LAND ROVER DISCOVERY 1999 Workshop Manual

MANUAL GEARBOX - R380
DESCRIPTION AND OPERATION 37-1
MANUAL GEARBOX - R380 DESCRIPTION AND OPERAT ION
R380 gearbox

MANUAL GEARBOX - R380
37-2 DESCRIPTION AND OPERATION
Gearbox casings, gear change and oil
pump

MANUAL GEARBOX - R380
DESCRIPTION AND OPERATION 37-3
1Front cover
2Input shaft oil seal
3Oil filler/level plug
4Sealing washer
5Oil drain plug
6Gear case
7Interlock spool retainer, bolt and 'O' ring
8Centre plate
9Locating dowels
10Selector plug, detent balls and spring
11Splash shield and retaining bolt
12Extension housing
13Gate plate and retaining bolt
14Interlock spool retainer, retaining bolt and 'O'
ring – if fitted – extension housing
15Inhibitor cam spring
16Inhibitor cam
17Reverse inhibitor shaft
18Output shaft oil seal
19Oil seal collar
20Oil pump and retaining bolt
21'O' ring
22Reverse lamp switch23Oil by-pass block - UK and European models
24Bolt - oil by-pass block
25'O' ring - oil by-pass block
26Thermostat and housing - non UK and non
European models
27'O' ring - thermostat housing
28Bolt - thermostat housing
29Oil pick-up pipe
30Oil filter
31Oil pick-up ring
32Rubber gaiter
33Cable tie
34Upper gear lever
35Clamp bolt
36Bias springs
37Bolts and washers - bias adjusting plate and
housing
38Bias adjusting plate
39Lower gear lever and ball
40Railko bush
41Oil seal
42Gear change housing

MANUAL GEARBOX - R380
37-4 DESCRIPTION AND OPERATION
Selector shaft and forks, synchromesh
assemblies and gear train

MANUAL GEARBOX - R380
DESCRIPTION AND OPERATION 37-5
13rd/4th gear selector fork
2Interlock spool
31st/2nd gear selector fork
4Selector shaft yoke pins
5Selector shaft
6Reverse/5th gear selector fork
7Selector yoke
8Setscrew
9Input shaft front taper bearing
10Input shaft
11 4th gear synchromesh ring
12Pilot taper bearing
13Spacer
143rd/4th gear synchromesh hub and sleeve
153rd gear synchromesh rings
163rd gear
17Needle roller bearings
18Output shaft
19Roll pin
20Needle bearing
212nd gear
222nd gear synchromesh rings
232nd/1st gear synchromesh hub and sleeve
241st gear synchromesh rings
251st gear
26Needle roller bearing
27Bush
28Output shaft taper bearing 29Selective shim
30Selective washer
31Bush
32Needle roller bearing
33Reverse gear
34Reverse gear synchromesh ring
35Reverse/5th gear synchromesh hub and sleeve
36Circlip
37Needle roller bearings
385th gear synchromesh ring
395th gear
405th gear segments
415th gear segment retaining ring
42Output shaft rear support bearing
43Layshaft support bearing
44Layshaft
45Layshaft support bearing
46Selective shim
47Layshaft reverse gear
48Layshaft 5th gear
49Split collar
505th gear nut
51Layshaft rear support bearing
52Spacer
53Reverse idler gear
54Needle roller bearing
55Reverse idler shaft

MANUAL GEARBOX - R380
37-6 DESCRIPTION AND OPERATION
R380 gearbox cross section
1Input shaft
2Breather
3Input shaft 4th gear
4Selector shaft
53rd/4th selector fork
6Output shaft 3rd gear
7Output shaft 2nd gear
81st/2nd selector fork
9Output shaft 1st gear
10Selective shims - output shaft and layshaft end-
float
11Selective shim - reverse gear idler shaft end-
float
125th/reverse selector fork
13Selector yoke14Gear change assembly
15Railko bush
16Output shaft 5th gear
17Output shaft oil seal
18Output shaft
19Oil pump
205th/reverse gear synchromesh assembly
21Output shaft reverse gear
22Centre plate
23Oil filter
241st/2nd synchromesh assembly
25Layshaft
263rd/4th gear synchromesh assembly
27Input shaft oil seal

MANUAL GEARBOX - R380
DESCRIPTION AND OPERATION 37-7
Description
General
The R380 all synchromesh gearbox has five forward speeds and reverse and is mounted in line with the engine. The
clutch bell housing is bolted to the front of the gearbox and the transfer box is mounted at the rear.
Gearbox casings
Gearbox casings consist of a front cover, gearcase, centre plate and extension housing. All casings with the exception
of the front cover are located to each other by dowels and sealed. Gearbox filler/level and drain plugs are located in
the gearcase.
Reverse lamp switch
A reverse lamp switch is inserted into the extension housing. Selection of reverse gear will close the switch allowing
current from fuse 25 to flow through the switch to illuminate the reverse lamps. The switch also provides a feed to the
BCU and the electrochromic automatic interior mirror - if fitted; the mirror moving from the dimmed position if
applicable.
Gearchange assembly
The gearchange assembly is bolted to the top of the gearcase, the upper gear lever being attached to the lower gear
lever by means of a clamp bolt. The lower gear lever ball is housed in a Railko bush inserted in the gear change
housing, the end of the lever locating in the selector yoke which is attached to the end of the selector shaft. Bias
springs provide a positive return of the gear lever to the neutral position with selection of 1st/2nd and 5th/reverse gears
being against bias spring pressure. Spring loaded detent balls fitted in the centre plate locate in grooves in the selector
shaft to provide positive gear and neutral selection.
Lubrication
Lubrication is by an oil pump located in the extension housing and driven by the layshaft with additional lubrication
being provided by splash. The pump directs oil via a filter and internal drillings in the output shaft to lubricate the
components. On non UK and non European models, provision for oil cooling is by means of a thermostat housed in
a cover bolted to the side of the extension housing. The cover incorporates tappings for connections to an oil cooler.
On UK and European models, the thermostat and cover are replaced by an oil by-pass block.
Internal pressures produced within the gearbox are vented to atmosphere via a plastic breather pipe. The pipe is
attached to the extension housing and is routed across the top of the gearcase and secured at the open end by a clip
attached to the engine cylinder block.
Selector shaft and forks
Selector forks for 1st/2nd, 3rd/4th and 5th/reverse gears are located on a single selector shaft; the 1st/2nd and 3rd/
4th selector forks are inside the main gearcase whilst the 5th/reverse selector fork is inside the extension housing.
Each of the selector forks locates inside its corresponding synchromesh hub.
Synchromesh assemblies
Each synchromesh assembly is located on the output shaft adjacent to its corresponding gears and comprises a
synchromesh ring, hub, slippers and sleeve. The hubs and slippers are retained in the sleeves by means of spring
clips. 1st/2nd and 3rd synchromesh assemblies are fitted with double synchromesh rings whilst 4th, 5th and reverse
assemblies are fitted with single rings.
The gear train
The gear train comprises an input shaft, output shaft, layshaft and reverse idler shaft together with their appropriate
gears and synchromesh assemblies.
The gear train input shaft, output shaft and layshaft are supported by taper roller bearings with all gears on the input
and output shafts running on caged needle roller bearings. Layshaft gears are integral with the shaft with the
exception of reverse/5th gears which are splined to the shaft and retained with a nut. 1st, 2nd, 3rd and 4th gears are
shot peened to improve durability. The reverse idler shaft and gear are supported in the centre plate by a caged
needle roller bearing. End-float of the output shaft and layshaft is controlled by selective shims located in the centre
plate whilst reverse idler shaft end-float is controlled by a selective shim located behind reverse gear.

MANUAL GEARBOX - R380
37-8 DESCRIPTION AND OPERATION
Operation
Drive is transmitted from the crankshaft, through the clutch to the gearbox input shaft which transmits drive via the
layshaft to the output shaft in all gears with the exception of 4th gear which provides a direct drive from the input shaft
to the output shaft. Drive from the gearbox output shaft is transmitted to the transfer box input shaft via a flange splined
to the output shaft.

MANUAL GEARBOX - R380
ADJUSTMENTS 37-9
ADJUST ME NTS
Spring - gear lever bias
$% 37.16.26
Adjust
1.Remove centre console.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.
2.Loosen pinch bolt and remove gear lever
extension.
3.Drill out 9 pop rivets and remove gear lever
cover plate and seal.
4.Remove retaining strap and remove gear lever
housing rubber boot.5.Loosen bias adjustment plate bolts.
6.Select 4th gear and move lever fully to the right
and tighten bias plate adjustment bolts to 25
Nm (18 lbf.ft).
7.Check adjustment is correct by selecting 3rd
and 4th gears.
8.Fit gear lever housing rubber and secure with
retaining strap.
9.Fit seal and cover plate and secure with pop
rivets.
10.Fit gear lever extension and tighten pinch bolt
to 25 Nm (18 lbf.ft).
11.Fit centre console.

+ INTERIOR TRIM COMPONENTS,
REPAIRS, Console - centre - manual
models.