1994 JAGUAR XJ6 wheel alignment

Suspension Systems
Application
Camber angle front suspension
Caster angle (Same setting each side of vehicle)
Wheel alignment
Specification
+0.3' to - 0.8'
3.0' to 6.0'
5'Toe-in f 10'
Note: Geometry is to be checked/set using the mid-laden setting-links. Setting height should correspond to thefol- lowing dimensions:
Front 153 f 5mm under front crossbeam (AJ16) Front 143 f 5mm under front crossbeam (V12) Rear 160 f 5mm under rear edge of 'A' frame
Issue 1 August 1994 iv X300 VSM

Suspension Systems
Fig. 1 Rear Suspension layout
11.3 REAR SUSPENSION, DESCRIPTION
The vehicle's rear suspension layout features a cast wishbone complete with integral lower spring pan (1 Fig.1) sup- porting the independently mounted damper (2 Fig.1) and road spring (3 Fig.1).
Thelowerwishbonearmis boltedtothehubcarrier(4 Fig.1) by meansofa pivot bolt (5Fig.l),allowingfortoe-in adjust- ment. When the pivot bolt is seated correctly in the plate located on the wishbone arm, it has a small clearance at the
sides but full clearance at the top and bottom.
Rotation of the bolt head, with eccentric constrained between the vertical faces, causes the bolt shank to be moved in
the horizontal plane, thus displacing the hub carrier and effecting wheel alignment adjustment.
The snubber
(6 Fig.1) positioned above the hub carrier, prevents this from touching the vehicle body.
The hub
carrier/wishbone assembly, is pivoted on the wishbone fulcrum bolt (7 Fig.1) and is then secured by a nut and
washerfixing arrangementtothe pendulum assembly (8 Fig.1) andthe wishbonetie assembly (9 Fig.l).The differential
strut (10 Fia.1) is fastened to the wishbone tie assemblv and to a bracket, welded to the vehicle bodv. Both, the pendu- lum and the wishbone tie assembly are fitted to the differential unit which is mounted on to a mounting frame and a rear frame carrier.
The supercharged vehicle (manual only), the XJ12 and the sport versions are equipped with
a rear stabilizer bar, a dif- ferential monostrut instead of two single struts, a modified wishbone tie and two stabilizer bar drop links which are
seated on the lower wishbone cast bosses.
0
0
e
Issue 1 August 1994 X300 VSM

may include:
0
0
Loose or worn wheel bearings.
Loose or worn suspensions or steering components.
0 Worn or damaged drive shaft slip yoke joint.
0 Front disc rotor runout.
o Loose engine or transmission supports.
0 Driveline alignment.
0 Engine driven accessories.
Suspension Systems
11.4 DIAGNOSIS AND TESTING
' 11.4.1 Tire Wear
Tires should be inspected as abnormal or excessive wear may becaused by incorrect wheel alignment, wheelbire im- balance, or incorrect tire pressure.
1 1.4.2 vibration and Roughness
Vibration, roughness, and shimmy conditions may be caused by excessive tire or wheel runout, worn or cupped tires,
or wheel and tire unbalance.
Most of these conditions are due to irregularities in the road surface, hence driving the vehicle on different types of
road surface will often indicate the cause of the condition.
Do not automatically suspect the tires when attempting to diagnose a vibration concern as other sources of vibration
Before investigating any other vibration concerns,
a roaG &est and a customer inter\,.dw (if possible) should be carried
out. This can provide much of the information needed to find the source of vibration.
Drive the vehicle on a road that is preferably smooth and free of undulation and
if vibration is apparent note, the speed at which thevibration occurs, whattype of vibration occurs in each speed range (mechanical or audible), howthevibra- tion is affected by changes in vehicle speed , engine speed and engine torque, and the type of vibration sensitivity
(torque sensitive, vehicle speed sensitive, or speed sensitive).
Some of the condition terms used when describing sources of vibration are explained as follows:
0 Torque Sensitive
This condition can be improved or worsened by accelerating, decelerating, coasting, maintaining
a steady
vehicle speed and application of engine torque.
0 Vehicle Speed Sensitive
This means that the vibration always occurs at the same vehicle speed and is not affected by engine torque,
engine rpm, or transmission gear selection.
B
0 Engine Speed Sensitive
This means that the vibration occurs
at varying vehicle speeds when a different transmission gear is selected.
It can sometimes be isolated by increasing or decreasing engine speed with the transmission in 'NEUTRAL', or
by stall testing with the engine in gear. If the condition is enginesensitive, the condition is not related to tires.
If the road tests indicates that the vibration is related to the tires or wheels,use a 'lire Wear Diagnosis Chart' to
investigate the cause of concern. Should the road test indicate that there is tire whine, but noshake or vibration,
the noise originates from the contact between the tire and the road surface.
X300 VSM 3 Issue 1 August 1994

Suspension Systems
11.4.3 Front End Inspection
Do not check and adjust front wheel alignment without carrying out the following inspection for front end damage and
wear:
. Check for specified air pressure in all four tires.
Raise front of vehicle off the floor; grasping upper and lower surface of the tire, shake each front wheel to check for
. Check front suspension lower arm ball joint and mounts for looseness, wear and damage.
Check steering gear mountings and all steering linkages for looseness.
. Renew parts if necessary.
. Grasp upper and lower surface of tire and shake each wheel to check wheel bearing end play.
. Check the action of the front dampers and the condition of their attachments, as sticking or binding front dampers
worn
bearings.
Check brake caliper mountings.
may not allow the vehicle to settle in to a normal level position, possibly affecting the front-wheel alignment.
m: Front wheel bearings are adjustable (0.001 to 0.003 in. endfloat).
11.4.4
. Check the wheel bearings.
. Inspect the front suspension upper joint and renew front suspension lower wishbone if needed.
Raise vehicle and position floor jacks beneath the front suspension lower wishbone.
Grasp the lower edge of the tire and move the wheel in and out.
While moving the wheel, observe the upper and lower wishbone.
. Movement between the vertical links and the wishbones indicates abnormal ball joint wear.
. Renew ball joints.
. Check the front wheel bearings.
. Check for excessive play and wear.
Upper / Lower Ball Joint Inspection
11.4.5 Damper Inspection
m: The gas-pressurized hydraulic front dampers are not serviceable, adjustable or refillable.
Verify that all attachments of the suspension components and the front dampers are tight. Renew any front damper
. Check front dampers for external damage.
. Check for oil leakage and vehicle sag.
that
has a damaged integral lower mounting bushing.
0 Oil Leak
Leakage is the condition in which the entire damper body is covered with oil and from where
it will drip on to
the pavement. Due to correct damper lubrication a light film of oil (weepage) can usually be seen on the upper
portion of the damper.
Should there be any leakage, ensure that the fluid does not originate from sources other than the front damper.
Renew worn or damaged dampers.
0 Vehicle Sag
Renewing front dampers will not correct the problem of vehicle sag, as basically this is controlled by the spring
units.
issue 1 August 1994 4 X300 VSM

Suspension Systems
1 1.4.8 Diagnostic Procedure
Condition
Hard steering
Shimmy
I----
Bump steer (unequal
side-to-side)
Sawtooth pattern or
t excessive tire wear
Uneven tire wear
(outer or inner
shoulder)
Fronvrear
suspension noises
Possible Cause
Side-to-side difference in caster.
Tire pressure Steering gear or linkage worn or defective.
Tire
conicity
Power steering gear or linkage worn,
damaged, or incorrect adjusted.
Wear of front suspension
lower/upper
wishbone ball joints.
Unequal tire pressure.
Brake system
fault(s)
Wheel/tire imbalance or runout.
Damaged tires, unbalanced or damaged
wheels.
Incorrect wheel alignment.
Steering system malfunction
Front damper malfunction.
Loose front damper mounting.
Damaged front suspension upper
or lower
ball joints.
Damaged or worn sub
-frame to body
mounting. Damaged or worn stabilizer bar insulators.
Damaged or worn stabilizer bar link.
Damaaed or worn wheel bearina.
Rear suspension damage.
Worn steering gear mounting bracket
housing insulators.
Excessive toe
-in (high edges inboard) or
toe-out (high edges outboard).
Incorrect tire pressure.
Excessive toe.
Excessive positive or negative camber.
Loose/missing front dampers and front
damper bolt to front suspension lower
wish bone.
Action
Check the alignment and if incorrect,
adjust the caster
if needed. Inspect
components for wear or damage.
Check for abnormal loading.
Check steering system
Inspect tire for excessive wear.
Check and adjust the tire air pressure.
Note: Excessively worn or uneven tires can
cause
pull/drift.
Check steering system.
Renew ball joints.
Inflate the tires to correct and uniform
pressure.
Check the brakes.
Check wheels and tires.
Check the tires and renew
if necessary.
Balance the wheels
if necessary.
Adjust wheel alignment.
Check steering system.
Renew front damper
if necessary.
Tighten front damper mounting.
-
Renew upper and lower ball joint.
Renew rear suspension bushing.
Renew insulators.
Renew link.
Renew/adjust wheel bearing.
If the caster is uniform, check and compare
the wheelbase at the right and left sides.
If
different, inspect the suspension
components for wear and damage.
Renew bracket housing insulators.
Check and adjust toe
-in.
Correct tire pressure.
Check toe and adjust
if needed.
Check the camber and
if incorrect inspect
the related components for wear or
damage.
Tighten/renew damper bolts.
Inspect wheel hubs.
0
0
0
lssue 1 August 1994 6 X300 VSM

Suspension Systems I.\" b-
1 1.4.8 Diagnostic Procedure (continued)
Condition
30dy 'rolls'
3ody leans
'oor ride comfort
Seneral driving
nstability
Steering wheel does
lot return properly
Steering wheel pulls
:o one side
4bnormal noise
from suspension
system
Possible Cause
Weak front stabilizer bar.
Damaged or worn lower wishbone stabilizer
bar insulator. Damaged or worn stabilizer bar link
Damaged or worn rear suspension
wishbone bushing.
Damper malfunction.
Worn or deteriorated rear stabilizer bar
bushing(s). (supercharged, sports and XJ12
only)
Damaged or worn rear wishbone bushing
and weak springs.
Worn or deteriorated rear stabilizer bar
bushing(s). (supercharged, sports and XJ12
only)
Front or rear damper malfunction.
Weak
spring(s1
Damaged tires or unbalanced wheels.
Incorrect wheel alignment.
Steering system malfunction.
Damaged front suspension lower and upper
ball joints.
Damaged or worn sub
-frame to body
mounting.
Damaged or worn stabilizer bar link
Damaged or worn lower wishbone stabilizer
bar insulator.
Weak
spring(s)
Worn or deteriorated rear stabilizer bushing
(s). (supercharged, sports and XJ12 only)
Damaged tires or unbalanced wheels and
incorrect tire pressure.
Incorrect wheel alignment.
Steering system malfunction.
Damaged front suspension lower and upper
ball joints.
Incorrect tire pressure.
Damaged front suspension lower and upper
ball joints. Braking system malfunction.
Steering system malfunction.
Damaged or worn sub
-frame to body
mounting.
Damaged tires, unbalanced wheels and
incorrect tire pressure.
Poor lubrication /wear of wheel bearing.
Wear of front suspension lower and upper
ball joints.
Damaged or worn front stabilizer bar
Damaged or worn stabilizer bar link.
Damaged or worn stabilizer bar bracket.
Looseness of suspension connections.
Damaged or worn rear wishbone bushing.
Front and rear damper malfunction.
Weak
spring.Worn or deteriorated rear
stabilizer bushing
(s). (supercharged, sports
and
XJ12 only)
Action
3enew front stabilizer bar.
3enew insulators.
3enew link.
Renew bushing.
Renew damper
if necessary.
Renew Bushina
Renew bushings and springs.
Renew Bushings.
Renew dampers.
Renew springs.
Check the tires.
Adjust the wheel alignment.
Check steering system.
Renew ball joints.
Renew bushing.
Renew link.
Renew insulator.
Renew springs.
Renew bushing
Check tires.
Adjust the wheel alignment.
Check steering system.
Renew ball joints.
Check and correct tire pressure.
Renew ball joints.
Check brakes.
Check steering system.
Renew bushing.
Check tires.
Renew wheel bearing.
Renew ball joints.
Renew stabilizer bar.
Renew link.
Renew bracket.
Tighten connections.
Renew bushing.
Renew dampers.
Renew bushing
Issue 1 August 1994 X300 VSM 7

12.2 FAULT DIAGNOSIS AND TESTING
rrouble
-ong brake pedal
dibration during braking
'oor braking performance
3rakes pull to one side
3rakes do not release
ixcessive pedal travel
Cause
Brake caliper piston or caliper guide
pins sticking
Worn
I damaged brake pads
Worn
1 damaged brake pads
Loose caliper mounting bolts
Insufficient grease on sliding parts
Foreign material
or scratches on
brake rotor contact surface
Damaged brake rotor contact surface
Leak
in hydraulic system
Air
in system
Worn
I damaged brake pads
Foreign material on brake pads
Brake caliper piston malfunction
Tandem master cylinder malfunction
Vacuum booster fault
Disconnected
or damaged vacuum
hose
Low brake
fluid level
Worn
I damaged brake pads
Foreign material on brake pad
Failing valves
in ABS valve block
Abnormal wear or distortion on front
brake rotor
Incorrect wheel alignment
Incorrect tire pressure
No brake pedal free play
Vacuum booster
binding
Tandem master cylinder return port faulty
Faulty valve
in ABS valve block
Leak
in hydraulic system
Air
in system
Remedy
Service or renew caliper or caliper
guide pins
Renew brake pads
Renew brake pads
Tighten caliper mounting bolts
Apply grease where necessary
Clean brake rotor contact surface
Renew brake
rotor
Repair leak. Check all pipework con-
nections. Refill and bleed the system
Check the system
for leaks and bleed
brakes
Renew brake pads
Examine brake pads and clean
or
renew as necessary
Renew faulty brake caliper piston
Service
or renew tandem master cyl- inder
Renew vacuum booster
Renew vacuum hose
Check for leaks, refill and bleed the
system
Renew brake pads
Examine brake pads and clean
or renew as necessary
Renew valve block
Examine front brake
rotor and service
or renew as necessary
Carry out wheel alignment. Refer to
Section
11, iv Service Data
Inflate tire
to correct pressure
Adjust brake pedal free play
Renew vacuum booster
Clean return
port on tandem master cy I i nder
Renew valve block
Repair leak. Check all pipework con
- nections. Refill and bleed the system
Check the system
for leaks and bleed
brakes
0
0
0
Issue 1 August 1994 16 X300 VSM

Steering and Suspension
W: When checking the steering geometry, use the pull-down tools front and rear to set the ride height front and
rear to the following dimensions:
Front ride height
................................................... 153 f 5mm to underside of front
crossbeam
Rear ride height
.................................................... 160 f 5mm to underside of rear
edge of A frame
Front ride height
................................................... 143 f 5mm to underside of front
crossbeam
Rear ride height
.................................................... 160 f 5mm to underside of rear
edge of A frame
U: Sportspack derivatives whose kerb height is below the above figures can have their geometry checked at that
height.
Front Suspension
..............................................................
0
Type Independent front suspension
consisting of double wishbones
with coil springs and separate
dampers and anti
-roll bar.
Dampers
.......................................................... Telescopic, gas pressurised
Caster angle
....................................................... 3,0° to 6,0° and with opposing
wheels within Io of each other
Camberangle
...................................................... 0,3°to-0,80
Front wheel alignment .............................................. Total toe: 5 minutes in f 10 minutes
Rear Suspension
Type .............................................................. Fully independent rear suspension of double wishbone principle with
axle shaft operating as upper
wishbone incorporating coaxial
springs and dampers with optional
rear anti
-roll bar.
Camber angle
(at design ride height):
all vehicles except supercharged ................................. -0,75O f 0,4O
supercharged only -1,6O f 0,4O ..............................................
0 Rear wheel alignment .............................................. Total toe: 15 minutes in f20
Dampers .......................................................... Telescopic, gas pressurised
minutes
Power Assisted Steering
Type .............................................................. ZF
Servotronic speed-sensitive rack
and pinion
Number
of turns lock to lock ........................................ 2,768
Turning circle: (wall to wall)
....................................................... 12,9m (42ft 4in)
(curb to curb) ...................................................... 12,4m (40ft 8in)
0
X300 VSM Issue 1 August 1994 AI-95MY 4 ~~~~