1998 JAGUAR X308 wheel

The rotary distri
butor and control sleeve turn relative to ea
ch other, forming the unequal restrictions which create the
differential pressures to operat e the rack piston; the displacement of the di stributor and sleeve being controlled by the
elastic deformation of a torsion bar which is concentric with the pinion and valve. Refer to Positive Center-Feel Torsion Bar
in this sub-sectio n.
The hydraulic reaction piston moves axially, relative to th e rotary distributor, and is connected to the control sleeve by a
three-bearing helical screw. Pressure applied either side of the hydraulic reaction piston is translated into a rotational force
which increases steering effort. For detail s of Servotronic speed-sensitive steering control, refer to Servotronic Control in
this sub-section.
When the vehicle is travelling straight ah ead, the valve restrictions are balanced, thus providing equal pressures on either
side of the rack piston. When load is a pplied at the steering wheel, the two halves of the control valve (rotary distributor
and control sleeve) are displaced making the restrictions unequa l. The resulting differential pressures on either side of the
rack piston, assist the steering rack to mo ve to left or right. As the turning load is removed, the pressures equalize again
and the steering return s to the straight ahead position , aided by suspension geometry.
Serv
otronic Control

P a
rts List
The Servotronic system provides steering assistance which is pr oportional to vehicle speed. It comprises the steering control
module, and Servotronic valve forming part of the hydraulic control valve assembly.
The Servotronic valve is an electro-hydrauli c device with a variable orifice, which varies in size according to the position of a
needle valve. The needle valve is controlled by a solenoid in response to a variable current input from the steering control
Ite
m
Part
Number
Descr
iption
1—Vehi
cl
e speed input
2—Steeri
ng control
module
3—Servotronic valve
4—Hydraulic

control valve housing
5—PAS stee
rin
g pump
6—Batt
ery

Power Steering - Steering Gear
Remo
val and Installation
Remov
a
l
All vehicles
S
p
ecial Tool(s)

Taper Sep
a
rator
211-098 (JD 100)
1. Centralize steeri ng the wheel.
2. Raise and support the vehicle on a four-post ramp.
3. Place a suitable drain pan under the stee ring gear.

4. Fr
om below the vehicle, check that
steering gear is centralized
by aligning the centralizing notc h on the dirt protection cover
with the location hole in the pinion housing casting.

5. NOTE : R
ight-hand shown, left-hand similar.
Remove and discard bo th tie rod end nuts.

6. NOTE : R
ight-hand shown, left-hand similar.
Detach both of the tie rod ends.
1. Fit the special tool to tie rod end.
2. Tighten the tool bolt to release the taper.
Re
move the tool.

Locate the ti
e rod end into the steering arm.
Inst

all a new nut.
Tigh

ten the nut to 22-28 Nm.

12
.
NOTE: Make sure the steering wheel and wheel and tire
assemblies are in the straight ah ead position before fitting the
steering column lower shaft.
Attach the steering column lower shaft.
1. Attach the steering column lower shaft.
2. Install the steering column lower shaft retaining bolt.
1. Tighten to 28 - 34 Nm
.
3

. Tighten to 28 - 34 Nm.
13. Fit a new power steering fluid re servoir, refill with new power
steering fluid and blee d air from the system.
For additional information, refer to: Power Steering System
Fillin
g and Bleeding

(211-00 Steering System - General
Information, Gene ral Procedures).
14. Check and adjust the front toe.
For additional information, refer to: Front Toe Adjustment

(204-00 Suspen
sion System -
General Information, General
Procedures).

Steering
Linkage - Steering Linkage
Descriptio
n and Operation

Parts List
The left- and right-hand tie rod assemblies:
T
ransmit steering forces from the steering rack to the st
eering arms which are integral with the vertical links.
Comprise the tie rod, inner
ball joint,
outer tie rod end and outer ball joint.
P
rovide front road wheel toe setting by adju
stment of the threaded outer tie rod ends.
• NOTE: Steering geometry adjustments must only be carried out wi th the vehicle on turn plates to allow the wheels to move
during adjustment.
The left- and right-hand steering rack gaiters:
Are
installed between the steering rack and the tie bars.
Are

of the concertina type.
R

etain lubricant and prevent th
e ingress of foreign matter.
P
ermit movement of the steering rack and tie rods.


ItemPa
rt Number
Descript
ion
1—St

eering rack assembly
2—St

eering rack gaiter
3—I

nner ball joint
4—Tie

rod
5—O

uter tie rod end
6—Lo

ck-nut
7—Oute

r ball joint
8—O

uter ball joint nut

Steering Column -
Torques



Comp

onent
Nm
Upper
steering column upp
er fixings
22
-
28
S
t
eering wheel to column securing bolt
34
-
46
Upper
bracket
to body screws
22
-
28
Upper
steering colu mn lower fi
xings
17
-
23
Lower steeri
ng col
umn pinch bolts (upper and lower)
28
-
34
U
pper
and lower cowl securing screws
1.
5 (
nominal)
D
river ai
r bag fixings
4 -
5
Colum
n switchgear to column
4 -
5

Steering Column - Steering Column
Description an
d Operation
Stee

ring Wheel

T
he steering wheel assembly incorporates:
The s

peed control switchpack.
The i

n-car entertainment (ICE) switchpack.
The h

orn pad.
The driver ai

r bag module; refer to Section
501
-20A Safety Belt
System
Sectio
n
501
-2
0B Supplemental Restraint
Sy

stem
.
I

CE Switchpack

The
in-car entertainment (ICE) switchpack is installed to the le
ft of the steering wheel center, controlling the ICE functions
and telephone (where fitted). The switchpack overrides the corresponding bu ttons on the ICE control panel and performs
the following functions:
1. 1. Increase the volume of the select ed audio output or telephone.
It
em
Par
t Number
De
scription
1-Spe

ed control switchpack
2-I

CE switchpack
3-Horn pad
4-Air bag lo

cation
It

em
Par
t Number
De
scription
1-Vol

ume increase

2-ICE func
tions/teleph
one mode select
3-Volum
e decrease
4-ICE pres

ets/telephone memory select

2.2. Press and rel e
ase to cycle through radio FM, radio AM,
tape cassette, or CD player. Press and hold for two
seconds to select telephone mode.
3. 3. Decrease the volume of the select ed audio output or telephone.
4. 4. Press and release to select the next pr eset radio station, or the next track on tape or CD. Press and hold for two
seconds to select the next radio station on the waveband upwards, or the next CD loaded in the player, or to
change the side of tape. When in te lephone mode, press and release to scroll up to the next memory location.
Press and hold for two seconds to send and end a call.
Speed Control Switchpa ck

The s p
eed control switchpack is installed to the right of th
e steering wheel center and performs the following functions:
1. 1. Set the desired speed or increase the set speed.
2. 2. Resume the previously set speed.
3. 3. Decrease the set speed.
4. 4. Cancel speed control without erasing the set speed.
Horn and Driver Airbag Location

Ite
m
Par
t
Number
De
scr
iption
1-Se
t
speed or increase speed
2-Re
sum
e
3-De
creas
e speed
4-Cancel
Ite

m
Part
Number
Descr
iption
1-Horn operatin
g pad

The ho
rn operating pad is mounted in the central area of the steering wheel.
2-Driver air bag location

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