1998 JAGUAR X308 transmission

Automatic Transmission/Transaxle - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26
-
Lubri c
ants, Fluids, Sealants and Adhesives - ZF Au
tomatic Transmission (Normally Aspirated Vehicles)
Capacities - ZF Automatic Transmission (Normally Aspirated Vehicles)
Torques - ZF Automatic Transmission (Normally Aspirated Vehicles)
Internal Gear Ratios


UnitS p
ecification
Transmissi
on fluidEsso
ATF LT 71141
Torque converter spigotMolyc
o
te or equivalent
UnitLi
t
ers
Transmissi
on fluid (with
torque converter)
10
,0
Com p
onent
Nm
Locki
n
g ferrule - Shift knob
7 -

10
P
l
ug - Drain fluid pan
27
-
33
P
l
ug - Level / fill (transmission case M18 x 1.5)
32
-
38
Tu
be
nut - Cooler pipe to transmission unit
17
-
23
B
o
lt - Drive plate to torque converter
43
-
57
B
o
lt - Driveshaft coupling to transmission
75
-
88
Bo
lt
- Fluid filter to valve block
4,
5 -
5,5
Bolt
-
Fluid pan to transmission case
9 -

11
B
o
lt - Rear extension housing to transmission case
21
-
25
Bolt
-
Rear engine (isolation) mounting to mounting bracket
22
-
28
Bolt -
Rear engine moun
ting bracket to body
22
-
28
Bolt
-
Rear engine mounting bracke
t to transmission rear extension
30 -
40
B
o
lt - Selector cable bracket to transmission case
7 -

10
Bolt
-
Transmission unit to engine
43
-
57
Nu
t -
Transmission drive flange
1
08 -
132
Nu
t -
Selector cable inner to shift lever
1,
5 -
2,5
Nu
t -
Selector cable inner to selector lever
7 -

10
Nu
t -
Selector cable outer to bracket
22
-
28
Nu
t
- Selector lever pivot shaft
7 -

10
Nu
t -
Shift interlock solenoid to housing
5 -
7
Nut -
Shift interlock solenoid actuating lever
11
-
13
Sc
re
w - Input sensor bracket to transmission case (M5)
4,
5 -
5,5
Screw
-
Output sensor bracket to transmission case (M6)
7,
5 -
8,5
Screw
-
Solenoid / regulator plate to valve body
4,
5 -
5,5
Sc
re
w - Valve block to transmission case
7,
5 -
8,5
GearRatio
1s
t3,57
1:1
2n
d2,2:
1
3r
d1,50
8:1
4t
h1,00
:1
5t
h0,80
3:1
Re
ve
rse
4,
06
3:1

Automatic Transmission/Transaxle - 4.0L NA V8 - AJ27/3.2L NA V8 - AJ26
- Transmission Descriptio
n
Description an
d Operation
Transmission As

sembly
Int
roduction

Compon
ent Descriptions
The t

orque converter:
Acts as a fluid

coupling between the
engine and transmission geartrain.
P
rovides multiplication of engine torque.
Cons

ists of an impeller, turbine and stat
or, housed within a converter cover.
Has a l
ock-up clutch with variable slip control.
The transmission casing:
Houses the geartrain and elec t
ro-hydraulic control unit.
Contains

the input speed sensor which measures turbine speed.
Contai

ns the output speed sensor which measures the transmission output speed.
It
em
Par
t Number
De
scription
1—Torque c

onverter housing
2—Tran

smission casing
3—Fluid pan


4—Transmission bre

ather
5—Re

ar extension housing
6—16

-way connector
7—Gear s

elector shaft

Contains th
e hydraulic system pump.
Contains
th
e fluid temperature sensor.
The epicyclic geartrain:
Provi des fi
ve forward gears and Reverse.
Has
h
ydraulically actuated, multi-disk clutches, to select the required gear ratios.
Feature

s clutch-to-clutch operation to permit
gear shifts for uninterrupted power flow.
The electro-hydraulic control unit:
Is lo c
ated in the lower part of
the unit, within the fluid pan.
Is controlled
by the TCM (transmissio
n control module), and the manual selector valve which is cable operated.
Re
gulates the flow of fluid to the ge
artrain clutches via three solenoid-operated valv es and the manual selector
valve.
Has fi ve pressure
regulators for controll
ing fluid pressures within the system.
Is con
nected to the TCM via a 16-way connector mounted on
the left-hand side of the transmission casing. Refer to
Connector Pins Identification, Section 307-01A.
The hydraulic system pump:
Is l o
cated at the front of the transmission casing.
Is dri
v
en from the impeller hub,
pressurising the fluid whenever the engine is running.
Supplie
s fluid under pressure to the torq
ue converter, geartrain, electro-hydr aulic control unit and the lubrication
circuit.
D r
aws fluid from the fluid pa
n below the transmission casing, through a filter.
The rear extension housing:
Is bolt
ed to the rear of the transmission casing.
Provides the rear engine / transmi

ssion mo
unting point; refer to section 303-01.
Carrie
s the transmission output shaft oil seal.
Filled-for-l
i
fe Fluid System
The
transm
ission is 'filled for life' and
does not require fluid changes, except where extreme driving conditions prevail.
Routine level checking is not required and a dipstick is not pr ovided. A level / filler plug is fitted for level checking and
replenishment, following service actions; see 303-01 General Procedures.
Transmission Torque Converter

Op
eration
The T
ransmission Control Module (TCM) is
able to monitor the state of the torque converter clut ch at all times.
There are three operating modes for the converter
1. 1. Fully open - Torque converter 'unlocked'
2. 2. Fully closed - Torque converter 'locked'
3. 3. Slip control - The TCM monitors slip and may apply sufficie nt pressure to allow a small degree of slip. This mode
maximises economy by reducing slip to a minimum whilst providing isolation from drive-line shunt and vibration.
The TCM constantly measures the slip within the torque conver ter by comparing engine speed (via CAN) and input (turbine
speed). Differences in these speeds indicate the amount of slip.
Clutch Hydraulic Pressure Regulation
The T
CM supplies an internally switched +1
2V supply to the #4 pressure regulator. The regulator is operated by switching
the other side of the operating winding to ground. Hydraulic pressure is controlled by 'pulse width modulation' (PWM) of the
ground switching signal i.e. the duty cycle; the time that the pressure regulator is switched on.
Hydraulic Control
- Transmission Pre
ssure Regulators an d Shift Solenoids

Opera
tion
F
l
uid flow within the transmission assembly is controlled
by three solenoid valves and five pressure regulators.
The TCM supplies an internally switched +12V supply to each sh ift solenoid and pressure regulator. Hydraulic pressure from
the pressure regulators is controlled by 'pulse width modulation' (PWM) of the ground switching signal i.e. the duty cycle;
the time that the pressure regu lator is switched on. Control of the solenoids is effected by switching one side to ground
through the TCM.
During normal operation the TCM monitors 'Switch On' of the so lenoids, regulators and the TCM output stages, but does not
check output stage 'Switch Off'.
It e
m
Par
t
Number
De
scr
iption
1—Shif
t Sole
noid #3
2—Shif
t Sole
noid #2
3—Shif
t Sole
noid #1
4—Pressure R
e
gulator #5
5—Pressure R
e
gulator #4
6—Pressure R
e
gulator #3
7—Pressure R
e
gulator #2
8—Pressure R
e
gulator #1

Voltage is monitored at the regulators and solenoids for continuity and shorts. For example, when a solenoid is ON the
voltage on the TCM side should be ground , when OFF the voltage should be +12.
Shift Solenoid

The function of the three soleno id valves is to control the flow of transmissi on oil to the various transmission components.
Three solenoid valves are located wi thin the transmission assembly, and are closed when not energized.
Pressure Regulator

The function of the five pressu re regulators is to modulate the oil pressure to the various transmission components. The
regulators are pulse width modulated by the TCM, switching to ground potential. The other side of the regulators being
connected, via an internal TCM relay, to battery voltage. The regulator is closed when not energized by the TCM.
Transmission Fluid Temperature Sensor

Operation
The transmission fluid temperature sensor is integrated into the internal harness within the fluid pan.
It should be noted that this component is not serviceable, ne cessitating the renewal of the internal harness should a fault
occur.
Following engine start-up, if the fluid temperature is < 20 °C and does not increase by 10 °C after 180 seconds, a failure
judgement is made. A similar judgement is made should the temperature change by more than 5 °C in <100 milliseconds.
The MIL is illuminated if the failure judgement is made on two successive trips.
Sensor output is continuously monitored for out of range values. If a sustained high, or low inpu t is sensed, indicating a
harness or connector fault, a failure judgement is made.
Location of Sensor Within The Harness

Temperature / Resistance Relationship Chart

Transmission Speed Sensors (Gear Shift Control)

Operation
There are two speed sensors within the transmission assembly; one on the input shaft or convertor turbine and the other on the output shaft.
Both sensors are of the inductive type and sense toothed wheels; the input wheel having 30 teeth and the output 36 teeth.

Temperature ( °C)Nominal Resistance (kOHM)
-20685
0812
20953
401107
601276
801458
1001653