PDF Shop Manual Komatsu WA320-5 Wheel Loader - 10 MB
This shop manual offers comprehensive service and repair information for the Komatsu WA320-5 Wheel Loader.
It contains technical data, troubleshooting charts, and detailed procedures for disassembly and reassembly of all major components.
This manual is designed for professional technicians to maintain and repair the WA320-5 to factory standards.
It is an essential resource for any workshop servicing this machine.
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--- Page 1 ---
SEBM0346-09
Machine model Serial number
WA320-5 C30001 and up
• This shop manual may contain attachments and optional equipment that are not available in
your area. Please consult your local Komatsu distributor for those items you may require.
Materials and specifications are subject to change without notice.
• WA320-5 mounts the SAA6D102E-2-A engine.
For details of the engine, see the 102 Series Engine Shop Manual.
© 2018
All Rights Reserved 00-1
Printed in Thailand 07-18 (01) (9)
--- Page 3 ---
FOREWORD HOISTING INSTRUCTIONS
HOISTING INSTRUCTIONS
HOISTING
k Heavy parts (25 kg or more) must be lifted
Slinging near the edge of the hook may cause
the rope to slip off the hook during hoisting, and
with a hoist, etc. In the DISASSEMBLY a serious accident can result. Hooks have max-
AND ASSEMBLY section, every part imum strength at the middle portion.
weighing 25 kg or more is indicated clearly
with the symbol 4
• If a part cannot be smoothly removed from the
machine by hoisting, the following checks
should be made:
1) Check for removal of all bolts fastening the 100% 88% 79% 71% 41%
part to the relative parts. SAD00479
2) Check for existence of another part causing
3) Do not sling a heavy load with one rope alone,
interference with the part to be removed.
but sling with two or more ropes symmetrically
k Slinging with one rope may cause turning
wound onto the load.
WIRE ROPES
1) Use adequate ropes depending on the
weight of parts to be hoisted, referring to of the load during hoisting, untwisting of
the table below: the rope, or slipping of the rope from its
original winding position on the load, which
Wire ropes can result in a dangerous accident.
(Standard "Z" or "S" twist ropes
without galvanizing) 4) Do not sling a heavy load with ropes forming a
wide hanging angle from the hook.
Rope diameter Allowable load
When hoisting a load with two or more ropes,
the force subjected to each rope will increase
mm kN tons with the hanging angles. The table below
shows the variation of allowable load kN {kg}
10 9.8 1.0 when hoisting is made with two ropes, each of
11.5 13.7 1.4 which is allowed to sling up to 9.8 kN {1000 kg}
12.5 15.7 1.6
vertically, at various hanging angles.
14 21.6 2.2
16 27.5 2.8
When two ropes sling a load vertically, up to
18 35.3 3.6 19.6 kN {2000 kg} of total weight can be sus-
20 43.1 4.4 pended. This weight becomes 9.8 kN {1000 kg}
22.4 54.9 5.6 when two ropes make a 120° hanging angle.
30 98.1 10.0 On the other hand, two ropes are subjected to
40 176.5 18.0 an excessive force as large as 39.2 kN {4000
50 274.6 28.0 kg} if they sling a 19.6 kN {2000 kg} load at a
60 392.2 40.0 lifting angle of 150°.
★ The allowable load value is estimated to be one-
sixth or one-seventh of the breaking strength of
the rope used.
2) Sling wire ropes from the middle portion of the
hook.
00-7
--- Page 4 ---
FOREWORD CONVERSION TABLE
Millimeters to Inches
1 mm = 0.03937 in
0 1 2 3 4 5 6 7 8 9
0 0 0.039 0.079 0.118 0.157 0.197 0.236 0.276 0.315 0.354
10 0.394 0.433 0.472 0.512 0.551 0.591 0.630 0.669 0.709 0.748
20 0.787 0.827 0.866 0.906 0.945 0.984 1.024 1.063 1.102 1.142
30 1.181 1.220 1.260 1.299 1.339 1.378 1.417 1.457 1.496 1.536
40 1.575 1.614 1.654 1.693 1.732 1.772 1.811 1.850 1.890 1.929
50 1.969 2.008 2.047 2.087 2.126 2.165 2.205 2.244 2.283 2.323
60 2.362 2.402 2.441 2.480 2.520 2.559 2.598 2.638 2.677 2.717
70 2.756 2.795 2.835 2.874 2.913 2.953 2.992 3.032 3.071 3.110
80 3.150 3.189 3.228 3.268 3.307 3.346 3.386 3.425 3.465 3.504
90 3.543 3.583 3.622 3.661 3.701 3.740 3.780 3.819 3.858 3.898
Kilogram to Pound
1 kg = 2.2046 lb
0 1 2 3 4 5 6 7 8 9
0 0 2.20 4.41 6.61 8.82 11.02 13.23 15.43 17.64 19.84
10 22.05 24.25 26.46 28.66 30.86 33.07 35.27 37.48 39.68 41.89
20 44.09 46.30 48.50 50.71 51.91 55.12 57.32 59.53 61.73 63.93
30 66.14 68.34 70.55 72.75 74.96 77.16 79.37 81.57 83.78 85.98
40 88.18 90.39 92.59 94.80 97.00 99.21 101.41 103.62 105.82 108.03
50 110.23 112.44 114.64 116.85 119.05 121.25 123.46 125.66 127.87 130.07
60 132.28 134.48 136.69 138.89 141.10 143.30 145.51 147.71 149.91 152.12
70 154.32 156.53 158.73 160.94 163.14 165.35 167.55 169.76 171.96 174.17
80 176.37 178.57 180.78 182.98 185.19 187.39 189.60 191.80 194.01 196.21
90 198.42 200.62 202.83 205.03 207.24 209.44 211.64 213.85 216.05 218.26
00-17
--- Page 5 ---
GENERAL SPECIFICATIONS
Machine model WA320-5
Serial No. C30001 and up
Type Articulated steering
Steering
control
Control Hydraulic control
Steering pump
• Type Gear type
• Delivery l / min 167
Work equipment pump
• Type Gear type
Hydraulic pump
• Delivery l / min 58
Brake and cooling fan pump
• Type Gear type
• Delivery l / min 31
Transfer lubrication pump
• Type Gear type
• Delivery l / min 22
Hydraulic system
Type Reciprocating piston type
Steering cylinder
Cylinder inner diameter mm 70
Piston rod diameter mm 40
Stroke mm 453
Max. length between pins mm 1,271
Min. length between pins mm 818
Type Reciprocating piston type
Cylinder inner diameter mm 140
Lift cylinder
Cylinder
Piston rod diameter mm 75
Stroke mm 740
Max. length between pins mm 1,969
Min. length between pins mm 1,229
Type Reciprocating piston type
Bucket cylinder
Cylinder inner diameter mm 160
Piston rod diameter mm 80
Stroke mm 532
Max. length between pins mm 1,559
Min. length between pins mm 1,027
WA320-5 01-5
--- Page 6 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD COOLING SYSTEM
Serial No. 60676 and up
WA320-5 10-4-1
(5)
--- Page 7 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD HIGH-PRESSURE RELIEF VALVE
Operation
• Port A is connected to the high-pressure circuit • If the oil pressure in port A and chamber B
of the HST pump and ports C and D are con- reaches the set pressure of poppet spring (3), pi-
nected to the low-pressure circuit of the HST lot poppet (7) opens and the oil in chamber B
pump. flows through chamber D to port C, and the oil
The oil fills chamber B through the orifice of pressure in chamber B lowers consequently.
main piston (5). If the oil pressure in chamber B lowers, a pres-
Pilot poppet (7) is seated on valve seat (6). sure difference is made between port A and
chamber B by the orifice of main piston (5). As
a result, main piston (5) is pushed open and the
oil in port A flows into port C to relieve the abnor-
mal pressure.
• The set pressure can be adjusted by increasing
or decreasing the tension of poppet spring (3).
To adjust the set pressure, remove the nut and
loosen the locknut. If the adjustment screw is
tightened, the set pressure is heightened. If the
former is loosened, the latter is lowered.
• If the oil pressure in port A lowers below that in
port C, check spring (4) pushes back main pis-
ton (5) and the oil in port C flows through cham-
ber D into port A so that the quantity of the oil in
port A will not become insufficient.
WA320-5 10-13
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STRUCTURE, FUNCTION AND MAINTENANCE STANDARD FORWARD-REVERSE SHUTTLE VALVE
FORWARD-REVERSE SHUTTLE VALVE
1. Forward-reverse shifting solenoid valve Operation
2. Forward-reverse shuttle valve • The electric signals given to the forward-reverse
shifting solenoid valve of the HST pump are
Function used for forward-reverse shifting solenoid valve
• The forward-reverse shuttle valve is installed to (1) and linked to the forward-reverse shifting
the rear part of HST motor 2 and used to grasp mechanism.
and change the position of the forward-reverse • Forward-reverse shuttle valve (2) changes the
shifting solenoid valve to control where to lead hydraulic pressure applied to the HA servo valve
the hydraulic pressure for the HA servo valve. according to the forward-reverse shifting com-
Accordingly, shocks made when the oil pressure mand.
changes for gear shifting are reduced.
WA320-5 10-23
--- Page 9 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD TRANSFER
Low-speed mode
Operation
• In the low-speed mode, transfer clutch (1) is
fixed and the power of both HST motor 1 (2) and
HST motor 2 (3) is transmitted to output shaft
(11).
• The power of HST motor 1 (2) is transmitted
through input shaft (4), sun gear (5), planetary
gear (6), carrier (7), motor 1 gear (8), and output
gear (10) to output shaft (11).
• The power of HST motor 2 (3) is transmitted
through motor 2 gear (9) and output gear (10) to
output shaft (11).
WA320-5 10-33
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STRUCTURE, FUNCTION AND MAINTENANCE STANDARD DIFFERENTIAL
Torque proportioning differential
Outline
• A 4-wheel-drive wheel loader, as a construction
machine, must naturally work on places where
the ground condition is bad. If its tires slip in
such places, its function lowers and the lives of
the tires are shortened. To solve this problem,
the torque proportioning differential is used.
• Differential pinion gear (4) of this differential has
an odd number of teeth. The meshing points of SAW02536
pinion gear (4) and side gears (3) change ac-
cording to the difference of the road resistance.
Consequently, the traction forces of the tires on
both sides change.
SEW00080
WA320-5 10-43
--- Page 11 ---
AXLE MOUNTING AND
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD CENTER HINGE PIN
1. Front axle Outline
2. Tension bolt • Since front axle (1) receives forces directly dur-
3. Front frame ing work, it is fixed to front frame (3) directly with
4. Center hinge pin tension bolts (2).
5. Rear axle • Rear axle (5) rocks at the center of rear frame (6)
6. Rear frame so that each tire will keep in contact with ground
7. Additional counterweight (If equipped) even when the machine travels on soft ground.
8. Counterweight • Front frame (3) and rear frame (6) are connected
by center hinge pin (4) with the bearing between
them. The steering cylinders on both sides con-
nect front frame (3) and rear frame (6) and move
to adjust the bending angle, or the turning radi-
us.
WA320-5 10-53
--- Page 12 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD ORBIT-ROLL VALVE
Outline Structure
• The orbit-roll valve is connected directly to the • Top (A) of spool (3) is connected to the drive
shaft of the steering wheel. It switches the flow shaft of the steering column and further connect-
of oil from the steering pump to the left and right ed to sleeve (5) through center pin (4) (which is
steering cylinders to determine the direction of not in contact with the spool while the steering
travel of the machine. wheel is in neutral) and centering spring (12).
• The orbit-roll valve, broadly speaking, consists • Top (B) of drive shaft (6) is engaged with center
of the following components: rotary type spool pin (4) and combined with sleeve (5) in one
(3) and sleeve (5), which have the function of se- body, and the bottom is engaged with the spline
lecting the direction, and the Girotor set (a com- of rotor (8) of the gerotor set.
bination of rotor (8) and stator (9)), which acts as • Valve body (2) has 5 ports, which are connected
a hydraulic motor during normal steering opera- to the pump circuit, tank circuit, left steering cir-
tions, and as a hand pump (in fact, the operating cuit, right steering circuit, and LS circuit respec-
force of the steering wheel is too high, so it can- tively. The ports on the pump side and tank side
not be operated) when the steering pump or en- are connected by the check valve in the body. If
gine have failed and the supply of oil has the pump or engine fails, the oil can be sucked
stopped. through this check valve directly from the tank
side.
WA320-5 10-63
--- Page 13 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD EMERGENCY STEERING PIPING
EMERGENCY STEERING PIPING
(If equipped)
1. Orbit-roll valve
2. Steering pump
3. HST motor 2
4. Emergency steering valve
5. Pressure switch (For detecting operation of emergency steering)
6. Priority valve
7. Check valve
8. Pressure switch (for detecting drop of steering oil pressure)
WA320-5 10-73
--- Page 15 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD BRAKE
Outline
• The brake has a wet-type multiple-disc struc-
ture, and consists of piston (3), inner ring (5),
disc (9), outer ring (8), and spring (4).
• The brake cylinder consists of differential hous-
ing (1) and bearing carrier (2), and piston (3) is
assembled in it.
Inner ring (5) and outer ring (8) are joined to
the spline portion of axle housing (7).
• Disc (9) has a lining stuck to both sides. It is as-
sembled between inner ring (5) and outer ring
(8), and is joined by the spline of sun gear shaft
(6).
Outline
When brake is applied When brake is released
• When the brake pedal is depressed, pressure oil • When the oil pressure is released, piston (2) is
P goes from the hydraulic tank through the returned to its original position by the force of
pump and brake charge valve. It acts on the pis- spring (8), a gap is formed between inner ring
ton inside the brake cylinder and the piston (2) (3) and outer ring (5), and discs (4) become free.
slides. Lattice shape grooves are cut into the lining
Therefore, piston (2) stops the rotation of discs stuck to disc (4), and when disc (4) is rotating,
(4) fitted between inner ring (3) and outer ring oil flows in the grooves and carries out cooling of
(5), and applies the brake to the machine. the lining.
WA320-5 10-93
--- Page 16 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD 4-GEAR PUMP UNIT
Unit: mm
No. Check item Criteria Remedy
Model Standard clearance Clearance limit
SAR(3)90
5 Side clearance SAR(2)32
0.10 – 0.15 0.19
SBR(1)18
SBR(1)12
SAR(3)90 0.083 – 0.144
Clearance between inside SAR(2)32 0.071 – 0.121
6 diameter of plain bearing and 0.20
SBR(1)18 Replace
outside diameter of gear shaft
0.068 – 0.115
SBR(1)12
Model Standard size Tolerance Repair limit
SAR(3)90 13
+0
SAR(2)32 12
7 Diving depth of pin -0.5
SBR(1)18 10 –
+0.5
SBR(1)12 7
+0
8 Spline rotating torque 13.8 – 28.5 Nm {1.4 – 2.9 kgm}
Discharge Standard Discharge
Speed pressure discharge amount
Model
(rpm) (MPa {kg/ amount limit
Discharge amount cm2} (l/min) (l/min.)
–
– Oil: SAE10W SAR(3)90 129 119
Oil temperature: 45 - 55°C
SAR(2)32 20.6 {210} 91 82
2,500
SBR(1)18 23 21
SBR(1)12 2.9 {30} 27 24
WA320-5 10-103
--- Page 17 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD WORK EQUIPMENT CONTROL VALVE
WORK EQUIPMENT CONTROL VALVE
1. 2-Spool valve
P1: From steering pump P1A:From PPC valve P1 port
T: Drain port (To tank) P1B:From PPC valve P2 port
A1: To bucket cylinder head P2A:From PPC valve P3 port
A2: To lift arm cylinder head P2B:From PPC valve P4 port
B1: To bucket cylinder bottom
B2: To lift arm cylinder bottom
WA320-5 10-113
--- Page 19 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD WORK EQUIPMENT CONTROL VALVE
(6) Bucket spool tilt position
Operation
• If the bucket control lever is pulled, the oil in port • The oil in the bucket cylinder head flows through
L of the PPC valve flows through port P to port R port H into drain port F and then returns to the
of the work equipment control valve. tank. Accordingly, the bucket is tilted.
• The oil in port V flows to the drain circuit. The oil
in port R sets bucket spool (2) in the tilt position.
• Since the oil from the pump is stopped by spool
(2), the oil from port A pushes check valve (7)
open.
• The oil from check valve (7) flows through port G
to the bucket cylinder bottom.
WA320-5 10-133
--- Page 20 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD WORK EQUIPMENT PPC VALVE
2. When in fine control
NEUTRAL o Fine control)
• If rod (7) and piston (13) are pushed by disc (8),
retainer (12) is pushed and spool (1) is also
pushed down through metering spring (2).
• Accordingly, fine control hole f is disconnected
from drain chamber D and connected to pump
pressure chamber PP almost simultaneously,
and then the pilot oil of the main pump flows
from port P1 to port PB.
• If the pressure in port P1 rises, spool (1) is
pushed back and fine control hole f is discon-
nected from pump pressure chamber PP and
connected to drain chamber D almost simultane-
ously to release the pressure in port P1.
• As a result, spool (1) moves up and down to bal-
ance the force of metering spring (2) with the
pressure in port P1.
The positional relationship between spool (1)
and body (14) (where fine control hole f is be-
tween drain chamber D and pump pressure
chamber PP) does not change until retainer (12)
comes in contact with spool (1).
• Since metering spring (2) is compressed in pro-
portion to the stroke of the control lever, the
pressure in port P1 rises in proportion to the
stroke of the control lever.
• Accordingly, the control valve spool moves to a
position at which the pressure in the chamber
PB (equal to the pressure in port P1) is balanced
with the force of the control valve spool return
spring.
WA320-5 10-143
--- Page 22 ---
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD MACHINE MONITORING SYSTEM
• This machine monitoring system is equipped
with the service mode function to facilitate the
troubleshooting work for respective controllers
(including the machine monitor itself) on the net-
work. The description below applies to the con-
tents of the main functions.
1. Electric fault history
This function will indicate the electric fault history
data of respective controllers being memorized
by the machine monitor. Also, it can be used to
delete the aforementioned data.
2. Machine fault history
This function will indicate the machine fault his-
tory and machine fault history data of respective
controllers being memorized by the machine
monitor.
3. Real time monitor
This function will make real time indications of
the inputting data and outputting data being rec-
ognized by respective controllers on the net-
work.
4. Maintenance monitor
This function is to be used for revisions of the
preset filter and oil changing time. (Revision of
the time for the maintenance monitor operation)
5. Selection of optional items
This function is used to set the machine model,
tier size, and optional equipment.
6. Controller initializing function
This function is being used to effect the settings
of this machine monitor before shipment from
our factory.
• The machine monitoring system consists of the
machine monitor proper, buzzer, and switches
that are used for inputting data to the machine
monitor proper, sensors, respective controller
on the network, and relevant switches and sen-
sors.
WA320-5 10-163
(3)
--- Page 23 ---
LIST OF ITEMS DISPLAYED
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD ON MONITOR
LIST OF ITEMS DISPLAYED ON MONITOR
Condition for judging running of engine: When running judgment A or B is satisfied, it is judged that the engine
is running.
1. Input is given to alternator terminal R (24 V).
2. Engine oil pressure is normal (Open).
3. Signal of terminal C has been input at least once after IGN_BR, and then it has been turned OFF at least
once.
Judgment of operation
A: After 1 and 2 are established simultaneously, it is judged that the engine is running until IGN_BR is turned
OFF.
B: If 1 and 3 are established simultaneously or 2 and 3 are established simultaneously, it is judged that the
engine is running. If both signals of 1 and 2 are lost, however, it is judged that the engine is stopped even
if IGN_BR is turned ON.
Pri-
Lamp Period of lamp Buzzer Condition for operation Period of buzzer
ority
Warning for dangerous Period: 1,600 msec
w: ON and OFF condition ON: 800 msec
Q: ON – 1
continuously (When error indication OFF: 800 msec
or caution is turned on) (DUTY 50%)
Period: 1,600 msec Caution for wrong oper-
Period: 240 msec
ON: 800 msec ation, etc. (When abnor-
w: Flash A: Intermittent ON 1: 80 msec 2
OFF: 800 msec mal operation is
OFF: 160 msec
(DUTY 50%) performed)
Period: 240 msec Cancellation of calibra-
E: Cancellation
A: Intermittent ON 1: 80 msec tion, etc. (When opera- ON: 1,000 msec (Once) 3
sound
OFF: 160 msec tion is not accepted)
ON: 1,000 msec.
E: Condition is Completion of calibra-
e: Completion OFF: 160 msec.
set sepa- – tion, etc. (When com- 4
sound ON: 1,000 msec (Once)
rately pleted normally)
WA320-5 10-173
--- Page 24 ---
LIST OF ITEMS DISPLAYED
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD ON MONITOR