gearbox LAND ROVER DISCOVERY 1995 Repair Manual

R380
1
DESCRIPTION AND OPERATION MANUAL TRANSMISSION
Description
The all synchromesh five speed manual gearbox unit,
is married to a LT230T 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.
1. Mainshaft 1st gear
2. Mainshaft 2nd gear
3. Mainshaft 3rd gear
4. Primary input shaft
5. Mainshaft 5th gear
6. Layshaft
7. Mainshaft
8. Lubrication pump9. Drain plug
10. Ventilation pipe
11. Single rail gear shift
12. 1st/2nd synchromesh
13. Oil seals
14. 3rd/4th synchromesh
15. 5th gear synchromesh

R380
1
FAULT DIAGNOSIS MANUAL 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.
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 remove and overhaul procedure.
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.
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 remove and overhaul procedure.
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.
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 remove and overhaul
procedure.
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 remove and
overhaul procedure.
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

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.

37MANUAL GEARBOX
2
REPAIR 25.Remove nuts and bolts securing transmission
cross-member to chassis.
26.Remove nuts and bolts securing cross-member
mountings to transmission.
27.Remove cross-member.
28.Manufacture an adapter plate to dimensions
given in service tool section and attach it to a
transmission hoist. To achieve balance of the
transmission unit when mounted to hoist, it is
essential that pointA,is situated over lifting hoist
ram. Drill holesBto suit hoist table. Secure the
transmission unit cradle at pointCusing the
lower bolts retaining transfer gearbox rear cover.
Raise hoist just enough to take weight of
transmission.
29.Lower hoist sufficiently to allow transfer gearbox
selector lever to clear transmission tunnel
aperture.
30.Disconnect differential lock switch connectors.
31.Disconnect reverse lamp switch connectors.
32.Remove clips securing gearbox breather pipes
to harness.
33.Support engine under sump with a jack.
CAUTION: Use a wooden block to protect
sump.
34.Remove bell housing nuts.
35.Withdraw transmission whilst ensuring all
connections to engine and chassis are released.36.Remove transmission assembly from hoist
cradle and position safely on a bench.
37.Remove breather pipes. Discard pipe union
sealing washers.
38.Remove 'Nyloc' nut, and remove bolt, securing
lever to high/low shaft.
39.Collect spacer washer.
40.Remove 2 clips and remove differential lock
lever link.
41.Remove lower locknut from high/low operating
rod.
42.Place a sling round transfer box and attach to
hoist.
43.Remove nut and 5 bolts securing transfer
gearbox to extension housing.
44.Withdraw transfer gearbox.

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.

R380
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Slave cylinder to bell housing 25....................................................................
Breather 15.....................................................................................................
Bell housing to cylinder block 40.....................................................................
High/low level to shaft 2.................................................................................
Transfer box to gearbox 45.............................................................................
NOTE: Torque values below apply to all screws and bolts used unless otherwise specified.
METRIC Nm
M5 6...........................................................................
M6 9...........................................................................
M8 25...........................................................................
M10 45.........................................................................
M12 90.........................................................................
M14 105.........................................................................
M16 180.........................................................................
UNC / UNF
1/4 9...........................................................................
5/16 24.........................................................................
3/8 39...........................................................................
7/16 78.........................................................................
1/2 90...........................................................................
5/8 136...........................................................................

R380
1
SERVICE TOOLS ADAPTER PLATE GEARBOX
Adapter plate for removing gearbox. This can be
manufactured locally to drawing shown.
MATERIAL AND WELDING SPECIFICATION
Steel Plate BS 1449 (Grade 4 or 14)
Tube BS 4848 (Part 2)
Arc Welding BS 5135

TRANSFER GEARBOX
1
DESCRIPTION AND OPERATION LT230T TRANSFER BOX
The LT230T transfer box 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.
A shiftlock device is fitted in some territories, it is used
as a park facility and prevents accidental gear
disengagement when the ignition is switched off. An
audible neutral alarm is also fitted. This alerts the
driver when parking to move the gear lever to the high
or low position.

41TRANSFER GEARBOX
2
DESCRIPTION AND OPERATION REAR OUTPUT DRIVE ASSEMBLY
1. Rear output shaft
2. Joint sealant
3. Speedometer drive housing
4. Speedometer drive pinion assembly
5. Speedometer worm drive
6. Spacer7. Ball bearing
8. Circlip
9. Oil seal
10. Oil shield
11. Rear output flange
12. Sealing washer