1994 JAGUAR XJ gearbox

ZF Automatic Transmissions Service Manual
1.3 FAULT DIAGNOSIS
The followina tables are intended as a auide to diaanosis of Dossible faults in the ZF 4 HP 22 transmission. When the
fault involvesa leak, it is recommendedthat it is located by the use of a crack detection fluid, eg Met-L-Check, which
is available in spray form and permits the leak to be located after a short test drive.
1.3.1 Initial Checks
Note: Before attempting diagnosis, ensure that the following settings are checked:
Transmission oil level.
. Ensure that the transmission is at normal operating temperature, eg by conducting a road test. If starting from cold,
. Check that the vehicle is on level ground.
. Firmly apply the parking and footbrakes and run the engine at idle speed.
. To ensure that the system is primed, slowly move the selector lever through all the gear positions.
. With the engine still running, engage ‘P‘ Park, withdraw the dipstick and wipe with a lint free cloth.
. Replace the dipstick slowly and withdraw it noting the level.
. Top up as required and recheck the level.
check
for presence of oil on dipstick at idle
in Park before start of road test.
1.3.2 Engine Tune
Selector cable adjustment.
Check gear selection in all selector positions.
If in doubt, select ’N’, disconnect the cable at the gearbox selector lever, check that the gearbox lever is in ’N’ position
. Adjust as necessary, see Vehicle Service Manual.
(third
detent from the rear) and refit the selector cable ball pin to the lever.
Kickdown switch adjustment, see Vehicle Service Manual.
1.3.3 Stall Test
. Ensure the transmission is at normal running temperature.
. Fully apply the parking brake.
. Fully depress the footbrake.
= Select position ‘D‘- Drive.
. Fully depress the accelerator(’kick-down’ detent fully depressed).
. Note the tachometer reading.
Start
the engine.
. Compare the tachometer reading to the specification.
CAUTION: This test must not last more than 5 seconds. Always allow the engine to idle for at least 2 minutes be- tween tests to allow the transmission fluid to cool down. Do not carry out more than three tests in any
half-hour.
1.3.4 Road Test
Fully check all shift speeds and note. Compare the results with the specification in addition to general observations
of transmission behaviour, noises, leaks etc., and consult the following Fault Finding Chart.
CAUTION: When renewing the transmission, ALWAYS flush out the oil cooler and feed and return pipes.
1.3.5 Electrical Checks
If any electrical component fault issuspected, referto the Electrical Diagnostic Manual (EDM) to verify the failure mode
before a repair or replacement is attempted.
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1.3.6 Fault Finding Chart (continued)
Problem
.oss of oil through breather
3il leak at intermediate plate
-eakage between gearbox and
2xtension housing
Uoises
iigh pitched squeaking noise,
jependant on engine RPM, in all
jears, when oil is warm and
accompanied by intermittent
hive after a long journey
iigh pitched noise in all
Dositions, especially if oil is cold.
Sucking noise from pump.
dery noisy in 'lock-up'
rorsional vibrations from engine
Nhen in 'lock-up'
-oud noisewhen converter
:lutch engages
Engine vibrations when
:onverter clutch engaged
Possible Cause
Oil level too high.
Incorrect oil.
Breather blocked.
No breather cap.
'0' ring breather damaged.
Securing clip faulty.
Blanking plug loose
Fastening screws loose.
Gasket faulty.
Dirty filter
Low oil level.
Filter not sealing.
Leaking valve block.
Filter damaged.
Torsion damper faulty
Engine
RPM is too low, 'lock-up'
shift point incorrect
Torsion damper defective
Change point too low
Action ___ Check level.
Remove transmission, ensuring that
it
is drained (including torque converter,
oil cooler and pipes).
Change breather, check for foul
condition
of foam insulation pad.
Fit cap or renew breather.
Remove tail housing and replace
'0'
ring.
Renew clip.
Tighten plugs. Renew sealing washers.
Tighten screws to specified torque.
Renew gasket.
If there is no debris in the sump, renew
the filter and oil.
If debris is present,
renew the transmission.
Top-up as necessary.
Check
I renew 0-ring.
Service
/ renew valve block.
Check filter.
Renew torque converter
Service
I renew valve block
Renew converter
Check valve block ~~
Issue 1 August 1994 38

ZF Automatic Transmissions Service Manual
Reverse Gear
Clutches 'B','D' and 'E' are engaged.
As the front planet gear carrier of epicyclic gear SE '9' is
locked, the direction of output shafgt rotation is reversed.
Epicyclic gear set '10' also rotates as a solid block. I
~~~-698
Fig. 1
2.1.4 Transmission Control Unit
The electronichydrauliccontrol unit comprising a series of valve blocks housing a cable-operated manual valve, con- trol pistons and pressure valves is attached to the underside of the transmission housing; the unit controls the oper- ation of the gear train clutches and directs oil pressure to the appropriate system components (refer to illustrations,
pages 43 to 46) to operate the transmission.
The four valve blocks in which the control valves, pistons etc are located, are mounted and connected through a main
gallery plate. The three solenoid valves
MVI, MV2 and MV3 and the pressure regulator operating solenoid are located
on the upper surface of the plate; electrical connections between the solenoids and the transmission and transmission
control unit are via cable harnesses (refer to relevant diagrams and tables for details of the various pin connections).
Operation of the transmission control unit is through an electronic Transmission Control Module
(TCM) which on re-
ceipt of electrical signalsfrom transmission and engine management sources, activates the hydraulic pressure regulat- ing and shift valves via solenoid valves located on the valve block. The gearshift selector transmits movement, via the
selector cable, to the selector lever on the side of the gearbox; this rotates the selector shaft which controls the manual
selector valve. The rotary position of the shaft is monitored by the rotary switch.
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ZF Automatic Transmissions Service Manual
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2.3 FAULT DIAGNOSIS
The following tables are intended as a guide to diagnosis of possible faults in the ZF 4 HP 24 E transmission. When
the fault involves a leak,
it is recommended that it is located by the use of a crack detection fluid, eg. Met-L-Check,
which is available in spray form and permits the leak to be located after a short test drive.
2.3.1 Initial Checks
&@: Before attempting fault diagnosis, ensure that the following settings are checked:
Transmission oil level
. Ensure that the transmission is at normal operating temperature, e.g. by conducting a 20 mile road test. If starting
. Check that the vehicle is on level ground.
. Firmly apply the parking and footbrakes and run the engine at idle speed.
. To ensure that the system is primed, slowly move the selector lever through all the gear positions.
. With the engine still running, engage 'P' Park, withdraw the dipstick and wipe with a lint free cloth.
. Replace the dipstick slowly and withdraw it noting the level.
. Top up as required and recheck the level.
from
cold: check for presence of
oil on dipstick at idle in 'P' Park before setting off.
Note: The oil level can only be accuratelychecked when at normal temperature-approximately 20 miles at moderate
speeds.
2.3.2 Engine Tune
Selector cable adjustment
. Check gear selection in all selector positions.
. If in doubt, select 'N', disconnect the cable at the gearbox selector lever, checkthat the gearbox lever is in 'N' position
. Adjust as necessary at the selector lever inside the vehicle.
(third detent from the rear) and refit the selector cable ball pin to the lever.
2.3.3 Stall Test
. Ensure the transmission is at normal running temperature.
. Fully apply the parking brake.
. Start the engine.
= Fully depress the footbrake.
. Select position 'D'- Drive.
. Fully depress the accelerator('kick-down' switch fully depressed).
. Note the tachometer reading.
. Compare the tachometer reading to the specification.
CAUTION: This test must not last more than 5 seconds. Always allow the engine to idle for at least 2 minutes between
tests to allow the transmission fluid to cool down. Do not carry out more than three tests in any half-hour.
Jaguar Diagnostic Equipment
(JDE) must be interrogated and any faults identified and rectified (see JDS Manual / In- structions). Check mode switch and gear selector positions using JDE.
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ZF Automatic Transmissions Service Manual
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3il in bell housing
2.3.6 Fault Finding Chart (continued)
Oil pump seal leaking.
Oil pump 0
-ring leaking.
Pump housing leaking.
Converter seam leaking.
Problem Possible Cause Action
:onverter clutch
-eakage between gearbox and
sump
Leakage between intermediate
date and gearbox
Leakage at harness plug
:onnector
Leakage at drive flange
:Iutch engagement speed
ncorrect
Loose fastening screws.
Sump gasket faulty.
Bell housing to gearbox screws loose
Connector 'O'ring faulty
Rear oil seal faulty
ingagement
too hard
Jo clutch engagement
Ionverter clutch engaging at
dle (engine will not idle in
'D')
Control circuit fault.
Speed sensor faulty.
Valve body problem.
Converter unit faulty
Control circuit fault
MV3 faulty.
Converter clutch valve seized.
Converter faulty. Pressure reducing valve
1 seized.
Incorrect oil level.
Oil filter not sealing.
Control circuit fault.
MV3 faulty.
MV3 wire earthed.
Converter clutch valve
sticking.
Check TCM Diagnostics / rectify
fault.
Check TCM Diagnostics
1 renew
speed sensor.
Renew valve body
Renew converter unit
Check TCM Diagnostics
1 rectify
fault.
Renew valve block.
Renew valve block.
Renew converter.
Renew valve block.
Check oil level.
Check 0
-ring etc.
Check TCM Diagnostics
/ rectify
fault.
Renew valve block.
Renew harness.
Renew valve block.
Renew oil pump seal.
Renew 0
-ring.
Renew oil pump.
Renew converter.
Torque tighten.
Renew gasket.
Torque tighten
Renew
'0' ring
Renew oil seal
Issue 1 August 1994 66
. _.~ -

ZF Automatic Transmissions Service Manual
2.3.6 Fault Finding Chart (continued)
a
0
0
a
Problem
Leakage at breather
Leakage from oil cooler circuit
Leakage at intermediate plate
Leakage between gearbox and
extension housing
General
Noise and associated
interruption of power
Loud noise with no drive
forward or reverse
Groaning or buzzing noise (can
sound like mechanical damage)
in all selector positions,
especially when cold.
Sucking noise from pump.
Loud noise on converter clutch
engagement
Engine vibrations when
converter clutch engaged
Possible Cause
Oil level too high.
Incorrect oil specification.
Breather cover missing.
Breather cover
'0' ring faulty.
Breather cover loose.
Pipe lock nuts loose.
Pipe line faulty.
Oil cooler leaking.
Intermediate plate plug leaking
Fastening screws loose. Gasket
faultv.
Oil filter dirty
Drive plate to converter connection
damaged.
Pump drive damaged.
Oil level too low.
Valve block leaking.
Torsion damper defective
Change point too low
Action
Rectify.
Change
oil and flush system.
Replace breather cover.
Renew
'0' ring.
Renew lockwasher.
Torque tighten.
Renew relevant pipes.
Renew oil cooler.
Torque tighten plug.
Renew sealing washer.
Torque tighten
Renew gasket.
Clean
/ replace filter. If clutch debris
found, renew transmission, flush
cooling system
Renew drive plate and converter as
necessary.
Renew transmission.
Rectify.
Renew valve block.
Renew converter
Check TCM
Issue 1 August 1994 67