JAGUAR X308 1998 2.G Repair Manual
Page 61 of 2490
Suspension System - General Information - Front Camber and Caster
Adjust
ment
Gen
eral Procedures
• NOTE: Before any work is commenced, th e vehicle must be checked to establish that it conforms to the Jaguar original
specification, e.g. wheels, ti res, tire pressures, etc.
• NOTE: The vehicle must be unladen and the fuel tank full when measuring suspension geometry.
1.
Road test the vehicle to establish the exact nature of the
complaint, e.g. pulling to one side, wander.
2. Measure the suspension geometry, fill in the 'Suspension
Geometry Record Form', and co ntact Jaguar Technical Support
for assistance.
3. Technical Support will give advice on the course of action to be
taken to rectify the problem.
4. Each lower wishbone pivots on and is secured to the front
crossbeam by two fulcrum bolts. A circular eccentric flange
formed under the hexagonal head of each fulcrum bolt, has
raised graduation marks to indicate radial position. A washer
with a 'D' shaped hole locates on a flat on the threaded section
of each bolt. This ensures that the washer rotates with the bolt,
maintaining an eccentric position corresponding with the
flanged head. The outer face of the washer is punch marked,
ensuring correct instal lation with the chamfered face inwards.
This permits the washer to rotate freely in the crossbeam cam
reaction plate during a djustm ent. Each fulcrum bolt and
washer are secured by a self locking nut.
On rotation of the bolt, lateral movement of the eccentric flange
and washer is restricted by the cam plate faces, forcing the bolt
shank to move laterally in the crossbeam slots. Lateral
movement of the bolt shank re sults in corresponding inward
and outward movement of th e wishbone arm, effecting
adjustment of wh eel alignment.
Rotation of the front fulcrum bolt principally adjusts wheel
caster angle, with a small amount of camber angle change.
Adjustment of the rear fulcrum bo lt mainly alters wheel camber
angle with a small amount of caster angle change.
On vehicles with VIN up to 833124, fulcrum bolt eccentric
flanges have raised graduation marks representing 15 degree
increments of bolt rotati on from 0 to 90 degrees.
On vehicles with VIN from 833125, the fulcrum bolt graduation
marks represent bolt shank ho rizontal movement in 1mm
increments from 0 to 3mm.
The upper wishbone and fulcrum shaft are not adjustable and
play no part in steering geometry adjustment.
Page 62 of 2490
Suspension System - General Information - Front Camber
, Caster and Toe
Adjustment
Gen e
ral Procedures
1.
NOTE: Before checking or adju sting any alignment, examine
the vehicle for curb impact dama ge on wheels and subsequent
damage to steering and suspension components.
• NOTE: Wheel alignment must no t be carried out with a space
saver wheel installed on any of the hubs.
• NOTE: Before carrying out any ch ecking or adjustment of wheel
alignment, ensure that the vehicl e wheels, tires and tire pressures
are to Jaguar specification.
• NOTE: Position steering wheel in straight ahead position before
adjusting front wheel toe evenly on both tie rods to maintain
centralization of steering wheel.
Position alignment checking equipment on vehicle and following
equipment manufacturer's instructions, check and if necessary
adjust to Specifications in Section 204-01.
2. Check and as necessary adjust front wheel caster. Refer to
57.65.05.
3. Check and as necessary adjust front wheel camber. Refer to
57.65.06.
4. Check and as necessary adjust fr ont wheel alignment. Refer to
57.65.01.
Page 63 of 2490
Suspension System - General Infor
mation - Front Toe Adjustment
Gen
eral Procedures
1.
NOTE: Before checking or adju sting front wheel alignment,
examine the vehicle for curb impact damage on wheels and
subsequent damage to steering and suspension components.
• NOTE: Wheel alignment must no t be carried out with a space
saver wheel installed on any of the hubs.
• NOTE: Before carrying out any ch ecking or adjustment of wheel
alignment, ensure that the vehicl e wheels, tires and tire pressures
are to Jaguar specification.
• NOTE: Position steering wheel in straight ahead position before
adjusting front wheel toe evenly on both tie rods to maintain
centralization of steering wheel.
Position alignment checking equipment on road wheels and
following equipment manufacturer's instructions, check and if
necessary adjust front wheel toe to Specifications in Section
204-01.
Page 64 of 2490
Suspension System - General Inform
ation - Rear Toe Adjustment
Gen
e
ral Procedures
1.
NOTE: Wheel alignment must not be carried out with a space
saver wheel installed on any of the hubs.
• NOTE: Before carrying out any ch ecking or adjustment of wheel
alignment, ensure that the vehicl e wheels, tires and tire pressures
are to Jaguar specification.
• NOTE: Before checking or ad justing rear wheel alignment,
examine the vehicle for curb impact damage on wheels and
subsequent damage to suspension components.
Position alignment checking equipment on road wheels and
following equipment manufacturer's instructions, check and if
necessary adjust rear wheel alignment to Specifications in
Section 204-02.
Page 65 of 2490
Suspension System - General Information - Wheel B
earing Circlip
Inspection
Gen
eral Procedures
1.
Wh
en installing the bearing circli
ps in the vertical link ensure
that the ears are located at the lowest position to permit water
drainage.
To achieve this, a perpendicular line drawn through the
suspension upper ball-joint will indicate the position of the gap
between the circlip ears. This procedure makes an allowance for
the caster angle prior to installing the vertical link.
Page 66 of 2490
Suspension System - General Information - Wheel Bearing Inspection
Gene
ral Procedures
1.
Dur
ing use, a small amount of surplus grease may appear
around the bearing seal, this does not indicate a failed bearing
or seal. The grease should not be removed as this will act as an
additional barrier to the ingress of water or foreign matter.
Excessive end float or bearing ru mble will indicate a failed
bearing; for maximum permissibl e end float see specification
section. Take care not to confuse suspension ball joint or upper
or lower fulcrum bu sh movement for bearing end float.
If the hub is removed for any reason, a new bearing assembly
must be installed. Never at tempt to re-use a bearing.
Page 67 of 2490
Front Suspension -
Lubri
cants, Fluids, Sealants and Adhesives
Press-In Loads
Torques
UnitS
pecification
Loctite27
0
Greas
e
Shell Retin
ax 'A'
Greas
e
Castro
l 'NTR'
Com
ponent
Kn
Ball join
t to upper wishbone
25
- 50
B
all joint to lower wishbone
25
- 50
Com
ponent
Nm
N
ut - ball joint, upper wishbone to vertical link.
60
-80
N
ut - ball joint, lower wishbone to vertical link.
60
-80
Nu
t - fulcrum bolt, upper wishbone.
60
-80
N
ut - ball joint, tie rod to steering arm.
71
-85
Bol
t - wheel speed sensor to vertical link.
8-1
0
Bol
t - front mounting to crossbeam.
22
-28
Bolt
- mounting , stabilizer bar.
30
-40
N
ut - link arm ball joint to stabilizer bar.
60
-80
Bolt
- mounting, steering rack to crossbeam.
41
-54
B
olt - front mounting, crossbeam to body.
22
-28
Bol
t - spring pan to lower wishbone.
70
-90
N
ut - shock absorber to upper mounting
(vehicles with adaptive damping).
16
-18
Nu
t - shock absorber to upper mounting (vehicles without adaptive damping).
30
-40
N
ut - shock absorber lower to wishbone.
43
-57
B
olt - engine Hydramount to crossbeam.
34
-46
B
olt - crossbeam rear mounting to body.
13
1-185
Bol
t - generator cooling du
ct deflector to crossbeam.
17
-23
N
ut - lower steering column to pinion shaft.
22
-28
N
ut - hub, speed sensor rotor.
27
0-330
B
olt - shield, brake disc.
9-1
2
Bol
t - lower wishbone, front arm to rear arm.
77
-103
Nu
t - stabilizer bar link arm to wishbone bracket.
41
-54
N
ut - wishbone front
eccentric bolt.
11
3-153
Nu
t - wishbone rear
eccentric bolt.
11
3-153
N
ut - fulcrum shaft, upper wishbone.
60
-80
Bolt -
power steering pi
pes to pinion housing.
9-1
2
Page 68 of 2490
Front Suspension - Front Suspension
Description and Operation
Ite
m
Par
t
Number
De
scr
iption
1—Suspensi
on C
rossbeam
2—Hub Assembly
3—Sprin
g
4—Shock Absorber
5—St
abil
izer Bar
Page 69 of 2490
Front C
rossbeam
A
fully stressed, pressed steel and tube fa
brication with integral lower wishbone tie bars, the crossbeam is secured to the
body on four resilient mountings.
The crossbeam incorporates mounting points for:
The u
pper and lower wish
bone fulcrum bolts.
The
stabilizer bar
The power steering rack. The engine h
ydramounts.
R
oad springs.
Slots and cam reaction pl ates on the crossbeam provide for ad justment of suspension geometry.
It
em
Par
t Number
De
scription
1—Cro
ssbeam
2—Upper
Wishbone
3—Lower Wi
shbone Arm, Front
4—Lower Wi
shbone Arm, Rear
5—Upper
Wishbone Ball Joint
6—Lower Wi
shbone Ball Joint
7—Ful
crum Bolt
8—Adjuster B
olt, Front
9—Adjuster B
olt, Rear
10—S
pring Pan
11—Shock Absorber Lower M
ounting Plate
12—Vertical Link
13—Hub Assembly
14—Sensor R
otor
15—B
olt, Wishbone to Link Arm
Page 70 of 2490
Upper
Wishbones
Each
upper wi
shbone assembly is a on
e-piece steel forging incorporating:
A pres
s-fit ball joint.
Press-fi
t bushes for location of the upper fulcrum bolt.
Lower Wishbones
Each l
o
wer wishbone comprising
forged steel front and rear arms bolted together, incorporates:
A p
ress-fit ball joint in the outer extremity of the rear arm.
Press-f
i
t bushes for location of the lower fulcrum bolts
Locati
on for the shock absor
b
er lower mounting plates.
Vertica l Links
The vertical
links are of forged steel
wi
th integral steering arms. Each is suppo rted between the upper and lower wishbones
by two ball joints and carries:
Front hub
Brake ca
liper and disc shield assembly
ABS se
nsor
.
Front Hub
s
Each f
o
rged steel front hub accommodates sealed for life cartridge
type wheel bearings, and carries:
The brake rotor assembl
y.
A
h
ub nut with toothed, integral ABS rotor.
Su
s
pension spring pi
n locking device.
Front Road
Springs
The road spri
ng
s are of coil type with their
rating dependent upon vehicle specification
Ea
ch spring is installed between the suspension crossbeam location and the lower wishbone spring pan.
Ru
bber seats ar
e installed betw
een the spring and the crossb eam and the spring pan.
Front Shock A
bsorbers
Th
e
shock absorbers are telescopic hydrau
lically operated units. Optional adaptive damping units incorporate a solenoid-
operated control valve at their upper extremity.
Each shoc
k absorber is installed between the lowe
r wishbone rear arm and a recess in the body.
The l
o
wer end of the shock absorber is se
cured to plates on the wishbone by a bolt that also serves as a pivot.
The u
pper en
d of each shock absorber is secured to the body location by a single nut.
Front Sta
b
ilizer Bar
A
front stabil
izer bar installed on all vehicles
is rated according to suspension specification.
Opera
tion
As each road wheel r
i
ses, move
ment is transmitted through the vertical link assembly to the lower wishbone. The resulting
rise of the wishbone compresses the road spring and partially telescopes the shock absorber. During this action, the spring
absorbs associated shocks and the shock absorber minimizes sprin
g os c
illation.
Du
ring cornering, vehicle weight
is transferred to the outer road wheel with a resulting tendency for the inner wheel to lift.
The stabilizer bar assists in minimizing this tendency by transf erring a proportion of potential lift of the inner wheel to the
outer wheel. This result s in enhanced body stability with improved corner ing capabilities.