Defender (1993+). Manual — part 38

ASSEMBLY RENEWAL

SPECIAL TOOLS

CLUTCH

The major part

of clutch assembly renewal is the

LRT-12-001 Clutch centralising tool

removal of the transmission

to

gain access to the

clutch. Because of the considerable combined weight

Remove

of

the main gearbox and transfer box and the off-set

centre

of

gravity,

it

is vital that clutch replacement

1.

Remove the transmission, see

SECTION

37.

must only be undertaken by organisations or

2. Mark the position of the clutch cover

to

the

individuals that have the necessary experience and

flywheel to assist

with

reassembly.

essential equipment

to

enable the transmission to be

3.

Working evenly and diagonally remove the

removed safely, without the risk

of personal injury

clutch cover securing bolts.

and damage

to

the transmission and vehicle. Details

4.

Do not disturb the three bolts in the clutch

of

the recommended transmission hoist and special

cover.

cradles are contained in

SECTION

37.

5.

Remove clutch cover assembly.

6.

Withdraw the clutch friction plate.

Always ascertain the reason for the necessity to
renew the clutch before attempting to

fit

a new

assembly. Careful examination of the clutch and the
associated components should be carried out. This
should

also

include checking the clutch hydraulic

system

if

the

reason for clutch failure is not

immediately apparent. See "Clutch

Fault Diagnosis".

If oil is present on the clutch lining the source of the

oil

contamination should be investigated.

If

necessary, the rear main bearing oil seal should be
renewed as described

in SECTION

12

.

Excessive wear of the clutch due to the vehicle
having been used continually for wading without the

flywheel housing plug being fitted, would be evident
by

rust on all parts including the release assembly

and splines of the primary shaft.

The clutch cover and friction plate should always be

7.

Reverse items 5 and

6,

aligning the assembly

renewed together. Also it would certainly be wise

to

replace the release bearing and possibly the

marks and using the centralising

tool

I

8.

Fit the cover securing bolts, working in a

When fitting the clutch

it

is

important that

the

splines

diagonal sequence. Finally tightening the bolts

to

a torque

of 28Nm.

of the primary shaft are smeared with Molybdenum

Disulphide grease such as Rocol

M.T.S.

1000

to

9.

Refit

the

transmission.

prevent seizure.

Also the friction plate must be

centralised while the cover bolts are evenly tightened

to the correct torque.

Refitting

remainder

of

the mechanism

if any wear

is

present.

LRT-12-001.

CLUTCH DRAGS

-

Start with check No. 20 and proceed as directed.

POSSIBLE CAUSES

CHECK AND ACTION

1

Free play at the clutch pedal

Yes

Check3

No

Check2

2

Clutch pedal tight on the pivot shaft

Yes

Free the clutch pedal and lubricate

No

Check 3.

3

Clutch release mechanism sticking

Yes

Free the mechanism

No

Check4

4

Clutch slave or master cylinder pistons seized or sticking

Yes

Repair or renew the cylinder

No

Check 5.

5

Clutch diaphragm cracked

Yes

Renew the cover plate

No

Check6

6.

Friction plate worn

Yes

Renew the friction plate

No

Check7

No

No

Check 9

No

Check 10

No

Check

11

piston seals leaking

No

Check 12

No

Check

13.

No

Check 14.

No

No

Check

16.

piston seals leaking

No

Check

17

No

Check 18.

No

Check 19

No

Check20

No

Check21

No

Check22

Yes

No

Check 23.

No

7

Oil on the friction plate linings

Yes

Renew

the

friction

plate and rectify the oil leak

Suspect the friction plate sticking on splines

8.

Engine or gearbox rnountings worn or slack

Yes

Tighten or renew the mountings

9

Drive shaft joints/propeller shaft joints or splines worn

Yes

Renew components as necessary

10.

Clutch release mechanism sticking or detective

Yes

Free

or

renew the release mechanism.

11.

Clutch slave or master cylinder pistons sticking or

Yes

Repair or renew the cylinder

12 Friction plate cushion springs broken or weak

Yes

Renew the clutch assembly complete.

13. Riven plate sticking on splines

Yes

Free

the

driven plate.

14 Friction plate distorted

or

oil

on the

linings

Yes

Renew

the

friction

plate and rectify the oil leak

i-

15.

Clutch release mechanism or dutch pedal sticking

Yes

Free

as

necessary.

16. Clutch slave or master cylinder piston sticking

or

Yes

Repair or renew the cylinder.

17.

Friction plate sticking on splines

Yes

Free

the

friction plate.

18

Friction plate distorted

Yes

Renew the friction plate.

19. Clutch diaphragm detective

Yes

Renew the cover plate

20

Internal or external clutch fluid leaks

Yes

Repair

or

renew as necessary

21

Friction plate sticking on splines

Yes

Free the friction plate

22. Oil on

the

friction plate

23

Friction plate distorted

Yes

Renew the friction plate

Suspect a faulty cover plate or damaged flywheel

Renew the friction plate and rectify the oil leak

Suspect a faulty cover plate

OVERHAUL RELEASE BEARING ASSEMBLY

OVERHAUL MASTER CYLINDER - All models

1.

Remove the clutch slave cylinder from the bell

Dismantle

2.

Withdraw the retaining staple,

if

fitted.

1.

Remove the master cylinder

from

the vehicle.

3.

Remove the release bearing assembly.

2.

Remove the circlip.

4.

Remove spring clip retaining bolt and spring.

3.

Withdraw the push-rod and retaining washer.

5.

Withdraw the release lever.

6.

Discard worn parts.

7.

Smear the pivot with grease and

fit

the

release lever and retain with the spring clip
and bolt.

8. Smear the release bearing sleeve inner

diameter with Molybdenum disulphide base
grease.

9.

Fit the release bearing assembly and retain

with the staple. The staple is

to

aid assembly

and has no other purpose.

It

may become

dislodged in service, without detriment.

housing.

4.

Withdraw the piston assembly.

If

necessary,

apply a low air pressure

to

the outlet

port to

expel the piston.

10.

Coat both sides of the backing plate with a
waterproof joint compound such as Hylomar
PL32M and locate the backing plate and dust
cover in position on the slave cylinder.

11. Check that the push-rod clip is in position.
12. Fit the slave cylinder, engaging the push-rod

through the centre of the dust cover and with
the bleed screw uppermost. secure the cylinder
with the two bolts, tighten evenly to the
correct torque.

CLUTCH

5.

Prise the locking prong of the spring retainer

Assemble

clear

of the piston shoulder and withdraw the

piston.

14.

Smear the seals with rubber grease and the
remaining internal items with brake and clutch

stem to align with the larger hole in the spring

15.

Fit the valve seal, flat side first, onto the end

retainer

of the valve stem.

16. Place the spring washer, domed side first,

over the small end

of the valve stem.

17. Fit the spacer, legs first.

6.

Withdraw the piston seal.

7. Compress the spring and position the valve

fluid.

8.

Withdraw the spring and retainer.

from the valve stem.

9.

Withdraw the valve spacer and spring washer

18.

Place the coil spring over the valve stem.

20.

Compress the spring and engage the valve
stem

in

the keyhole slot in the retainer.

10.

Remove the valve seal.

19.

Insert the retainer into the spring.

Inspection

11.

Clean all components

in cleaning fluid and

allow

to dry.

12.

Examine the cylinder bore and piston, ensure

that they are smooth

to

the to

u

ch w

i

th no

corrosion, score marks or ridges.

If

there is

any doubt, fit new replacements.

13.

The seals should

be

replaced

with

new

21.

Fit the seal, large diameter last, to the piston.

22.

Insert the piston into the spring retainer and

engage the locking prong.

components.