2002 LAND ROVER DISCOVERY drain bolt

TRANSFER BOX - LT230SE
DESCRIPTION AND OPERATION 41-5
Main casing components – Vehicles
from 03 model year
1Retaining plate
2Stake nut - intermediate shaft
3Bolt - retaining plate
4'O' rings - intermediate shaft
5Bearings and outer tracks - mainshaft input
gear
6Mainshaft input gear bearing housing
7Cover plate
8Bolt - cover plate
9Selective shim
10Mainshaft input gear
11Oil filler/level plug
12Oil temperature switch - if fitted
13Bearings and outer tracks - intermediate gears14Intermediate gears
15Bottom cover plate
16Bolt - bottom cover plate
17Selective spacer
18Mainshaft oil seal
19Oil drain plug
20Main casing
21Intermediate shaft
22Locating dowel
23Detent ball - high/low selector
24Detent spring - high/low selector
25Detent plug - high/low selector
26Neutral warning switch - Automatic gearbox
only - North America and Japan

TRANSFER BOX - LT230SE
DESCRIPTION AND OPERATION 41-17
Lubrication
Lubrication is by splash, oil filler/level and drain plugs being located in the main casing.
Internal pressures caused by thermal expansion and contraction are avoided by the use of a plastic breather pipe
venting the interior of the box to atmosphere. The pipe is attached to the top of the high/low selector housing by a
banjo bolt and is then routed in a continuously rising path into the engine compartment where the open end is secured
by a clip attached to the engine cylinder block.
Oil temperature warning lamp switch
An oil temperature switch is fitted to V8 engine models. In the event of the transfer box oil approaching maximum
recommended working temperature of 145
°C (293°F), the switch will close and a warning lamp in the instrument pack
will be illuminated.
High/Low range and differential lock selector lever assembly – Vehicles from 03 model year
1Selector lever
2High/Low range cable
3Differential lock cable
4Interlock solenoid

TRANSFER BOX - LT230SE
REPAIRS 41-23
REPAIRS
Bottom cover - transfer box
$% 41.20.06
Remove
1.Raise vehicle on ramp.
2.Drain transfer box oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
3.Remove 8 bolts securing cross member to
chassis and remove cross member.
4.Remove 10 bolts securing bottom cover to
transfer box and remove cover. Refit
1.Clean bottom plate and mating face on transfer
box.
2.Clean bolt threads.
3.Apply sealant, Part No. STC 3254 to bottom
plate sealing face.
4.Apply Loctite 290 to bolt threads.
5.Position bottom plate and tighten bolts to 25
Nm (18 lbf.ft).
6.Position cross member to chassis and tighten
bolts to 26 Nm (19 lbf.ft).
7.Fill transfer box with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
8.Lower vehicle on ramp.

TRANSFER BOX - LT230SE
41-24 REPAIRS
Transfer box - Diesel
$% 41.20.25.99
Remove
1.Remove front exhaust pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - Td5, REPAIRS, Pipe - front.
2.Raise vehicle on ramp.
3.Drain transfer box oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
4.Remove 3 nuts securing intermediate silencer
to tail pipe.
5.Release silencer from mounting rubbers.
6.Remove silencer and discard gasket.
7.Remove front propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
8.Remove rear propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.9.Remove handbrake drum retaining screw and
remove drum.
10.Remove 4 bolts from handbrake back plate,
release back plate and tie aside.
11.Remove clevis pin securing high/low ratio
selector cable to selector lever, remove 'C' clip
and release outer cable from abutment bracket.

TRANSFER BOX - LT230SE
REPAIRS 41-27
Transfer box - V8
$% 41.20.25.99
Remove
1.Remove front exhaust pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
2.Drain transfer box oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
3.Remove 8 bolts securing rear cross member
and remove cross member.
4.Remove 3 nuts securing intermediate silencer
to tail pipe.
5.Release silencer from mounting rubbers,
remove silencer and discard gasket.
6.Remove front propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
7.Remove rear propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.8.Remove handbrake drum retaining screw and
remove handbrake drum.
9.Remove 4 bolts from handbrake back plate,
release back plate and tie aside.
10.Remove clevis pin and 'C' washer securing
high/low ratio selector cable to selector lever
and release cable from abutment bracket.

TRANSFER BOX - LT230SE
REPAIRS 41-35
3.Fit new seal using tool LRT-41-012.
4.Position drive flange, fit new felt and steel
washers.
5.Position tool LRT-51-003 and tighten new
drive flange nut to 148 Nm (109 lbf.ft).
6.Position handbrake drum and tighten screw.
7.Tighten brake shoe adjuster bolt to 25 Nm (18
lbf.ft) then loosen one and a half turns.
8.Check that brake drum is free to rotate.
9.Fit propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
10.Top-up transfer box oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
Gasket - rear output shaft housing
$% 41.20.55
Remove
1.Drain transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
2.Remove rear output shaft seal.

+ TRANSFER BOX - LT230SE,
REPAIRS, Seal - rear output shaft.
3.Mark output shaft housing to main casing for
assembly purposes.
4.Note position of shoulder bolt, remove 6 bolts
securing housing to main casing.
Refit
1.Clean output shaft housing, mating face on
main casing and sealant from bolt threads.
2.Apply sealant, Part No. STC 3254 to mating
flange on output shaft housing.
3.Fit output shaft housing to main casing.
4.Apply Loctite 290 to bolt threads.
5.Fit output shaft housing bolts and tighten by
diagonal selection to 45 Nm (33 lbf.ft).
6.Fit rear output shaft seal.

+ TRANSFER BOX - LT230SE,
REPAIRS, Seal - rear output shaft.
7.Fill transfer gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-6 DESCRIPTION AND OPERATION
Gearbox
Diesel gearbox shown, V8 gearbox similar
1Torque converter
2Torque converter housing
3Fluid pump
4Breather tube
5Intermediate plate
6Gearbox housing
7Rear extension housing
8Electrical connector
9Gear position switch
10Selector lever
11Mounting bracket12Heat shield
13Rubber mounting
14Gasket
15Sump
16'O' ring seal
17Drain plug
18'O' ring seal
19Filler/level plug
20Bolt
21Clamp

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-10 DESCRIPTION AND OPERATION
The lock-up and brake clutches are operated by pressurised transmission fluid from the valve block in the sump. A
manual valve and four solenoid valves, also known as Motorised Valves (MV), control the supply of pressurised
transmission fluid from the valve block:
lThe manual valve controls the supply in P, R, N and D.
lSolenoid valves MV 1 and MV 2 control the supplies that operate the brake clutches for shift control.
lSolenoid valve MV 3 controls the supply that operates the lock-up clutch.
lSolenoid valve MV 4 modulates the pressure of the supplies to the brake clutches, to control shift quality.
Operation of the manual valve is controlled by the selector lever assembly. In the gearbox, a selector shaft engages
with the manual valve. The selector shaft is connected to the selector lever assembly via the selector cable and a
selector lever on the left side of the gearbox. The selector shaft also operates a mechanism that locks the output shaft
when P is selected.
Operation of the solenoid valves is controlled by the EAT ECU.
An output shaft speed sensor in the gearbox housing outputs a signal to the EAT ECU. The EAT ECU compares
output shaft speed with engine speed to determine the engaged gear, and output shaft speed with vehicle speed to
confirm the range selected on the transfer box.
A bayonet lock electrical connector in the gearbox casing, to the rear of the selector lever, connects the solenoid
valves and the output shaft speed sensor to the vehicle wiring.
A pressed steel sump encloses the valve block and collects transmission fluid draining from the gearbox housing. A
suction pipe and filter on the underside of the valve block connect to the inlet side of the fluid pump. A magnet is
installed in the sump to collect any magnetic particles that may be present. A level plug and a drain plug are installed
in the sump for servicing.
Rear extension housing
The rear extension housing provides the interface between the gearbox housing and the transfer box. A splined
extension shaft, secured to the gearbox output shaft by a bolt, transmits the drive from the gearbox to the transfer
box. A seal in the rear of the housing prevents leakage past the extension shaft. A breather pipe, attached to the left
side of the rear extension housing, ventilates the interior of the gearbox and rear extension housings to atmosphere.
The open end of the breather pipe is located in the engine compartment at the right front corner of the engine sump
on gearboxes fitted to early vehicles and is clipped to the top of the gearbox on later vehicles.
Gearbox power flows
The following Figures show the power flow through the gearbox for each forward gear when D is selected, and for
reverse. The key to the Item numbers on the Figures, and in parenthesis in the accompanying text, can be found on
the 'Sectioned view of gearbox' Figure, above.
1st Gear (D selected)
Clutches (4) and (11) are engaged. The front planet gear carrier of gear set (9) locks against the gearbox housing
through freewheel (15) when the engine powers the vehicle, and freewheels when the vehicle is coasting. Gear set
(10) rotates as a solid unit with the front planet gear carrier. In 1st gear hold brake clutch (8) is applied to provide
overrun braking.