clutch LAND ROVER DISCOVERY 1995 Service Service Manual

37MANUAL GEARBOX
2
FAULT DIAGNOSIS 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 remove and overhaul
procedure.
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 remove and overhaul
procedure.

R380
1
REPAIR R380 MANUAL GEARBOX
Service repair no - 37.20.02
Remove
WARNING: Where the use of a
transmission hoist is necessary, it is
absolutely essential to follow the
manufacturer's instructions to ensure safe and
effective use of equipment.
1.Install vehicle on a ramp [hoist].
2.Disconnect battery earth lead.
3.Remove centre console.
See CHASSIS AND
BODY, Repair, Centre Console
4.Remove sound insulation from top of
transmission tunnel.
5.Remove bolt and remove upper gear lever.
6.Remove screws securing gear selector lever and
high/low selector lever draft excluders.
7.Remove draft excluder clamp rings.
8.Remove handbrake cable clevis pin clip and
clevis pin.
9.Remove 'C' clip and cable adjuster.
10.Select low range to prevent gear lever fouling
tunnel when removing gearbox.
11.Remove bolt securing gearbox breather pipe clip
to cylinder block.
12.Remove bolts securing fan cowl to radiator.
13.Release fan cowl from radiator and lay over fan
blades.
14.Raise ramp [hoist].
15.Drain oil from main gearbox and transfer
gearbox.
See SECTION 10, Maintenance,
Under Vehicle Maintenance
16.Remove exhaust front pipe(s).See MANIFOLD
AND EXHAUST SYSTEM, Repair, Exhaust
System Complete
17.Release intermediate exhaust pipe(s) from
mountings and tie aside.
18.Remove bolts securing clutch slave cylinder.
19.Release slave cylinder from clutch housing and
collect spacer.
20.Mark propeller shaft drive flange relationships for
reassembly.
21.Disconnect front and rear propeller shafts from
transfer gearbox. Tie shafts aside.
22.Remove clamp and disconnect speedometer
cable from transfer gearbox.
23.Release handbrake cable from transmission
tunnel.
24.Temporarily support transmission in a way which
enables the crossmember to be removed and a
hoist cradle to be fitted.

R380
3
REPAIR Assembling transfer gearbox to main gearbox
45.Clean extension housing and transfer gearbox
mating faces.
46.Ensuring loose upper dowel is fitted, hoist
transfer gearbox into position.
47.Fit and tighten nut and bolts to
34Nm.
48.Connect high/low operating rod, fit and tighten
locknut.
49.Fit link to differential lock lever and secure with 2
clips
50.Align lever to high/low shaft, position washer, fit
bolt and new Nyloc nut. Tighten to
2Nm.
51.Position breather pipes, secure pipe unions
using new sealing washers. Tighten unions to
15Nm.
Fitting transfer gearbox and main gearbox
assembly to engine
52.Position transmission assembly to hoist cradle.
53.Clean bell housing and engine mating faces.
54.Temporarily fit gear lever and select any gear in
main gearbox to facilitate entry of gearbox input
shaft.
55.Position and raise hoist, and fit transmission to
engine whilst keeping wires and pipes clear to
prevent trapping.
56.Fit and tighten nuts securing transmission to
engine.
57.Connect reverse lamp switch connectors and
differential lock switch connectors.
58.Secure breather pipes to harness with clips.
59.Position temporary support.
60.Remove 2 bolts securing lifting cradle to
transmission and remove hoist. Apply Loctite
290 to bolts and refit bolts.
61.Position cross-member, loosely fit nuts and bolts
securing cross-member mountings to
transmission.62.Raise transmission, align cross-member and
loosely fit nuts and bolts securing cross-member
to chassis.
63.Tighten all securing nuts and bolts. Remove
supporting jack from under sump.
64.Remove temporary support.
65.Fit handbrake cable through transmission tunnel
and secure gaiter.
66.Connect speedometer cable to transfer gearbox.
67.Line up marks and connect front and rear
propeller shafts.
68.Clean spacer, clutch slave cylinder and gearbox
mating faces.
69.Position spacer and slave cylinder, fit bolts.
Tighten to
25Nm.
70.Untie intermediate exhaust pipe(s) and refit
exhaust front pipe(s).
See MANIFOLD AND
EXHAUST SYSTEM, Repair, Exhaust System
Complete
71.Refill main gearbox and transfer gearbox with oil.
See SECTION 10, Maintenance, Under
Vehicle Maintenance
72.Lower ramp [hoist].
73.Fit fan cowl, fit and tighten bolts.
74.Align breather pipe clip to cylinder block, fit and
tighten bolts.
75.Fit handbrake cable adjuster and secure with 'C'
clip.
76.Align cable trunnion to handbrake lever, fit clevis
pin and secure with clip.
77.Check handbrake adjustment.
See SECTION
10, Maintenance, Vehicle Interior
78.Fit upper gear lever, fit and tighten bolt.
79.Fit gear selector lever and high/low selector
lever draft excluders.
80.Position draft excluder clamp rings, fit and
tighten screws.
81.Refit sound insulation.
82.Refit centre console.
See CHASSIS AND
BODY, Repair, Centre Console
83.Connect battery earth lead.

TRANSFER GEARBOX
3
DESCRIPTION AND OPERATION DIFFERENTIAL AND OUTPUT DRIVE ASSEMBLY
1. Differential selector assembly
2. Front output housing
3. High-low ratio cross shaft assembly
4. High-low selector shaft and lever
5. High-low selector fork and shaft
6. High-low selector finger
7. Differential lock selector shaft
8. Differential lock selector fork
9. Differential lock spring and clips
10. Front output housing cover and housing
11. Felt washer, steel washer and flange nut
12. Front output flange
13. Mud shield
14. Oil seal
15. Bearing
16. Spacer
17. Circlip
18. Differential carrier, front half19. Differential carrier, rear half
20. Retaining ring
21. Front output shaft
22. Dog clutch, front drive lock-up
23. Selective shim
24. Bearing
25. Selective thrust washers
26. Sun and planet gears
27. Thrust washers
28. Cross shafts
29. Gear low
30. Hub and sleeve assembly
31. High output gear
32. Bush
33. Bearing
34. Bearing retaining nut
35. Differential lock switch
36. Differential lock detent ball and spring

41TRANSFER GEARBOX
2
FAULT DIAGNOSIS PROCEDURE
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
the system the 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 the oil and remove the leaking output
flange.
2.Inspect the seal track on the flange for surface
damage. If damaged renew component.
3.Remove and discard the oil seal.
4.Inspect the seal locating bore and remove any
sharp edges which may damage the new oil
seal.
5.Fit new seal.
6.Fit the output flange and all the other parts.
7.Add oil to correct level into the gearbox.
See
LUBRICANTS, FLUIDS AND CAPACITIES,
Information, Recommended Lubricants and
Fluids
Cover plate gasket leaking.
1.Drain the oil and remove the 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 the bolts which come
into contact with gearbox oil.
5.Refit cover plate.
CAUTION: Care must be taken not to
overtighten the fixings.Leak between the main and transfer gearboxes.
1.Site vehicle onto a ramp [hoist].
2.Select neutral in transfer box and select 4th gear
in the main gearbox.
3.Run engine at 2000 rpm with the clutch/drive
engaged.
4.Observe joint between the main and transfer
boxes.
5.If oil leak is found establish if it is gear oil.
6.If so, the leak is originating from the transfer box.
7.Check the two inner (main/transfer) bolts are oil
tight, as these holes are tapped through into the
main transfer case.
8.Remove the transfer box to inspect the
mainshaft collar seal track condition, and the
front face of the transfer case for porosity.
See
Repair, LT230T Transfer Gearbox
9.If these areas require servicing, the transfer
gearbox input seal must also be renewed.
CAUTION: Avoid damaging the new seal
lip and ensure the seal is fitted flush with
the machined face. Also ensure the new
seal is not damaged when refitting the transfer
gearbox.
10.If red A.T.F type oil is seen leaking during the
workshop test, investigate the 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 the transfer case and
therefore should be considered when looking for
the source of the leak.

ZF
1
DESCRIPTION AND OPERATION DESCRIPTION
The automatic transmission is specially tailored version of the ZF4 HP22, used by many manufacturer's of high
performance vehicles.
A three element torque converter delivers the power to a four speed epicyclic transmission. First, second and third
gears are reduction ratios but fourth is an overdrive gear for high speed cruising. A direct drive clutch, integral with
the torque converter operates to engage fourth gear.
The gear selector has seven positions as follows:
P = Park provides a mechanical lock on the output shaft.
R = Reverse gear.
N = Neutral.
D = Provides a 1st gear start and automatic shifts 1-2-3-4-3-2-1.
3 = Provides a 1st gear start and automatic shifts 1-2-3-2-1.
2 = Provides a 1st gear start and automatic shifts 1-2-1 or 3-2-1.
1 = Provides a 1st gear start with no up shifts, or 3-2-1.
All automatic shifts are automatically controlled by the valve block and an hydraulic governor driven by the output
shaft.

44AUTOMATIC GEARBOX
2
DESCRIPTION AND OPERATION Power flow
1st gear D selected
With D selected 1st gear engaged, clutches 4 and 11 are operative. The front planet gear carrier of gear set 9 is
locked against the housing through freewheel 15 when the engine is pulling but freewheels when the vehicle is
coasting. Epicyclic gear set 10 rotates as a solid unit with the front planet gear carrier. In selector position 1 with
1st gear engaged, clutch 8 operates to prevent the loss of drive on the overrun through freewheel 15, to provide
engine braking.
2nd gear D selected
Clutches 4, 6, 7 and 11 are engaged. Freewheel 15 overruns, the hollow shaft with the sun wheel of epicyclic gear
set 9 is locked. Epicyclic gear set 10 also rotates as a solid unit.

ZF
3
DESCRIPTION AND OPERATION 3rd gear D selected
Clutches 4, 5, 7 and 11 are engaged. Freewheel 15 and 16 are overrun. Epicyclic gear set 9 and 10 rotate as a
solid unit at a ratio of 1:1.
4th gear D selected
Clutches 4, 5, 7 and 12 are engaged. Freewheel 14, 15 and 16 are overrun. Epicyclic gear set 9 rotates as a solid
unit. The hollow shaft with the sun wheel of epicyclic gear set 10 is locked.
Above a predetermined road speed, clutch 2 locks the gearbox power input direct to the engine, by-passing the
torque converter.

44AUTOMATIC GEARBOX
4
DESCRIPTION AND OPERATION Reverse gear
Clutches 5, 8 and 11 are engaged. Since the front planet gear carrier of epicyclic gear set 9 is locked, the direction
of output-shaft rotation is reversed. Epicyclic gear set 10 also rotates as a solid block.

44AUTOMATIC GEARBOX
2
FAULT DIAGNOSIS ROAD TEST PROCEDURE
Follow the procedure given commencing each test,
from a standing start, on a level road, in good weather
conditions.
ROADTEST 1 = CHECKS 1-2-3-4-5-6-7-8
D SELECTED KICKDOWN START FROM REST
CHECK 1
Check for clutch squeal and slip. Check pressure is
150lbf/in
2
CHECK 2
Check 1st to 2nd upshift speed and quality. Pressure
should fall to 120 lbf/in
2.
CHECK 3
Check 2nd-3rd upshift speed and quality. Pressure
should fall to 100 lbf/in
2
CHECK 4
Release throttle to allow simultaneous engagement
4th + DDC. Check shift quality and engine rpm drop of
approximately 500 rpm.
CHECK 5
To proceed to Check 5 release throttle and check
drop out speed of direct drive clutch to 4th.
CHECK 6
Check down shift speed and quality 4th to 3rd.
NOTE: This shift is usually very smooth
and difficult to detect.
CHECK 7
Check downshift speed and quality 3rd to 2nd.
CHECK 8
Check downshift speed and quality 2nd to 1st. Also
difficult to detect.
END OF ROADTEST 1ROADTEST 2 CHECKS = 9-10-11
D SELECTED FROM REST
FULL THROTTLE START
CHECK 9
Check 1st-2nd upshift speed and quality.
CHECK 10
Check 2nd 3rd upshift speed and quality.
CHECK 11
Check 3rd 4th and direct drive clutch upshift speed
and quality.
NOTE: 4th and the direct drive clutch
engage simultaneously.
END OF ROADTEST 2