1996 LAND ROVER DEFENDER clutch

CLUTCH
1
OVERHAUL MASTER CYLINDER - OVERHAUL
Service repair no - 33.20.07
Dismantle
1.Remove master cylinder from vehicle
See
Repair, Master cylinder
.
2.Remove circlip.
3.Withdraw push-rod and retaining washer.
4.Withdraw the piston assembly. If necessary,
apply a low air pressure to outlet port to expel
piston.
5.Prise locking prong of spring retainer clear of
piston shoulder and withdraw piston.
6.Withdraw piston seal.
7.Compress spring and position valve stem to
align with larger hole in spring retainer.
8.Withdraw spring and retainer.
9.Withdraw valve spacer and spring washer from
valve stem.
10.Remove valve seal.
Inspection
11.Clean all components in new hydraulic fluid and
allow to dry.
12.Examine cylinder bore and piston, ensure that
they are smooth to touch with no corrosion,
score marks or ridges. If there is any doubt, fit
new components.
13.The seals should be renewed with seals from
master cylinder overhaul kit.
Assemble
14.Smear seals with suitable rubber grease and
remaining internal items with new hydraulic fluid.
15.Fit valve seal, flat side first, on end of valve
stem.
16.Place bowed washer, domed side first, over
small end of valve stem, see J6281.
17.Fit spacer to valve, legs first.

33CLUTCH
2
OVERHAUL
18.Place coil spring over valve stem.
19.Insert retainer into spring.
20.Compress spring and engage valve stem in
keyhole slot in retainer.
21.Fit seal, large diameter last, to piston.
22.Insert piston into spring retainer and engage
locking prong.
23.Smear piston with suitable rubber grease and
insert assembly, valve end first, into cylinder.
24.Fit push-rod, retaining washer and circlip.
25.Fit clutch master cylinder to vehicle
See Repair,
Master cylinder
.SLAVE CYLINDER - OVERHAUL
Service repair no - 33.35.07
Dismantle
1.Remove slave cylinder
See Repair, Slave
cylinder
.
2.Withdraw dust cover.
3.Expel piston assembly, applying low pressure air
to fluid inlet.
4.Withdraw spring.
5.Remove seal from piston.
6.Remove bleed valve.
Inspection
7.Clean all components with new hydraulic fluid
fluid and allow to dry.
8.Examine cylinder bore and piston, ensure that
they are smooth to touch with no corrosion,
score marks or ridges. If there is any doubt, fit
new components.
9.Renew seal and dust cover from slave cylinder
overhaul kit.

CLUTCH
3
OVERHAUL Assemble
10.Fit bleed valve to cylinder body, do not
overtighten.
11.Lubricate seals, piston and bore with new
hydraulic fluid.
12.Fit seal into piston groove with lip of seal
towards fluid inlet end of cylinder.
13.Locate spring over front end of piston.
14.Fit assembly, spring first, into cylinder ensuring
seal lip does not fold back.
15.Fill dust cover with suitable rubber grease and fit
cover to cylinder.
16.Fit slave cylinder
See Repair, Slave cylinder.

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.

MANUAL GEARBOX
3
REPAIR
24.Remove 2 bolts, withdraw clutch slave cylinder
and backing plate from bell housing, and tie
aside.
25.Mark rear propeller shaft drive flange and
transmission brake drum for reassembly.
26.Remove 4 nuts, disconnect propeller shaft from
brake drum, and tie aside.
27.Remove front pipe from exhaust manifold
See
MANIFOLD AND EXHAUST SYSTEM, Repair,
Exhaust front pipe
.
28.Remove intermediate silencer.
See MANIFOLD
AND EXHAUST SYSTEM, Repair,
Intermediate pipe - 90
orSee MANIFOLD
AND EXHAUST SYSTEM, Repair,
Intermediate pipe - 110/130
29.Temporarily support transmission.
30.Remove nut securing gearbox LH mounting
rubber to chassis crossmember.
31.Remove 4 nuts and bolts securing crossmember
to chassis longitudinals.
32.Remove nut securing transfer box mounting
rubber to RH side of crossmember.
33.Remove 4 nuts and bolts securing crossmember
to chassis longitudinals.
34.With assistance and using a body jack between
chassis longitudinals, jack chassis sufficiently to
enable removal of crossmember.
35.Remove chasss crossmember.
36.Remove 4 bolts from both sides and remove LH
and RH mounting brackets.

37MANUAL GEARBOX
6
REPAIRREV: 05/99 78.Position crossmember and locate over fixing
studs of LH and RH gearbox mounting rubbers.
79.Align crossmember and secure to chassis with 4
nuts and bolts on each side.
NOTE: Fit battery earth strap retaining clip
to LH top bolt.
80.Fit intermediate silencer.
See MANIFOLD AND
EXHAUST SYSTEM, Repair, Intermediate
pipe - 90
orSee MANIFOLD AND EXHAUST
SYSTEM, Repair, Intermediate pipe - 110/130
.
81.Fit front pipe to exhaust manifold
See
MANIFOLD AND EXHAUST SYSTEM, Repair,
Exhaust front pipe
.
82.Fit rear propeller shaft to transmission brake
drum. Tighten nuts to
47 Nm (33 lbf/ft).
83.Remove 3 bolts securing support cradle to
transmission and remove hoist.
84.Reconnect battery earth strap to transfer box
fixing.
85.Connect speedometer cable to transfer box and
secure with retaining clip.
86.Coat both sides of clutch slave clinder backing
plate with Hylomar P232M waterproof sealant.
87.Locate backing plate on slave cylinder.
88.Fit slave cylinder to bell housing, engaging
push-rod through centre of dust cover, and with
bleed screw uppermost. Tighten bolts to
25 Nm
(18 lbf/ft).
89.Fit front propeller shaft to transfer box. Tighten
nuts to
47 Nm (33 lbf/ft).
90.Refill main gearbox and transfer boxSee
MAINTENANCE , Under vehicle maintenance
.
91.Feed transmission brake cable through heel
board and ensure grommet is correctly located.
NOTE: Apply a soap solution to aid fitment
of cable.
92.Lower vehicle on ramp.
93.Fit ties to secure gearbox harness to
transmission breather pipes.
94.Fit breather pipe retaining clip to rear of engine.
95.Reconnect charge air hose at turbocharger.
96.Reconnect intake hose at induction manifold. If
EGR system is fitted, reconnect intake hose at
intercooler.
97.Reconnect radiator top hose at thermostat
housing.
98.Fit viscous fan unit
See COOLING SYSTEM,
Repair, Viscous coupling and fan
.
99.Reconnect battery.100.Refill cooling system
See COOLING SYSTEM,
Adjustment, Drain and refill cooling system
.
101.Connect cable clevis to handbrake lever and fit
handbrake gaiter.
102.Locate insulation pad over gear levers and fit to
tunnel cover.
103.Fit gear lever with gaiter to lower lever spline
and secure with retaining nut.
104.Fit gear lever cover.
105.Fit gear lever and transfer box lever knobs.
106.Fit gearbox cover carpet.
107.Check operation of handbrake and adjust as
necessary
See MAINTENANCE , Under
vehicle maintenance
.

TRANSFER GEARBOX
1
DESCRIPTION AND OPERATION TRANSFER GEARBOX
Description
The transfer gearbox is a permanent 4 wheel drive,
two speed ratio reducing gearbox, incorporating high
and low range outputs with mechanically lockable
centre differential (diff-lock). High/low range and
diff-lock selection are made via a single lever located
forward of the main gear lever.
The transfer gearbox is mounted at the rear of the
main gearbox, the mainshaft of which extends into the
transfer casing. A transfer gear, supported on taper
roller bearings and splined to the gearbox mainshaft,
passes the drive to an intermediate gear cluster
supported on a single shaft and rotating on taper roller
bearings.The intermediate gears pass the drive to high and low
speed gears on the rear output shaft. The rear output
shaft passes through the speedo drive housing, which
also forms the mounting for the transmission brake. A
worm gear fitted to the rear output shaft drives a
pinion fitted in the speedo housing.
Integral with the output shafts is a differential
assembly which compensates for speed differences
between the front and rear prop shafts. To prevent all
the power being transmitted to the axle offering the
least resistance, a diff-lock is provided. The differential
lock should only be engaged during severe off-road
conditions and should be disengaged as soon as
conditions permit. Selection of differential lock
engages, through mechanical linkage, a dog clutch
with the front output shaft, this action locks the centre
differential and provides a fixed drive, giving equal
power to the front and rear output shafts.

41TRANSFER GEARBOX
2
FAULT DIAGNOSIS OIL LEAKS
Verify that oil leak is from transfer box and not main
gearbox before proceeding with checks.
Prior to road test
1.Check oil level in transfer box is correct.
2.Check tightness of level and drain plugs.
3.Check breather system for blockage. To validate
system pipe must be removed, inspected,
rectified as necessary and refitted.
4.Remove all traces of oil from exterior of transfer
box.
Take vehicle for short road test.
5.Identify source of leaks and rectify as follows.
Front or rear output seal leaking:-
1.Drain oil and remove leaking output flange.
2.Inspect seal track on flange for surface damage.
If damaged renew component.
3.Remove and discard oil seal.
4.Inspect seal locating bore and remove any sharp
edges which may damage new oil seal.
5.Fit new seal.
6.Fit output flange and all other parts.
7.Add oil to correct level into gearbox
See
SECTION 10, Maintenance, Under vehicle
maintenance
.
Cover plate sealant leaking.
1.Drain oil and remove leaking cover plate.
2.Remove all traces of joint sealant from both joint
faces.
3.Degrease all components and apply a thin film of
Hylomar sealant, to both joint faces.
4.Apply thread sealant to bolts which come into
contact with gearbox oil.
5.Refit cover plate.
CAUTION: Care must be taken not to
overtighten fixings.Leak between main and transfer gearboxes.
1.Site vehicle onto a ramp .
2.Select neutral in transfer box and select 4th gear
in main gearbox.
3.Run engine at 2000 rpm with clutch/drive
engaged.
4.Observe joint between main and transfer boxes.
5.If oil leak is found establish if it is gear oil.
6.If so, leak is originating from transfer box.
7.Check two inner (main/transfer) bolts are oil
tight, as these holes are tapped into main
transfer case.
8.Remove transfer box to inspect mainshaft collar
seal track condition, and front face of transfer
case for porosity
See Repair, Transfer
gearbox
.
9.If these areas require servicing, transfer gearbox
input seal must also be renewed.
CAUTION: Avoid damaging new seal lip
and ensure seal is fitted flush with
machined face. Also ensure new seal is
not damaged when refitting transfer gearbox.
10.If red ATF type oil is seen leaking during
workshop test, investigate main gearbox for
cause of leak.
Detent plug or electrical switch leaks.
1.Detent plugs and electrical switches do not
usually leak. It must be noted that they fit into
open tapped holes in transfer case and therefore
should be considered when looking for source of
leak.