service LAND ROVER DEFENDER 1999 Manual Online

33CLUTCH
8
DESCRIPTION AND OPERATION The dual mass flywheel is bolted on the rear of the crankshaft with eight bolts. A dowel on the crankshaft flange
ensures that the flywheel is correctly located. A ring gear is fitted on the outer diameter of the flywheel. The ring
gear is not serviceable. Thirty blind holes are drilled in the outer diameter of the flywheel adjacent to the ring gear.
The holes are positioned at 10°intervals with four 20°spaces. The holes are used by the crankshaft position
sensor for engine management.
The dual mass flywheel is used to insulate the gearbox from torsional and transient vibrations produced by the
engine. The flywheel comprises primary and secondary flywheels with the drive between the two transferred by a
torsional damper which comprises four coil springs. The springs are located in the inside diameter of the primary
flywheel. Two of the springs are of smaller diameter and fit inside the larger diameter springs.
The primary flywheel locates the ring gear and is attached to the crankshaft flange with eight bolts. The two pairs
of coil springs are located in a recess in the flywheel between two riveted retainers. A roller bearing is pressed
onto the central boss of the primary flywheel and retained with a riveted plate. The bearing provides the mounting
for the secondary flywheel.
The secondary flywheel comprises two parts; an outer flywheel which provides the friction surface for the clutch
drive plate and an inner drive plate which transfers the drive from the primary flywheel, via the coil springs, to the
outer flywheel. The two components of the secondary flywheel are secured to each other with rivets. The inner
drive plate is located between the two pairs of coil springs and can rotate on the ball bearing in either direction
against the combined compression force of the four coil springs. Under high torque loading conditions the
secondary flywheel can rotate in either direction up to 70°in relation to the primary flywheel.
The operating face of the secondary flywheel is machined to provide a smooth surface for the drive plate to
engage on. Three dowels and six studs and nuts provide for the location and attachment of the pressure plate.
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CLUTCH
1
ADJUSTMENT HYDRAULIC SYSTEM - BLEED
Service repair no - 33.15.01
Check
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.
1.Top up clutch system reservoir.
2.Raise front of vehicle and support on stands.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
3.Remove dust cap, connect bleed tube to bleed
screw and submerge free end into a clear
container of 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 pedal down and tighten bleed screw to9
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 vehicle.
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CLUTCH
1
REPAIR CLUTCH ASSEMBLY
Service repair no - 33.10.01.01
Remove
1.Remove gearbox assembly.See MANUAL
GEARBOX, Repair.
2.Restrain flywheel.
3.Working in sequence, loosen 6 nuts securing
clutch cover to flywheel.
4.Remove clutch cover and clutch plate.
Refit
5.Clean clutch cover and flywheel mating faces
and spigot bush in end of crankshaft.
6.Position clutch drive plate to flywheel with
’gearbox side’ facing towards gearbox.
7.PositionLRT-12-152alignment tool through
drive plate into spigot bearing in crankshaft.8.Fit clutch cover and locate on dowels.
9.Position clutch cover nuts and tighten in diagonal
sequence to25 Nm (18 lbf.ft).
10.Fit gearbox assembly.See MANUAL
GEARBOX, Repair.
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33CLUTCH
2
REPAIR BEARING - CLUTCH RELEASE
Service repair no - 33.25.12
Remove
1.Remove gearbox assembly.See MANUAL
GEARBOX, Repair.
2.Remove retaining peg and remove release
bearing.
3.Remove bolt securing clutch release fork,
remove retaining clip and remove clutch release
fork.
Refit
4.Clean release fork.
5.Examine clutch release fork pivot points for
wear.
6.Apply a smear of Molybdenum disulphide grease
to release fork pivot points.
7.Fit retaining clip ensuring it locates over pivot
point washer.
8.Fit bolt and tighten to10 Nm (7 lbf.ft).
9.Clean release bearing and bearing sleeve
mating faces.
10.Apply smear of Molybdenum disulphide grease
to release bearing sleeve.
11.Fit release bearing and secure with retaining
peg.
12.Fit gearbox assembly.See MANUAL
GEARBOX, Repair.CLUTCH - MASTER CYLINDER LH DRIVE
Service repair no - 33.20.01
Remove
1.Remove 3 screws securing closing panel to
lower’A’post.
2.Release closing panel sufficient to gain access
to clutch and brake pedal bracket bolts.
3.Remove clutch pedal rubber.
4.Remove 12 bolts securing clutch and brake
pedal brackets to body.
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33CLUTCH
4
REPAIR Clutch pedal setting
1.Loosen both locknuts on master cylinder push
rod.
2.Check distance from lower edge of clutch pedal
to floor. Correct measurement is 140 mm (5.50
in) without floor mat.
3.Adjust pedal stop to obtain correct setting.
4.Adjust master cylinder push rod to obtain
approximately 1.5 mm (0.06 in) free play
between push rod and master cylinder piston.
5.Tighten push rod locknuts.
6.Check operation of clutch pedal and ensure that
there is minimum of 6 mm (0.25in) of free play
before pressure is felt.
7.Fit pedal box top cover and multiplug bracket
using a new gasket and secure with screws.
8.Connect multiplug and harness clip to pedal
bracket.
9.Bleed clutch hydraulic system.See
Adjustment.CYLINDER - CLUTCH SLAVE
Service repair no - 33.35.01
Remove
1.Disconnect pipe from slave cylinder.
CAUTION: Plug the connections.
2.Position container to catch spillage.
3.Remove 2 bolts securing slave cylinder to bell
housing.
4.Withdraw slave cylinder from bell housing and
push rod.
Refit
5.Clean ends of pipes, bell housing and slave
cylinder mating faces.
6.Lubricate end of push rod with Molybdenum
disulphide gease.
7.Locate slave cylinder to push rod and bell
housing.
8.Fit bolts and tighten to25 Nm (18 lbf.ft).
9.Connect clutch pipe to slave clyinder.
10.Bleed clutch system.See Adjustment.
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MANUAL GEARBOX
1
ADJUSTMENT SPRINGS - GEAR LEVER BIAS
Service repair no - 37.16.26
Check
NOTE: The purpose of this adjustment is
to set both bolts so that the bias spring
legs apply equal pressure on both ends of
the gear lever cross pin when 3rd or 4th gear is
engaged. This will ensure that when the gear lever
is in neutral, the gear change mechanism is
automatically aligned for 3rd or 4th gears.
1.Remove gear lever knobs.
2.Release and remove gear lever gaiter.
3.Select 3rd or 4th gear.
4.Adjust the two adjusting screws until both legs of
the spring are approximately 0.5 mm (0.02 in)
clear of cross pin in the gear lever.
5.Apply a light load to the gear lever in a RH
direction and adjust the LH adjusting screw
downwards until the LH spring leg just makes
contact with the cross pin.
6.Repeat the same procedure for the RH adjusting
screw.
7.Lower both adjusting screws equal amounts until
the radial play is just eliminated. Tighten lock
nuts.
8.Return gear lever to neutral position and move
gear lever across the gate several times. The
gear lever should return to the 3rd and 4th gate.
9.Fit gear lever gaiter.
10.Fit gear lever knobs.
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37MANUAL GEARBOX
2
ADJUSTMENT GEARBOX OIL - DRAIN AND REFILL
Service repair no - 37.24.01
Drain
1.The oil should be drained when the gearbox is
warm and the vehicle is standing on a level
surface.
WARNING: Observe due care when
draining gearbox as oil can be very hot.
2.Raise vehicle on ramp.
3.Position container to collect oil.
4.Clean area around filler/level plug.
5.Remove filler/level plug.
NOTE: Later gearboxes: Use No. 55 Torx
bit to remove filler/level plug.
6.Remove gearbox drain plug and discard sealing
washer.Refill
1.Clean gearbox drain plug and fit new sealing
washer.
2.Fit gearbox drain plug and tighten to50 Nm (36
lbf.ft).
3.Fill gearbox with correct grade of oil.See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information.
4.Apply Loctite 290 to the filler/level plug and
tighten to30 Nm (22 lbf.ft).
5.Remove fluid container.
6.Lower vehicle on ramp.
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MANUAL GEARBOX
1
REPAIR COVER - FRONT - RESEAL AND FIT NEW INPUT
SHAFT OIL SEAL
Service repair no - 37.12.33.01
Remove
1.Remove gearbox.See this Section.
2.Remove retaining peg and remove release
bearing.
3.Remove bolt securing clutch release fork,
remove retaining clip and remove clutch release
fork.
4.Remove 2 bolts securing release bearing sleeve,
remove bearing sleeve.
5.Remove 6 bolts securing clutch housing, remove
housing.
6.Remove and discard 6 bolts securing front
cover, remove cover.
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MANUAL GEARBOX
3
REPAIR LEVER - GEAR CHANGE
Service repair no - 37.16.04
Remove
1.Remove gear lever knob.
2.Release and remove gear lever gaiter(s).
3.Remove nut securing upper gear lever to lower
gear lever.
4.Remove upper gear lever from lower gear lever.
5.Using a suitable piece of tubing fitted over end of
bias spring, release both ends of bias spring
from ball pins.
6.Remove bolt and special washer securing gear
lever to housing.
7.Carefully withdraw gear lever from housing
ensuring that spring loaded nylon pad is retained
during removal.
WARNING: Personal injury may result if
nylon pad is not retained.
Refit
8.Clean gear lever, housing and nylon pad.
9.Lubricate ball pin with multi-purpose grease and
fit nylon pad and spring.
10.Depress nylon pad against spring pressure,
position gear lever in housing with the nylon pad
facing away from bias spring location.
11.Fit gear lever retaining bolt and special washer
and tighten bolt to10 Nm (7 lbf.ft).
12.Using a suitable piece of tubing fitted over ends
of bias spring, locate each end of bias spring to
ball pins.
13.Fit upper gear lever to lower gear lever and
tighten retaining nut to25 Nm (18 lbf.ft).
14.Adjust bias spring.See Adjustment.
15.Fit gear lever gaiter(s).
16.Fit gear lever knob.
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37MANUAL GEARBOX
4
REPAIR MECHANISM AND HOUSING - GEAR SELECTOR
Service repair no - 37.16.37
Remove
1.Remove gear lever knobs.
2.Remove gearbox tunnel carpet.
3.Remove gear lever gaiter(s)
4.Release and remove insulation pad from around
gear levers.
5.Remove 2 screws securing relay/fuse panel and
collect 2 spacers.
6.Release bulkhead carpet from LH side of tunnel
and move aside.
7.Remove 13 screws securing tunnel cover.
8.Release and remove tunnel cover.
9.Remove 4 bolts securing gear change housing,
remove housing, remove and discard gasket.
10.Using a suitable piece of tubing located over
ends of bias spring, release both ends of bias
spring from ball pins.
11.Loosen locknuts and remove bias spring
adjusting screws.
12.Drift out roll pin, remove bias spring.
13.Remove nut and extension from lower gear
lever.
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