1998 ISUZU TROOPER gas type

4A2B±2DIFFERENTIAL (REAR 244mm)
General Description
The rear axle assembly is of the semi±floating type in
which the vehicle weight is carried on the axle housing .
The center line of the pinion gear is below the center line
of the ring gear (hypoid drive).
All parts necessary to transmit power from the propeller
shaft to the rear wheels are enclosed in a banjo type axle
housing.
The 9.61 inch ring gear rear axle uses a conventional ring
and pinion gear set to transmit the driving force of the
engine to the rear wheels. This gear set transfers thisdriving force at a 90 degree angle from the propeller shaft
to the drive shafts.
The axle shafts are supported at the wheel end of the
shaft by a roller bearing.
The pinion gear is supported by two tapered roller
bearings. The pinion depth is set by a shim pack located
between the gear end of the pinion and the roller bearing
that is pressed onto the pinion. The pinion bearing
preload is set by crushing a collapsible spacer between
the bearings in the axle housing.
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The ring gear is bolted onto the differential cage with 12
bolts.
The differential cage is supported in the axle housing by
two tapered roller bearings. The differential and ring gear
are located in relationship to the pinion by using selective
shims and spacers between the bearing and the axle
housing. To move the ring gear, shims are deleted from
one side and an equal amount are added to the other side.
These shims are also used to preload the bearings whichare pressed onto the differential cage. Two bearing caps
are used to hold the differential into the rear axle housing.
The differential is used to allow the wheels to turn at
different rates of speed while the rear axle continues to
transmit the driving force. This prevents tire scuffing
when going around corners and prevents premature wear
on internal axle parts.
The rear axle is sealed with a pinion seal, a seal at each
axle shaft end, and by a liquid gasket between the
differential carrier and the axle housing.

4B2±11 DRIVE LINE CONTROL SYSTEM (TOD)
The CHECK lamp also has the following functions.
D-G MAP recognition and display (The control unit
displays what type of vehicle, diesel or gasoline
vehicle, it recognizes.)
1. Short-circuit the self-diagnostic connector.
2. Turn on the starter switch. (Displays with respect to
the self-diagnosis begin to appear.)
NOTE: Do not start the engine.
3. Shift the transfer lever to the neutral position between
HIGH and 4L.
4. After all the conditions in 1 through 3 above are met,
set the throttle to the WOT (wide open throttle)
position (i.e., full open position). The display of the
self-diagnosis is temporarily suspended, and the
CHECK lamp begins to display that MAP is
recognized by the TPS (throttle position sensor)
according to the current conditions.NOTE: If the TPS has failed, this function might not work.
1. When the control unit recognizes the vehicle as
gasoline type, the CHECK lamp is turned on for five
seconds and this mode is repeated at an interval of
0.3 second.
2. When the control unit recognizes the vehicle as
diesel type, the CHECK lamp is turned off for five
seconds and this mode is repeated at an interval of
0.3 seconds.
3. Upon completion of step 4, the system resumes the
self-diagnosis. (The self-diagnosis is executed
from the beginning.)
5. Turn off the starter switch once. When above
conditions are met again in the future, the TPS MAP
control can be started.
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TRANSFER CASE (STANDARD TYPE)
4D1±13
10. Offset the actuator assembly.
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11. Remove the actuator assembly.
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Legend
(7) Position: 4WD
(8) Mode: 2WD
12. Remove the transfer rear cover assembly from the
transfer case assembly.
Installation
1. Apply the recommended liquid gasket (LOCTITE
17430) or its equivalent to the transfer rear cover
fitting faces.
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2. Install the transfer rear cover assembly to the transfer
case assembly.
3. Perform the following steps before fitting the transfer
rear case:
1. Shift the high±low shift rod to the 4H side.
2. The cut±away portion of the select rod head (9)
should align with that of the rear case hole's
stopper (10).
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4. Tighten the transfer rear case bolts to the specified
torque.
Torque: 37 N´m (3.8kg´m/27 lb ft)
5. Shift the 2WD±4WD shift rod (11) to the 4WD side.

4D1±20
TRANSFER CASE (STANDARD TYPE)
Removal
1. Remove the speedometer sensor.
2. Remove the plate.
3. Remove the speedometer driven gear bushing and
driven gear.
NOTE: Apply a reference mark to the driven gear bushing
before removal.
4. Remove the front companion flange and the rear
companion flange, using the flange companion holder
5±8840±0133±0 (J±8614±11) to remove the end
nuts.
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NOTE: U s e a u n i v e r s a l p u l l e r t o remove the rear
companion flange.
5. Disconnect the transfer breather hose from the
control box.
6. Remove the control box assembly.
7. Remove the transfer rear cover assembly from the
transfer case assembly.
Installation
1. Apply the recommended liquid gasket (LOCTITE
17430) or its equivalent to the transfer rear cover
fitting faces.
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2. Install the transfer rear cover assembly to the transfer
case assembly.
3. Perform the following steps before fitting the transfer
rear case:
1. Shift the high±low shift rod to the 4H side.
2. Turn the select rod counterclockwise so that the
select block projection may enter into the
2WD±4WD shift block.
3. The cut±away portion of the select rod head (9)
should align with that of the rear case hole's
stopper (10).
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4. Tighten the transfer rear case bolts to the specified
torque.
Torque: 37 N´m (3.8kg´m/27 lb ft)

4D1±28
TRANSFER CASE (STANDARD TYPE)
Inspection and Repair
Refer to ªTRANSFER CASE ASSEMBLYº in this section
for inspection and repair.
Reassembly
1. Place the shift block (15) in the transfer case (16).
2. Set the shift arm (14) on the High±Low sleeve.
3. Push the High±Low shift rod (13) through the shift
arm (14) and block (14).
4. Engage the High±Low sleeve with the 4H (1) side.
5. Install the spring pins (12) to the shift block (15) and
shift arm (14).
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6. Install the select rod assembly (11), joining its lever to
the shift block groove.
7. Engage the High±Low sleeve with the 4H side and
install the the interlock pin (9) and spring (10) in the
proper direction.
8. Place the 2WD±4WD shift block (7) in the transfer
case (16).
9. Set the 2WD±4WD shift arm (6) on the 2WD±4WD
sleeve.
10. Push the 2WD±4WD shift rod (5) through the
2WD±4WD shift arm (6) and 2WD±4WD shift block
(7).
11. Install the 2WD±4WD shift rod (5) with the interlock
pin pushed in.
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Legend
(18) 2WD±4WD
(19) 4H Side
(20) Interlock pin
(21) 2WD
(22) 4WD
(23) Rod: 2±4
(24) Rod: H±L
(25) 4H
(26) 4L
(27) 4y2
(28) 4y4
12. Install the 4WD indicator switch and gasket (8).
Tighten to the specified torque.
Torque: 39 N´m (4.0kg´m/29 lb ft)
13. Install the spring (4).

POWER ASSISTED BRAKE SYSTEM 5C – 7
MAIN DATA AND SPECIFICATIONS
MASTER CYLINDER
Type Dual-circuit
Piston Bore Diameter mm (in) 25.4 (1.000)
VACUUM BOOSTER
Diaphragm Diameter
Front; mm (in) 205 (8.07) (Gasoline) / 180 (7.09) (Diesel)
Rear; mm (in) 230 (9.06) (Gasoline) / 205 (8.07) (Diesel)
Push Rod Stroke mm (in) More than 32.0 (1.26)
Plunger Diameter mm (in) 10.13 (0.399)
Push Rod Diameter mm (in) 27.4 (1.08)
FRONT DISC BRAKE
Type Floating, Pin Slide
Pad Dimension cm
2(in2) 55 (8.52)
Adjusting Method Self-adjusting
Piston Diameter mm (in) 60.33 (2.38)
Disc (Rotor) Type Ventilated
Disc (Rotor) Thickness mm (in) 26 (1.02)
Disc (Rotor) Effective Diameter mm (in) 222 (8.74)
REAR DISC BRAKE
Type Floating, Pin Slide
Pad Dimension cm
2(in2) 33 (5.11)
Adjusting Method Self-adjusting
Piston Diameter mm (in) 41.3 (1.63)
Disc (Rotor) Type Ventilated
Disc (Rotor) Thickness mm (in) 18 (0.71)
Disc (Rotor) Effective Diameter mm (in) 269.2 (10.60)

6D1±2
ENGINE ELECTRICAL
Battery
General Description
There are six battery fluid caps on top of the battery.
These are covered by a paper label.
The battery is completely sealed except for the six small
vent holes on the side. These vent holes permit the
escape of small amounts of gas generated by the battery.
This type of battery has the following advantages over
conventional batteries:
1. There is no need to add water during the entire
service life of the battery.
2. The battery protects itself against overcharging.
The battery will refuse to accept an extensive charge.
(A conventional battery will accept an excessive
charge, resulting in gassing and loss of battery fluid.)
3. The battery is much less vulnerable to self discharge
than a conventional type battery.
Diagnosis
1. Visual Inspection
Inspect the battery for obvious physical damage, such as
a cracked or broken case, which would permit electrolyte
loss.
Replace the battery if obvious physical damage is
discovered during inspection.
Check for any other physical damage and correct it as
necessary.
2. Hydrometer Check
There is a built±in hydrometer (Charge test indicator(1))
at the top of the battery. It is designed to be used during
diagnostic procedures.
Before trying to read the hydrometer, carefully clean the
upper battery surface.
If your work area is poorly lit, additional light may be
necessary to read the hydrometer.
a. BLUE RING OR DOT VISIBLE(5) ± Go to Step 4.
b. BLUE RING OR DOT NOT VISIBLE(4) ± Go to Step
3.
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3. Fluid Level Check
The fluid level should be between the upper level line(2)
and lower level line(3) on side of battery.
a. CORRECT FLUID LEVEL ± Charge the battery.
b. BELOW LOWER LEVEL ± Replace battery.
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4. Voltage Check
1. Put voltmeter test leads to battery terminals.
a. VOLTAGE IS 12.4V OR ABOVE ± Go to Step 5.
b. VOLTAGE IS UNDER 12.4V ± Go to procedure (2)
below.
2. Determine fast charge amperage from specification.
(See Main Data and Specifications in this section).
Fast charge battery for 30 minutes at amperage rate
no higher than specified value.
Take voltage and amperage readings after charge.
a. VOLTAGE IS ABOVE 16V AT BELOW 1/3 OF
AMPERAGE RATE ± Replace battery.
b. VOLTAGE IS ABOVE 16V AT ABOVE 1/3 OF
AMPERAGE RATE ± Drop charging voltage to
15V and charge for 10 ± 15 hours. Then go to Step
5.
c. VOLTAGE IS BETWEEN 12V AND 16V ±
Continue charging at the same rate for an
additional 3±1/2 hours. Then go to Step 5.
d. VOLTAGE BELOW 12V ± Replace Battery.
5. Load Test
1. Connect a voltmeter and a battery load tester across
the battery terminals.
2. Apply 300 ampere load for 15 seconds to remove
surface charge from the battery. Remove load.
3. Wait 15 seconds to let battery recover. Then apply
specified load from specifications (See Main Data
and Specifications in this section).
Read voltage after 15 seconds, then remove load.

6D2±4
IGNITION SYSTEM
Spark Plug
Removal
1. Remove spark plugs.
Inspection and Repair
The spark plug affects entire engine performance and
therefore its inspection is very important.

Check electrode and insulator for presence of cracks,
and replace if any.

Check electrode for wear, and replace if necessary.

Check gasket for damage, and replace if necessary.

Measure insulation resistance with an ohmmeter, and
replace if faulty.

Adjust spark plug gap to 1.0 mm (0.04 in) ~ 1.1 mm
(0.043 in).

Check fuel and electrical systems if spark plug is
extremely dirty.

Use spark plugs having low heat value (hot type plug)
if fuel and electrical systems are normal.

Use spark plugs having high heat value (cold type
plug) if insulator and electrode are extremely burned.
Sooty Spark Plugs
Much deposit of carbon or oil on the electrode and
insulator of spark plug reduces the engine performance.
Possible causes:

Too rich mixture

Presence of oil in combustion chamber

Incorrectly adjusted spark plug gap
Burning Electrodes
This fault is characterized by scorched or heavily oxidized
electrode or blistered insulator nose.
Possible causes:

Too lean mixture

Improper heat value
Measuring Insulation Resistance

Measure insulation resistance using a 500 volt
megaohm meter.

Replace spark plugs if measured value is out of
standard.
Insulation resistance: 50 M
or more
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Cleaning Spark Plugs

Clean spark plugs with a spark plug cleaner.

Raise the ground electrode to an angle of 45 to 60
degrees. If electrode is wet, dry it before cleaning.

After spark plug is thoroughly cleaned, check
insulator for presence of cracks.

Clean threads and metal body with a wire brush.

File the electrode tip if electrode is extremely worn.

Bend the ground electrode to adjust the spark plug
gap.
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Installation
1. Spark plugs

Tighten spark plugs to the specified torque.
Torque: 18 N´m (1.8 Kg´m/13 lb ft)