wheel torque JAGUAR XFR 2010 1.G Owner's Guide

Noise

Symptom Possible Causes Action











Continuous noise

Low power steering fluid level
Check for leaks and rectify as required. For further
information refer to the symptom charts for
leakage in this section. Fill power steering fluid
reservoir to correct level
NOTE: Look for small air bubbles
visible in the fluid, air may also get
trapped in the hydraulic system

Air in hydraulic system
Bleed the power steering system.
REFER to: Power Steering System Bleeding (211-00 Steering System - General Information,
General Procedures).
Power steering pipe/hose in
contact with the vehicle body
Check and reposition, or install new IF
damaged/deformed, power steering pipe/hose
Power steering pipe/hose
restricted or twisted
Check and clear restriction to pipe/hose
Reposition power steering pipe/hose. Install new
pipe/hose IF permanently damaged/deformed

Power steering pump mounting
bolts loose
Tighten the power steering pump mounting bolts
to the correct torque.
REFER to: Specifications (211-00 Steering System - General Information, Specifications).


Noise gets worse
when system is
loaded

NOTE: Refer to the power
steering pressure check in this section

Low power steering fluid level
Aerated fluid
Low power steering pump
pressure
Check and fill power steering fluid reservoir to
correct level
Bleed the power steering system.
REFER to: Power Steering System Bleeding (211-00 Steering System - General Information,
General Procedures).
Check power steering pump pressure. If the pump
pressure is low, install a new power steering
pump
Front End Accessory
Drive (FEAD) belt
squeal
FEAD belt incorrectly tensioned
or glazed
Check FEAD belt tension
Check FEAD belt condition and install a new belt
as required
Chirp noise from the
steering pump when a
load is applied
Loose or worn FEAD belt
Check FEAD belt tension
Check FEAD belt condition and install a new belt
as required
Scrape/grind noise
from behind steering
wheel while steering
Steering column shroud foul
condition or clockspring
Correctly install the steering column shroud to
eliminate the foul condition
Install a new clockspring as required
Foreign objects
Remove foreign objects from between steering
column shroud and steering wheel/steering
column rotating components
Click
Clockspring or steering column
multifunction switch LH
Correctly install and install new components as
required
Loose universal joint pinch bolt
Install a new universal joint pinch bolt and
tighten to correct specification.
REFER to: Specifications (211-00 Steering System - General Information, Specifications).
Squeak
Steering column shroud joints
Apply Krytox spray to steering column shroud
joints
Clockspring
Install new clockspring as required

Steering nibble is a rotary oscillation or vibration of the steering wheel, which can be excited at a specific vehicle speed.
Nibble is driven by wheel and tire imbalance exciting a suspension recession mode, which then translates into steering gear
travel and finally steering wheel nibble.

Shudder (Judder)

Shudder is a low frequency oscillation of the entire steering system (tire, wheels, steering gear and linkage, etc.) when the
vehicle is steered during static-park or at low speeds. Shudder is very dependent on road surface.

Torque/Velocity Variation (Phasing/Effort Cycling)

Steering wheel torque variation occurring twice in one revolution is normally as a result of problems with the lower steering
column (intermediate shaft), but foul conditions generally result in either constant stiffness or single point stiffness.
Depending upon the orientation of the joints, the steering can feel asymmetric (torque falling off in one direction and rising in
the other) or else it can simply have pronounced peaks and troughs as the steering moves from lock to lock.

Wheel Fight (Kick Back)

Wheel fight is excess feedback of sudden road forces through the steering system and back to the driver. It is evaluated at all
vehicle speeds over cobblestones, rough roads, and potholes. The tires, wheels, and suspension generate forces into the
steering systems. Steering friction, hydraulic damping, hydraulic compliance, mechanical compliance, steering ratio, and assist
gain all affect how much is transmitted to the driver.

compartment, forward of the front suspension housing.

On petrol engine vehicles, a fluid cooler is located in front of the engine cooling radiator. Diesel models do not have a fluid
cooler.

Servotronic 2 adds electronic control and speed sensitive steering to the steering gear. The Servotronic 2 feature provides easy
and comfortable steering operation when parking, improved 'road feel' at increased road speeds and adds an integrated,
positive center feel feature which optimises steering wheel torque during high speed driving. The Servotronic 2 system is
controlled by software which is incorporated into the instrument cluster. The software responds to road speed signals and
controls the power assistance via a transducer valve located on the steering gear valve housing.

18 Pinion 19 Steering gear rack bar 20 Valve sleeve The valve unit is an integral part of the steering gear. The principle function of the valve unit is to provide power assistance
(i.e. when parking) to optimize the effort required to turn the steering wheel.

The pinion housing of the valve is an integral part of the main steering gear casting. The pinion housing has four machined
ports which provide connections for pressure feed from the power steering pump, return fluid to the reservoir and pressure
feeds to each side of the cylinder piston.

The valve unit comprises an outer sleeve, an input shaft, a torsion bar and a pinion shaft. The valve unit is co-axial with the
pinion shaft which is connected to the steering column via the input shaft. The valve unit components are located in the
steering gear pinion housing which is sealed with a cap.

The outer sleeve is located in the main bore of the pinion housing. Three annular grooves are machined on its outer diameter.
PTFE (polytetrafluoroethylene) rings are located between the grooves and seal against the bore of the pinion housing. Holes
are drilled radially in each annular groove through the wall of the sleeve. The bore of the outer sleeve is machined to accept
the input shaft. Six equally spaced slots are machined in the bore of the sleeve. The ends of the slots are closed and do not
continue to the end of the outer sleeve. The radial holes in the outer sleeve are drilled into each slot.

The input shaft has two machined flats at its outer end which allow for the attachment of the steering column intermediate
shaft yoke. The flats ensure that the intermediate shaft is fitted in the correct position. The inner end of the input shaft forms
a dog-tooth which mates with a slot in the pinion shaft. The fit of the dog-tooth in the slot allows a small amount of relative
rotation between the input shaft and the pinion shaft before the dog-tooth contacts the wall of the slot. This ensures that, if
the power assistance fails, the steering can be operated manually without over stressing the torsion bar. The central portion of
the input shaft has equally spaced longitudinal slots machined in its circumference. The slots are arranged alternately around
the input shaft.

The torsion bar is fitted inside the input shaft and is an interference fit in the pinion shaft. The torsion bar is connected to the
input shaft by a drive pin. The torsion bar is machined to a smaller diameter in its central section. The smaller diameter allows
the torsion bar to twist in response to torque applied from the steering wheel in relation to the grip of the tyres on the road
surface.

The pinion shaft has machined teeth on its central diameter which mate with teeth on the steering gear rack. A slot, machined
in the upper end of the pinion shaft mates with the dog-tooth on the input shaft. The pinion shaft locates in the pinion
housing and rotates on ball and roller bearings.

Servotronic Valve

The Servotronic transducer valve is located in a port in the side of the steering gear valve housing. The valve is sealed in the
housing with an O-ring seal and is secured with two long screws into threaded holes in the housing. The Servotronic valve is a
transducer controlled valve which responds to control signals supplied from Servotronic software in the instrument cluster.

The Servotronic valve determines the hydraulic reaction at the steering gear rotary valve and controls the input torque required
to turn the steering wheel. The Servotronic system allows the steering to be turned with the optimum effort when the vehicle
is stationary or manoeuvred at slow speed. The hydraulic reaction changes proportional to the vehicle speed, with the required
steering effort increasing as the vehicle moves faster. At high speeds, the Servotronic system provides the driver with a good
feedback through the steering providing precise steering and improved stability.

The instrument cluster receives road speed signals from the ABS module and calculates the correct controlling signal for the Servotronic valve. The Servotronic software within the instrument cluster has a diagnostic capability which allows a Jaguar
approved diagnostic system to check the tune of the steering and retrieve fault codes relating to the Servotronic valve. Two
fault codes are stored relating to the valve for positive connection short to ground or battery and negative connection short to
ground or battery.

The Servotronic software within the instrument cluster also contains a number of steering maps which are selected via the car
configuration file depending on the vehicle model and tire fitment.

If a failure of the Servotronic valve or software occurs, the system will suspend Servotronic assistance and only a default level
of assistance will be available. Fault codes relating to the fault are stored in the instrument cluster. No warning lamps are
illuminated and the driver may be aware of the steering being 'heavier' than usual.
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16 Ball (12 off) 17 Distance keeper 18 Crash tube The column comprises a cast magnesium mounting bracket which provides the attachment to the cross-beam. Attached to the
mounting bracket is a rake lever which is attached to the mounting bracket at the lower end with two pivot bearings. The
bearings allow the rake lever to rotate upwards or downward to adjust the column rake.

The rake lever also provides for the attachment of the rake housing which can slide within the lever to provide the reach
adjustment. Within the rake housing is the axial housing which is supported on each side with 6 ball bearings which allow the
rake housing to move forward or backwards. The bearings on each side are arranged in groups of 3 bearings and are separated
by a distance keeper which allows the housing to supported on bearings along its length. Within the axial housing is a tube
which is supported at the upper end of the column on the upper bearing. The tube has a central splined hole which provides for
the fitment of the splined shaft. The splined shaft can slide within the tube on the splines when the column reach is adjusted
or the column collapses in a crash condition. The splined shaft also passes rotary motion from the steering wheel through the
length of the column to the outer clamping yoke which is supported on the lower bearing.

The electric steering column lock is attached to the top of the rake lever. A lock bolt within the steering column lock engages in
one of 8 slots in the locking sleeve located at the lower end of the column preventing rotation of the steering wheel. The
locking sleeve is retained by a tolerance ring which in turn is located on the outer diameter of the tube yoke. The tolerance
ring allows a specified amount of torque to be applied to the splined shaft before it slips, preventing damage to the column
lock due to excessive force being applied to the steering wheel when the lock is engaged. The tolerance ring is designed to
slip on the splined shaft when the applied torque exceeds the fitted slip load of 200 Nm minimum. Repeated rotation of the
lock collar will reduce its slipping torque to 100 Nm minimum. The lock is controlled by the CJB.
A steering angle sensor is located at the upper end of the steering column and is attached to the crash adaptor. The sensor
measures steering rotation via a toothed wheel located on the splined tube at the upper end of the column. The sensor
receives a power supply from the CJB and supplies 2 signals (A and B) relating to the steering rotation to the ABS (anti-lock brake system) module. The module transmits this data on the high speed CAN bus for use by other vehicle systems. Refer to: Anti-Lock Control - Stability Assist (206-09 Anti-Lock Control - Stability Assist, Description and Operation).
The steering column is adjustable electrically, for reach and rake. The adjustment mechanism comprises an electric adjustment
motor, a lead screw, a rake solenoid, a reach solenoid, a reach clutch and a rake clutch. The column adjustment is controlled
manually using a joystick switch located on the LH (left-hand) side of the column lower cowl. The joystick can be moved
forward and backward to adjust the column reach in and out and moved up and down to adjust the rake. The switch selection
energizes the adjustment motor in the applicable direction and also engages the applicable solenoid and clutch.

When the joystick switch is rotated to the 'auto' position, the steering column will adjust to the uppermost rake position when
the ignition is switched off. It will re-adjust to the position corresponding to the memory position for the remote handset when
the ignition is switched on.

The memory function of the electric column is linked to and controlled by the driver's seat module. The module provides for the
storage of three separate memory positions which are stored against 3 individual remote handsets.
Refer to: Seats (501-10 Seating, Description and Operation).
The steering wheel locates on a splined shaft in the upper column assembly and is secured with a bolt. The steering wheel
houses the driver's airbag and switches for the audio system, gear change and speed control. A clockspring is used to connect
the steering wheel electrical components to the vehicle harness.

Two plastic shrouds are fitted to the upper column assembly. The lower shroud is fitted with an energy absorbing foam pad to
minimize leg injury in the event of an accident.
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Component Tests
Engine Oil Leaks


NOTE: Before installing new gaskets or oil seals, make sure that the fault is clearly established.

If the oil leak cannot be identified clearly by a visual inspection, carry out an Ultraviolet test:

Fluorescent Oil Additive Method

1. Clean the engine with a suitable cleaning fluid (brake cleaner).

2. Drain the engine oil and refill with recommended oil, premixed with Diesel Engine Oil Dye or equivalent. Use a minimum
14.8 ml (0.5 ounce) to a maximum 29.6 ml (1 ounce) of fluorescent additive to all engines. If oil is not premixed,
fluorescent additive must first be added to the crankcase.

3. Run engine for 15 minutes. Stop the engine and inspect all seal and gasket areas for leaks using a 12 Volt Master UV
Diagnostic Inspection Kit or equivalent. A clear bright yellow or orange area will identify leak. For extremely small
leaks, several hours may be required for the leak to appear.

4. As necessary, pressurize the main oil gallery system to locate leaks due to incorrectly sealed, loose or cocked plugs. If
the flywheel bolts leak oil, look for sealer on the threads.
5. Repair all leaks as necessary.

Compression Test General Remarks
NOTES:

Removing fuses and disconnecting electrical components may cause the Engine Control Module (ECM) to log Diagnostic
Trouble Codes (DTCs). After the measurements have been carried out, DTCs should be cleared from memory by connecting to
the Manufacturer Approved Diagnostic System.


Only check the compression pressure with the valves set to the prescribed clearance (if this can be adjusted).
The compression pressure should be checked with the engine at normal operating temperature.

Check the Compression Pressure


WARNING: Move gear selector lever to 'P' position. Failure to follow this instruction may result in personal injury.
1. Remove the fuel pump relay.

2. Start the engine - the engine will start, run for a few seconds then stall.

3. Remove the spark plugs.
4. Install the compression tester.

5. Install an auxiliary starter switch in the starting circuit. With the ignition switch OFF, using the auxiliary starter switch,
crank the engine a minimum of five compression strokes and record the highest reading. Note the approximate number
of compression strokes required to obtain the highest reading.
6. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.
7. Install the removed components in reverse order, observing the specified tightening torques.

8. Clear all DTCs from the ECM.
Interpretation of the Results


NOTE: Due to the possibility of loose carbon that has become trapped between the valve face and seat effecting the
pressure readings, when carrying out a compression test and cylinders are found to have low pressures, install the spark plugs,
road test the vehicle and re-test the suspect cylinders. If the correct pressures are restored, no further action is required.

The indicated compression pressures are considered within specification if the lowest reading cylinder is within 75% of the
highest reading.

If the cylinder pressures are found to be low, carry out a leakdown test to determine the location of the fault (if any leakback
can be heard through the engine breather system suspect the piston rings, if any leakback can be heard through the inlet
system suspect the inlet valve or seat, if any leakback can be heard through the exhaust manifold suspect the exhaust valve
or seat. If the measurements for two cylinders next to each other are both too low then it is very likely that the cylinder head
gasket between them is burnt through. This can also be recognized by traces of engine oil in the coolant and/or coolant in the

Published: 11-May-2011
Automatic Transmission/Transaxle - TDV6 3.0L Diesel /V8 5.0L Petrol/V8 S/C 5.0L Petrol - Transmission Description - Overview
Description and Operation

OVERVIEW

The ZF 6HP28 transmission is an electronically controlled, hydraulically operated, six speed automatic unit. The hydraulic and
electronic control elements of the transmission, including the TCM (transmission control module), are incorporated in a single
unit located inside the transmission and is known as 'Mechatronic'.

5.1 L SC (supercharger) and 3.0L diesel models use an uprated derivative of the ZF 6HP28 transmission used in the 5.0L
naturally aspirated models.
The ZF 6HP28 transmission has the following features:
Designed to be maintenance free
Transmission fluid is 'fill for life'
The torque converter features a controlled slip feature with electronically regulated control of lock-up, creating a smooth
transition to the fully locked condition
Shift programs controlled by the TCM Electronic park lock, controlled by the TCM, with a mechanical emergency release ASIS (adaptive shift strategy), to provide continuous adaptation of shift changes to suit the driving style of the driver,
which can vary from sporting to economical.
Connected to the ECM (engine control module) via the high speed CAN (controller area network) bus for communications
Default mode if major faults occur
Diagnostics available from the TCM via the high speed CAN bus.
The transmission selections are made using the rotary JaguarDrive selector in the floor console and two paddle switches on the
steering wheel. For additional information, refer to 307-05B Automatic Transmission/Transaxle External Controls - 5.0L/3.0L
Diesel).

TCM (transmission control module) 6 Diagnostic socket 7 Instrument cluster 8 JaguarDrive selector 9 Clockspring 10 Steering wheel audio switches 11 Downshift paddle switch 12 Upshift paddle switch 13 ECM (engine control module)


POWER FLOWS System Operation

Operation of the transmission is controlled by the TCM (transmission control module), which electrically activates various
solenoids to control the transmission gear selection. The sequence of solenoid activation is based on programmed information
in the TCM memory and physical transmission operating conditions such as vehicle speed, throttle position, engine load and JaguarDrive selector position.



Item Description 1 Torque input from engine 2 Torque converter lock-up clutch 3 Single web planetary gear carrier 4 Single web planetary gears 5 Single web sunwheel 1 6 Double web sunwheel 2 7 Double web planetary gears - long 8 Double web planetary gear carrier 9 Double web planetary gears - short 10 Double web sunwheel 3 11 Torque output from transmission A Multiplate clutch B Multiplate clutch C Multiplate brake D Multiplate brake E Multiplate clutch Engine torque is transferred, via operation of single or combinations of clutches to the 2 planetary gear trains. Both gear trains
are controlled by reactionary inputs from brake clutches to produce the 6 forward gears and 1 reverse gear. The ratios are as
follows: www.JagDocs.com

Ration 4.171 2.340 1.521 1.143 0.867 0.691 3.403 Shift Elements



Item Description 1 Turbine shaft 2 Stator shaft 3 Single web planetary gear train 4 Ring gear 1 5 Clutch A 6 Clutch B 7 Clutch E 8 Brake clutch C 9 Fixed connection to transmission housing 10 Shaft key 11 Brake clutch D 12 Double web planetary gear train 13 Planetary gears - long 14 Ring gear 2 15 Sunwheel 2 16 Sunwheel 3 17 Double web planetary gear carrier 18 Planetary gears - short 19 Single web planetary gear carrier 20 Sunwheel 1 The shift elements are three rotating multiplate clutches (A, B and E) and two fixed multiplate brakes (C and D). All shifts
from 1st to 6th gears are power-on overlapping shifts. Overlapping shifts can be described as one of the clutches continuing to
transmit drive at a lower main pressure until the next required clutch is able to accept the input torque.

The shift elements, clutches and brakes are actuated hydraulically. Fluid pressure is applied to the required clutch and/or brake,
pressing the plates together and allowing drive to be transmitted through the plates. The purpose of the shift elements
is to perform power-on shifts with no interruption to traction and smooth transition between gear ratios.

The JaguarDrive selector and the selector valve spool are in the 'D' position. Engine torque is transmitted from the torque
converter turbine shaft to the ring gear 1 of the single web planetary gear train and the outer plate carrier of clutch 'E'.

Ring gear 1 drives the planetary gears which rotate around sunwheel 1. This drives the planetary gear carrier 1 and also the
outer plate carrier of clutch 'A' and the inner plate carrier of clutch 'B'.

When clutch 'A' is engaged, sunwheel 3 in the double web planetary gear train is driven and meshes with the short planetary
gears.

The double web planetary gear train is locked against the transmission housing by brake 'D'. This allows ring gear 2 (output
shaft) to be driven in the same direction as the engine via the long planetary gears.


NOTE: Refer to 'Shift Elements' illustration for key

Power Flow 1st Gear