engine LAND ROVER DISCOVERY 1995 Workshop Manual

ZF
1
FAULT DIAGNOSIS ZF AUTOMATIC GEARBOX
Before referring to fault symptoms, carry out initial
static checks first:
INITIAL STATIC CHECKS
Check start positions 'P' & 'N' only........................................................
Reverse lights 'R' only..................................................................
Gear engagements N-D,N-3,N-2,N-1,N-R..........................................................
Full throttle Engine switched off, check full travel at engine and at.......................................................................
pedal.
Oil level 'N' selected, engine running at normal running............................................................................
temperature.
Pressure test
2000 rev/min 10±0.3 bar, 150±5 lbf/in
2....................................................................
Idle pressure 6.9±0.3 bar, 100±5 lbf/in2at 665 to 735 rev/min. ....................................................................
To fit pressure gauge
Service tools:
See Service tools, Automatic
Gearbox
0 to 20 bar, 0 to 300 lbf/in2Pressure gauge.
Flexible hose adaptor.
1.Site vehicle on a ramp [hoist].
2.From under gearbox, remove socket head plug
(located 10cm from oil pipe) Fit hose adaptor
LST502-1.
3.Fit hose to adaptor.
4.Fit gauge 18G502A to hose and route into
vehicle, ensuring hose is clear of rotating parts
and exhaust pipes.
5.Carry out road test.
See Road Test Procedure
Remove pressure gauge
6.Reverse removal procedure.

44AUTOMATIC GEARBOX
2
FAULT DIAGNOSIS ROAD TEST PROCEDURE
Follow the procedure given commencing each test,
from a standing start, on a level road, in good weather
conditions.
ROADTEST 1 = CHECKS 1-2-3-4-5-6-7-8
D SELECTED KICKDOWN START FROM REST
CHECK 1
Check for clutch squeal and slip. Check pressure is
150lbf/in
2
CHECK 2
Check 1st to 2nd upshift speed and quality. Pressure
should fall to 120 lbf/in
2.
CHECK 3
Check 2nd-3rd upshift speed and quality. Pressure
should fall to 100 lbf/in
2
CHECK 4
Release throttle to allow simultaneous engagement
4th + DDC. Check shift quality and engine rpm drop of
approximately 500 rpm.
CHECK 5
To proceed to Check 5 release throttle and check
drop out speed of direct drive clutch to 4th.
CHECK 6
Check down shift speed and quality 4th to 3rd.
NOTE: This shift is usually very smooth
and difficult to detect.
CHECK 7
Check downshift speed and quality 3rd to 2nd.
CHECK 8
Check downshift speed and quality 2nd to 1st. Also
difficult to detect.
END OF ROADTEST 1ROADTEST 2 CHECKS = 9-10-11
D SELECTED FROM REST
FULL THROTTLE START
CHECK 9
Check 1st-2nd upshift speed and quality.
CHECK 10
Check 2nd 3rd upshift speed and quality.
CHECK 11
Check 3rd 4th and direct drive clutch upshift speed
and quality.
NOTE: 4th and the direct drive clutch
engage simultaneously.
END OF ROADTEST 2

ZF
3
FAULT DIAGNOSIS ROADTEST 3 = CHECKS
12-13-14-15-16-17-18-19-20-21-22-23
D SELECTED FROM REST
LIGHT THROTTLE START
CHECK 12
Check 1st 2nd upshift speed and quality.
CHECK 13
Check 2nd 3rd upshift speed and quality.
CHECK 14
Check 3rd 4th upshift speed and quality.
NOTE: This shift is usually very difficult to
detect but can be confirmed by a 200 rpm
drop in engine speed.
CHECK 15
Check speed and quality of shift into direct drive
clutch, confirmed by 300 rpm drop in engine speed.
NOTE: An intermediate throttle position
engagement of 4th and the direct drive
clutch, which is indicated by a fall of
500rpm in engine speed.
CHECK 16
At approximately 88 kph (55 mph) depress throttle to
kickdown - gearbox should change down to 2nd -
release throttle to re-engage 4th direct drive clutch
continue to accelerate gently.
CHECK 17
At approximately 128 kph (80 mph) depress throttle to
kickdown - gearbox should change down to 3rd -
release throttle to re-engage 4th direct drive clutch
and continue to accelerate gently.CHECK 18
At approximately 138 kph (85 mph) select 3rd,
gearbox should change immediately down to 3rd.
Release throttle.
CHECK 19
De-accelerate to approximately 47 kph (30 mph)
depress throttle to kickdown - geabox should
downshift to 1st gear, continue accelerating at full
throttle until 3rd gear is attained. To do this you will
have repeated check 2 of Test 1.
CHECK 20
At 128 kph (80 mph) select 2nd no downshift should
occur. Release throttle.
CHECK 21
At 104 kph (65 mph) an automatic downshift into 2nd
gear should occur. Continue to de-accelerate.
CHECK 22
At 88 kph (55 mph) select 1st. No downshift should
occur. Continue to de-accelerate.
CHECK 23
With 1 selected 2nd gear engaged continue to
de-accelerate and at 45 kph (28 mph) the box should
automatically downshift to 1st gear after which no
upshifts will occur in this selector position.
END OF ROADTEST

44AUTOMATIC GEARBOX
10
FAULT DIAGNOSIS FAULT SYMPTOMS
SYMPTOM 1 - Intermittent drive and high pitched
noise
FAULT - Low fluid level or restricted filter
SYMPTOM 2 - No drive in reverse
Select 'D'
ú No drive
FAULT - Continue with Symptom 3
ú Drives forward
FAULT - Reverse gear interlock valve
seized
Select '1'
ú No engine braking
FAULT - Clutch brake 3
SYMPTOM 3 - No drive from rest with 'D' selected
Select '1'
ú Vehicle drives
FAULT - No 2 freewheel
ú No drive
Carry out main line pressure check
ú Normal pressure
FAULT - Clutch A
ú No pressure
FAULT - Blocked filter or pump failure
ú Low pressure
FAULT - Restricted filter or sticking primary
regulator
SYMPTOM 4 - Slip in all forward gears
Carry out main line pressure check
ú No pressure
FAULT - Blocked filter or pump failure
ú Low pressure
FAULT - Restricted filter or sticking primary
regulator
ú Normal pressure
FAULT - Clutch 'A'SYMPTOM 5 - Harsh engagement 'N' to 'D'
Check engine idle speed
Carry out main line pressure check
ú High pressure
FAULT - Primary regulator stuck
ú Normal pressure
FAULT - Clutch 'A' or damper for clutch'A'
SYMPTOM 6 - Fierce shift or flare 1st to 2nd shift
Check engine idle speed
Carry out mainline pressure check
ú High pressure
FAULT - Continue with symptom 5
ú Normal pressure
FAULT - Modulator valve or dampers for
clutch brake CB1 and/or clutch brake CB2
FAULT - Clutch brake CB1 and/or clutch
brake CB2
SYMPTOM 7 - Fierce shift or flare 2nd to 3rd
Carry out mainline pressure check
ú High pressure
FAULT - Continue with symptom 5
ú Normal pressure
FAULT - Modulator valve or clutch 'B'
damper
FAULT - Clutch 'B'
SYMPTOM 8 - No 3rd gear
FAULT - 2-3 shift valve
FAULT - Clutch 'B'
SYMPTOM 9 - No 4th gear 'D' selected
FAULT - 4th to 3rd downshift valve stuck or
3rd to 4th upshift valve stuck
FAULT - Clutch brake 4

ZF
11
FAULT DIAGNOSIS SYMPTOM 10 - None or harsh engagement of
direct drive clutch
NOTE: The direct drive clutch will only
engage if 4th gear is engaged at 40 to 45
mph.
Carry out road test pressure check with gauge
connected to torque converter.
ú Normal pressure
FAULT - Failed direct drive clutch
ú Pressures correct but remains high
FAULTS POSSIBLE -
Direct drive clutch and torque converter
control valve stuck
Hysteresis valve stuck
Direct drive clutch control valve stuck
SYMPTOM 11 - Direct drive clutch shift point
incorrect or at low speed
NOTE: Direct drive clutch engagement at
low speed will cause vibration in the
torque converter
Carry out mainline and torque converter pressure
check
ú Normal pressure
FAULT - Governor valve sticking
ú Low or incorrect pressure
FAULTS POSSIBLE -
Direct drive clutch and torque converter
control valve sticking.
Hysteresis valve stuck.
Direct drive clutch control valve stuck.
SYMPTOM 12 - Drives in 'D' but immediately
upshifts to 3rd
FAULT - 2nd to 3rd shift valve stuck.
SYMPTOM 13 - With 'D' selected vehicle starts in
2nd
FAULTS POSSIBLE -
1st and 2nd shift valve stuck.
Governor sleeve sticking.
SYMPTOM 14 - With 'D' selected vehicle starts in
3rd
FAULTS POSSIBLE -
1st to 2nd and 2nd to 3rd shift valves stuck.
Governor sleeve sticking.SYMPTOM 15 - No kickdown 4th to 3rd
FAULT - 4th to 3rd kickdown valve stuck.
SYMPTOM 16 - Upshifts/downshifts and kickdown
shifts at incorrect road speeds
Check throttle kickdown cable adjustment
Carry out main line pressure check
ú Normal pressure
FAULT - Governor valve sticking
ú Incorrect pressure
FAULTS POSSIBLE -
Incorrect throttle valve adjustment
Primary regulator sticking
SYMPTOM 17 - No upshifts at light throttle
FAULTS POSSIBLE
Governor valve sticking
Shift valves sticking
SYMPTOM 18 - No engine braking '3' selected 3rd
gear
FAULT - Clutch 'C'
SYMPTOM 19 - Delayed or no downshift occurs
when making a manual selection from '3' to '2'
FAULTS POSSIBLE -
2nd and 3rd upshift valve sticking.
Governor valve sticking.
'2' Position interlock valve sticking.
SYMPTOM 20 - At speeds below 28 mph when
making a manual selection from '2' to '1',
downshift is delayed or does not occur
FAULTS POSSIBLE -
Governor sticking.
1st to 2nd shift valve sticking.
'1' Position interlock valve sticking.
SYMPTOM 21 - '1' Selected 1st gear no engine
braking
FAULT - Clutch brake 3
SYMPTOM 22 - '2' Selected 2nd gear no engine
braking
FAULT - Clutch brake 1
SYMPTOM 23 - Vehicle drives forward in 'N'
FAULT - Clutch 'A' stuck

ZF
1
REPAIR LT230T TRANSFER GEARBOX WITH AUTOMATIC
GEARBOX ASSEMBLY - V8i
Service repair no - 44.20.04
Removal from V8i engine
The assembled transfer gearbox, automatic gearbox
and torque converter is removed from underneath the
vehicle. Use a transmission hoist with an adaptor
plate for securing the assembly to the hoist. The
adaptor can be manufactured locally to the drawing
below or purchased from:- Straight Set Engineering,
England. Tel.01909 480055
WARNING: When using a transmission
hoist it is essential to follow the hoist
manufacturer's instructions.

ZF
3
REPAIR 19.Disconnect rear propeller shaft to output flange,
and tie to one side.
20.Repeat instructions 18 and 19 on front propeller
shaft to main gearbox.
21.Remove bolts retaining silencer front and rear
securing brackets and tie silencer to one side.
22.Disconnect oil cooler feed and return pipes from
bottom and side of main gearbox.
23.Release cooler pipes from clamp at engine sump
and remove distance piece.
24.Blank pipe ends and unions.
25.Move oil cooler pipes clear of transmission and
tie aside.
26.Disconnect selector cable from operating lever.
27.Disconnect inhibitor switch at multiplug.
28.Attach adaptor plate to hoist.
29.Remove two bolts from transfer gearbox rear
cover.
30.Raise hoist to align adaptor plate with transfer
gearbox and transmission. Secure to transfer
gearbox at rear cover with two bolts removed.
31.Adjust hoist to take weight of transmission.
32.Remove nuts and bolts securing right transfer
gearbox mounting bracket to chassis.
33.Repeat for the left mounting bracket. Removal of
these fixings will also free speedometer
transducer bracket
34.Remove right side mounting bracket to flexible
mounting rubber retaining nut.
35.Lower hoist until rear brake drum clears
passenger footwell. Check engine does not
crush any components while lowering.
36.Remove clip and clevis pin from park brake
lever.
37.Remove clip securing outer brake cable
38.The park brake cable is now free.
39.Disconnect leads from transfer gearbox
temperature sensor and differential lock warning
light switch.
40.Remove ties securing breather pipes to harness.
41.Remove bell housing access plate complete with
gasket.
42.Rotate engine, using crankshaft pulley, until two
access holes are visible in drive plate/ring gear
assembly through bell housing bottom cover
opening.
43.Identify an access hole and bolt hole to aid
reassembly.
44.Remove bolts securing drive plate to convertor
through access holes.
45.Rotate crankshaft half turn to access and
remove remaining bolts.
46.Disconnect oil dipstick tube at main gearbox.
47.Remove bolt at bell housing and detach dipstick
tube. Blank pipe end and union.
48.Position hoist jack channel under engine and
support using a wooden block.
49.Remove bell housing to engine securing bolts,
also detach harness bracket from bell housing.
50.Ease transmission rearwards to allow access to
secure torque converter in bell housing.
51.Lower hoist and complete removal of
transmission.
Refit
52.Ensure torque converter is retained in bell
housing.
53.Secure transmission to adaptor plate on lifting
hoist.
54.Raise hoist and locate transmission with engine.
55.Remove torque converter retainer.
56.Complete attachment of transmission to engine
and fit bell housing bolts. Fit the dipstick tube
bracket and harness bracket to their respective
bolts.
57.Complete refitting by reversing removal
procedure. Note the following important points.
58.Drive plate to torque converter bolts are to be
coated with Loctite 290 prior to assembly.
59.Refill transfer and main gearboxes with correct
grade oil.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
60.Check operation of parking brake and adjust as
necessary.
See SECTION 10, Maintenance,
Vehicle Interior

44AUTOMATIC GEARBOX
4
REPAIR LT230T TRANSFER GEARBOX WITH AUTOMATIC
GEARBOX ASSEMBLY - Tdi
Service repair no - 44.20.04
Removal from Tdi engine
The assembled transfer gearbox, automatic gearbox
and torque converter is removed from underneath the
vehicle. Use a transmission hoist with an adaptor
plate for securing the assembly to the hoist.
WARNING: When using a transmission
hoist it is essential to follow the hoist
manufacturer's instructions.

44AUTOMATIC GEARBOX
6
REPAIR 13.Remove starter.
14.Working through starter aperture note position of
torque converter flexible drive plate to facilitate
refitting.
15.Remove the four torque convertor to flexible
drive securing bolts, rotating engine to gain
access to each individual bolt.
16.Raise vehicle on four post ramp [hoist].
17.Drain lubrication oil from transfer and main
gearboxes.
18.Disconnect speedometer cable from transfer
gearbox and disconnect associated clipping.
19.Remove rear propeller shaft.
See PROPELLER
SHAFTS, Overhaul, Flexible Coupling
20.Disconnect front propeller shaft at transfer
gearbox and tie to one side.
21.Remove exhaust front pipe.
22.Remove bolts securing front and centre silencer
mounting brackets and tie silencer to one side.
23.Disconnect oil cooler pipes from gearbox.
24.Blank off pipes and union connections.
25.Remove bolt securing retaining bracket to sump
and move cooler pipes aside.
26.Disconnect selector cable from lever on side of
gearbox.
27.Disconnect inhibitor switch multi-plug.
28.Disconnect park brake cable from linkage to park
brake lever.
29.Disconnect electrical connections from
differential lock switch on transfer gearbox.
30.Remove two lower bolts from transfer gearbox
input bearing support plate.
31.Assemble approved support cradle to
transmission hoist.32.Raise hoist and secure cradle to transfer
gearbox input bearing support plate using bolts
removed.
33.Disconnect gearbox mounting brackets from
chassis cross member.
34.Remove chassis cross member.
35.Lower transmission sufficiently to allow access
to items attached to top of gearbox.
36.Remove left hand gearbox mounting bracket
assembly.
37.Remove ties from breather pipes and harness.
38.Remove nut securing gearbox oil filler/dip stick
tube to bell housing.
39.Release union nut at gearbox sump and remove
filler/dipstick tube. Fit blanking plugs.
40.Support engine using a wooden block with a
suitable ramp [hoist] jack.
41.Remove nut securing kick down cable bracket to
bell housing.
42.Remove two bolts securing top of bell housing to
flywheel housing.
43.Remove nuts securing bell housing to flywheel
housing and withdraw transmission assembly
from engine.
44.Fit a suitable torque converter retaining strap to
the bell housing.
45.Remove hoist and transmission from under
vehicle.
46.Fit lifting eyes to transmission.
47.Using suitable chains and lifting tackle take
weight of transmission assembly.
48.Remove bolts securing transmission cradle to
transfer box and withdraw hoist complete with
cradle.
49.Refit bolts to cover plate.

ZF
7
REPAIR Accessories removal/fitting
If fitting a replacement transmission assembly to the
vehicle, remove the following items from the existing
assembly and fit to the replacement.
CAUTION: It is important to remove the
spacer from the extension shaft and fit
onto the replacement unit.
50.Breather pipe union and washers from main
gearbox.
51.Breather pipe, union and washers from transfer
gearbox.
52.Main gearbox selector lever.
53.RH mounting bracket assembly.
54.Oil cooler pipe unions.
55.Fit blanks to all apertures where unions have
been removed and blank off pipe ends.
Refit
1.Fit transmission to cradle and hoist.
2.Locate hoist under vehicle and remove torque
convertor retaining strap.
3.Ensure low range gear is engaged.
4.Apply approved sealant to bell housing face.
5.Carefully raise assembly, align bell housing with
flywheel housing and bring mating faces
together.
6.Fit nuts and bolts to secure transmission to
engine.
7.Locate electrical wiring and breather pipes to
position.
8.Secure kick down cable clip to bell housing.
9.Raise hoist sufficiently to take weight.
10.Remove block and jack from engine sump.
11.Fit filler/dipstick tube to gearbox sump and
secure bracket to bell housing.
12.Apply Loctite to torque convertor bolts
13.Working through starter aperture refit the four
torque convertor to flexible drive securing bolts,
rotating crankshaft to gain access to bolt
locations.
14.Refit starter and heatshield.
15.Secure breather pipes and harness with ties.
16.Fit left hand mounting bracket assembly to
gearbox.
17.Raise transmission and support with a suitable
ramp [hoist] jack.
18.Remove two bolts securing transmission to
cradle, lower hoist and remove from under
vehicle.
19.Apply Loctite to above bolts and fit to transfer
gearbox input bearing support plate.
20.Fit chassis cross member.21.Secure gearbox mounting brackets to chassis
cross member.
22.Remove ramp [hoist] jack.
23.Connect electrical leads to differential lock
switch.
24.Connect inhibitor switch multi-plug.
25.Connect selector cable to lever on side of
gearbox.
26.Connect oil cooler pipes to gearbox and secure
retaining bracket to gearbox sump.
27.Secure silencer to chassis and refit exhaust front
pipe.
28.Refit front propeller shaft to transfer gearbox.
29.Refit rear propeller shaft.
See PROPELLER
SHAFTS, Overhaul, Flexible Coupling
30.Connect speedometer cable to transfer gearbox.
31.Refill transfer gearbox with correct grade of
lubricating oil.
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information,
Recommended Lubricants and Fluids
32.Lower ramp [hoist] to ground level.
33.Reconnect turbo-charger hose to inter-cooler.
34.Reconnect top hose to radiator.
35.Refill cooling system with correct mixture of
coolant.
See LUBRICANTS, FLUIDS AND
CAPACITIES, Information, Recommended
Lubricants and Fluids
36.Reconnect kick down cable to fuel injection
pump.
37.Secure breather pipe clip to rear of cylinder
head.
38.Engage harness with clips along top of
bulkhead.
39.On left hand drive vehicles only, connect
multi-plug to top of brake fluid reservoir.
40.Refit insulation pad to rocker cover and inlet
manifold, secure with oil filler cap.
41.Refit gaiter and knob to transfer gear lever.
42.Select high range gear.
43.Reconnect battery terminals.
44.Refill main gearbox with correct grade of
lubricating oil.
See LUBRICANTS, FLUIDS
AND CAPACITIES, Information,
Recommended Lubricants and Fluids