
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
ADJUSTMENT GEAR CHANGE LEVER BIAS SPRING - ADJUST
Service repair no - 37.16.26
1.Remove gear lever and transfer box lever knobs.
2.Remove gear lever cover.
3.Remove nut and washer securing gear lever.
4.Mark gear lever spline setting, remove lever and
gaiter from lower lever.
5.Remove insulation pad from tunnel aperture.
6.Fit gear lever and select 3rd or 4th gear.
7.Slacken adjustment screw locknuts.
8.Adjust screws until both legs of bias springs are
approximately 0.5mm clear of gear lever cross
pin.
9.Apply a slight load to gear lever in a LH direction
and adjust RH screw downward until RH spring
leg just makes contact with cross pin.
10.Repeat procedure for LH adjustment screw.
11.Lower both adjustment screws equal amounts
until radial play is eliminated.
12.Tighten locknuts.
13.Return gear lever to neutral position and rock
across gate several times. The gear lever should
return to 3rd and 4th gate.
14.Remove gear lever.
15.Fit insulation pad.
16.Locate gaiter over lower lever and bias springs.
17.Fit gear lever to lower lever spline, secure with
new nyloc nut and tighten to
25 Nm (18 lbf/ft).
18.Fit gear lever cover.
19.Fit gear lever and transfer box lever knobs.

MANUAL GEARBOX
3
ADJUSTMENT
12.Slacken stop screw locknut.
13.Apply light pressure to gear lever towards LH
side and turn screw clockwise until it abuts yoke.
14.Turn screw anti-clockwise until 25 mm freeplay
is felt at gear lever knob. Ensure 5th gear can be
engaged.
15.Tighten stop screw locknut.
16.Check that all other gears are selectable.
17.Remove gear lever.
18.Manouvre tunnel cover into position and secure
with 16 screws.
19.Fit fuse box and cover.
20.Fit tunnel carpet.
21.Fit insulation pad into tunnel aperture.
22.Locate gaiter over lower lever and bias springs.
23.Fit gear lever to lower lever spline, secure with
new nyloc nut and tighten to
25 Nm (18 lbf/ft).
24.Fit gear lever cover.
25.Fit gear lever and transfer box lever knobs.

37MANUAL GEARBOX
4
REPAIR
37.Pull handbrake cable through heel board and tie
aside.
38.Remove retaining nut, release clamp, and
disconnect speedometer cable from transfer box.
39.Release speedometer cable from retaining clip
on transfer box.
40.Remove retaining nut and release battery earth
strap from transfer box.
41.Secure manufactured cradleLRT-99-007to a
suitable hydraulic hoist.
42.Raise hoist and secure to gearbox with 3 bolts in
location provided.
43.Lower hoist sufficiently to allow transfer lever to
clear transmission tunnel aperture.
44.Disconnect differential lock switch and reverse
light connectors.
45.Remove bolt and release earth leads from RH
side of transfer box.
46.Support engine under sump with a jack.
47.Remove 14 bell housing to engine fixings.
48.Withdraw transmission whilst ensuring all
connections to engine and chassis are released.
49.Lower hoist and remove gearbox assembly.

MANUAL GEARBOX
5
REPAIR Separating transfer gearbox from main gearbox
50.Remove transmission assembly from hoist
cradle and position safely on a bench.
51.Remove breather pipes. Discard pipe union
sealing washers.
52.Remove 'Nyloc' nut, and remove bolt, securing
lever to high/low shaft.
53.Collect spacer washer.
54.Remove 2 clips and remove differential lock
lever link.
55.Remove lower locknut from high/low operating
rod.
56.Place a sling round transfer box and attach to
hoist.
57.Remove nut and 4 bolts securing transfer
gearbox to extension housing.
58.Withdraw transfer gearbox.
Assembling transfer gearbox to main gearbox
59.Clean extension housing and transfer gearbox
mating faces.
60.Ensuring loose upper dowel is fitted, hoist
transfer gearbox into position.
61.Secure transfer box to extension housing.
Tighten fixings to
40 Nm (30 lbf/ft).
62.Connect high/low operating rod, fit and tighten
locknut.
63.Fit link to differential lock lever and secure with 2
clips
64.Align lever to high/low shaft, position washer, fit
bolt and new Nyloc nut. Tighten to
2 Nm (1.5
lbf/ft).
65.Position breather pipes, secure pipe unions
using new sealing washers. Tighten unions to
15
Nm (11 lbf/ft).
Fitting transfer gearbox and main gearbox
assembly
66.Position transmission assembly to hoist cradle.
67.Clean bell housing and engine mating faces.
Apply sealant to both mating faces.
68.Temporarily fit gear lever and select any gear in
main gearbox to facilitate entry of gearbox input
shaft. Engage low range.
69.Position and raise hoist, fit transmission to
engine whilst keeping harness and pipes clear to
prevent trapping.
70.Secure transmission to engine. Tighten fixings to
45 Nm (33 lbf/ft).
71.Secure earth leads to RH side of transfer box.
72.Connect reverse lamp switch connectors and
differential lock switch connectors.
73.Secure breather pipes to harness with clips.
74.Remove support from engine sump.
75.Position temporary support under transmission.
76.Secure LH and RH mounting brackets to
gearbox. Tighten fixings to
55 Nm (41 lbf/ft).
77.With assistance and using a body jack between
chassis longitudinals, jack chassis sufficiently to
enable fitment of crossmember.

MANUAL GEARBOX
1
SPECIFICATIONS, TORQUE REV: 05/99 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....................................................................................................

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.