STEERING
SYSTEM
GENERAL ................................................................................ST - 2
SPECIFICATION ......................................................................ST - 6
SERVICE STANDARDS ...........................................................ST - 7
TIGHTENING TORQUE ............................................................ ST - 8
TROUBLESHOOTING ............................................................. ST - 9
SERVICE PROCEDURE .......................................................... ST-14
INTEGRAL POWER STEERING GEAR .................................. ST-27
POWER STEERING OIL PUMP ............................................... ST-37
POWER STEERING OIL TANK ................................................ ST-43
ST-2 STEERING SYSTEM
GENERAL
The steering system allows the driver to freely change the traveling direction of the vehicle. The steering force of the
steering wheel is transmitted through the steering shaft, power steering gear, pitman arm and drag link to the knuckle arm
to steer the vehicle.
The system has an integral type power steering gear installed in the gear box to reduce the steering effort.
The power steering system hydraulic pressure circuits are as shown below.
ECYST01A
Oil Tank
Oil Pump Power Steering Gear
Piping
Knuckle arm
Power steering
oil pump
Pitman arm
Power steering
oil reservoir tank
Slave lever
Power steering gear
1st drag link

MA560060
Slave lever
1st drag link
2nd drag link
GENERAL
ST-4 STEERING SYSTEM
Right Turn
When the steering wheel is turned clockwise, the load from the tires acts on the worm shaft to twist the torsion bar. As a
result, the rotor turns clockwise with respect to the worm shaft, decreasing the axial direction groove clearance. This limits
flow of the hydraulic oil to the oil tank and now the hydraulic oil from thr oil pump enters the cylinder chamber A to cause the
piston to move to the cylinder chamber B.
The hydraulic oil in the cylinder chamber moves, the torsion bar that has been twisted returns to the neutral position. The
force that has caused twisted returns to the neutral position. The force that has caused twisting of the torsion bar during
steering is transmitted to the steering wheel as a steering reaction force which gives the driver a sence of steering response.
A left turn is also made on the same operating principles as the right turn but in opposite direction.
Integral Power Steering Gear
This device consisting of the power cylinder section (output section) that also serves as the steering gear and the control
valve section (control section) reduces the power required to operate the steering wheel.
Straight Ahead Driving
When there is no steering torque from the steering wheel, no relative displacement is caused between the stub shaft and
th worm shaft and hence the rotor (or spool) is at the neutral position on the worm shaft (or sleeve). Accordingly, the
hydraulic oil supplied by the oil pump is allowed to flow through the worm shaft groove back to the oil tank.
Namely, no pressure diffference develops between cylinder chambers A and B so that the piston (ball nut) remains
stationay at the neutral position.
CYST001C / CYST001D
CYST001E/ CYST001F
Cylinder chamber B
Worm shaft
Stub shaft
Piston

Worm shaft
To oil tank
To cylinder
chamber B
To cylinder
chamber A
To oil tank
From oil pump
From oil pump
From cylinder
chamber B
Rotor
Rotor
Cylinder chamber A
Stub shaft
Piston
Worm shaft
Cylinder chamber B
Torison bar
ST-5
MA560110
MA560120
Delivery stroke
Suction stroke
Delivery stroke
Metering orifice
(develops pressure
difference P
P=P1-P2
Rotor turning

Torsion bar
MA560130
Chamber A
Chamber B
Relief spring
Pump
scution port
Metering orifice
2. Relief Valve
This valve keeps a constant hydraulic pressure.
As shown right, the flow control valve and the relief valve work
together to keep a constant operating pressure.
GENERAL
ST-6 STEERING SYSTEM
SPECIFICATIONS
Item
Steering wheel
Steering shaft type
Steering gear type
Power steering gear
Power steering oil pump
Power steering oil
reservoir
Steering angle
(Turning wheel angle)
Type
O.D (Outer Diameter)
Type
Cylinder I.D.
Stroke

45
37
42
35
0°
-2°
0°
-2°
0°
-2°
Inner
Outer
Inner
Outer
0°
-2°
Normal miximum hydraulic
pressure MPa (kgf/cm
2
)
Regulated pressure rpm
(relief valve) MPa (kgf/cm
2
)
ST-7
Steering wheel play
Steering upper
shaft
SERVICE STANDARDS
Unit : mm

47.97
-
-
10.3 MPa
(105 kgf/cm
2
)
-
-
-
-
0.4
0.4
37.9
-
-
0.16
0.04
-
0.03 or more
57.87
47.87
0.09
0.03
-
Remedy and
remarks
Adjust
Correct or replace
assembly

Sector shaft outside
diameter
Steering gear backlash
(Straight ahead position)
Worm starting torque after completion of
assembly (straight ahead position) Ncm (kgf·cm)
Body (cylinder) to ball screw (piston) clearance
Ball screw assembly play in axial direction
Sttering gear backlash
Sleeve to rotor clearance
Sector shaft O.D.
Ridge wear of pressure plate and side plate
rotor and vane sliding portion
Flow control valve to rear body clearance
Pump relief set pressure (at 1,800 rpm)
Maintenance item Limit
Play in axial direction
(vertical)
Pitman arm side
Side cover side
Packing portion
Bearing portion
SERVICE STANDARDS
ST-8 STEERING SYSTEM
TIGHTENING TORQUE
Steering
shaft
Linkage
Link and
bracket

Rear body bolt
Flow control valve plug
Hose connector bolt
Oil pump gear mounting bolt
Plate screw
Thread size Dia.
x Pitch mm
M20 x 1.5
M52 x 1.5
M10 x 1.25
M5 x 0.8
M20 x 1.25
M6 x 0.75
M20 x 1.5
M12 x 1.25
M8 x 1.25
M12 x 1.25
M36 x 1.5
M6 x 1.0
PT 1/8
M32 x 1.5
M14 x 1.5
M12 x 1.25
M80 x 1.5
M16 x 1.5
M10 x 1.25
M80 x 1.5
M48 x 1.5
-
-

4-7
4.9-6.4
0.4-0.65
5.0-5.5
0.3-0.5
20.7-34.5
3.7
1
2
40-45
0.45-0.55
0.9-1.3
12-13
5.5-6.5
23-25
12-13
0.7-1.3
30-40
0.6-0.9
5-6
5-6
1.8-2.5
9
0.4-0.5
Tighten fully, turn back by 180°, tighten
again to 39 (4), then turn back by 20°
and stake.
Tighten to 115 (12) and stake at 2 point
Part to be tightened
Nm Kgf·m

Low fluid level in oil tank
Air in oil circuit not completely bled
Improper fluid viscosity
Trouble in power steering gear system
Incorrect pipe connections
Defective oil pump (or malfunction)
Flow control valve in faulty operation
Universal joint abnormally worn, damaged or
poorly lubricated
Deformed link
King pin poorly lubricated
Poor front wheel alignments(toe-in, camber, caster)
Front wheel tires underinflated
Thrust bearing damaged
Cargo and passengers are unevenly loaded in the front.
Worn rack and gear in ball screw unit
Worn bearing in sector shaft
Worn ball in ball screw
Loose power steering gear mounting bolts
Air trapped and air not completely bled
Looseness in universal joint
Looseness in drag link ball stud
Looseness in tie rod end ball stud
Worn wheel hub bearing
Worn king pin or bushing
Uneven brake application
TROUBLESHOOTING
Replace screw and housing
assembly
Replace screw and housing

Replace
Replace
Readjust or replace lining
Symptom
Remedy
TROUBLESHOOTING
ST-10 STEERING SYSTEM
Vehicle pulls to
one side
Steering wheel
shimmy
Improper wheel alignment
Deformed front axle
Worn or deformed wheel hub bearing
Worn or deformed king pin
Steering wheel is off-center
Power steering gear defective
Broken leaf spring
Uneven brake application
Right and left tires unevenly inflated
Right and left tires greatly different in the
degree of wear
Right and left tires different in axial distance
Bent rear axle housing
Excessive clearance between king pin and bushing
Worn or deteriorated wheel hub bearing
Improper wheel alignment
(particularly camber and caster)
Looseness in knuckle arm or tie rod ball stud
Excessively uneven tire pressure

Replace knuckle arm or
tie rod end
Adjust tire pressure
Tighten to specified torque
Tighten to specified torque
Correct wheel balance
Adjust
Replace
Correct or replace
Replace knuckle arm,
pitman arm or drag link
Replace sector shaft and bearing
Replace screw and housing
assembly
Correct or replace
Replace pinion and gear
or correct tooth contact
Repair or replace
Front axle
steering system
defective
Other troubles
Front axle
assembly
defective
Power steering
system defective
Other troubles
Probable causeSymptom Remedy
ST-11

hydraulic fluid, and clean and check
inside surface of body and sliding
surface of piston, or replace screw
and housing assembly.
Adjust stub shaft rotating torque
Check and correct hydraulic circuit or
replace screw and housing assembly
Bleed air and then add fluid
Check and correct valve or replace
screw and housing assembly
Correct or replace oil pump
Correct or replace piping
Pack joints with grease
Adjust to the specified air pressure
Measure wheel alignments.
If incorrect, adjust to the specified
value
Correct or replace
Apply grease to king pin
Replace screw and housing assembly
Replace with the specified
hydraulic fluid
Low pressure due to fluid leaks
Valve malfunctioning
Piston damaged or foreign substance
trapped
Power steering
gear system
defective
Power steering

Abnormal
hydraulic
pressure in oil
pump
Strange sound,
vibration or noise
Uneven tire pressure
Incorrect front wheel alignment
ront wheels out of balance
Worn drag link or tie rod end ball joint
Worn king pin and king pin bushing
Rack torque out of adjustment
Clogged hydraulic circuit
Clogged hydraulic piping
Front wheel alignment off
Adjust to specified pressure
Measure wheel alignment.
If incorrect, adjust to specified
value
Rebalance with wheel balancer
or replace tires or wheels
Replace drag link assembly or
tie rod end
Disassembly and replace if
defective
Adjust stub shaft torque
Check and correct circuit or
replace screw and housing
assembly
Correct or replace piping

clogged hydraulic line
The oil pump produces some howling sound which is not an indication
of any functional problem(particularly when turning the steering wheel
while the vehicle in standstill)
ST-13
• Worn front wheel bearings
• Mounted or jointed parts loose
• Incorrect pitman arm mounting angle
• Knuckle stopper bolt out of adjustment
• Fluid leaks from steering gear
• Fluid leaks from power steering gear
Steering angle is
insufficient or clock-
wise and counter-
clockwise steering
angles are differnet
Fluid leaks
Fluid leaks from
oil pump
Fluid leaks from
oil tank
• Defective oil pump housing
• Defective gasket, oil seal
• Loose bolts
• Fluid leaks from oil tank due to overfilling
• Fluid leaks from oil tank due to trapped air
• Improperly welded pipes
• Loose hydraulic piping and connections
Replace
Retighten to specified torque

2nd drag link
Lock lever
49 - 54 Nm
(5.0~5.5 kgf·m)
Integral power
steering booster
200 - 340 Nm
(20.7~34.5 kgf·m)
1st drag link
200-340 Nm
(20.7~34.5 kgf·m)
Knuckle arm
200-340 Nm
(20.7~34.5 kgf·m)
78 - 107.8 Nm
(8~11 kgf·m)
12.7 - 22 Nm
(1.3~1.5 kgf·m)
78 - 107.8 Nm
(8.0~11.0kgf·m)
78 Nm (8 kgf·m)
ECYST06A
ST-15
MA560160
Clip
Starter Switch
Removal and Installation
Removal
1. Disconnect the battery (-) terminal.
2. Detach the column cover.

Dust cover
Spline shaft
Spline tube
MA560170
MA560180
Screw extractor
Bolt head detached
surface
SERVICE PROCEDURE
ST-16 STEERING SYSTEM
MA560190
Lower cover
Installation
1. Tighten a new twist off bolt to 12.7~14.7 Nm (1.3~1.5kgf·m)
and extract the twist off bolt head.
2. Inspect the function of steering lock operation after installation.
3. Installation is the reverse procedure of removal.
Steering Wheel
1. Remove the horn pad.
MA560200
Twister off bolt
12.7 - 14.7 Nm (1.3~1.5 kgf·m)
Starter switch
Horn pad
Steering wheel
Steering wheel puller
2. Remove the wheel using a steering wheel puller.
Mark an mating mark for reassembly.
MA560210
ST-17

3. Remove the link and steering shaft attaching bolt of bracket.
4. Remove the steering shaft joint attaching bolt.
5. Remove the steering shaft assembly from stub shaft with in-
stalled starter switch.
Steering
upper shaft
attaching
bolt
Locker lever
Link and
steering shaft
attaching bolt of
bracket
Cyline shaft
assembly
Steering
cover
mounting
bolt
Dust cover
Mating
mark
Steering
cover
MA560220
1
2
3
4
5

direction.
Fix the 4
points of
circle
When assembling, the yoke surface should
be the same direction
Reassemby sequence
1. Steering shaft
2. Yoke
3. Bearing
4. Ball bearing
5. Spline shaft
6. Dust seal
7. Cover
1
2
3
4
5
6
7
A
A
2.9-4.9 Nm (0.3-0.5 kgf·m)