1999 JAGUAR S TYPE transmission

Introduction
Manual Transmission AJ-V6/AJ28
64In Europeon markets only, manual transmission is fitted as standard on the V6 entry S-TYPE model and
as an option on the V6 high specification model. Manual transmission is not available for the V8 variant.
The manual transmission is a 5 speed Getrag 221 unit with the following features:
¥ direct gearing (1:1) on 5th gear (it is normally on 4th) reduces losses
¥ twin synchronising cones on 1st and 2nd gears provide a smoother change
¥ four plane shift gate (R-1-3-5) with Ôknock-overÕ protection on the Reverse position.
A reverse light switch and speed sensor are fitted on the LH side of the gearbox. The speed sensor
monitors output shaft speed to provide an input to the PCM in addition to the signals received from the
road wheel speed sensors.
Specification:
Gear ratios: 1st 2nd 3rd 4th 5th Reverse
4.23 : 1 2.52 : 1 1.67 : 1 1.22 : 1 1 : 1 4.14 : 1
Weight: 33 kg (72 lbs)
Oil specification: ESSOD21065
Oil change interval: 60,000 miles (96,000 km)
D.307.312
MANUAL TRANSMISSION, CLUTCH ASSEMBLY AND DUAL MASS FLYWHEEL
D.307.312
Reverse Light Switch
Speed Sensor

Manual TransmissionAJ-V6/AJ28
65
D.307.315
Gear Selector Control
The gear selector mechanism is designed to give a
smooth positive action. The lever assembly is
mounted via a bracket to the floor, not the
transmission. Further isolation is provided by the
use of low friction bushes and tuned shift
mechanism compliance.
Flywheel and Clutch
The clutch system is based on the established
principle of a single driven plate and diaphragm
spring hydraulically actuated from the clutch pedal
but incorporates the following special features:
¥ dual mass flywheel
¥ self adjusting clutch
¥ concentric slave cylinder.
Flywheel
While the use of a dual mass flywheel is not new
to Jaguar, the model described here incorporates
the latest refinements in the technology. Relative
rotational movement between the primary and
secondary flywheel masses via the damper system
is greater than on previous vehicles, giving further
improvements in torsional vibration isolation
(engine irregularities) and reducing stresses on the
crankshaft and drivetrain. Steel pressings rather
than castings are used to reduce the weight of the
assembly. The flywheel assembly is not a
serviceable item but the bearing can be released
for servicing.
Self Adjusting Clutch
The self adjusting clutch is an innovative feature
which improves operation and driver comfort by
enabling a constant pedal pressure to be applied
as the friction faces wear, unlike conventional
types of clutch which require increasing pressure
with wear. GEARSHIFT CONTROL LINKAGE
D.303.315

Manual Transmission AJ-V6/AJ28
66With a conventional clutch, increased lining wear
causes the angle of the actuating diaphragm
spring to change as the pressure plate moves
axially towards the engine, requiring a greater
force to operate the clutch (diaphragm actuating
force varies with diaphragm angle). The self
adjusting clutch eliminates the problem by
allowing the diaphragm spring to follow the axial
movement of the pressure plate thus maintaining
the diaphragm spring at the same angle
throughout the life of the clutch. As well as
maintaining a constant pedal pressure, the clamp
force on the pressure plate also remains constant
with wear.
The operation is shown in the diagram. The
diaphragm spring is not fixed at its rotation point
like the conventional system but pivots between a
sensor spring and an adjuster ring. The sensor
spring provides a counter force which is just
sufficient to retain the diaphragm spring axially
against the cover via the adjuster ring and during
normal actuation of the clutch. As the linings
wear, the tendency of the diaphragm angle to
change causes an increase in the actuation force
required to operate the clutch. When this
increased effort exceeds the counter force of the
sensor spring, the diaphragm spring moves axially
towards the pressure plate until the original angle
is restored. At this point the actuation force
required drops to the level of the opposing sensor
spring force, restoring equilibrium with the
diaphragm spring at its new location.
During the axial movement of the diaphragm
spring, the increased distance between the spring
and cover is taken up by the adjuster ring. This
ring has fifteen raised segments, each having a
ramp profile which fits into a corresponding
shape in the clutch cover. When the diaphragm
spring moves axially for wear compensation,
three pre-loaded coil springs in the clutch cover
cause the adjuster ring to rotate, moving up the
ramps and taking up the extra distance between
the diaphragm spring and clutch cover.
Note that, in operation, the adjuster ring rotates
in a clockwise direction, as viewed from the
transmission. If a worn driven plate is replaced in
service and the clutch cover assembly is to be re-
used, the adjuster ring must be rotated back to its
pre-loaded position (see JTIS service instructions).
J.307.318
DUAL MASS FLYWHEEL AND CLUTCH ASSEMBLY
J.307.318
J.307.319
OPERATION OF SELF ADJUSTING CLUTCH
J.307.319
Dual Mass
Flywheel
Assembly
Self Adjusting
Clutch
Driven Plate
Concentric
Slave Cylinder
Adjuster
Ring
Conventional
Clutch
Sensor Spring
Diaphragm
Spring
Self Adjusting
Clutch
Diaphragm
Spring

Manual TransmissionAJ-V6/AJ28
67
D.307.311
CONCENTRIC SLAVE CYLINDER
J.307.319
Bleed Point
Hydraulic
Connection
Concentric Hydraulic Cylinder
The clutch diaphragm spring is operated directly
by a slave hydraulic cylinder located
concentrically about the transmission input shaft.
This system eliminates the need for a release lever
mechanism and improves operating efficiency.

Manual Transmission AJ-V6/AJ28
68
Clutch Pedal Assembly
The clutch pedal is mounted on a combined
assembly with the brake pedal. The clutch master
cylinder is directly actuated by the pedal and
shares a common reservoir with the brake system.
An assistor spring is fitted to the clutch pedal to
reduce the actuation load.
Operation of the pedal when in cruise control
mode activates a switch which cancels this mode.
D.307.316
CLUTCH PEDAL ASSEMBLY
D.307.316
Cruise Deactivate
Switch
Slave Cylinder
Hydraulic
Connection
Fluid from Brake
Reservoir
Clutch Master
Cylinder

Powertrain ManagementAJ-V6/AJ28
69
Introduction
All powertrain and associated management
functions are controlled from a single unit, the
powertrain control module (PCM). These
functions are as follows:
¥ overall monitoring and control of
performance, fuel economy, emissions,
driveability and safety
¥ receives and processes direct inputs from
engine, transmission, fuel system and
ancillary systems sensors
¥ provides direct control of actuator devices
¥ communicates with other modules via the
SCP bus (eg to obtain wheel speed
information)
¥ provides system diagnostics to conform to
OBDII requirements.
Powertrain Control Module (PCM)
The basic PCM is common to the V6 and V8
engines but with unique programming to suit the
respective engine characteristics and some
differences in the interface circuits for the
different sensors and actuators.
The PCM is located below the LH or RH mounted
A/C evaporator/blower unit and has a single
connector panel which protrudes through the
forward bulkhead into the engine bay.
The PCM has three connectors:
¥ a 60 pin connector which provides the
interfacing with the engine wiring harness:
carries engine mounted sensor inputs and
output control signals
¥ a 32 pin connector which carries the
transmission sensing and control signals and
also the rear HO2 sensor inputs
¥ a 58 pin connector which carries non engine
mounted sensor and actuator signals and
provides the PCM link to the SCP bus.
Powertrain Sub-Systems
Brief descriptions of PCM control of new
subsystems are given in the relevant engine and
transmission sections (electronic throttle,
returnless fuel etc).
J.303.1393
POWERTRAIN CONTROL MODULE
J.303.1393