1999 LAND ROVER DISCOVERY drain bolt

TRANSFER BOX - LT230SE
REPAIRS 41-39
Refit
1.Clean seal mating faces.
2.Fit new seal using tool LRT-41-012.
CAUTION: Oil seal must be fitted dry.
3.Position drive flange, fit new felt and steel
washers.
4.Position tool LRT-51-003 and tighten new
drive flange nut to 148 Nm (109 lbf.ft).
5.Position handbrake drum and tighten screw.
6.Tighten brake shoe adjuster bolt to 25 Nm (18
lbf.ft) then loosen one and a half turns.
7.Check that brake drum is free to rotate.
8.Fit propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
9.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 4600 to mating
flange on output shaft housing.
3.Fit output shaft housing to main casing.
4.Apply sealant, Part No. STC 50552 to output
shaft housing 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.

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-27
Gearbox - convertor and transfer
gearbox - Diesel
$% 44.20.04.99
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Raise vehicle on a ramp.
4.Remove starter motor.

+ CHARGING AND STARTING,
REPAIRS, Starter motor - diesel.
5.Remove 2 upper bolts securing gearbox
housing to engine.
6.Remove bolt securing closing plate to gearbox
housing.
7.Remove exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - Td5, REPAIRS, Pipe - front.
8.Remove 3 nuts securing intermediate silencer
to tail pipe.
9.Release and remove silencer from rubber
mountings. 10.Drain automatic gearbox oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
11.Drain transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
12.Remove front propeller shaft.

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

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.
14.Remove and discard 3 bolts securing torque
converter to drive plate.

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-32 REPAIRS
Gearbox - convertor and transfer
gearbox - V8
$% 44.20.04.99
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Raise vehicle on a ramp.
4.Remove 8 bolts securing centre cross member
and remove cross member.
5.Remove exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
6.Remove 3 nuts securing intermediate silencer
to tail pipe.
7.Release and remove silencer from rubber
mountings.
8.Drain automatic gearbox oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
9.Drain transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
10.Remove front propeller shaft

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.11.Remove rear propeller shaft

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.
12.Remove plug from torque converter housing to
access torque converter bolts.
13.Remove and discard 4 bolts securing torque
converter to drive plate.
14.Remove hand brake drum retaining screw and
remove brake drum.
15.Remove 4 bolts from hand brake back plate,
release back plate and tie aside.

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-45
Gasket - rear extension housing.
$% 44.20.19
Remove
1.Drain automatic gearbox oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
2.Remove transfer gearbox.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - Diesel.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - V8.
3.Remove 9 bolts securing rear extension
housing to gearbox case and remove housing.
4.Remove and discard gasket. Reassembly
1.Clean rear extension and mating face.
2.Position new gasket to gearbox case.
3.Position rear extension housing and tighten
bolts to 25 Nm (18 lbf.ft).
4.Fit transfer gearbox.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - Diesel.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - V8.
5.Fill automatic gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-46 REPAIRS
Parking pawl assembly.
$% 44.28.07
Remove
1.Drain automatic gearbox oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
2.Remove transfer gearbox.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - Diesel.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - V8.
3.Remove and discard 9 bolts securing extension
housing to gearbox case.
4.Remove extension housing and discard gasket. 5.Remove Torx screw and discard, lift off parking
pawl guide and guide plate.
6.Remove ratchet, spring and pivot pin.
7. Td5 models: Remove spacer from output
shaft.
8.Remove park lock gear.
9.Remove and discard 'O' ring from output shaft.
M44 1109B
97
8

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-47
Refit
1.Clean park lock components.
2.Lubricate and fit new 'O' ring to output shaft.
3.Position park lock gear on the output shaft.
4. Td5 models: Fit the spacer.
CAUTION: Ensure that spacer is fitted on
output shaft - Tdi Models only. If spacer is
omitted, park gear and speed sensor may
move out of position.
5.Position pivot pin, spring and ratchet.
6.Position parking pawl guide and guide plate,
tighten Torx screw to 10 Nm (8 lbf.ft).
7.Clean extension housing and gearbox case.
8.Position new gasket to gearbox case.
9.Position extension housing and tighten bolts to
25 Nm (18 lbf.ft).
10.Fit transfer gearbox.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - Diesel.

+ TRANSFER BOX - LT230SE,
REPAIRS, Transfer box - V8.
11.Fill automatic gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
Gasket - oil sump
$% 44.24.05
Remove
1.Raise vehicle on ramp.
2.Drain automatic gearbox oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
3.Remove 6 bolts and spacers securing oil sump
to gearbox, remove sump and discard gasket.
Refit
1.Clean oil sump and mating face.
2.Fit new gasket to oil sump, position sump to
gearbox.
3.Position spacers and tighten bolts to 8 Nm (6
lbf. ft).
4.Fill automatic gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
5.Lower vehicle.