ISUZU TROOPER 1995 Workshop Manual

DIAGNOSIS 3-11
I RADIAL TIRE LEAD/PULL CORRECTION CHART I
I INFLATE TIRES TO RECOMMENDED I
PRESSURE
I
ROAD TEST VEHICLE ON LEVEL
I UNCROWNED ROAD
I SWITCH FRONT TIRES SIDE TO SIDE I
AND ROAD TEST AGAIN
LEADS IN
SAME LEAD CORRECTED LEAD REVERSES
DIRECTION
IF ROUGHNESS RESULTS, DIRECTION
REPLACE TIRES.
PUT TIRES
BACK IN INSTALL KNOWN GOOD
ORIGINAL POSITION
TIRE ON
AND CHECK ALIGNMENT ONE FRONT SIDE
LEAD CORRECTED LEAD REMAINS. INSTALL
REPLACE TIRE
A KNOWN GOOD TIRE IN
PLACE OF OTHER FRONT TIRE
LEAD CORRECTED
REPLACE TIRE
Fig. 3-5

MEMO

FRONT END ALIGNMENT 3A-1
SECTION3A
FRONT END ALIGNMENT
CAUTION:
When fasteners are removed, always reinstall them at the same location from which they were removed. If
a fastener needs to be replaced, use the correct part number fastener for that application. If the correct part
number fastener is not available, a fastener of equal size and strength (or stronger) may be used. Fasteners
that are not reused, and those requiring thread locking compound will be called out. The correcttorque value
must be used when installing fasteners that require it. If the above conditions are not followed, parts or
system damage could result.
CONTENTS
General Description ................................ 3A-1
Camber Adjustment ............................. 3A-4
Definition of Terms .............................. 3A·2 Toe-in Adjustment ............................... 3A-5
On-Vehicle Service ................................. 3A-3 Maximum Steering Angle Adjustment ....... 3A-5
Inspection ......................................... 3A-3 Main Data and Specifications ..................... 3A-6
Trim Height Adjustment ........................ 3A-3 General Specifications .......................... 3A-6
Caster
Adjustment ............................... 3A-3 Torque Specifications ........................... 3A-6
GENERAL DESCRIPTION
"Front End Alignment" refers to the angular
relationship between the front wheels, the front
suspension attaching parts and the ground.
Proper front end alignment must be maintained in
order to insure efficient steering, good directional
stability and to prevent abnormal tire wear.
The
most important factors of front end alignment are
wheel toe-in, wheel camber and axle caster.

3A-2 FRONT END ALIGNMENT
DEFINITION OF TERMS
CAMBER (Fig. 3A-1)
Camber is the inward or outward tilting of the front
wheels from the vertical. When the wheels tilt outward
at the top, the camber is
positive(+). When the wheels
tilt inward at the top, the camber is negative(-). The
amount
of tilt measured in degrees from the vertical is
called the camber angle.
If camber is extreme or unequal between the wheels,
improper steering and excessive tire
wear will result.
Negative camber causes
wear on the inside of the tire,
while positive camber causes wear to the outside.
Left front view
Positive direction
Fig. 3A-1
CASTER (Fig. 3A-2)
Caster is the tilting of the wheel axis either forward or
backward from the vertical (when viewed from the side
of the vehicle). A backward tilt is positive(+) and a
forward tilt is
negative(-).
On the short and long arm type suspension you cannot
see a caster angle
without a special instrument, but if
you look straight down from the top of the upper
control arm to the ground, the
ball joints do not line up
(fore and aft) when a caster angle other than
0 degree is
present. With a positive angle, the lower
ball joint
would be slightly ahead (toward the front of the
vehicle)
of the upper ball joint center line .
• Front
Fig. 3A-2
TOE-IN (Fig. 3A-3)
Toe-in is the turning of the front wheels. The actual
amount of toe-in is normally a fraction of a degree.
Toe-in is measured
from the center of the tire treads or
from the inside of the tires. The purpose of toe-in is to
insure
parallel rolling of the front wheels and to offset
any
small deflections of the wheel support system
which occurs
when the vehicle is rolling forward.
lncorrecttoe-in results in excessive toe-in and unstable
steering. Toe-in is the last alignment to
be set in the
front end alignment procedure.
Fig. 3A-3
•

FRONT END ALIGNMENT 3A-3
ON-VEHICLE SERVICE
INSPECTION
Before making any adjustments affecting caster,
camber or toe-in, the following front end inspection
should be made.
I L•IINSPECT
1. Tires for proper inflation pressure. Refer to
"Wheels and Tires" in section 3E.
2. Front wheel bearings for proper adjustment.
Refer to "Front Wheel Drive" in section 4C.
3. Ball joints, tie rod ends and relay rods. If
excessive looseness is noted, correct before
adjusting. Refer
to "Steering Linkage" in section
3B3.
4. Wheel and tires for run-out. Refer to "Wheels
and Tires" in section 3E.
5. Trim height. If not within specifications, the
correction
must be made before adjusting caster.
6. Steering gear for looseness at the frame.
7. Shock absorbers for leaks or any noticeable
noise.
Refer
to "Front Suspension" in section 3C.
8. Control arms or stabilizer bar attachment for
looseness. Refer to "Front Suspension" in section
3C.
9. Alignment equipment. Follow the manufacturer's
instructions.
10. Level of the vehicle. The vehicle must be on a
level surface.
TRIM HEIGHT ADJUSTMENT
Adjust the trim height by means of the adjusting bolt
on the height control arms (Fig. 3A-4 and 5).
W CAUTION:
When adjusting front end alignment, be sure to
begin with trim height as trim height adjustment
may change other adjusted alignments.
1. Check and adjust the tire inflation pressures.
2. Park the vehicle on a level ground and move the
front of the vehicle up and down several times to
settle the suspension.
3. Make necessary adjustment with the adjusting
bolt on the height control arms.
WHEEL
ALIGNMENT SPECIFICATION
Trim height (Z) 129 mm (5.08 in)
Lower
ball joint
B
Fig. 3A-4
Fig. 3A-5
CASTER ADJUSTMENT
Level ground
The caster angle can be adjusted by means of the
caster shims installed between the chassis frame and
fulcrum pins (Fig. 3A-6 and 7).
WHEEL
ALIGNMENT SPECIFICATION
LWB
Caster angle
SWB
W CAUTION:
Left and right side to be equal within 30'
NOTE:
Difference of the caster shim front/rear thickness shall
be 3.6
mm (0.142 in) or less. Overall thickness of caster
shim and camber shim shall be 10.8 mm (0.425 in) or
less.

3A-4 FRONT END ALIGNMENT
• Tighten the fulcrum pin bolt to the specified torque.
1~1 Torque N·m (lb·ft) 152 (112)
Fig. 3A-6
0 t Front
0
Fig. 3A-8
Fig. 3A-9
\fl CAUTION:
t Front
'(/ Left and right side to be equal within 30'
NOTE:
Fig. 3A-7
CAMBER ADJUSTMENT
Overall thickness of caster shim and camber shim shall
be 10.8 mm (0.425 in) or less.
The camber angle can be adjusted by means of the
camber shims
installed in position between the chassis
frame and
fulcrum pins (Fig. 3A-8 and 9).
• Tighten the fulcrum pin bolt to the specified torque.
~~~ Torque N·m (lb·ft) 152 (112)
WHEEL ALIGNMENT SPECIFICATION
Camber angle o· ± 30'
King pin inclination 12° 30' ± 30'
Position of shims
Front side Rear
side Camber angle Caster angle
1---When
added When
removed Decreases Decreases
When removed When
added
Increases Increases Caster shim
When removed Unchanged Decreases
When added Unchanged
Increases
When added Decreases
Unchanged
Camber shim
When removed
Increases Unchanged

TOE-IN ADJUSTMENT
1. To adjust the toe-in angle, loosen the lock nuts on
the outer track rods and turn the outer track rods.
Turn both rods the same amount, to keep the
steering
wheel centered (Fig. 3A-1 0).
WHEEL ALIGNMENT SPECIFICATIONS
Toe-in mm (in) I 0 ± 2 (0 ± 0.08)
2. Tighten the lock nut to the specified torque.
~~~ Torque N·m (lb·ft) 118 (87)
Outer track rod
Lock nut
Fig. 3A-10
MAXIMUM STEERING ANGLE
ADJUSTMENT
The maximum steering angle of the front wheels can
be adjusted
with the stopper bolts under the frame side
members (Fig. 3A-11 ).
1. Position each front wheel on the turning radius
gauge in a straight-ahead position.
2. Set the parking brake firmly.
3. Adjust the inside wheel angle of each side with the
stopper
bolts.
NOTE: • The maximum protruding length (L) of
stopper bolt from the lock nut should be
10 mm or less (Fig. 3A-12)
4. Similarly adjust the inside wheel angle of the other
side
with stopper bolt.
WHEEL ALIGNMENT SPECIFICATION
Inside wheel
34° ~~:
Outside wheel 32°
NOTE:
Maximum steering angles should be set after adjusting
front wheel alignment.
FRONT END ALIGNMENT 3A-5
5. If the stopper between the lower link end and the
knuckle comes ahead of the stopper bolt (Fig. 3A-
13), adjust the stopper
bolt so that inner stopper
bolt touches the drop arm (relay lever).
6. Tighten the lock nut to the specified torque.
~~~ Torque N·m (lb·ft) 23 (17)
Fig. 3A-11
L
Stopper bolt Lock nut
Fig. 3A-12
Stopper
Fig. 3A-13

3A-6 FRONT END ALIGNMENT
MAIN DATE AND SPECIFICATION
GENERAL SPECIFICATION
Caster
Camber
King pin inclination
Toe-in
Max. steering
angle
TORQUE SPECIFICATION
mm (in)
(inside)
(outside)
2° 10' ± 45'(LWB) 2° ± 45' (SWB)
oo ± 30'
12° 30' ± 30'
0 ± 2 (0 ± 0.08)
34° ~~:
32°
1152 (112)~ ~1
,I~
Fig. 3A-14
N·m (lb·ft)

POWER STEERING GEAR AND PUMP 381 -1
SECTION 381
POWER STEERING GEAR AND PUMP
w CAUTION:
When fasteners are removed, always reinstall them at the same location from which they were removed.
If a fastener needs to be replaced, use the correct part number fastener for that application. If the correct
part
number fastener is not available, a fastener of equal size and strength (or stronger) may be used.
Fasteners
that are not reused, and those requiring thread locking compound, will be called out. The correct
torque value must be used when installing fasteners that require it. If the above conditions are not
followed, parts or system damage could result.
CONTENTS
General Description ............................ 3B1- 1
Steering Wheel Free Play Adjustment .... 3B1-5
Power Steering
Gear........................ 3B1-1
Steering Gear ................................ 3B1-6
Hydraulic Pump .............................. 3B1- 1
Power Steering Pump ...................... 3B1-8
Pressure Switch
............................. 3B1-1
Unit Repair ...................................... 3B1- 9
Power Steering System Test
................. 3B1-3
Steering Gear ................................ 3B1-9
On-Vehicle Service ............................. 3B1- 4
Power Steering Pump ...................... 3B1-14
Maintenance
................................. 3B1- 4
Main Data and Specifications ................ 3B1-17
Fluid Level .................................... 3B1- 4 General Specifications ...................... 3B1-17
Bleeding The Power Steering System .... 3B1-4
Torque Specifications ....................... 3B1-17
Bleeding Procedure ......................... 3B1-4 Special Tools.................................... 3B1-18
Flushing The Power Steering System .... 3B1-4
GENERAL DESCRIPTION
The hydraulic power steering system consists of a
pump, an oil reservoir, a steering gear, a pressure
hose and a return hose.
POWER STEERING GEAR
The power steering gear has a recirculating ball
system which acts as a rolling thread between the
worm shaft and the rack piston. When the worm shaft
is
turned right, the rack piston moves up in gear.
Turning the worm shaft left moves the rack piston
down in gear. The rack piston teeth mesh with the
sector, which is part ofthe sector shaft.
Turning the worm shaft turns the sector shaft, which
turns the wheels through the steering linkage.
The control valve in the steering gear directs the
power steering fluid to either side of the rack piston.
The rack
piston converts the hydraulic pressure into
a mechanical force. If the steering system becomes
damaged and loses hydraulic pressure, the vehicle
can be controlled manually (Fig. 381-1).
HYDRAULIC PUMP
The hydraulic pump is vane-type design. The
submerged pump has housing and internal parts that
are inside the reservoir and operate submerged in oil.
There are two bore openings at the rear of the pump
housing. The larger opening contains the cam ring,
pressure
plate, thrust plate, rotor and vane assembly,
and end plate. The smaller opening contains the
pressure
line union, flow control valve and spring
(Fig. 381-2).
PRESSURE SWITCH
When hydraulic pressure reaches 3920 ± 690 kPa
(570 ± 100 psi), the pressure switch closes causing
Engine
Control Module (ECM) to actuate the idle air
control valve to prevent the overload-induced engine
speed down. The switch opens
when hydraulic
pressure drops to 2970 ± 560 kPa (430 ± 80 psi).

381-2 POWER STEERING GEAR AND PUMP
Fig. 381-1
II
Fig. 381-2
•