1994 JAGUAR XJ lock

ZF Automatic Transmissions Service Manual
CON TENTS
Section Title SRO Page
Foreword ........................................................................\
... ii
I ................ Service Tools & Equipment ........................................................... iii
I1 ................ Torque Tightening Specifications ....................................................... iii
111 ............... Service Materials .................................................................... iii
IV ............... Service Data ....................................................................... \
iii
1.1 .......................................... 1
1.1.7 ............. Torqueconverter .................................................................... 1
1.1.2 ............. Four-speed Epicyclic Gear Train ........................................................ 2
1.1.3
............. Operation Of Gear Train Clutches ...................................................... 3
1.1.4
............. Transmission Output Shaft Extension Housing ............................................ 4
1.1.5.
............ Transmission Control Unit ............................................................. 4
1.1.6 ............. Gearshift Selection ................................................................... 8
1.1.7. ............ Throttle Valve Mechanism (kickdown) ................................................. 8
1.1.8
............. Starter Inhibit Switch ................................................................. 8
1.1.9
............. Gearshift Interlock ................................................................... 8
1.2
.............. Hydraulic Circuit Diagrams ........................................................... 9
1.3
.............. Fault Diagnosis ..................................................................... 33
1.3.1
............. Initial Checks ...................................................................... 33
1.3.2
............. Engine Tune ........................................................................\
33
1.3.3
............. Stall Test ........................................................................\
.. 33
1.3.4
............. Road Test ........................................................................\
.. 33
1.3.5
............. Electrical Checks ................................................................... 33
1.3.6
............. Fault Finding Chart .................................................................. 34
2.1
.............. ZF 4 HP 24 E Transmission - General Description ........................................ 39
2.1.1
............. Torqueconverter ................................................................... 39
2.1.2
............. Four-speed Epicyclic Gear Train ....................................................... 40
2.1.3
............. Operation Of Gear Train Clutches ..................................................... 41
2.1.4
............. Transmission Control Unit ............................................................ 42
2.1.5
............. Transmission Control Module (TCM) ................................................... 46
2.1.6
............. Transmission Rotary Switch ........................................................... 47
2.1.7
............. Decoder Module .................................................................... 47
2.1.8 ............. Performance Modeswitch ............................................................ 47
2.1.9
............. 'Kick-down' Mechanism ............................................................. 47
2.1.10.
........... Reverse Safety Inhibit ................................................................ 47
2.1.11
............ Gearshift Interlock .................................................................. 47
2.1.12.
........... Starter Inhibit Switch ................................................................ 47
2.1.13 ............ Harness Connections ................................................................ 48
2.1.14. ........... Rotary Switch Harness ............................................................... 49
2.1.15 ............ Main Harness Connectors- 12 wayand8 way .......................................... 50
2.2
.............. Hydraulic Circuit Diagrams .......................................................... 51
2.3
.............. Fault Diagnosis ..................................................................... 60
2.3.1 ............. Initial Checks ...................................................................... 60
2.3.2 ............. Engine Tune ........................................................................\
60
2.3.3 ............. Stall Test ........................................................................\
.. 60
2.3.4 ............. Road Test ........................................................................\
.. 61
2.3.5 ............. Electrical Checks ................................................................... 61
2.3.6 ............. Fault Finding Chart .................................................................. 61
2.4
.............. Service Operations ................................................................. 68
............... ZF 4 HP 22 Transmission . General Description
i Issue 1 August 1994

ZF Automatic Transmissions Service Manual
1.1 ZF 4 HP 22 TRANSMISSION, GENERAL DESCRIPTION
The ZF Automatic Transmission covered in this section comprises a hydrodynamic torque converter, four speed gear
train and a hydraulic transmission control unit.
1. Torque converter
2. Throttle cable 3. 4-speed gear train 4. Output flange 5. Transmission control unit
Fig.
P \R
HP 22 ZF
6. Oil outlet (drain plug)
7. Selector cable attachment 8. Selector lever positions (see text) 9. Dipstick / oil filler tube 10. Oil cooler connection
.ansmission -
The transmission provides six gearshift positions:
0 Position 'P': Park - in this position the driven wheels are mechanically locked at the transmission.
0 Position 'R': Reverse - reverse gear selected.
0 Position 'N': Neutral - engine disconnected from driveline and wheels.
0 Position 'D': Drive - all four speed ranges are selected automatically with lock-up available in top gear only.
0 Position '3': automatic selection of the lowest three speed ranges only.
0 Position '2': automatic selection of the lowest two speed ranges only, transmission is prevented from shifting
up to the third and top speed ranges.
Immediate selection of a lower ratio is also available by 'kick-down' (pressing the accelerator down beyond the normal
full throttle position) for example when overtaking.
1.1.1 Torque Converter
The torque converter serves two main functions: it acts as a fluid coupling between engine and transmission geartrain
and it provides multiplication of engine torque when required.
The torque converter consists of an impeller, a turbine and a stator which is mounted on a one
-way clutch. The
converter cover is fixed to the impeller to seal the three elements within a common housing forming a closed circuit
through which oil flows when the transmission is in operation. The impeller is therefore connected to the engine and
rotates at engine speed when the engine is operating.
Torque multiplication is at its greatest when the vehicle is driven away from standstill. The stator bears against the
housing through its one
-way clutch and deflects the oil so that the flow is accelerated. As road speed builds up, the
impeller and turbine wheels turn at almost the same speed, so that the stator ceases to accelerate the oil flow and in- stead is disengaged from the housing and turns freely in the flow of oil. At this stage, the torque converter acts as a
fluid coupling.
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ZF Automatic Transmissions Service Manual
The torque converter acts in all four forward gears and in reverse. The converter lock-up clutch closes in 4th gear at
a point depending on road speed and accelerator position; engine power is then transmitted by purely mechanical
means.
A low-loss oil pump in the front of the transmission housing supplies the converter, the automatic gear shift and the
lubrication circuit; oil is drawn from a sump in the bottom of the gear train housing through a filter. The pump drive
gear is keyed to the converter impeller hub and therefore turns when the engine is running, thereby pressurizing the
oil.
Selected ratios
Di, 31, 21
1.1.2 Four-speed Epicychc Gear Train
The torque converter drives a mechanical epicyclic gear train providing four forward ratios and reverse. Individual ra-
tios are obtained by coupling togetherthevarious parts of the geartrain by means of hydraulically actuated multi-disc
clutches and brakes; built in freewheels permit gear shifts without any interruption of the power flow. Operation of the
clutches and gear sets is described
in sub-section 1.1.3.
Each epicyclic (or planetary) gear set comprises a central, sungear, an annulus and a planetary carrier which supports
four small planet gears or pinions. Two gear sets are used in this transmission. A compound gear set comprising front
annulus and planet carrier, rear annulus and planet carrier and a common sungear transmits the drive
in all gears ex- cept REVERSE; a single planetary carrier, annulus and sungear transmits the fourth gear drive. The table below shows
the resulting clutch operation
in the selected gear ratios.
Resulting clutch operation
A Clutch drives annulus clockwise
E Clutch
& OWC drives output shaft clockwise
D2,32,22
D3,33, 23
04
R
Park, Neutral
A Clutch drives annulus clockwise
C1 Clutch holds sungear against anti-clockwise
C Clutch
& OWC holds sungear against anti-clockwise
A Clutch drives annulus clockwise
B Clutch drives sungear clockwise
C Clutch
& OWC holds sungear against anti-clockwise
A Clutch drives annulus clockwise
B Clutch drives sungear clockwise
C Clutch & OWC holds sungear against anti-clockwise
B Clutch drives sungear clockwise
D Clutch holds carrier against clockwise
E Clutch
& OWC drives output shaft anti-clockwise
E Clutch
& OWC applied (hydraulics)
OWC = one way clutch
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ZF Automatic Transmissions Service Manual
1.1.3 Opera tion Of Gear Train Clutches
1st Gear
Clutches 'A' and 'E' are engaged.
The front planet gear carrier of gear set
'1' is locked against
the housing of through freewheel '2'when the engine is pul- ling, but is over-run when the engine is coasting.
Epicyclic gear set '2' rotates as a solid block
with the second
planet set.
2nd Gear
Clutches 'A','Cl','C' and 'E' are engaged.
Freewheel
'4' over-runs.
Clutches
'Cl' and 'C' lock the sun gear to the housing.
3rd Gear
Clutches 'A','B','C' and 'E' are engaged.
Freewheels
'4' and '5' are over-run.
Epicyclic gear sets
'1' and '2' rotate as a solid block at
of 1:l.
ratio
4th Gear
Clutches 'A','B','C' and 'F' are engaged.
Freewheels
'3'.'4' and '5' are over-run.
Epicyclic gear set
'1' rotates as a solid block.
The hollow shaft
with the sun wheel of epicyclic gear set '2'
is locked.
Above a predetermined road speed, lock
-up clutch '6 locks
torque converter '7' solid to prevent slip.
JLL-694 Fig. 1
JLL-69 Fig. 2
54
JLL-69 Fig. 3
JLL - 6 97 Fig. 4
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ZF Automatic Transmissions Service Manual
Valve
Reverse Gear
Clutches 'B','D' and 'E' are
engaged.
As the front planet gear carrier of epicyclic gear set
'1' is
locked, the direction of output shaft rotation is reversed.
Epicyclic gear set
'2' also rotates as a solid block.
Summary of function
J4L-698
Fig. 1
Pressure regulating
1-2 shift valve
2
-3 shift valve
1.1.4
This housing contains the output shaft and speed governor and the parking lock mechanism. The governor comprises
two spring loaded valves, a spindle and a weight; the governor is influenced by centrifugal and hydraulic forces and
supplies a varying hydraulic pressure.
The parking lock pawl operates on
a toothed wheel attached to the output shaft speed governor; the mechanism is
operated from the selector (position 'I") by actuator rod.
Transmission Output Shaft Extension Housing
Varies line pressure as required
Line pressure to
C & C1 clutch valves and dampers
Line pressure to
C1 clutch (2nd); line pressure to B clutch (3rd)
1.1.5 Transmission Control Unit
The hydraulic control unit comprising a series of valve blocks housing the manual (selector) valve, control pistons and
pressure valves, is attached to the underside of the transmission housing; the unit controls the operation of the gear
train clutches and directs oil pressure to the appropriate system components (refer to illustrations, pages 5 to 7 ) to
operate the transmission. The valve blocks are connected to a main gallery plate.
Line pressure from the hydraulic pump is supplied initially to the pressure regulating valve, manual valve, governor,
3
-4 shift valve, 'E' clutch and damper, throttle valve, modulator valve and torque converter pressure (and reversing)
valve. The function of each of the valves in the control unit and the governor valve is summarised in the table below.
2nd gear inhibit
3
-4 shift valve
Throttle valve
Modulator
Converter
& Reversing
Reverse inhibit
F Clutch inhibit
Converter clutch hysteresis
Converter clutch lock
-up
Converter clutch damper
Clutch valves
& Dampers
Governor Line pressure
to 2
-3 shift valve
Line pressure to
E clutch (3rd); line pressure to F clutch (4th)
Throttle pressure to modulator and shift valves
Modulated throttle pressure fed to clutch dampers and valves
Line pressure to lock
-up clutch; lubrication oil to cooler
Line pressure to B
& D clutches
Governor pressure to 3
-4 shift valve inhibited in reverse
Governor pressure to converter clutch hysteresis valve
Line pressure to converter pressure valve
(D4 selected)
Aids quality of converter clutch application
Aids quality of clutch application relevant to modulator
& line pressures
Varies pressure in accordance with road speed
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1.1.6 Gearshift Selection
Gearshift selection is by movement of the shift lever which through a selector cable causes repositioning ofthe manual
(selector) valve to direct oil pressure to the required shift valve. The automatic shift points are determined by acceler- ator position and road speed: throttle movement moves a cam on the throttle valve, directing oil pressure to the shift
valves and modulator valve, road speed modulates hydraulic pressure through a centrifugal governor driven by the
transmission output shaft. Operation
of the hydraulic control system is shown diagrammatically in the circuit dia
-
grams on the following pages.
I I
I
I
2 -3- I
I I
I
I
- I
I I 1 4 -5 - - -
+ ! + I I 'I 10 I I
I
I 1
1, 1-Y I
I I
I
I
1. Engine 8. Pump regulator valve 2. Torque converter 9. Damper
3. Pump 10. Governor valve 4. Clutch & gears 11. Shift valve 5. Governor 12. Kickdown cable &throttle cam 6. Shift 13. Throttle / modulator valves 7. Solenoid valve 14. Transmission housing
Fig.
1 Schematic Diagram of Hydraulic Control
I. 1.7 Throttle Valve Mechanism (kick-down)
The throttlevalve or 'kick-down' mechanism comprises a cable connected between throttle body pedal and the throttle
valve cam/ quadrant located on the selector valve shaft; the cam operates the throttle valve housed within the throttle
valve block. The travel of the valve is proportional to throttle positions and alters shift speeds and pressures during
gearshifts to take account of throttle position. The mechanism also provides for immediate selection of a lower
ratio (eg when overtaking) by depressing the accelerator beyond the normal full
-throttle position. 'Kick-down' is oper- ated by movement of the throttle cable into the 'kick-down' position causing full movement of the throttle valve and
directing oil flow to the shift valves.
1.1.8 Starter Inhibit Switch
The starter inhibit switch prevents the starter motor from being operated when the shift lever is not in position 'P' - Park or position 'N'- Neutral. The switch is located in the gear selector housing.
I. I. 9 Gearshift Interlock
A brake pedal /shift lever interlock is incorporated in the gearselector mechanism. Theshift lever may only be moved
from the 'P'- Park position if the ignition key switch is in position '11', and the foot brake pedal is applied. The ignition
key cannot be removed from the ignition switch unless the shift lever is in the 'P' -Park position. Once the ignition key
has been removed, the shift lever is locked in the park position.
The gearshift interlock is operated by an electrical solenoid located adjacent to the selector; an override latch is incorpo
- rated into the mechanism to enable the gearshift interlock to be manually overridden in the event of electrical failure
or when towing.
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ZF Automatic Transmissions Service Manual
2
A. C1 Clutch valve B. 2-3 shift valve piston
C. C clutch damper valve
D. B clutch damper E. 1-2 shift valve piston F. D clutch valve and piston G. Pressure regulating valve
H. Manual (selector) valve I. A clutch damper J. 1-2 shift valve K. B clutch damper valve L. C clutch damper
M. 2-3 shift valve N. Converter pressure valve
M: Numerical annotations are not used in this application.
Fig.
1 Manual Valve Block
1
I
JLL-699
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ZF Automatic Transmissions Service Manual
1
JL4-70
A. One way valve (lubrication) B. 2nd gear inhibit valve C. F clutch damper D. F clutch inhibit valve (reverse)
E. 3-4 shift valve piston
F. 3-4 shift valve G. 1st gear inhibitvalve H. F clutch valve I. E clutch damper
J. C1 clutch damper
Note: Numerical annotations are not used in this application.
Fig.
1 Rear Valve Block
6 Issue 1 August 1994