gearbox LAND ROVER DEFENDER 1996 Owner's Manual

ENGINE
17
REPAIR 11.Refit clutch.
See CLUTCH, Repair, Clutch
assembly
12.Refit gearbox.See MANUAL GEARBOX,
Repair, R380 gearbox
13.Reconnect battery.
CRANKSHAFT BEARING BUSH
Service repair no - 12.21.45
Remove
1.Disconnect battery.
2.Remove gearbox.
See MANUAL GEARBOX,
Repair, R380 gearbox
3.Remove clutch.See CLUTCH, Repair, Clutch
assembly
4.Remove flywheel.See Flywheel
5.Remove bearing bush.
NOTE: The bearing bush can be removed
by using one of the following methods.
Method 1.
Obtain a short length of steel rod of a diameter having
a good slide fit in the bore of the bush. Pack the bore
with grease and insert the steel rod into the end of the
bore, give a sharp blow with a hammer and the
grease should drive out the bush. It is recommended
that the bush and rod be covered by a suitable cloth
or rag to prevent grease from splashing.Method 2.
Thread the bore of the existing bush and using a
suitable bolt extract the bush. Thoroughly clean bush
location ensuring all swarf is removed.
Refit
1.Fit new bush using a suitable shouldered drift,
inserting bush flush with end of crankshaft.
2.Refit flywheel.
See Flywheel
3.Refit clutch.See CLUTCH, Repair, Clutch
assembly
4.Refit gearbox.See MANUAL GEARBOX,
Repair, R380 gearbox
5.Reconnect battery.

12ENGINE
18
REPAIR FLYWHEEL HOUSING
Service repair no - 12.53.01
Remove
1.Disconnect battery.
2.Remove gearbox.
See MANUAL GEARBOX,
Repair, R380 gearbox
3.Remove clutch.See CLUTCH, Repair, Clutch
assembly
4.Remove flywheel.See Flywheel
5.Remove 3 fixings and withdraw starter motor.
6.Remove 2 bolts from top of flywheel housing.
7.Remove 4 bolts securing bottom of flywheel
housing to engine mounting brackets.
8.Remove inner bolts and lift off flywheel housing.Refit
9.Clean rear face of housing and mating face on
block, ensuring all old sealant is removed.
10.Apply sealant to flywheel housing mating face on
cylinder block.
11.Fit housing to cylinder block. Tighten retaining
bolts to
45 Nm (33 lbf/ft).
12.Remove surplus sealant from block.
13.Fit starter motor.
14.Fit flywheel.
See Flywheel
15.Fit clutch.See CLUTCH, Repair, Clutch
assembly
16.Fit gearbox.See MANUAL GEARBOX, Repair,
R380 gearbox
17.Reconnect battery.

CLUTCH
1
DESCRIPTION AND OPERATION DESCRIPTION
The clutch unit 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.
Clutch components
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 bearing10.Release lever
11.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

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
disconnecting the drive between the engine and the
gearbox.

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
The items refered to in this chart relate to the clutch components shown in J6270 and J6271.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,
R380 gearbox
.
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, R380 gearbox
.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.
Remove
1.Remove gearbox
See MANUAL GEARBOX,
Repair, R380 Gearbox
.
2.Mark position of clutch pressure plate to flywheel
for reassembly.
3.Remove pressure plate securing bolts, working
evenly and diagonally.
4.Remove clutch assembly.
5.Withdraw clutch driven plate.
Refit
NOTE: To prevent driven plate sticking,
lubricate splines using Rocol MV 3 or
Rocol MTS 1000 grease.
6.Using centralising toolLRT-12-040to support
clutch driven plate locate pressure plate on
flywheel dowels. If fitting original pressure plate,
align assembly marks.
7.Secure pressure plate cover fixings evenly,
working in a diagonal sequence. Tighten to
34Nm (25 lbf/ft).
8.Fit gearbox to engineSee MANUAL
GEARBOX, Repair, R380 Gearbox
.BLEED HYDRAULIC SYSTEM
Service repair no - 33.15.01
Procedure
NOTE: During bleed procedure, keep fluid
reservoir topped up to avoid introducing
air to system. For hydraulic fluid
recommendations
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information, Recommended
lubricants and fluids
.
1.Attach suitable tubing to slave cylinder bleed
screw.
2.Place free end of tube in a glass jar containing
clutch fluid.
3.Loosen bleed screw.
4.Pump clutch pedal, pausing at end of each
stroke, until fluid from tubing is free of air.
NOTE: Keep free end of tube below
surface of fluid.
5.Hold clutch pedal down, tighten bleed screw.
6.Top up fluid reservoir.

33CLUTCH
4
REPAIR RELEASE BEARING ASSEMBLY
Service repair no - 33.10.07
Remove
1.Remove gearbox
See MANUAL GEARBOX,
Repair, R380 Gearbox
.
2.Remove clutch slave cylinder
See Slave
cylinder
.
3.Remove release bearing sleeve retainer staple.
4.Withdraw bearing and sleeve.
5.Remove clutch release lever from bearing guide,
complete with sliper pads.
6.If necessary, unscrew 2 bolts and remove
bearing guide from bell housing.
Refit
7.If removed, fit bearing guide to bell housing.
Tighten bolts to
25 Nm (18 lbf/ft).
8.Prior to reassembly, grease pivot post, socket,
slipper pads, pins, and ball end of slave cylinder
push-rod.
9.Fit slipper pads onto release lever pins and
locate lever on pivot post.
10.Smear release bearing sleeve inner diameter
with molybdenum disulphide grease and fit to
bearing guide, locating slipper pads to sleeve
flats.
11.Fit new bearing sleeve retainer staple.
12.Fit clutch slave cylinder
See Slave cylinder.
13.Fit gearbox
See MANUAL GEARBOX, Repair,
R380 Gearbox
.SLAVE CYLINDER
Service repair no - 33.35.01
NOTE: All hose and pipe connections and
joints should be tightened to
15 Nm (11
lbf/ft).
Remove
1.Drain hydraulic fluid from system at slave
cylinder bleed valve.
2.Disconnect fluid pipe.
3.Remove 2 bolts and withdraw slave cylinder and
backing plate.
4.If dust cover is not withdrawn with slave cylinder,
withdraw it from bell housing.
CAUTION: If removing slave cylinder with
gearbox in situ, DO NOT detach push-rod
and clip from clutch release lever in bell
housing.
Refit
5.Coat both sides of backing plate with Hylomar
P232M waterproof jointing compound.
6.Locate backing plate and dust cover in position
on slave cylinder.
7.Fit slave cylinder, engaging push-rod through
centre of dust cover and with bleed screw
uppermost.
8.Reconnect fluid pipe.
9.Replenish and bleed clutch hydraulic system
See Bleed hydraulic system.
10.Check for fluid leaks with pedal depressed and
also with system at rest.

MANUAL GEARBOX
1
DESCRIPTION AND OPERATION R380 GEARBOX
Description
The all synchromesh five speed manual gearbox unit,
is married to a two speed transfer gearbox.
All the gears, including reverse, run on needle roller
bearings and the main, layshaft and primary shafts
are supported by tapered roller bearings.The whole of the geartrain is lubricated through
drillings in the shafts, supplied by a low pressure
pump driven from the rear of the layshaft. The gear
change has a single rail selector and spool type
interlock. The main and transfer gearboxes ventilate
through nylon pipes, which terminate high up in the
engine compartment to prevent water entry when the
vehicle is operating in adverse conditions.
R380 Gearbox Components
1.Mainshaft 1st gear
2.Mainshaft 2nd gear
3.Mainshaft 3rd gear
4.Primary input shaft/4th gear
5.Mainshaft 5th gear
6.Layshaft
7.Mainshaft
8.Lubrication pump
9.Oil filter10.Ventilation pipe
11.Single rail gear shift
12.1st/2nd synchromesh
13.Oil seals
14.3rd/4th synchromesh
15.5th/reverse gear synchromesh
16.Selective spacers (mainshaft/layshaft end float)
17.Selective spacer (5th gear/reverse hub)

MANUAL GEARBOX
1
FAULT DIAGNOSIS R380 GEARBOX
Symptom - Gear jumps out of engagement (any
forward gear)
1.Check condition and security of transmission
and engine mountings.
2.Check in situ, gear lever and selector
adjustments
See Adjustment, Gear change
lever bias spring - adjust
andSee
Adjustment, Fifth gear stop screw adjust
.
3.In situ, remove gearshift and check selector rail
yoke security.
Also check selector detent spring tension and
both spool retainers.
Suspect internal fault, see Overhaul Manual.
4.Check action/operation of main selector rail and
forks.
5.Check condition of synchromesh and gear dog
teeth.
6.Check main and layshaft end floats bearings and
adjustments.
7.Check condition of all gearbox components,
ensure clearances and adjustments are correct
on reassembly.
Symptom - Reverse gear only jumps out of
engagment
1.Check condition and security of transmission
and engine mountings.
2.Check in situ, gear lever and selector
adjustments
See Adjustment, Gear change
lever bias spring adjust
andSee Adjustment,
Fifth gear stop screw adjust
.
3.In situ, remove gearshift and check selector rail
yoke security.
Also check selector detent spring tension and
both spool retainers.
Suspect internal fault, see Overhaul Manual.
4.Check action/operation of main selector rail and
reverse lever.
5.Check condition of reverse gear, angled
bearings and shaft.
6.Check condition of all gearbox components,
ensure clearances and adjustments are correct
on reassembly.Symptom - Excessive force required to engage or
change gear, vehicle stationary or moving.
1.Check lubricant specification and level, if low do
not top up at this stage.
2.In situ, lubricate gear mechanism, and check
selector adjustments
See Adjustment, Gear
change lever bias spring - adjust
andSee
Adjustment, Fifth gear stop screw adjust
.
3.In situ, remove gearshift and check selector rail
is free and that the yoke is secure. Also check
selector detent spring tension and both spool
retainers.
4.Drain lubricant and check for contamination or
metal particles.
Suspect worn synchromesh unit or baulk rings
on affected gears, see Overhaul Manual.
Symptom - Noisy gear engagement, vehicle
stationary
See CLUTCH, Fault diagnosis, Clutch
Noise - Mechanical Faults
.
Symptom - Noisy gear selection, vehicle moving.
1.Confirm that clutch operation is satisfactory.
2.Establish which gear/gears is causing noise.
3.Check lubricant specification and level, if low do
not top up at this stage.
4.Drain lubricant and check for contamination or
metal particles.
Suspect worn synchromesh, see Overhaul
Manual.
5.Check condition of synchromesh unit, springs
and cones for distortion and wear. Also check
dog teeth for damage and cone mating surface
on gear for signs of overheating.
6.Check condition of all gearbox components,
ensure clearances and adjustments are correct
on reassembly.
Symptom - Noise from gearbox in neutral, which
changes tone or becomes worse when clutch is
depressed,
See CLUTCH, Fault diagnosis, Clutch
Noise - Mechanical Faults
.
Symptom - Noise from gearbox in neutral, which
disappears when clutch is depressed.
1.Check lubricant specification and level, if low do
not top up at this stage.
2.Drain lubricant and check for contamination or
metal particles.
Suspect worn bearings on layshaft, primary shaft
or front of main shaft, see Overhaul Manual.

37MANUAL GEARBOX
2
FAULT DIAGNOSIS Symptom - Noise from gearbox in one or more
gears when being driven.
1.Check lubricant specification and level, if low do
not top up at this stage.
2.Drain lubricant and check for contamination or
metal particles.
Suspect worn roller bearings on particular
mainshaft gears, see Overhaul Manual.