transmission JAGUAR S TYPE 1999 1.G Powertrain Manual

Preface AJ-V6/AJ28
This Technical Guide introduces the engines and transmissions for the new S-TYPE sports sedan.
It is intended to give Jaguar Dealer workshop personnel an overview of their construction and operation,
and is for information purposes only.
The contents of this Technical Guide must not be used as a reference source for servicing procedures; all
servicing must be carried out in accordance with the appropriate JTIS disc.
This Technical Guide will not be updated. While every effort is made to ensure accuracy, changes may
occur between going to press and the equipment being introduced to the market. Once the equipment is
in service, details of changes can be obtained from Service Bulletins and revisions to the JTIS disc.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or
transmitted, in any form, electronic, mechanical, photocopying, recording or other means without prior
written permission from the Service Division of Jaguar Cars Limited.

IntroductionAJ-V6/AJ28
3 The new S-TYPE sports sedan has an in-line powertrain and rear wheel drive configuration and is
available with either a 3 Litre V6 or a 4 Litre V8 engine, both normally aspirated. The V6 engine,
designated AJ-V6 is new to the Jaguar range and provides expected Jaguar levels of performance with
smooth power delivery, economy and excellent torque characteristics across the engine speed/load
range. The engine is of a lightweight but rigid design with particular attention paid to minimising noise
and vibration. A major innovation is the use of a variable geometry air intake manifold, which is
controlled, via valves, by the engine management system and produces optimised volumetric efficiency
at all engine speeds. Two stage variable valve timing is also fitted and both systems are optimised
together to achieve the wide torque delivery at all engine speeds.
The V8 engine, designated AJ28, is a developement of the now established engine fitted to the
successfull XK Series sports and XJ Series sedan and incorporates the latest modifications fitted to the
AJ27 variant, in particular the continuously variable valve timing system and air assisted fuel injection.
Both the V6 and V8 engines are fitted with a new, common, electronic throttle which does not require a
mechanical cable. Another new feature, also common to both engines, is the use of a returnless fuel
system to reduce the formation of fuel vapour (evaporative emissions).
A new 5-speed automatic transmission is fitted (with slight differences) to both engines. In certain
markets only, an optional 5-speed manual transmission, with new self-adjusting clutch, is available for
the V6 engine only.
Both engines and the automatic transmission are controlled by a completely new powertrain control
system.

V6 Engine AJ-V6/AJ28
34Coolant Pump
The coolant pump is fitted via three bolts to the
engine front cover. The pulley is mounted in-
board of the pump assembly, between the pump
and front cover, and has a smooth surface which
is driven from the outer, non ribbed side of the
drive belt.
Coolant returns from the radiator and cabin
heater system are connected via hoses to inlets on
the front of the pump assembly. The outlet from
the pump is connected to the engine block via a
hose and a tubular casting bolted to the top front
of the block between the cylinders.
Radiator and Cooling Fan Assembly
The engine radiator is one component of the
cooling pack assembly which also includes the
PAS and transmission heat exchangers and the
A/C condenser. The cooling pack assembly and
the PAS and A/C systems are described in the
ÔS-TYPE IntroductionÕ Technical Guide and
transmission cooling is described elsewhere in
this Guide.
The radiator consists of an aluminium core,
26mm in thickness, with crimped on plastic end
tanks. A single electrical cooling fan and a fan
D.303.1213
COOLANT PUMP
D.303.1213
D.303.1375
RADIATOR AND FAN SHROUD ASSEMBLY
D.303.1375
Fan Speed
Regulator Module

V6 Engine AJ-V6/AJ28
38
J.303.1348
Generator
The 120AH generator is fitted with a special casing
to enable it to be bolted directly to the engine via
three fixing points.
On the manual transmission vehicles, sudden
deceleration may result in generator momentum
driving the belt against the engine which is
slowing down, with possible effects on the life of
the drive belt. The generator pulley fitted to the
manual transmission vehicle incorporates a clutch
mechanism which allows it to freewheel in the
reverse drive (anti-clockwise) direction. Note that
a special tool is required to remove the pulley.
To improve generator control on all
engine/transmission variants, the generator now
has a four pin connector to provide two new
sensing signals:
¥ pin S is directly connected to the battery to
provide voltage feedback to the regulator
¥ the regulator senses field current and
produces a PWM signal from pin FR to the
PCM to indicate the generator duty cycle.
D.303.1350
DRIVE BELT TENSIONER
GENERATOR
D.303-1350
Drive Belt Tensioner
The drive belt tensioner is a similar type to that
fitted to the V8 engines. An index on the
tensioned arm rotates with wear against three
markings on the tensioner spring cap which
indicate the minimum and maximum lengths for a
new belt and the point at which the belt must be
replaced.
Replace Belt
Belt Wear
Indicator
New Belt Maximum Length
New Belt Minimum Length
Manual
transmission
pulleyAutomatic
transmission
pulley
J.303.1348

V8 Engine AJ-V6/AJ28
46
Basic Engine
Bottom End
Changes to the cylinder block, connecting rods
and pistons which were introduced for the AJ27
N/A engine are also applicable to the AJ28 unit
and are described in the ÔXK and XJ series 1999
MY updateÕ Technical Guide.
Oil Sump Body and Pan
A revised oil sump body and sump pan are
necessary to accommodate the V8 engine in the
S-TYPE model but the sump capacity is
unchanged.
D.303.1184
OIL SUMP AND PAN
D.303-1184
J.303.1317
TRANSMISSION DRIVE PLATE
J.303.1317
Transmission Drive Plate
The transmission drive plate is similar to AJ27 but
is fixed with eight bolts to an adaptor plate on the
torque converter (see Transmission sections). The
crankshaft sensor ring is fitted to the engine side
of the drive plate as for the previous V8 engines.

Automatic TransmissionAJ-V6/AJ28
61
Introduction
The 5R55N type 5-speed automatic transmission is fitted to both the V6 and V8 engines. The
transmission is controlled electronically by the powertrain control module (PCM) without the use of a
dedicated control module. Normal P, R, N, D drive functions plus manual selection of 4th, 3th and 2nd
gears are provided by a Jaguar style ÔJÕ gate (not the same as XJ and XK Series - see ÔS-TYPE IntroductionÕ
Techical Guide). Sports mode and traction assistance are selected at the ÔJÕ gate.
Specification
Transmission weight with fluid: 90 kg (198 lbs)
Oil type: Mercon V semi-synthetic (not compatible with other fluids)
Oil capacity: 9 Litres (9.5 quarts) - new
5 Litres (5.3 quarts) - after draining
Oil Fill/change: Filled for life, no top up required (no dipstick)
Gear ratios: 1st 2nd 3rd 4th 5th Rev
3.24 : 1 2.44 : 1 1.55 : 1 1 : 1 0.75 : 1 3.07 : 1
D.307.313
5R55N AUTOMATIC TRANSMISSION
D.303.313
Vent Tube
Turbine Speed
Sensor
Intermediate
Speed Sensor
Output Speed
Sensor
Range Switch
Rear Mounting
BracketJ-gate Selector
Cable Lever

Automatic Transmission AJ-V6/AJ28
62
D.307.321
V8 Engine Adaptor Plate
D.307.321
1. J-gate selector cable lever
2. Range switch
3. Control Module
4. Solenoid block assembly5. Filter assembly
6. Sump
7. Drain plug
Construction and Operation
The transmission housing consists of a one piece
die cast aluminium case with re-inforcement ribs
to minimise noise, vibration, and harshness
(NVH). To allow for the different physical size of
the engines, there are two transmission variants
with different overall lengths and bell housings to
match the respective engines, the V8 variant being
shorter. Different torque converters are necessary
and the V8 variant is also fitted with an adaptorplate to mate the torque converter to the larger
diameter drive plate on the V8 engine.
The main features of the transmission unit are :
¥ torque converter with a twin friction face
lock-up clutch and torsional damper
¥ geartrain consisting of three epicyclic gearsets
¥ shift elements consisting of multi-plate
clutches, brakes and one way clutches
¥ control actuators: four shift solenoids, three
variable force solenoids and a PWM 5R55N AUTOMATIC TRANSMISSION
1
3
7
6
5
24

Automatic TransmissionAJ-V6/AJ28
63 controlled solenoid are mounted on an
integral, replaceable, control module
¥ three speed sensors mounted on the external
casing: turbine speed sensor, intermediate
speed sensor and output speed sensor
¥ an oil temperature sensor is fitted inside the
transmission.
The gear select lever is connected via a Bowden
cable to an operating lever on the left side of the
transmission casing. A digital rotary switch, the
transmission range switch, fits over the shaft of
the operating lever and is fixed by two bolts to
the transmission casing. Selection of a particular
drive function generates a 4 bit binary coded
signal which is transmitted directly to the PCM
over a four wire parallel interface. As on the XK
and XJ Series, lateral movement of the gear select
lever across the gate, D to 4 or 4 to D, operates a
switch which indicates the selected function to
the PCM (the Bowden cable is not actuated
laterally).
The PCM directly controls the transmission
actuators as a response to driver demand, engine
requirements and according to the selected shift
mode. Gear selection is controlled by commands
to the four shift solenoids. If, during gear
selection, the relative speeds monitored by the
speed sensors are not as expected, the PCM
varies the analogue signal to the variable force
solenoids to increase/decrease the clutch pressure
(closed loop control). Increased engagement times
due to ageing are also controlled by adaptive shiftpressure.
Apart from the sports mode and traction mode
selected by the driver, there are pre-programmed
modes selected by the PCM in response to sensed
driving conditions :
¥ increased load such as gradients and trailer
towing
¥ cruise control
¥ hot mode: strategies including clutch lock up
are applied to reduce heat.
Transmission Oil Cooler
The transmission fluid is cooled externally by a
dedicated oil to air radiator which is mounted in
the integral cooling pack between the engine
radiator and A/C condenser and below the PAS
cooler.
D.307.320
TRANSMISSION OIL COOLING
Transmission
Oil Cooler
D.307.320

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