1994 JAGUAR XJ6 Diagnostic

rn Cooling System (VI 2)
Diagnostic Procedures (continued)
Symptom
-0ss of cool-
ant
Possible Cause
Loose clips on hoses
Hoses perished
Radiator core leaking
Water pump seal leaking
Thermostat
gasket(s) leaking
Header tank cap defective
Porosity in castings
Corrosion caused by con
- centration of anti-freeze being
too low
Cylinder head
gasket(4 leak- ing
Cracked or damaged internal
engine component
Check
Check clips for correct tight-
ness
Visual check
Pressure
-test system
Pressure
-test system
Pressure
-test system. (Check
for distortion of thermostat
housing(s))
Inspect cap or test cap spring
pressure
Pressure
-test system
Pressure
-test system. Check
strength of coolant
Pressure
-test system. Check
for contamination of coolant
and engine lubrication system
Identify
component(s) affected. (Check for
contamination of engine
lubrication system)
Remedy
Tighten clips as required
Renew hoses as required
Repair or renew radiator
Renew water pump
Renew gasket. Renew
hous-
ing(s) if required
Renew cap Rectify as required
Rectify as required. Drain and
fill with coolant of correct con
-
centration
Renew head
gasket(s)
Rectify as required
Issue 1 August 1994 6 X300 VSM

SECTION CONTENTS 0
Sub-Section Title SRO Page
i to iii ............ Preliminary Pages ................................................................ i To iv
10.1
............. Steering System Description ........................................................... 1
10.1.1 ............ Steering System Description. Steering Column Major Components ........................... 1
10.1 .2 ............ Steering System Description. Steering Column Operating Principle ........................... 1
10.1.3 ............ Steering System Description. Hydraulic System Major Components .......................... 2
10.1.4
............ Steering System Description. Hydraulic System Features .................................... 2
10.1.5
............ Steering System Description. Hydraulic System Operating Principle .......................... 2
10.2 ............. Service Procedures-Safety Related ...................................................... 5
10.2.1
............ Service ProceduresSafety Related. Airbag ............................................... 5
10.3
............. Service Procedures ................................................................... 5
10.3.1
............ Service Procedures Working Practices ................................................... 5
10.3.2
............ Service Procedures Working Practices. Fluid Level Check & Topup .......................... 5
10.3.3
............ Service Procedures Working Practices. System Bleed ...................................... 5
10.3.4
............ Service Procedures Working Practices. Fluid Reservoir ..................................... 5
10.3.5.
........... Service Procedures Working Practices. Hydraulic Connections .............................. 5
10.4
............. Diagnostic Procedure ................................................................. 6
10.4.1 ............ Diagnostic Procedure. introduction ..................................................... 6
10.4.2. ........... Diagnostic Procedure. Preliminary Action ................................................ 6
10.4.3 ............ Diagnostic Chart 1 ................................................................... 6
10.4.4. ........... Diagnostic Chart 2 ................................................................... 7
10.4.5 ............ Diagnostic Chart3 ................................................................... 8
10.5
............. Outer Track Rod Ball Joint. Renew ................................ 57.55.02 ............. 9
10.6 ............. Front Hub Assembly, Renew ..................................... 60.25.01 ............. 9
10.7
............. Front Hub Bearing End Float. Check & Adjust ...................... 60.25.12 ............. 9
10.8
............. Front Hub Bearing. Renew ...................................... 60.25.16 ............. 9
10.9
............. Front Hub Oil Seal. Renew ...................................... 60.25.17 ............. 9
X300 VSM i Issue 1 August 1994

10.2 SERVICE
PROCEDURES - SAFETY RELATED
10.2.1
Airbag
The electrically activated driver's side airbag is attached to the steering wheel hub and is fed by two wires from the
column stalk assembly. Electrical input to the column stalk assembly for the airbag is provided by a dedicated harness
which is encased in a yellow sleeve. A mechanism in the stalk assembly called the 'cable reel cassette' provides conti
-
nuity from the static column to the steering wheel. The 'cable reel cassette' is driven by a tang which locates in the
steering wheel. Because the connection is by wires, and the cassette assembly is only capable of approximately five
(5) full turns,
it is critically important that initial positioning is correct, see Section 15. It is equally important that fitting of the steering wheel, connection of the column, lower shaft and steering rackshould
ONLY be made with the steering rack in the center of its travel.
WARNING: DO NOT REMOVE THE STEERING COLUMN FROM THE VEHICLE WITH THE STEERING WHEEL AT- TACHED UNLESS THE STEERING IS CENTERED AND THE COLUMN LOCK IS ENGAGED. IF THE LOCK
BARREL
IS TO BE RENEWED, 'LOCK-WIRE THE ASSEMBLY TO PREVENT ROTATION. FAILURE TO OB- SERVE THIS AND CONSEQUENT DAMAGE TO THE 'CABLE REEL CASSETTE MAY RESULT IN AN INOP- ERATIVE AIRBAG SYSTEM. SEE LABEL ON STEERING WHEEL HUB.
10.3 SERVICE PROCEDURES
10.3.1 Working Practices
It is not recommended that either the steering rack or engine driven pump assemblies are repaired in any way other
than in accordance with the repair procedures described in this manual. The fluid reservoir and filter is a disposable
assembly and no attempt should be made to clean it internally. Genuine replacement units must be fitted following
routine service or diagnostic confirmation of the failure of any component.
The importance of cleanliness cannot be over
-stressed, not only with new parts but also those which may havefailed.
In-service contamination of the hydraulic system is a major cause of failures and may be avoided with good working
practices and care. All new units and pipes must be supplied with suitable blanks in every orifice. Should a unit not
have blanks fitted, do not use
it - return it to the supplier with an appropriate reason for your action.
To help the manufacturer diagnose problems and avoid post-removal contamination; provide full details of the fault
and plug all connections as soon as they are released. All suspect units must be returned to Jaguar Cars complete
with relevant documentation.
CAUTION: It is imperative that the power steering system does not become contaminated in any way. Always de- cant fluid from afresh sealed container and clean the area around the reservoir neck both before and after topping-up. Never return drained fluid to the system.
10.3.2
Position the vehicle on a level surface with the engine sta- tionary and fluid cold. Add fluid, if required, so that the level
falls BETWEEN the marks
Fig.1.
10.3.3 System Bleed (following maintenance)
To avoid fluid aeration and possible pump damage, the in- itial fill process must be carried out with the ignition OFF.
Set the fluid level approximately 20 mm above the upper
dipstick level, and cycle the steering no less than three (3) times from lock to lock (this may be best achieved with the
front wheels off the ground). As air is expelled thefluid level
will fall, the level should be corrected. Start the engine and
further cycle thesteering until the fluid level becomes stable.
Stop the engine and finally set the level in accordance
with the fluid level check procedure.
10.3.4 Fluid Reservoir
The reservoir has an integral, non-serviceable, return-side
filter. Should any component be renewed or the system
'broken into' for any reason,
it is essential that the reservoir and the fluid are changed. Under normal operating condi- tions it is not necessary to change the fluid.
10.3.5 Hydraulic Connections
Fluid
Level Check and
Top-up
Jf7-281
Fig. 1
All hydraulic connections and surrounding areas should be scrupulously cleaned before and after work. Please note
that the steering rack valve block connections for FEED and RETURN are common in size. Ensure that the pipes are
correctly fitted, the uppermost one being the high pressure FEEDfrom the steering pump and the lower (RETURN) hav- ing a double depth hexagon tube nut.
X300 VSM 5 issue 1 August 1994

@ Steering
Cause
Fluid level low?
Drive belt slack
(V12)
Pump drive loose (6cyl)
center pressures low
Air in system due to loose connection
Pump shaft seal faulty (fluid loss)
Delivery pressure or flow too low
Return flow restricted by blocked reser
-
voir filter
Both check valves blocked
Rack damper too
tight
Lower column incorrectly set
Excessive upper column friction
Faulty rotary valve or seal
Drive belt slack
(VI217
Engine idle speed too low
Pump drive loose
(6cyl)
Air in system due to loose connection
Pump shaft seal faulty (fluid
loss)
Delivery pressure or flow too low
Fluid level low?
tire pressures
high
Air in system due to loose connection
Stiff or seized steering joint
Rack damper too tight
Castor or tracking error
Lower column over extended
Fluid level low?
Air
in system due to loose connection
Pump shaft seal faulty (fluid
loss)
Rack damper loose
Pinion bearing faulty
Rack or column fixings loose
Rack mounting bracket loose
Rack mounting bush loose
Free play in column assembly
10.4 DIAGNOSTIC PROCEDURE
10.4.1 Introduction
The following diagnostic procedures are provided to rapidly pin-point mechanical faults which are not interrogated
by electrical means. Diagnostic procedures which require dedicated electrically operated equipment are dealt with in the 'Electrical Diagnostic Manual' (EDM) but may be mentioned here for reference.
10.4.2 Preliminary Action
Before any problem solving is undertaken it is essential that the fluid level and where applicable, belt tension, is
checked and if required corrected.
CAUTION: It is imperative that the power steering system does not become contaminated in any way. Always de cant fluid from a fresh sealed container and clean the area around the reservoir neck both before and after
topping-up. Never return drained fluid to the system.
10.4.2 Diagnostic Chart 1
Remedy
Rectify fluid loss and or top up
Re
-tension belt
Renew pump
Set to specification
Secure connection and bleed air out
Renew pump
Renew pump
Renew reservoir
Renew rack
Renew rack
Set to specification
Renew upper column
Renew rack
Retension belt
Reset idle speed
Renew
pump
Secure connection and bleed air out
Renew
pump
Renew pump
Rectify
fluid loss and or top up
Set to specification
Secure connection and bleed air out
Test and renew faulty joint
Renew rack
Check geometry and rectify
if required
Set to specification
Rectify fluid
loss and or top up
Secure connection and bleed air out
Renew pump
Renew rack
Renew rack
Tighten to specification
Renew rack
Renew rack
Check and rectify as required
Trouble
Heavy on both sides
Heavy on one side
Heavy when steering
rapidly
Vague feel about center
Knocking
1 vibration felt
at steering wheel
0
0
0
0
Issue 1 August 1994 6 X300 VSM

10.4.3 Diagnostic chart 2
0 Trouble
'lay at steering wheel
ieavy when stationary
Excessively heavy when
hiving, stationary effort
3K
Too easy when driving,
itationary effort OK
fffort not equal side to
;ide from center
dariation from heavy to
?asy when driving
:yclic load variation at steering wheel - 2 per
.evolution
:losely spaced cyclic
oad variation at steering
Nheel
Cause
Rack damper loose
Pinion bearing loose
Worn intermediate shaft joint
Worn suspension joint
Loose lower column 'pinch' bolt
Transducer not closed
Transducer not closed
- ground short
Transducer not closed
- no feed voltage
Transducer not closed
- defective cable
SCM defective
Delivery pressure or flow too low
Internal rack leakage
tire pressures low
Transducer open too early
Transducer open too early, incorrect SCM
h/Pe
Transducer open too early, incorrect
speedometer signal
Rack 'reaction limitation valve' CLOSED
or setting incorrect
Transducer not open (no oil flow)
Transducer not open, SCM faulty
Transducer not open, incorrect speedom
-
eter signal
Rack 'reaction limiting valve' OPEN or
setting incorrect
Low pressure pipe 'flattened' or re
-
stricted
Blocked reservoir filter
tire pressure high
Rack check valve leak
Rotary valve blockage Incorrect lower column assembly, see
'Cyclic load variations'
Incorrect speedometer signal
Transducer cable
/ connection faulty or
grounded
Lower column universal joint fitting error
Rack damper too tight
Remedy
Renew rack
Renew rack
Renew joint
Renew joint
Tighten to specification
Inspect and check for debris
Renew transducer*
Investigate and repair
Renew cable
Renew module*
Renew pump
Renew rack
Set to specification
Renew transducer*
Renew
SCM*
Renew speedometer transmitter*
Renew rack
Inspect and check for debris
Renew
SCM*
Renew speedometer transmitter*
Renew rack
Renew pipe
Renew filter
Set to specification
Renew rack
Renew rack
Rectify as required
Renew speedometer transmitter*
Investigate and repair
Verify that the lower column assembly is
correct for that drive.
RH and LH assem- blies MUST NOT be interchanged due to
joint phase differences
Renew rack
W: Items marked * should be validated using EDM test procedures.
X300 VSM 7 Issue 1 August 1994

@ Steering
10.4.4 Diagnostic chart 3
Trouble
Hydraulic noise when
turning lock to lock
Continuous pressure
relief valve operation
Continuous noise
Cause
Fluid level low?
Air ingress at connections
Air ingress through feed hose lining
or
skin
Air ingress at pump front seal
Water contamination caused by fractured
cooler pipe within engine coolant radi
-
ator
Pump starvation or cavitation caused by
twisted or trapped feed hose
Pump starvation caused by blocked filter
Worn
pump
High pressure hose (pump to rack) dam-
aged or restricted
Fluid level low?
Drive belt loose
(12 cyl only)
Drive pulley loose
Steering pump mounting
(4 loose
Drive 'dog' loose, slipping or incorrectly
fitted
(6 cyl only)-
Hose or pipe fretting on body or chassis
structure
Hose twisted or restricted
Remedy
Rectify fluid loss and or top up
Check and tighten all connections to spec
-
ification
Renew faulty
'0' rings or Dowty washers
Renew porous
1 damaged hoses
Renew
pump
Renew radiator. Flush and drain steering
system twice
minimum, check for noise
and system performance (Pump is most
susceptible to damage due to
loss of lu-
brication and may have to be renewed)
Reroute or relieve pressure
Renew reservoir
Renew pump
Renew hose
Rectify
fluid loss and or top up
Inspect for damage and renew as required
Tighten pulley to specification
Tighten to specification
Investigate
& rectify as required
Rectify routing
Rectify routing
Issue 1 August 1994 8 X300 VSM

Suspension Systems
. .
SECTION CON TENTS
Subsection Tjf/e
.
SRO
I to IV ........... Preliminary Pages ................................................................... i
11.1 ............. Introduction ........................................................................\
. 1
11.2 ............. Front Suspension. Description ......................................... ..
Page
11.3 ............. Rearsuspension. Description .......................................................... 2
11.4.1
............ Diagnosis & Testing. Tire Wear ......................................................... 3
11.4.2
............ Diagnosis & Testing. Vibration & Roughness .............................................. 3
11.4.3
............ Diagnosis & Testing. Front End Inspection ................................................ 4
11.4.4 ............ Diagnosis & Testing. Upper/Lower Ball Joint Inspection ................................... 4
11.4.5
............ Diagnosis & Testing. Damper Inspection ................................................. 4
11.4.6
............ Diagnosis & Testing. Rear Suspension Inspection .......................................... 5
11.4.7. ........... Diagnosis & Testing. Vehicle Inspection .................................................. 5
11.4 ............. Diagnosis & Testing .................................................................. 3
. 1 1.4.8 ............ Diagnosis & Testing. Diagnostic Procedure Chart ............ ...
. .
........ .....
-
I X300 VSM i Issue 1 August 1994
.
............. 1
............. 6

Suspension Systems
11.1 INTRODUCTION
This section describes the front and rear suspension systems, and also covers diagnostic procedures.
Fig. 1 Front Suspension Layout
11.2 FRONT SUSPENSION, DESCRIPTION
Theupperrearwishbone(1 Fig.l)andthe upperfrontwishbone(2 Fig.1)arepivotedon the upperfulcrum bolt (3Fig.l), passing through the front cross beam assembly. They are also fitted via an upper ball joint assembly (4 Fig.1) to a verti- cal linkaccommodating the stub axle (5 Fig.l), whereas the vertical linkisfittedvia a lower ball joint assembly (6 Fig.1) to the lower wishbone assembly.
The lower wishbone assembly comprises
a lower rear wishbone (7 Fig.l), lower front wishbone (8 Fig.l), damper (9 Fig.1) (incorporating damper bush 10 Fig.1) and spring pan (1 1 Fig.1) supporting the road spring (12 Fig.1). The lower
wishbone assembly is pivoted on the bushed lower fulcrum shaft (13 Fig.1) which also passes through thecross beam
assembly.
Both independent front suspension assemblies are linked by a stabilizer bar (14 Fig.1) which is secured to the cross
member using a fixing arrangement of mounting rubbers (15 Fig.1, clamps (16 Fig.l), nuts bolts, washers (17 Fig.1) and two link arm assemblies (18 Fig.1). Each link arm assembly is fitted to one end of the stabilizer bar and to one end
of the lower front wishbone using a fixing arrangement of bolts washers and self locking nuts.
All suspension loads, except the damper, are fed into a pressed steel crossbeam which is isolated from the body by
rubber bushes. This mounting method allows the necessary amount of compliance.
The degree
of caster is adjustable via shims positioned on either side of the upper ball joint assembly but camber is facton/ set and is not adjustable. The vertical link and the steering arm form a single forging. Cast iron hubs rotate
on twin tapered roller bearings.
X300 VSM 1 Issue 1 August 1994