2002 LAND ROVER DISCOVERY torque

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-37
Gasket - intermediate plate
$% 44.20.11
Remove
1.Remove torque converter oil seal.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, REPAIRS, Torque converter and oil
seal.
2.Remove 12 bolts and plain washers securing
converter housing and intermediate plate to
gearbox casing. Note the position of the 4 bolts
that have sealant applied to the bolt threads.
3.Hold input shaft in position and carefully lift off
converter housing and intermediate plate as an
assembly. Note the position of the Torrington
race on the forward clutch hub, and the thrust
washer which will stay attached to the
intermediate plate by fluid adhesion.
4.Remove and discard intermediate plate gasket.
5.Remove thrust washer from intermediate plate.Refit
1.Clean intermediate plate and mating face on
gearbox casing.
2.Apply Petroleum Jelly to new gasket and
position on gearbox casing.
3.Apply Petroleum Jelly to thrust washer and
Torrington race.
4.Correctly position Torrington race and thrust
washer to forward clutch hub.
5.Position converter housing and intermediate
plate assembly to gearbox casing.
6.Clean bolts and plain washers and old sealant
from 4 bolt threads.
7.Apply High Formular Hylomar sealant to 4
longer bolt threads and fit bolts in position
shown.
8.Fit remaining bolts and tighten progressively in
a diagonal sequence to 46 Nm (34lbf. ft).
9.Place LRT-44-003/1 into pump housing, tighten
screws to secure LRT-44-003/1 to input shaft.
10.Clamp a suitable steel base to converter
housing flange.
M44 1344
M44 1345
M44 1344
M44 1358
LRT-44-003/1

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-38 REPAIRS
11.Mount DTI gauge and position gauge probe
onto LRT-44-003/1 and zero gauge.
12.Check that the axial end-float is between 0.2 to
0.4 mm (0.008 to 0.016 in). If end-float in not
within limits, replace existing thrust washer,
positioned at rear of intermediate plate, with a
suitable thickness thrust washer to give the
required end-float.
13.Remove DTI gauge and base plate.
14.Fit torque converter oil seal.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, REPAIRS, Torque converter and oil
seal.
Intermediate plate
$% 44.17.20
Remove
1.Remove intermediate plate gasket.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, REPAIRS, Gasket - intermediate plate.
2.Remove selective thrust washer from
intermediate plate.
3.Remove 2 M14 Allen plugs from intermediate
plate, remove and discard sealing washers.
4.Remove 2 M20 plugs from intermediate plate,
remove and discard sealing washers.
5.Remove 2 oil cooler pipe adaptors from
intermediate plate.
6.Remove 8 bolts securing fluid pump to
intermediate plate and carefully remove pump
from intermediate plate.
2443
M44 1356
3
M44 1336

REAR AXLE
51-12 OVERHAUL
6.Ensure original head bearing shim is clean and
free from burrs and fit under bearing race.
7.Ensure pinion bearing cup recesses are clean
and free of burrs and using LRT-51-018-4 fit
pinion head and tail bearing races.
8.Fit pinion head bearing to pinion.
9.Lubricate bearings with thin oil.
10.Ensure original tail bearing shim is clean and
free from burrs and fit under bearing race.
11.Fit pinion and pinion tail bearing.
12.Fit pinion flange, washer and bolt.
13.Use LRT-51-003 to restrain pinion flange.
14.Tighten pinion flange bolt to 100 Nm (74 lbf.ft).
15.Check pinion for end float. Should read zero.
16.Rotate pinion several times to settle bearings,
check pinion Torque to Turn. Torque to Turn
should be recorded during pinion rotation.
Pinion Torque to Turn should be 4 to 6 Nm (3 to
4.5 lbf.ft).
17.Adjust size of tail bearing shim to obtain correct
pinion Torque to Turn (0.025 mm = 1 Nm
(0.001' = 0.7 lbf.ft) approximately).
18.Position LRT-51-018-7 on surface plate,
establish zero and reference DTI.19.Ensure pinion height setting block, setting
gauge and mating faces are clean and free
from burrs.
20.Locate setting block LRT-51-018/11 over
pinion head, ensure it is fully seated in position.
21. Pinion height setting procedure:
l'A' = Nominal pinion height setting, 74.390.
l'B' = Setting block height.
l'C' = Head height setting.
l'C' = 'A' - 'B'. Subtract nominal pinion height
'A' from setting block height 'B' (on side of
setting block).
lExample: 74.390 - 73.130 = 1.26 mm
(2.929' - 2.88' = 0.049'). Therefore pinion
head height reading is 1.260 mm
± 0.025
mm (0.049'
± 0.001').
CAUTION: Setting block height must be
checked using figures on side of block.

REAR AXLE
OVERHAUL 51-13
22.Align setting gauge LRT-51-018/7 to setting
block, rock gauge to obtain minimum reading. If
reading is lower than required reading,
decrease shim size. If reading is higher than
required reading, increase shim size.
23.Using LRT-51-003 to restrain pinion flange,
remove bolt and washer. Remove pinion
flange.
24.Remove pinion, collect tail bearing and tail
bearing shim.
25.Remove pinion head bearing outer race and
shim. Discard shim. Ensure bearing race
recess is clean and free from burrs.
26.Fit calculated shim, and using LRT-51-018/4 fit
head bearing outer race.
27.Fit pinion, pinion tail bearing and tail bearing
shim.
28.Fit pinion flange and bolt and washer. Using
LRT-51-003 to restrain pinion flange, tighten
bolt to 100 Nm (74 lbf.ft).
29.Rotate pinion in both directions to settle
bearings.
30.Recheck pinion Torque to Turn, adjust if
necessary.
31.Recheck pinion head height.
32.Using LRT-51-003 to restrain pinion flange,
remove bolt and washer. Remove pinion
flange.
33.Discard bolt.34.Using LRT-51-010 fit pinion seal.
35.Ensure spacer and tail bearing are correctly
located.
36.Fit pinion, pinion flange and washer.
37.Fit new pinion flange bolt and tighten to 100 Nm
(74 lbf.ft).
38.Lightly oil differential bearings.
39.Ensure spring dowels are fitted in bearing caps.
40.Fit differential bearing outer races and locate
differential assembly into housing.
41.Fit bearing caps and tighten bolts to 10 Nm (7.5
lbf.ft).
42.Fit adjusting nuts, tighten crown wheel side nut
to 22 Nm (16 lbf.ft). Ensure opposing nut is
loose.
43.Position DTI to check crown wheel backlash.
Adjust opposing nut to obtain correct crown
wheel backlash.
44.Rotate pinion in both directions to settle
bearings.
45.Measure in 3 places to obtain correct crown
wheel backlash.
NOTE: Crown wheel backlash should be within
0.076 mm - 0.177 mm (0.003' - 0.007').
46.Align adjusting nuts to next roll pin slot, do not
loosen nuts to align slots.

REAR AXLE
51-14 OVERHAUL
47.Tighten bearing cap bolts to 90 Nm (66.5 lbf.ft).
48.Secure adjusting nuts with new roll pins.
49.Apply Prussian Blue to crown wheel teeth to
check tooth contact.
50.Rotate pinion several times to obtain full tooth
contact.51.A = Normal pattern, the drive pattern should be
centred on the gear teeth. The coast pattern
should be centred on the gear teeth but may be
towards the toe. There should be some
clearance between the pattern and the top of
the gear teeth.
52.B = Backlash correct, thinner pinion shim
required.
53.C = Backlash correct, thicker pinion shim
required.
54.D = Pinion shim correct, decrease backlash.
55.E = Pinion shim correct, increase backlash.
56.Note assembly Torque to Turn when checking
tooth contact. Total Torque to Turn should not
exceed 10.85 Nm (8 lbf.ft).
Reassembly
1.Fit differential assembly.

STEERING
57-6 DESCRIPTION AND OPERATION
Tilt adjustment
The column tilt adjuster lever mechanism is located on the LH side of the steering column and allows the upper column
tube, nacelle and steering wheel assemblies to be tilted up or down a maximum of 7.5
° or 47 mm (NAS vehicles have
a smaller range of movement than the ROW vehicles).
The pawl of the mechanism is attached to the lower column and is allowed to pivot, a toothed quadrant is fixed to the
upper column tube.
When the lever on the LH side of the steering column is raised the mechanism releases the pawl from the toothed
quadrant, this allows the column to be moved. When the lever is released two return springs pull the pawl into
engagement with the toothed quadrant.
Steering column lock (All except NAS)
The steering column lock houses the ignition switch, ignition illumination light ring, key lock barrel and the alarm
passive coil. The steering lock is attached to the upper column with two shear bolts. The bolts are tightened to a
torque which shears off the heads of the bolts preventing easy removal of the steering lock.
The steering lock operates by a bolt, which emerges when the ignition key is turned to position 'O' and the ignition key
removed. The bolt engages in a lock collar located on the upper shaft in the upper column tube. The lock collar is
attached to the upper shaft by a 'wave form' interference ring. If a high torque is applied via the steering wheel with
the lock engaged, the lock collar will slip on the upper shaft. This prevents damage to the steering lock, yet still
prevents the vehicle from being driven.
Steering column lock (NAS only)
The steering column lock houses the ignition switch, ignition illumination light ring, key lock barrel and the alarm
passive coil. The steering lock is attached to the upper column with two shear bolts. The bolts are tightened to a
torque which shears off the heads of the bolts preventing easy removal of the steering lock.
The steering column lock operates by a bolt, which emerges when the ignition key is turned to position 'O' and the
ignition key removed. The bolt engages in a groove machined into the upper shaft in the column tube.
Steering wheel
The steering wheel comprises a cast centre and wire frame onto which the soft polyurethane foam is moulded. The
steering wheel is located on the upper column shaft by a spline and is secured with a nut. A remote radio control switch
(if fitted) is located on the LH side of the steering wheel, a cruise control switch may be located on the RH side. Horn
switches are located on each side of the centre of the steering wheel and protrude through the airbag module cover.
Both switches are connected by wires to the rotary coupler connector.
Intermediate shaft
One end of the intermediate shaft is attached to the steering column lower shaft by a splined universal joint and a bolt,
the universal joint is part of a rubber coupling assembly. The rubber coupling assembly is covered by a heat shield
and connects to the lower section of the intermediate shaft via a decouple joint. The rubber coupling reduces the
shocks felt by the driver through the steering wheel. A second universal joint on the other end of the intermediate shaft
is held in by a bolt. The universal joint is splined and engages with the splined rotor (input) shaft of the steering box.
The decouple joint consists of a metal plate that has open ended slots, the plate is bolted through the slots into the
other half of the decouple joint. The top half of the decouple joint has a slot that accepts the lower section of the
intermediate shaft. The slotted metal plate clamps the lower section of the intermediate shaft to the top section. An
indicator clip is installed between the slotted metal plate and the top half of the decouple joint.
If the intermediate shaft is compressed in an accident, the slotted metal plate in the decouple joint will disengage if
sufficient force is applied to the front end of the shaft. If the forces involved do not disengage the shaft, the red
indicator clip located in the decouple joint will break off if the shaft moves. The intermediate shaft cannot be repaired
and must be replaced as an assembly if accident damage occurs.

STEERING
DESCRIPTION AND OPERATION 57-9
Principle of operation
Movement of the input shaft is transferred through the pin to the torsion bar and valve rotor on the input shaft. As the
input shaft turns, the spline of the torsion bar turns the worm gear. This action causes the roller to rotate on its bearings
and move. As the roller is located by a pin to a yoke on the output shaft, the output shaft rotates in the steering box
housing. As the amount of torque acting on the input shaft increases the torsion bar starts to twist. As the torsion bar
twists the valve rotor turns in the valve sleeve. When the ports in the valve rotor and valve sleeve are turned, hydraulic
fluid is directed to chamber 'A' or 'B' in the power cylinder.
With hydraulic fluid in one chamber under high pressure, the piston moves. The return line ports in the rotary valve,
aligned by the movement of the valve rotor, allow the fluid in the opposite chamber to flow to return. The teeth of the
rack move and transfer the force from the piston to the output shaft, giving assistance to move the drop arm. As the
output shaft rotates the torsion bar load is decreased. The rotor on the input shaft will return as the torsion bar
unwinds, the rotary valve will then be in a neutral position and the pressure in chambers 'A' and 'B' will equalise. With
no high pressure acting on the piston, force on the piston and rack is released.
To prevent heat accumulation at full steering lock due to excessive pressure, a relief valve inside the steering box is
opened as the box approaches full lock. The relief valve pins are located in the cylinder cover and housing and are
not to be adjusted.
The steering box design ensures a mechanical link through the course spline on the control valve rotor, the spline will
become engaged if:
lThe hydraulic pressure fails.
lThe steering box rotary control valve fails.
The course spline may also engage in some full lock situations if sufficient torque is applied to the input shaft.
Rotary control valve
The rotary valve assembly comprises of three parts. The valve sleeve is fixed inside one end of the worm gear, the
valve sleeve has ports through it to allow the passage of hydraulic fluid. The input shaft has a valve rotor machined
on one end, the valve rotor also has ports through it and can rotate in the valve sleeve. A torsion bar is attached to
the input shaft by a pin, the torsion bar goes through the input shaft and valve rotor and is engaged by a spline into
the worm gear.
The course spline on the end of the valve rotor is loosely engaged in the worm gear, the course spline can make
contact and drive the worm gear in some full lock and in no pressure conditions. In the event of a torsion bar failure,
power assistance will be lost, the course spline will drive the worm gear and enable the vehicle to be steered and
driver control maintained.

STEERING
57-10 DESCRIPTION AND OPERATION
Rotary control valve at neutral
1Worm gear
2Torsion bar
3Valve sleeve
4Pin5Input shaft and valve rotor
6Piston/rack
7Coarse spline
8Spline (torque shaft to worm gear)
When there is no demand for assistance the torsion bar holds the ports in the valve sleeve and valve rotor in a neutral
relationship to one another. The ports in the valve sleeve and the valve rotor are so aligned to allow equal (low) fluid
pressure on each side of the piston. Excess fluid flows through ports in the valve rotor through the valve sleeve and
back to the reservoir.