1998 JAGUAR X308 service

The
measurement of the maximum system pressure, (which is
governed by the pressure relief valve) is achieved by
inserting the Service Tool (pressure gauge and adaptors) into th e fluid circuit of the power steering system. Run the engine
at idle speed, turn the st eering from lock to lock and read the ma ximum pressure recorded on the gauge.
Installin
g Test Equipment
To
in
stall the pressure test equipment:
Pla
c
e a suitable drain tray be
low the power steering pump.
Install a hose clamp on
the re
servoir to pump hose prior to disconnecting any hoses, to avoid unnecessary loss of
fluid.
Disc
onnect the hose from the power st
eering pump high pressure outlet.
Install the pu
mp outlet to hose adaptor (5
). Do not omit the 'O' ring seal (9).
Connect the power steering
pump
adaptor to control valve hose (6) of the test equipment.
Install th e adaptor (4) in th
e high
pressure hose previously removed from the power steering pump outlet.
Conn
ect the connector (3) of the test equipment hose (2) to the adaptor (4).
R
e
move the hose clamp fro
m the reservoir hose.
Start th
e engine.
With the control valve (7) OPEN and the engine idli ng, the following system pressures may be checked:
Du
ring turning.
W
h
en the steering is
held on full lock.
With
the steeri
ng at rest.
• CAUTIONS:
To avoid excessive heating of the po wer steering pump, do not close the valve for longer than 5 seconds maximum.
Do not drive the vehicle with the test equipment installed.
With the control valve (7) CLOSED the power steering pump maximum ou tput pressure can be checked.
Removing Test Equipment
To
remove the test equipment:
Install a hose clamp
on
the reservoir to power steering pump hose.
Re
movi
ng the test equipmen
t is a reversal of the in stallation instructions.
Install a new '
O
' ring seal (9) to the power steering pump high pressu
re outlet to hose connection.
Instal
l the original hose to
the power steering pump.
Re
move the clamp from the reservoir to
the power steering pump hose.
Top-up the reservoir flui
d.
Ble
e
d the power steerin
g system. For additional information,
REFER to Power Steering System Bleeding
- in thi
s section.
Stee
ring Fault Diagnosis by Sympt
om Charts
Leakage
52
11-0
11-03/1
Pump High Pressure Ou
tlet
to Hose Adaptor
621
1
-011-02
Pump Adaptor
to Contro
l Valve Hose
721
1
-011-01
Control Valve
82
11-
011
Pressure Gauge
9-'O
'
Ring Seal
Cond
iti
on
Possib
l
e Sources
Acti
o
n
Co
nfirm
the position of the fluid
leak.
CLEAN th
e area of the leak.
In
s
pect the area and confirm the exact position of leak.
Make sure the fluid
is not from anoth
er system on
the vehicle.

Description of General Stee
ring System Noises
Boom
Rh
ythmic sound like a drum roll or distant
thunder. May cause pressure on the ear drum.
Buzz
Low-pitched soun
d, like a bee. Usually associated with vibrations.
Chatt

er
Rapidly rep

eating
metallic sound.
Chuckle
Rapid noise that soun
ds like
a stick against the spokes of a spinning bicycle wheel.
F
eedback (knocking noises in the
steering gear) - condition where roughness is felt in the steering
wheel by the driver when the vehicle
is driven over rough surfaces
REF
ER to Section 211
-0
3 Steering Linkage
.
Steeri

ng gear
retaining bolts
loose or damaged.
CAU
TION: DO NOT attempt to adjust the
steering gear yoke. Failure to follow this instruction
will result in the steering gear warranty to become
invalid.
CHECK
and TIGHTEN the steering gear
retaining bolts.
INST
ALL new retaining bolts as necessary.
For additional information,
REFER to Section 211
-0
2 Power Steering
.
L

oose suspension
bushing, bolts or ball joints.
TIGHTE
N or INSTALL new components as
necessary. For additi onal information,
REFER to Section 204
-01
Front Suspension
.
Steeri

ng column
retaining bolts loose.
CAU
TION: DO NOT attempt to adjust the
steering gear yoke. Failure to follow this instruction
will result in the steering gear warranty to become
invalid.
CHECK
and TIGHTEN the steering column
retaining bolts/nuts and pinch bolts if required. For additional information,
REFER to Section 211
-0
4 Steering Column
.
Exce

ssive wear in
steering column assembly.
CHECK
for steering column for wear in the
universal joints and be arings. If wear is
present, INSTALL a new steering column as
necessary. For additi onal information,
REFER to Section 211
-0
4 Steering Column
.
Ni

bble (Shimmy) Oscillation of the
steering wheel (not vertical which is SHAKE). This is driven by road wheel imbalance.
Road wh
eel
imbalance.
CHECK
for road wh
eel imbalance.
CHECK for
rele
vant SERVICE
BULLETINS/SERVICE ACTIONS for the
vehicle on Jaguar Communications Online (JCOL) or in hard copy form.
S
teering wheel
replacement.
CHECK for
rele
vant SERVICE
BULLETINS/SERVICE ACTIONS for the
vehicle on Jaguar Communications Online (JCOL) or in hard copy form.
Rac
k replacement.

CHECK for
rele
vant SERVICE
BULLETINS/SERVICE ACTIONS for the
vehicle on Jaguar Communications Online (JCOL) or in hard copy form.

The steering rack assembly :
Is mounted on the
rear face of the
front suspension crossbeam by two forg ed mounting brackets with resilient
bushes. The bushes are handed (pinion side and non-pinion side) and are orientated according to the vehicle range
application.
Convert s
the rotary motion of the steering wheel, via the steering gear pinion, to the lateral motion of the rack.
F
e
atures a variable ratio steering
rack with integral hydraulic po wer steering cylinder and piston.
Has a hydrauli
c control valve with Servotronic co
ntrol and positive center feel torsion bar.
The basic steering rack assembly is not serviceable. The following components are serviceable items:
Transfer pipework
.
Servotronic valve. Cent
ralizing cap.

O
u
ter ball joint.
Rac
k
gaiter.
Clips and

fittings.
Steering Rack Components
It e
m
Par
t
Number
De
scr
iption
1—Front
su
spension crossbeam
2—Steeri
ng rack housi
ng
3—Hydraulic

control valve housing
4—Moun
ting bracke
t
5—Gait
er

6—Tie
rod

7—O
u
ter ball joint

Steering R
a
ck Assembly

P a
rts List
The power assisted steering pump:
Is mo u
nted on a bracket installe
d on the front of the engine.
Provides hydraul
ic pressure fo
r the power steering system.
Is of the roll
er vane type.
Is belt driven from th
e en
gine crankshaft.
Will provide 1
05 bar f
luid pressure.
The pump is not serviceable and should be renewed as a complete assembly.
Fluid Reservoir
Re
servoir and Hoses

Ite
m
Par
t
Number
De
scr
iption
1—Power as
si
sted steering pump
2—Engine
m
ounting bracket
3—High
pressure port

Power Assisted Steering Pump

P a
rts List
The supply and return pipes are secured to the hydraulic control valve housing by a latch-plate having a single fixing screw.
The latch-plate is captive to the supply pipe. Each pipe has an O-ri ng which is a serviceable item.
In-Line Quick-Fit Connector

Parts List

Ite
m
Par
t
Number
De
scr
iption
1—Return
pipe (RH drive)
2—Supply pipe (RH
drive)
3—Latc
h-plate
4—Latch-
plate securing screw
It
e
m
Par
t
Number
De
scr
iption
1—Qu
ic
k-fit connector
2—Return
pipe

Latch
-Plate Location

m
ember. The quick-fit connector O-rings are not serviceable.
Special tool JD 182 is required to disconnect the quick-fit connector.
Hydraulic System


P
arts List
Hydraulic System

Op
erating Principle
The rot
ary motion of the steering wheel is converted, via the st
eering rack pinion, to the lateral motion of the rack. Steering
assistance is provided by pressurized fluid being directed against a piston operating within the rack cylinder. Rack
movement is achieved by diffe rential pressures being applied on either si de of the rack piston, caused by unequal
restrictions within the hydraulic control valve.
The main components of the hydraulic control valve are the rota ry distributor, control sleeve and hydraulic reaction piston.
It
em
Par
t Number
De
scription
1—F

luid reservoir
2—Pum

p
3—Pressure and fl

ow limiting valve
4—Supply line
5—R

eturn line
6—Steeri

ng rack
7—Pin

ion
8—O

perating cylinder and piston
9—Hydrau

lic control valve
10—Hydraulic reaction

piston
11—Control

sleeve
12—R

otary distributor
13—F

luid cooler


A
quick-fit connector with double O-ring se
als is incorporated in the return line and is clipped to the right-hand chassis side

The driver air bag is moun
ted below the horn operat
ing pad area, adjacent to the steering wheel hub.
For air bag safety and service information, refer to Section 501
-20A Safety Belt
System
Sectio
n
501
-2
0B Supplemental
Re

straint System
.
Upper Steering Column


Motorized Upper Colu
mn Assembly

The motorized upper steering column:
Is adjustable for both til
t and reach.
Has a col

umn adjustment switch installed on
the left-hand side of the lower cowl.
W
ill automatically move to the uppermost tilt and innermost reach position, when the automatic driver entry and exit

function is selected.
Has an instrument li
ghti
ng dimmer switch installed on the left-hand side of the lower cowl.
The steering column adjustment switch:
Controls steeri
ng column reach by
movement of the switch towards an d away from the steering wheel.
Controls steeri
ng column tilt by mo
vement of the switch up and down.
Has two
rotary positions, AUTO and OFF, for selecting the
automatic entry and exit steering column tilt function.
It
em
Par
t Number
De
scription
1-Upper

cowl

2-Lower cowl
3-Ste
ering column adjustment switch
4-Di

mmer switch

The te
lescopic slider provides driver crash
protection by retracting automatically in the event of an accident; it is clamped in
position to a preset torque.
The motorized upper steering column has the following serviceable parts:
Igniti
on switch assembly.
Igni
ti
on key interlock solenoid.
Ti
lt
motor assembly.
Reach motor assembly.
Manu al Upper Column Assembly


Ite
m
Par
t
Number
De
scr
iption
1-L
o
wer mounting bracket
2-Crash tube
3-Harnes
s c
onnector bracket
4-Tilt motor

5-Reach m
otor
6-Upper
moun
ting bracket
7-Ignition switc
h
(hidden)
8-Igni
ti
on key interlock solenoid
9-S
t
eering wheel mounting shaft
It
e
m
Par
t
Number
De
scr
iption
1-Upper
cowl
2-Lower cowl
3-Colu
mn tilt adjustment lever

4-Col
u
mn reach adjustment lever
5-Di
mm
er switch
Motorized Upper Co
lumn Components