corresponding increase in
vehicle speed.
Clutch slip can develop to the stage where no power
is transmitted through the clutch as the pedal is
released.
CLUTCH JUDDER - FIERCE
Symptoms
Clutch judder or fierce engagement, like slip, is most
likely to occur when the vehicle is moving off from
stationary. As the clutch pedal is released the vehicle
will move rapidly or in a series of jerks, which can not
be controlled even by careful operation of the clutch
by the driver.
It should be noted that a vehicle may display all the
symptoms or any combination of the symptoms
described, depending on the driving conditions vehicle
load and operating temperatures.

33CLUTCH
2
FAULT DIAGNOSIS FAULT/SYMPTOM CHART
Symptoms
Slip Spin/Drag Judder/Fierce Fault Item
* * * Worn or oil on clutch linings 2
* * * Mechanical damage45678
* * Distorted clutch plate 2
* Failed or air in hydraulic system 12 13
* * Primary shaft tight fit in crankshaft bush 15 17
* Clutch splines sticking 2 15
* Weak clutch plate springs or insecure/worn
engine/gearbox mountings6
* Insecure/worn propeller shafts
* Insecure/worn suspension components/rubber
bushes
For items refered to in this chart.See Description and operation, Description
CLUTCH NOISE - MECHANICAL FAULTS
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox input/primary shaft bearings.
See MANUAL GEARBOX, Fault diagnosis,
Manual Gearbox
- Noise from gearbox in neutral, which
disappears when clutch is depressed
Noise from clutch or gearbox in neutral, which
changes tone or becomes worse when the clutch
is depressed.
Suspect worn release bearing.
Knocking/rattling from clutch or gearbox in
neutral, which is reduced or disappears when the
clutch is depressed.
Suspect worn/weak release lever retainer or
clutch unit.
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox fault.
See MANUAL GEARBOX, Fault diagnosis,
Manual Gearbox
- Noise from gearbox in neutral, which
disappears when clutch is depressed.HYDRAULIC FAULTS
Unable to dis-engage clutch, little or no pedal
resistance.
1.Check condition, specification and level of fluid.
2.Check pipes and cylinders for leaks.
3.Check that air vent in reservoir lid is clear.
Suspect faulty master cylinder if no fluid leaks
present.
See Repair, Master Cylinder
Spongy pedal operation
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect air in fluid.
See Repair, Bleed Hydraulic System
Clutch is difficult to dis-engage and/or does not
immediately re-engage when pedal is released.
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect pedal pivot, master cylinder or slave
cylinder seizure.
See Repair, Master Cylinder

CLUTCH
1
REPAIR CLUTCH ASSEMBLY
Service repair no - 33.10.01
Clutch pressure plate
Renew pressure plate if diaphragm spring fingers are
worn or if pressure plate shows signs of wear, cracks
or burning.
Clutch driven plate
Renew driven plate if centre hub splines are worn or if
lining is contaminated, burned or unevenly worn.
Service tools:
Clutch centralising tool
LRT-12-001 - V8
LRT-12-040 - Tdi
LRT-12-057 - Mpi
Remove
1.Remove gearbox.
See MANUAL GEARBOX,
Repair, R380 Manual Gearbox
2.Mark position of clutch cover to flywheel for
reassembly.
3.Remove clutch cover securing bolts, working
evenly and diagonally.
4.Do not disturb three bolts in clutch cover.
5.Remove clutch assembly.
6.Withdraw clutch driven plate.
Refit
NOTE: To prevent clutch plate sticking,
lubricate splines using Rocol MV 3 or
Rocol MTS 1000 grease.
7.Renew/refit clutch driver plate and clutch
assembly using centralising tool, where
applicable, align assembly marks.
8.Secure clutch assembly cover fixings evenly,
working in a diagonal sequence. Tighten to
28
Nm.
9.Fit gearbox to engine.