This Workshop Manual tells the servicing personnel about the mechanism, servicing and
maintenance of the G23 and G26. It contains 4 parts: "Information", "General", "Mechanism" and"Servicing".
Q Information
This section contains information below.
• Safety First
• Safety Label
• Specification
• Dimension
Q General
This section contains information below.
• Engine Identification
• Model Identification
• General Precautions
• Maintenance Check List
• Check and Maintenance
• Special Tools
Q Mechanism
This section contains information on the structure and the function of the unit. Before you continue
with the subsequent sections, make sure that you read this section.
Refer to the latest version of Workshop Manual (Code No. 9Y021-01870) for the diesel engine
mechanism that this workshop manual does not include.
Q Servicing
This section contains information below.
• Troubleshooting
• Servicing Specifications
• Tightening Torques
• Checking, Disassembling and Servicing
All illustrations, photographs and specifications contained in this manual are of the newest
information available at the time of publication.
KUBOTA reserves the right to change all information at any time without notice.
Since this manual includes many models, information or illustrations and photographs can show
• This symbol, the industry's "Safe ty Alert Symbol", is us ed throughout this manual and o n labels on the
machine itself to warn of the possibility of personal injury. Read these instructions carefully.
• It is essential that you read the instructions and safety regulations before you attempt to repair or use
this unit.
• Indicates an imminently hazardous situation which, if not a voided, will result in death or serious injury.
• Indicates a potentially hazardous situ ation which, if not av oided, could result in de ath or serious injury.
• Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate
injury.
• Indicates that equipment or property damage could result if instructions are not followed.
• Gives helpful information.
WSM000001INI0001US1
BEFORE YOU START SERVICE
• Read all instructions and safety instructions in this
manual and on your machine safety decals.
• Clean the work area and machine.
• Park the machine on a stable and level ground, and
set the parking brake.
• Lower the implement to the ground.
• Stop the engine, then remove the key.
• Disconnect the battery negative cable.
• Hang a "DO NOT OPERATE" tag in the operator
station.
WSM000001INI0010US1
START SAFELY
• Do not do the procedures below when you start the
engine.
–short across starter terminals
–bypass the safety start switch
• Do not alter or remove any part of machine safety
system.
• Before you start the engine, make sure that all shift
levers are in neutral positions or in disengaged
positions.
• Do not start the engine when you stay on the ground.
Start the engine only from operator's seat.
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I-1
(EU)
G23, G26, WSM
KiSC issued 08, 2009 A
INFORMATION
OPERATE SAFELY
• Do not use the machine after you consume alcohol
or medication or when you are tired.
• Put on applicable clothing and safety equipment.
• Use applicable tools only. Do not use alternative
tools or parts.
• When 2 or more persons do servicing, make sure
that you do it safely.
• Do not operate below the machine that only a jack
holds. Always use a safety stand to hold the
machine.
• Do not touch the hot parts or parts that turn when the
engine operates.
• Do not remove the radiator cap when the engine
operates, or immediately after it stops. If not, hot
water can spout out from the radiator. Only remove
the radiator cap when it is at a sufficiently low
temperature to touch with bare hands. Slowly loosen
the cap to release the pressure before you remove it
fully.
• Released fluid (fuel or hydraulic oil) under pressure
can cause damage to the skin and cause serious
injury. Release the pressure before you disconnect
hydraulic or fuel lines. Tighten all connections before
you apply the pressure.
• Do not open a fuel system under high pressure.
The fluid under high pressure that stays in fuel lines
can cause serious injury. Do not disconnect or repair
the fuel lines, sensors, or any other components
between the fuel pump and injectors on engines with
a common rail fuel system under high pressure.
• Put on an applicable ear protective device (earmuffs
or earplugs) to prevent injury against loud noises.
• Be careful about electric shock. The engine
generates a high voltage of more than DC100 V in
the ECU and is applied to the injector.
WSM000001INI0012US1
PREVENT A FIRE
• Fuel is very flammable and explosive under some
conditions. Do not smoke or let flames or sparks in
your work area.
• To prevent sparks from an accidental short circuit,
always disconnect the battery negative cable first
and connect it last.
• The battery gas can cause an explosion. Keep the
sparks and open flame away from the top of battery,
especially when you charge the battery.
• Make sure that you do not spill fuel on the engine.
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I-2
(EU)
G23, G26, WSM
KiSC issued 08, 2009 A
INFORMATION
KEEP A GOOD AIRFLOW IN THE WORK AREA
• If the engine is in operation, make sure that the area
has good airflow. Do not operate the engine in a
closed area. The exhaust gas contains poisonous
carbon monoxide.
WSM000001INI0006US1
DISCARD FLUIDS CORRECTLY
• Do not discard fluids on the ground, down the drain,
into a stream, pond, or lake. Obey related
environmental protection regulations when you
discard oil, fuel, coolant, electrolyte and other
dangerous waste.
WSM000001INI0007US1
PREVENT ACID BURNS
• Keep electrolyte away from your eyes, hands and
clothing. Sulfuric acid in battery electrolyte is
poisonous and it can burn your skin and clothing and
cause blindness. If you spill electrolyte on yourself,
clean yourself with water, and get medical aid
immediately.
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PREPARE FOR EMERGENCIES
• Keep a first aid kit and fire extinguisher ready at all
times.
• Keep the emergency contact telephone numbers
near your telephone at all times.
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INFORMATION
2.SAFETY DECALS
The following safety decals (pictorial safety labels) are installed on the machine. If a decal becomes
damaged, illegible or is not on the machine, replace it. The decal part number is listed in the parts list.
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INFORMATION
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KiSC issued 08, 2009 A
INFORMATION
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INFORMATION
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KiSC issued 08, 2009 A
INFORMATION
CARE OF PICTORIAL SAFETY LABELS
1. Keep pictorial safety labels clean and free from obstructing material.
2. Clean pictorial safety labels with soap and water, dry with a soft cloth.
3. Replace damaged or missing pictorial safety labels with new labels.
4. If a component with pictorial safety label(s) affixed is replace with new part, make sure new label(s) is (are)
attached in the same locations(s) as the replace component.
5. Mount new pictorial safety labels by applying on a clean dry surface and pressure any bubbles to outside edge.
I-8
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(EU)
G23, G26, WSM
KiSC issued 08, 2009 A
3.SPECIFICATIONS
INFORMATION
Model
Maximum gross power17.1 kW (23.3 HP)18.8 kW (25.5 HP)
ModelD902-E3-GTD1005-E3-GT
TypeIndirect injection, vertical, water cooled, 4-cycle diesel engine
Number of cylinders3
Bore and stroke72 × 73.6 mm (2.83 × 2.90 in.)76 × 73.6 mm (2.99 × 2.90 in.)
Total displacement898 cm
Rated revolution3200 min
Combustion chamberSpherical type (E-TVCS)
Fuel injection pumpBosch MD type mini pump
GovernorCentrifugal ball mechanical governor
Injection nozzleBosch throttle type
Injection timing0.28 to 0.31 rad (16 ° to 18 °) before T.D.C.
Engine
Capacities
Tyres
Traveling
speeds
Dimensions
Weight (Without mower deck and grass
collector)
PTOShaft drive
PTO clutchBelt tensionWet disks
Revolution (PTO speed)2600 min
PTO brakeShoeWet disks
SteeringHydrostatic type power steering
TransmissionHydrostatic transmission
BrakeWet disks
Injection order1-2-3
Injection pressure13.73 MPa (140 kgf/cm
Compression ratio24 : 1
Lubricating systemForced lubrication by gear pump
Cooling systemPressurized radiator, forced circulation with water pump
Lubricating oil
Starting systemElectric starter (12 V, 1.0 kW)
Battery51R (12V, 450CCA)
Fuel
Fuel tank20.5 L (5.4 U.S.gals, 4.5 Imp.gals)
Engine crankcase3.1 L (3.3 U.S.qts, 2.7 Imp.qts)3.5 L (3.7 U.S.qts, 3.1 Imp.qts)
Engine coolant
(with recovery tank)
Transmission case11.0 L (11.6 U.S.qts, 9.7 Imp.qts)
Mower gear case oil1.9 L (2.0 U.S.qts, 1.7 Imp.qts)2.1 L (2.2 U.S.qts, 1.8 Imp.qts)
Front16 × 7.50-8 (4PR) Turf
Rear24 × 12.00-12 (4PR) Turf
Forward0 to 15.5 km/h (0 to 9.6 mph)0 to 17.0 km/h (0 to 10.6 mph)
Reverse0 to 10.0 km/h (0 to 6.2 mph)
Overall length
(with grass collector), without
front weight bracket for HD
Overall width (with mower)1226 mm (48.3 in.)1418 mm (55.9 in.)
Overall height1350 mm (53.1 in.)1600 mm (63.0 in.)1350 mm (53.1 in.)1600 mm (63.0 in.)
Wheel base1390 mm (54.7 in.)1460 mm (57.5 in.)
Tread
Front900 mm (35.4 in.)
Rear840 mm (33.1 in.)
2980 mm (117.3 in.)3160 mm (124.4 in.)3035 mm (119.5 in.)3215 mm (126.6 in.)
LDHDLDHD
3.1 L (3.3 U.S.qts, 2.7 Imp.qts)3.3 L (3.5 U.S.qts, 2.9 Imp.qts)
535 kg (1180 lbs)500 kg (1103 lbs)565 kg (1246 lbs)535 kg (1180 lbs)
G23G26
3
(54.8 cu.in.)1001 cm3 (61.1 cu.in.)
API Service Classification CD, CE or CF
Below 0 °C (32 °F) : SAE10W, SAE10W-30 or 15W-40
0 to 25 °C (32 to 77 °F) : SAE20, SAE10W-30 or 15W-40
Above 25 °C (77 °F) : SAE30, SAE10W-30 or 15W-40
No.2-D diesel fuel (ASTM D975)
[No.1-D diesel fuel, if temperature is below – 10 °C (14 °F)]
-1
(rpm)
-1
(rpm)
2
, 1991 psi)
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INFORMATION
Model
ModelRCK48-G23RCK54-G26
Total length895 mm (35.2 in.)980 mm (38.6 in.)
Total width1266 mm (49.8 in.)1418 mm (55.8 in.)
Total height400 mm (15.8 in.)
Mounting methodQuick joint, parallel linkage
Mower
Grass
collector
The company reserves the right to change the specifications without notice.
Adjustment of cutting heightDial gauge
Cutting width1219 mm (48.0 in.)1372 mm (54.0 in.)
Cutting height25 to 102 mm (1.0 to 4.0 in.)
Number of blades2
Weight (Approx.)120 kg (265 lbs)135 kg (298 lbs)
Discharge directionRear side
ModelGCK-G23LDGCK-G26HD
Container capacity560 L (148 U.S.gals, 110 Imp.gals)640 L (169 U.S.gals, 141 Imp.gals)
When contacting your local KUBOTA distributor, always specify
engine serial number, tractor serial number and hour meter reading.
(1) Machine Serial Number
(2) Engine Serial Number
GENERAL
(3) Mower Serial Number
(To be continued)
G-1
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G23, G26, WSM
KiSC issued 08, 2009 A
(Continued)
GENERAL
(4) Grass Catcher Serial Number (LD)
(5) Grass Catcher Serial Number (HD)
(6) Hour Meter / Tachometer
9Y1210294GEG0001US0
[2]CYLINDER NUMBER
You can see the cylinder numbers of KUBOTA diesel engine in
the figure. The sequence of cylinder numbers is No. 1, No. 2 and
No. 3 and it starts from the gear case side.
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KiSC issued 08, 2009 A
2.GENERAL PRECAUTIONS
• When you disassemble, carefully put the parts in a clean area
to make it easy to find the parts. You must install the screws,
bolts and nuts in their initial position to prevent the reassembly
errors.
• When it is necessary to use special tools, use KUBOTA special
tools. Refer to the drawings when you make special tools that
you do not use frequently.
• Before you disassemble or repair machine, make sure that you
always disconnect the ground cable from the battery first.
• Remove oil and dirt from parts before you measure.
• Use only KUBOTA genuine parts for replacement to keep the
machine performance and to make sure of safety.
• You must replace the gaskets and O-rings when you assemble
again. Apply grease (1) to new O-rings or oil seals before you
assemble.
• When you assemble the external or internal snap rings, make
sure that the sharp edge (3) faces against the direction from
which force (2) is applied.
• When inserting spring pins, their splits must face the direction
from which a force is applied. See the figure left side.
• To prevent damage to the hydraulic system, use only specified
fluid or equivalent.
(1) Grease
(2) Force
(3) Sharp Edge
(4) Axial Force
(5) Rotating Movement
GENERAL
(A) External Snap Ring
(B) Internal Snap Ring
WSM000001GEG0092US0
G-3
(EU)
G23, G26, WSM
IMPORTANT
KiSC issued 08, 2009 A
GENERAL
3.HANDLING PRECAUTIONS FOR ELECTRICAL
PARTS AND WIRING
To ensure safety and prevent damage to the machine and
surrounding equipment, heed the following precautions in handling
electrical parts and wiring.
• Check electrical wiring for damage and loosened
connection every year. To this end, educate the customer
to do his or her own check and at the same time
recommend the dealer to perform periodic check for a fee.
• Do not attempt to modify or remodel any electrical parts
and wiring.
• When removing the battery cables, disconnect the ne gative
cable first. When installing the battery cables, connect the
positive cable first.
(1) Negative Terminal(2) Positive Terminal
WSM000001GEG0062US1
[1]WIRING
• Securely tighten wiring terminals.
(1) Correct
(Securely Tighten)
(2) Incorrect
(Loosening Leads to Faulty Contact)
WSM000001GEG0063US1
• Do not let wiring contact dangerous part.
(1) Dangerous Part (Sharp Edge)
(2) Wiring (Incorrect)
(3) Wiring (Correct)
(4) Dangerous Part
• Securely insert grommet.
(1) Grommet(A) Correct
(B) Incorrect
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GENERAL
• Securely clamp, being careful not to damage wiring.
(1) Clamp
(Wind Clamp Spirally)
(2) Wire Harness
(3) Clamp
(4) Welding Dent
WSM000001GEG0067US1
• Clamp wiring so that there is no twist, unnecessary sag, or
excessive tension, except for movable part, where sag be
required.
(1) Wiring
(2) Clamp
(A) Correct
(B) Incorrect
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• In installing a part, take care not to get wiring caught by it.
(1) Wiring(A) Incorrect
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• After installing wiring, check protection of terminals and
clamped condition of wiring, only connect battery.
(1) Cover
(Securely Install Cover)
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G23, G26, WSM
CAUTION
KiSC issued 08, 2009 A
[2]BATTERY
GENERAL
• Take care not to confuse positive and negative terminal posts.
• When removing battery cables, disconnect negative cable first.
When installing battery cables, check for polarity and connect
positive cable first.
• Do not install any battery with capacity other than is specified
(Ah).
• After connecting cables to battery terminal posts, apply high
temperature grease to them and securely install terminal covers
on them.
• Do not allow dirt and dust to collect on battery.
• Take care not to let battery liquid spill on your skin and
clothes. If contaminated, wash it off with water
immediately.
• Before recharging the battery, r emove it fro m the ma chine.
• Before recharging, remove cell caps.
• Do recharging in a well-ventilated place where there is no
open flame nearby, as hydrogen gas and oxygen are
formed.
WSM000001GEG0071US1
[3]FUSE
[4]CONNECTOR
• Use fuses with specified capacity.
Neither too large or small capacity fuse is acceptable.
• Never use steel or copper wire in place of fuse.
• Do not install working light, radio set, etc. on machine which is
not provided with reserve power supply.
• Do not install accessories if fuse capacity of reserve power
supply is exceeded.
(1) Fuse
(2) Fusible Link
(3) Slow Blow Fuse
WSM000001GEG0072US1
• For connector with lock, push lock to separate.
(A) Push
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• In separating connectors, do not pull wire harnesses.
• Hold connector bodies to separate.
(A) Correct(B) Incorrect
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(EU)
G23, G26, WSM
KiSC issued 08, 2009 A
GENERAL
• Use sandpaper to remove rust from terminals.
• Repair deformed terminal. Make certain there is no terminal
being exposed or displaced.
(1) Exposed Terminal
(2) Deformed Terminal
(3) Sandpaper
(4) Rust
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• Make certain that there is no female connector being too open.
(A) Correct(B) Incorrect
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• Make certain plastic cover is large enough to cover whole
connector.
(1) Cover(A) Correct
(B) Incorrect
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[5]HANDLING OF CIRCUIT TESTER
• Use tester correctly following manual provided with tester.
• Check for polarity and range.
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[6]COLOR OF WIRING
GENERAL
• Colors of wire are specified to the color codes.
• This symbol of "/" shows color with stripe(s).
(An example)
Red stripe on white color : W/R
Color of wiringColor code
BlackB
BrownBr
GreenG
GrayGy or Gr
BlueL
Light GreenLg
OrangeOr
PinkP
PurplePu or V
RedR
Sky BlueSb
WhiteW
Yell owY
(1) Wire Color(2) Stripe
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G23, G26, WSM
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4.LUBRICANTS, FUEL AND COOLANT
Capacities
No.Place
LDHDLDHD
1Fuel
Coolant
2
(with recovery tank)
3Engine crankcase
4Transmission case
5Mower gear box
3.1 L
3.3 U.S.qts
2.7 Imp.qts
3.1 L*
3.3 U.S.qts
2.7 Imp.qts
1.9 L
2.0 U.S.qts
1.7 Imp.qts
20.5 L
5.4 U.S.gals
4.5 Imp.gals
3.3 L
3.5 U.S.qts
2.9 Imp.qts
3.5 L*
3.7 U.S.qts
3.1 Imp.qts
11.0 L
11. 6 U.S.qts
9.7 Imp.qts
2.1 L
2.2 U.S.qts
1.8 Imp.qts
• No. 2-D diesel fuel
• No. 1-D diesel fuel if temperature
is below –10 °C (14 °F)
Fresh clean water with anti-freeze
Engine oil
API Service Classification CD, CE
or CF
• Above 25 °C (77 °F)
SAE30W,
SAE10W-30 or 15W-40
• 0 to 25 °C (32 to 77 °F)
SAE20, SAE10W-30 or 15W-40
• Below 0 °C (32 °F)
SAE10W,
SAE10W-30 or 15W-40
KUBOTA UDT or SUPER UDT fluid*
KUBOTA UDT or SUPER UDT fluid*
GENERAL
LubricantsG23G26
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(EU)
G23, G26, WSM
NOTE
IMPORTANT
KiSC issued 08, 2009 A
No.Place
Front axle (King pin)2
Front axle (Centre pin)1
Brake pedal7
HST speed change
pedal
HST pedal boss1
Tension PTO arm1
PTO1
Parking lock pedal2
Cruise control2
Differential lock pedal4
Cutting height cam3
Under duct5
Sensor rod2
Duct cleanup system3
6
Seat adjuster4
Throttle cable1Moderate amountOil
Mower universal joint5
Mower lift cylinder5
Front RH link1
Front link3
Rear link2
Link arm front2
Link arm rear2
Dump cylinder2–2–
Bush4–4–
Lock lever2–2–
Grass catcher–10–10
Grass container lift
cylinder
Dump flap–2–2
Greasing
No. of greasing point
LDHDLDHD
2
–4–4
CapacityType of greaseG23G26
Until grease overflows
Until grease overflows
GENERAL
Multipurpose EP2 grease
(NLGI Grade No.2)
Multipurpose EP2 grease
(NLGI Grade No.2)
• * KUBOTA original transmission hydraulic fluid.
• To prevent serious damage to hydraulic system, use only KUBOTA genuine fluid or its equivalent.
G-10
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(EU)
G23, G26, WSM
NOTE
KiSC issued 08, 2009 A
GENERAL
Engine Oil :
• Oil used in the engine should have an American Petroleum Institute (API) service classification and
Proper SAE Engine Oil according to the ambient temperatures as shown in the table.
• With the emission control now in effect, the CF-4 and CG-4 lubricating oils have been developed for use
of a low-sulfur fuel on on-road vehicle engines. When an off-road vehicle engine runs on a high-sulfur
fuel, it is advisable to emplo y the CF, CD or CE lubricating oil with a high total base number. If the CF-4
or CG-4 lubricating oil is used with a high-sulfur fuel, change the lubricating oil at shorter intervals.
• Lubricating oil recommended when a low-sulfur or high-sulfur fuel is employed.
P : RecommendableX : Not Recommendable
Lubricating
oil class
Low-sulfurHigh-sulfur
Fuel
Remark
CFPPTBN ≥ 10
CF-4PX
CG-4PX
Transmission oil (KUBOTA SUPER UDT *1) :
• KUBOTA Original Transmission hydraulic fluid
The oil used to lubricate the transmission is also used as hydraulic fluid. To insure proper operation of
the hydraulic system and complete lubrication of the transmission, it is important that a multi-grade
transmission fluid be used in this system. We recommend the use of KUBOTA UDT or SUPER UDT fluid
for optimum protection and performance.
Do not mix different brands together.
• Indicated capacity of water and oil are manufacturer's estimate.
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G23, G26, WSM
KiSC issued 08, 2009 A
GENERAL
5.TIGHTENING TORQUES
[1]GENERAL USE SCREWS, BOLTS AND NUTS
Screws, bolts and nuts whose tightening torques are not specified in this Workshop Manual should be
tightened according to the table b elow .
Indication on top of bolt
Indication on top of nut
Material of opponent partOrdinarinessAluminumOrdinarinessAluminumOrdinariness