Always pay attention to “Safety” before starting any work — this is important.
Never attempt any work where danger to yourself or to other persons.
Whenever work requiring safety precautions are described in this manual, a flag mark
inserted, always make double sure that safety measures are taken.
Other unmarked work, should always be performed after studying and using your
common sense to prevent accidents.
DESCRIPTION OF THE SYMBOLS
The symbols described below are used in this manual for convenience and better understanding.
SymbolItemDescription
SafetySpecial safety precautions are needed to perform the work.
NoteSpecial technical precautions are needed to perform the work
Tightening torqueFastening parts that require specified tightening force when assembling.
WeightWeight of parts or systems
CoatPlaces to be coated with adhesives, etc. when assembling
00-2AX50/BX50 Series
Page 3
SECTION INDEX
00. FOREWORD
10. GENERAL AND SPECIFICATIONS
20. INSOECTION AND ADJUSTMENT
30. REMOVAL AND INSTALLATION
40. DISASSEMBLY AND ASSEMBLY
50. MAINTENANCE STANDARD
60. STRUCTURE AND FUNCTION
80. CRITERIA FOR PERIODICAL INSPECTION AND JUDGMENT
For operation safety, never fail to perform periodic maintenance or make periodic replacement of the consumable parts listed in the following.
These parts may deteriorate in time and are susceptible
to wear. It is difficult to estimate the degree of wear at
time of periodic mainten ance; th erefore, even if no apparent wear is found, always replace with new parts within
the prescribed period of replacement (or earlier if trouble
is found).
Note that periodic replacement has nothing to do with
guarantee service.
No.Part name
1Master cylinder and wheel cylinder cups, dust sealsEvery 1 year
2Rubber parts of brake boosterEvery 1 year
3Brake hose or tubeEvery 2 years
4Reservior tank and tubeEvery 2 years
5Power steering hose Every 2 years
6Stop lamp switch (Oil pressure type)Every 2 years
7Fuel hoseEvery 2 years
8Rubber parts of power steeringEvery 2 years
9Lift chainEvery 3 years
10Hose of load handingEvery 2 years
Period of
replacement
10-12AX50/BX50 Series
Page 17
GENERAL AND SPECIFICATIONS
SAFETY ITEMS FOR MAINTENANCE
SAFETY ITEMS FOR MAINTENANCE
FOR SAFETY OPERATION
USE QUALIFIED PERSONNEL FOR INSPECTION AND MAINTENANCE
• Only persons authori zed by the owner or operator of the equipment and having proper cer tification
(local or national) may carry out inspection, maintenance and repairs of the lift truck.
If inspection, maintenance, or repair work is carried out incorrectly, it is very dangerous.
MAINTENANCE LOCATION
• When carrying out inspection and maintenance, use a level, dry, dust–free area.
• If the work is carried out inside a building, make sure that there is ample ventilation.
PRECAUTIONS FOR INSPECTION AND MAINTENANCE
• To be prep ared in the event of a fire, have a fire extinguisher near by and make sure that you know
how to use it.
• Before carrying out inspection, lower the forks to the ground and stop the machine.
• Do not run the engine unless it is necessary.
• Place the directional lever, speed lever, and work equipment control levers in neutral.
PRECAUTIONS WHEN CARRYING OUT INSPECTION AND MAINTENANCE
• Wipe off any oil or grease. Immediately wipe up any oil that has leaked.
If the lift truck is dirty, it becomes difficult or impossible to find cracks or other problems. Always clean
the lift truck before starting inspection.
• Do not smoke or allow any flame to exist under any circumstances.
Do not use any cloth which is soaked in fuel, oil, or grease. There is danger that it may catch fire.
• Wear suitable clothes for the job.
• Use suitable safety and protective equipment ( hard hat, safety boots, safety glasses, gloves) for the
job.
• When working on top of the lift truck, be careful not to fall.
• Do not put your feet under the forks.
• When opening or closing the floor pla te or engine hood, be careful not to get your hands or body
caught.
• When carrying out inspection with the forks raised, inse rt a stand under the inne r mast to pr event the
forks and mast from dropping.
• When carrying ou t job with another worker, decide who is the leader and carr y out the job in acc ordance with instructions from that person.
• After repairing, make sure that the trouble has been corrected by performing a trial run.
• During the trial run , start/operate th e lift tr uck carefu lly b ecaus e it is possible tha t the trouble ha s not
been fully corrected or that defective parts have not been removed.
AX50/BX50 Series10-13
Page 18
SAFETY ITEMS FOR MAINTENANCE
USE SUITABLE TOOLS
• Always use tools that are suited for inspection and
maintenance.
It is extremely dangerous t o us e br oken tools or too ls
designed for another purpose.
REPLACE SAFETY CRITICAL PARTS PERIODICALLY
• Even if no abnormality is found, always replace safety critical parts periodically.
As time passes, these parts deteriorate and may cause fire of failure in the work equipment system.
• However, if these parts show any abnormality before the replacement interval has passed, they
should be repaired or replaced immediately.
GENERAL AND SPECIFICATIONS
PRECAUTIONS WITH HIGH TEMPERATURE COOLANT
• Immediately after using the lift truck, the engine coolant is at high temperature and high pressure. Do
not remove the radiator cap under these conditions.
Hot water may spurt out and cause burns.
• When removing the radiator cap, turn it slowly to
release the internal press ure.
• When checking the coolant level, stop the engine and
wait for the engine and radiator to cool down before
checking. For lift trucks equipped with a subtank or
reservoir, check the level in the subtank.
• When adding water on lift trucks equipped with a subtank, add the water to the subtank.
10-14AX50/BX50 Series
Page 19
GENERAL AND SPECIFICATIONS
PRECAUTIONS WITH HIGH PRESSURE, HIGH TEMPERATURE OIL
• Immediately after using the lift tr uck, the oil is at high te mperature. Do not drain the oil or replace the
filter when the oil is hot. Hot oil may spurt out and cause burns.
• When carrying out inspection and maintenance,
wait for the oil temperature to go d own, and carr y
out the operation in the order given in this manual.
• Do not forget that the work eq uipment c ircuits ar e
always under pressure. Do not add oil, drain oil, or
carry out main tenance or inspection before completely releasing the internal pressure.
• If oil is leaking under high pressure from small
holes, it is dangerous if the jet of high–pressure oil
hits your skin or eyes. Always wear safety glasses
and thick gloves, and use a piece of cardboa rd or
a sheet of plywood to check for oil leakage.
• Release the internal pressure be fore checking the
accumulator piping.
• If you are hit by a jet of high pressure oil, consult a
doctor immediately.
SAFETY ITEMS FOR MAINTENANCE
ROTATING FAN AND BELT
• It is extremely dangerous if you or any tool
touches or gets c aught in the fan or fan belt when
the fan is rotating. Never touch the fan when it is
rotating.
• Always stop the engine before inspecting rotating
parts.
• When inspecting the area s around rotating par ts,
do not allow anything to come close which may
get caught.
AX50/BX50 Series10-15
Page 20
SAFETY ITEMS FOR MAINTENANCE
BE CAREFUL NOT T O GET CAUGHT OR FALL
• Never put your hands or feet into the mast structure.
There is danger that you will get caught in moving par ts
and be serious injured.
• Do not use the mast as a ladder. If you slip, there is danger that you will fall.
GENERAL AND SPECIFICATIONS
CHECKING AND INFLATING TIRES
• If the tire inflation pressur e is low, it will affect truck stability. However, do not inflate the tires immediately. The inflation pressure may have gone down because of damage to the rim. If the rim is damaged or cracked and the tires are inflated, there is danger that the rim will break when the tire is under
high pressure, and this may cause personal injury or death.For safety, when checking tire pressure,
place your body in front of the tread face of the tire. Do not check from the side face of the tire.
• Suitable qualifications are needed for tire inflation work.
Always have the work carried out by properly qualified
personnel.
• The tire inflation pressure on a forklift truck is several
times higher than the pressur e on an automobile. When
the tires are being inflated, there is danger that dir t or
dust may be thrown up by the compressed air and enter
your e yes, so always wear safety glasses.
10-16AX50/BX50 Series
Page 21
GENERAL AND SPECIFICATIONS
HANDLING TIRES
Disassembly and assembly of tires should be carried out by tire dealer.
The tire inflation pressure is extremely high, so caution is needed when handling tires.
• The wheel is fitted with mounting nuts. It also has rim nuts and bolts used to join the rim halves. When
removing the tire from t he li ft tr uck, do no t loos en the r im nuts a nd bol ts. The tir e is u nde r high pressure, and there is a signific ant risk that the rim nuts an d bo lts may fly off. Relief tire infl ati on p re ssur e
before removing.
• When the tires have been replaced, carr y out a test drive and check again for any loose mounting
nuts. If the tightening torque is low, tighten to the specified torque.
JACKING UP LIFT TRUCK (when checking or replacing tires)
• Do not go under the forklift truck when it is jacked up.
• Check the following before jacking up the lift truck.
1) Check that there is no one on the lift truck.
2) Check that there is no load on the forks.
• When jacking up, stop when the tires com e off the
ground surface. Put blocks under both sides of the
frame to prevent the lift truck from coming down.
• Put blocks under any tires contacting th e ground
to prevent the lift truck from moving.
SAFETY ITEMS FOR MAINTENANCE
LIFTING LIFT TRUCK (when checking tires)
• Lift truck slinging wor k should b e carried o ut by a
qualified person who has completed a course in
correct lifting methods.
• Fit wire ropes to the specified lifting points.
• When lifting the lift truck, check that the wire ropes
have ample strength and are not damaged.
• Block the tires contacting the ground to prevent
the lift truck from moving.
• Insert blocks to prevent the truck from coming
down.
• Do not go under the lift truck during the lifting
operation.
• If the specified lifting point is the counterweight,
check that the counterweight mounting bolts are
tightened to the specified torque before carrying
out the lifting operation. check also that there is no
damage to the lifting portion on the counterweight.
AX50/BX50 Series10-17
Page 22
SAFETY ITEMS FOR MAINTENANCE
BATTERY HAZARD PREVENTION
• Battery electrolyte contains sulfuric acid and can quickly burn the skin and eat holes in clothing. If you
spill electrolyte on yourself, immediately flush the area with a large quantity of water.
• Battery ele ctrolyte can cause blindness if splas hed into the eyes. If electrolyte gets into your eyes,
flush them immediately with large quantities of water and consult a doctor at once.
• If you accidentally drink electrolyte, drink a large quantity of water, or milk mixed with beaten eggwhite
or vegetable oil. Call a doctor or poison prevention center immediately.
• When working with batteries, ALWAYS wear safety glasses or goggles.
• Batteries generate hydrogen ga s. Hydrogen gas is highly EXPLOS IVE, and is easily ignited with a
small spark or flame. Do not smoke or create any spark near the battery.
• Before working with batteries, stop the engine and turn the starting switch to the OFF position.
• When removing the batter y, remove the cable from
the negative terminal first. When installing the
battery, install the cable to the positive terminal
first.
• Avoid short–circuiting the batter y terminals through
accidental contac t with tools or other metal o bjects
across the terminals.Tighten the battery terminals
securely. Loose terminals can generate sparks and
lead to an explosion.
• When removing or installing the battery, confirm
which is the p os iti ve ter min al a nd neg ati ve terminal. Be careful not to connect the cables to the
opposite terminals.
• Tighten the battery caps securely.
• When cleaning the battery, leave the battery caps
tightened.
GENERAL AND SPECIFICATIONS
DO NOT PUT METAL OBJECTS ON TOP OF BATTERY
• Never place any metal objects on top of the battery. There is danger that they will cause a short circuit
and start a fire.
10-18AX50/BX50 Series
Page 23
GENERAL AND SPECIFICATIONS
SAFETY ITEMS FOR MAINTENANCE
PRECAUTIONS WHEN CHARGING
When the batter y is charged, hydrogen gas is generated and the battery is heated by the chemical
change. To prevent the danger of gas explosion, always do as follows.
• Carry out the charging operation in a well–ventilated place.
• Do not smoke or allow any flame.
• Start the charging operation when the temperature of the battery electrolyte is below 35
the temperature goes a bove 50°
35°
C (95°F) before starting charging operation again.)
C (122°F) during the ch arging ope ration, wait for it to go down below
°C (95). (If
• When using a battery charger to charge the battery, take the battery caps off.
STARTING WITH BOOSTER CABLES
• ALWAYS wear safety glasses or goggles when starting the lift truck with booster cables.
• When starting using the battery of another lift truck, do not allow the two lift trucks to touch. For details
of the order of operations when using a booster cable.
• Stop the engine before connecting the cables.
• e extremely careful not to let the cables get caught in the fan or fan belt.
• Connect the batteries in paral le l: po si tive to positi ve and negati ve to negative. Never connect positive
to negative.
DO NOT PUSH START
• Do not push the lift truck to start the engine. There is danger that the lift truck may suddenly start and
operate unexpectedly.
HANDLING BRAKE FLUID
It is dangerous if the brakes do not wor k because in this condition, the lift truck ca nnot be stopped.
Always do the following.
• Check the level of the brake fluid periodically.
• Always use the specified brake fluid.
• Check that the breather of the brake fluid reserve tank is not clogged.
• Be careful not to let dirt or dust get into the brake fluid reserve tank.
AX50/BX50 Series10-19
Page 24
SAFETY ITEMS FOR MAINTENANCE
HANDLING ANTIFREEZE
• Antifreeze can be a flammable. Keep away from flame when handling.
• Antifreeze is poisonous, so do not drink it. If you drink i t by mistake, drink large amounts of water,
vomit it out, and get medical attention immediately. Follow safety precautions on container.
WASTE MATERIALS
• Obey appropriate laws and regulations when disposing
of harmful objects such as oil, fuel, solvent, filters, and
batteries.
GENERAL AND SPECIFICATIONS
10-20AX50/BX50 Series
Page 25
GENERAL AND SPECIFICATIONS
STANDARD TIGHTENING TORQUE FOR BOLTS
STANDARD TIGHTENING TORQUE FOR BOLTS
For unspecified bolts and nuts, use the torques specified
in this list.
Select a proper torque corresponding to the width across
flats (b) of bolts and nuts.
When replacing bolts and nuts, always use genuine
Komatsu Forklift parts the same size as the previous
ones.
Width across flats B (mm)223036
Width D (mm)192230
Tightening torqueN m {kgm}29.4–39.2 {3–4}78.5–103 {8–10.5}117.7–161.8 {12–16.5}
Port size (inch)3/4–16UNF7/8–14UNF–
Tightening torqueNm {kgm}68.6–73.6 {7–7.5}78.5–83.3 {8–8.5}–
High–pressure rubber hoses, pipes and sleeve nuts
Width across flats B (mm)1924273236
Bore A (mm)1418222430
Tightening torque Nm {kgm}
19.6–29.4
{2–3}
23.5–68.6
{3–7}
58.8–98.1
{6–10}
108–167
{11–17}
147–206
{15–21}
10-22AX50/BX50 Series
Page 27
20. TESTING AND ADJUSTING
SERVICE DATA.....................................................................................20-2
More than 32.5 for 2-ton trucks,
more than 36 for 2.5 ton trucks,
more than 39.5 for 3-ton trucks
Less than 330 for 2 - 2.5 ton trucks,
less than 550 for 3-ton trucks
18 {185}18 {185}18 {185}
}
FD20H/25H/
30H/35A
147 – 196
{15 – 20}
(*1)
176 – 196
{18 – 20}
FD20N/25N/
30N
147 – 196
{15 – 20}
(*1)
176 – 196
{18 – 20}
Notes
*1: Apply 245 – 294 N (25 – 30 kgf) for FD35A and forklift trucks equipped with power brake.
AX50/BX50 Series
20-9
Page 36
GASOLINE ENGINE
GASOLINE ENGINE
WARNING
Before starting maintenance of the engine, stop the
engine and wait until cooling down completely.
1.CHANGE OF ENGINE OIL
1)Removing the drain plug, drain the oil and
tighten the plug again after draining.
2)Fill the engine oil up to the specified level.
3)Check the engine oil level with the oil level
gauge.
Refill Engine Oil Level
K15 Engine3.8
K21 Engine3.8
K25 Engine3.8
TESTING AND ADJUSTING
2.REPLACEMENT OF ENGINE OIL FILTER
1)Remove the cartridge with the filter wrench.
2)Clean the filter mounting up and apply the
engine oil to the thread as well as the seal of
the new cartridge before installation.
IMPORTANT
After installing the cartridge, start the engine and
check to make sur e that the re is no oi l leakage f rom
the filter mounting surface.
20-10AX50/BX50 Se ries
Page 37
TESTING AND ADJUSTING
3.REPLACEMENT OF FUEL FILTER
1)Loosen the nut to remove the cover and take
the filter out.
2)Clean the dirt at the bottom and drain the
water.
3)Replace with a new filter.
IMPORTANT
•If any damage is found on the gasket of the cover,
replace it with a new one.
•After replacement, check the hose fitting area for no
fuel leakage.
4.INSPECTION OF SPAK PLUG
1)Remove the spark plug with the special plug
wrench.
2)Clean the carbon up stuck on the plug head
and the surroundings.
3)Measure the plug gap A as shown on the il lustration on the right with the plug gap gauge.
Plug gap A: 0.7 to 0.8 mm
Good
No good
No good
GASOLINE ENGINE
Maker and Model Name of Spark Plug
NGKFR24-D, BP4ES, BPR4ES
AX50/BX50 Series
20-11
Page 38
DIESEL ENGINE
DIESEL ENGINE
4D92E, 4D94E and 4D98E ENGINE
TESTING AND ADJUSTING
1.CHANGE OF ENGINE OIL
1)Drain the engine oil removing the drain plug
and tighten it again.
2)Remo ve the oil lev e l gaug e .
3)Refill the engine oil up to the specified level. Be
careful not to let it overflow.
4)Check the oil level with the engine oil level
gauge.
Refill Engine Oil Level
4D92E Engine7.5
4D94LE Engine7.5
4D98E Engine7.5
2.REPLACEMENT OF ENGINE OIL FILTER
1)Remove the cartridge with the filter wrench.
2)Clean the filter mounting and apply the engine
oil on the thread as well as the seal of the new
cartridge before installation.
After installation of the cartridge, start the engine
and check the f i lte r -m oun t i ng s urface for n o oi l le a kage.
20-12AX50/BX50 Se ries
Page 39
TESTING AND ADJUSTING
3.DRAINING OF WATER FROM FUEL FILTER
1)Loosen the combination sensor plug (1) and
drain the water as well as sediment accumulated at the bottom.
IMPORTANT
•Prepare a container to catch the drained water
possibly mixed with the fuel.
•Always make sure to wipe up spilled fuel if any.
4.REPLACEMENT OF FUEL FILTER
1)Remove the combination sensor plug (4) at the
bottom of the cartridge.
2)Remove the cartridge (3) with the filter wrench.
3)Install the combination sensor plug to the new
cartridge (3).
4)Fill the new cartridge with the fuel and apply
the thin layer of engine oil before installation.
5)Loosen the plug (2) and pump the knob (1) up
and down until no mor e bubbles com e ou t wi th
the fuel.
6)Tighten the plug (2).
DIESEL ENGINE
As for draining the water from the fuel filter and
bleeding the air af ter replacement of the cartridge,
the fuel may come out mixed with draining water
and bleeding air. Always make sure to prepare the
container for receiving those matters and wipe up
spilled fuel if any, because it may be in danger to
cause fire if fuel sticks here and there.
AX50/BX50 Series
20-13
Page 40
AIR CLEANER
AIR CLEANER (1.0 – 1.75 TON)
WARNING
• Neither cleaning of the air cleaner nor replacement
of the element is allowed while the engine is in
motion.
• Always put the safety glasses on to protect your
eyes when using the compressed air for cleaning
the element upÅD
IMPORTANT
•If any grease or carbon is found stuck on the element, clean it up with a special cleaner according
to the instruction for the air cleaner.
•In case of sever working conditions or environments, clean or replace the element earlier than
regular maintenance.
TESTING AND ADJUSTING
Element
[Single Element Type]
CLEANING OF ELEMENT
1.Remove the element and blow the dry compressed
air ( 0.69 MPa {7 kgf/cm
the element for cleaning the whole element.
2.Put the cleaned element back to the air cleaner.
2
}) from inside to outside of
INSPECTION
Visually check the element for damage.
REPLACEMENT OF ELEMENT
1.Remove the element from the air cleaner.
2.Cover the air connector with clean cloth or tape.
3.Clean the interior of the air cleaner and remove the
cover from the air cleaner.
4.Put a new element into the air cleaner.
20-14AX50/BX50 Se ries
Page 41
TESTING AND ADJUSTING
AIR CLEANER (2 TON)
WARNING
• Neither cleaning of the air cleaner nor replacement
of the element is allowed while the engine is in
motion.
• Always put the safety glasses on to protect your
eyes when using the compressed air for cleaning
the element up.
IMPORTANT
•If any grease or carbon is found stuck on the element, clean it up with a special cleaner according
to the instruction for the air cleaner.
•Never remove the inner element.
[FD20 (H) – FD30 (H)]
•In case of sever working conditions or environments, clean or replace the element earlier than
regular maintenance.
AIR CLEANER
Element
[Single Element Type]
Element
CLEANING OF ELEMENT
1.Remove the element and blow the dry compressed
air ( 0.69 MPa {7 kgf/cm
the element for cleaning the whole element.
2.Put the cleaned element back to the air cleaner.
2
}) from inside to outside of
INSPECTION
Visually check the element for damage.
REPLACEMENT OF ELEMENT
1.Remove the element from the air cleaner.
2.Remove the inner element.
3.Cover the air connector with clean cloth or tape.
4.Clean the interior of the air cleaner and remove the
cover from the air cleaner.
5.Put a new element into the air cleaner.
Inner Element
[Double Element Type]
AX50/BX50 Series
20-15
Page 42
ADJUSTMENT OF IGNITION TIMING
ADJUSTMENT OF IGNITION TIMING
GASOLINE ENGINE
1.Connect the timing advance tester (1) as shown in
the diagram on the right.
2.Turn the power switch on and adjust the timing position of the advance adjustment knob (2).
3.Start the engine and run at the specified idling
speed.
4.Glow the timing light ( 3) an d chec k to mak e sure th at
the indicator and the timing mark stamped on the
crankshaft pulley and flywheel are correctly aligned.
5.If the timing is wrong, turn the distributor (4) to the
right or the left for further adjustment.
TESTING AND ADJUSTING
6.Check that ignition timing advances quickly when
the engine is revved up.
20-16AX50/BX50 Se ries
Page 43
TESTING AND ADJUSTING
ADJUSTMENT OF FUEL INJECTION TIMING
ADJUSTMENT OF FUEL INJECTION TIMING
DIESEL ENGINE (4D92E, 4D94LE and 4D98E)
INSPECTION AND ADJUSTMENT OF FUEL
INJECTION TIMING MARK
WHEN DISASSEMBLING AND ASSEMBLING
1.Match the injection pump with the A mark.
2.Match the top mark B with the ATDC 5 degrees.
3.Make sure that the plunger lift is in 1 mm.
4.If the plunger lift is not in 1 mm, adjust the angle of
the injection pump mounting.
INSPECTION
Implement the above mentioned items 2, 3 and 4 for
inspection.
AX50/BX50 Series
20-17
Page 44
MEASUREMENT OF COMPRESSION
MEASUREMENT OF COMPRESSION
TESTING AND ADJUSTING
1.Warm up the engine to get the coolant temperature
at 75 – 85 °C.
2.Stop the engine and remove all the spark plugs on
gasoline engines or the nozzle holders on diesel
engines as well as the air cleaner.
3.Disconnect the coil cord from the ignition coil on the
gasoline engine. Set the fuel control lever to the
non-injection position or disconnect the wiring of the
fuel cut solenoid on diesel engines.
4.Fix the adaptor to the nozzle holder mounting of the
cylinder that is to be checked and tighten to the
specified torque on diesel engines.
5.Install the compression gauge to the cylinder to be
checked.
6.For pneumatic governor, floor the accelerator pedal
and crank the engine with the starter motor to get
the maximum reading of the gauge.
Take a measurement more than twice on each
engine to avoid measurement errors and average the values.
Discharge battery may not give sufficient revolutions. Use fully charged battery.
Gasoline Engine
Diesel Engine
CAUSES FOR INSUFFICIENT COMPRESSION
1.Poor adjustment of valve clearance
2.Pressure leakage from valve seat
3.Seize of valve stems
4.Defective or broken valve spring
5.Pressure leakage from cylinder head gasket
6.Sticking or breakage of piston rings
7.Wear of piston rings or cylinders
20-18AX50/BX50 Se ries
Page 45
TESTING AND ADJUSTING
ADJUSTMENT OF VA LVE CLEARANCE
1.Remove the cylinder head cover.
2.Tur n the crankshaft to match the top mark A of the
crank pulley (1) and the pointer (2). Check to make
sure that the compression upper dead center is
attained with the No.1 cylinder and the No.4 cylinder.
Upper dead center of the piston can be
checked under the state that both of intake and
exhaust valves are closed, which means the
cylinder that both the locker arms are being in
free state is at the compression upper dead
center.
ADJUSTMENT OF VALVE CLEARANCE
3.Adjust the clearance beginning with the cylinder at
the compression upper dead center.
When the No.1 cylinder is at the compression
top dead center, adjust the valves marked with
for clearance listed on the table and give a
turn to the crankshaft in the positive direction.
Then, adjus t the re maini ng valves mar ked wit h
for clearance.
When the No.4 cylinder is at the compression
top dead center, adjust the valves marked with
for clearance and give a turn to the crankshaft in the positive direction. Then, adjust the
remaining valves marked with for clearance.
4.Loosen the lockn ut (3) of t he adju sting s cre w (4) and
insert the specified thickness gauge between the
val ve ste m (6) and the locker arm (5) to allow the
gauge to move smoothly and adjust the gap. Then,
tighten the locknut to fix the adjustment screw.
Engine with ignition sequence of 1-2-4-3
1Cylinder No.234
Exhaust
valve
Intake
valve
Engine with ignition sequence of 1-3-4-2
1Cylinder No.234
Exhaust
valve
Intake
valve
AX50/BX50 Series
20-19
Page 46
TIGHTENING TORQUE OF CYLINDER HEAD MOUNTING BOLTS
TESTING AND ADJUSTING
TIGHTENING TORQUE OF CYLINDER HEAD MOUNTING BOLT S
K15/K21/K25 ENGINE
1.Put the steel plate side of the cylinder head gasket
on the cylinder block side. Then, set it on top of the
cylinder block.
2.Set the cylinder head in position, apply the engine
oil to the cylinder bolts. Then, tighten in the order
shown in the diagram on the right ( through ) to
the specified tightening torq ue as follows:
Cylinder Head Bolt:
1)29.4 Nm {3.0 kgm}
2)78.5 Nm {8.0 kgm}
3)0 Nm {0 kgm} Loosen
4)29.4 Nm {3.0 kgm}
5)73.5 – 83.4 Nm {7.5 – 8.5 kgm}
Tighten temporarily
Tighten
again
4D92E, 4D94LE and 4D98E ENGINE
1.Apply the engine oil to the cylinder head mounting
bolts coating evenly by hand.
2.Tighten twice in the order i n the dia g ram on the right
( through ) as follows:
Cylinder Head Bolt:
Fist Time:58.8 Nm {6 kgm}
Second Time:117.6 Nm {12 kgm}
20-20AX50/BX50 Se ries
Page 47
TESTING AND ADJUSTING
REPLACEMENT OF CLUTCH DISC
REMOVAL OF CLUTCH DISC
1.Open the clutch case cover.
2.Fix the pressure plate with the pressure plate
mounting bolt.
Fixing Bolt:
Part Name01010-51065
SizeM10
Pitch × Length1.5 × 65
3.Slide the snap ring (1) and remove the pin (2).
REPLACEMENT OF CLUTCH DISC
2
4.Push the shaft toward the transmission.
5.Remove the pressure plate mounting bolt (3) and
slide the pressure plate. Then, remove the clutch
disc.
Be careful not to damage the spring when sliding the pressure plate.
1
P
P
AX50/BX50 Series
20-21
Page 48
REPLACEMENT OF CLUTCH DISC
INSTALLATION OF CLUTCH DISC
1.Install the clutch disc.
Put the flat side of the clutch disc to face
toward the flywheel when assembling.
Apply the thin layer of grease paste to the
spline (a).
TESTING AND ADJUSTING
Flywheel side
a
Q
Q
2.Return the shaft to the flywheel side and push it into
the flywheel through the spline of the clutch disc.
3.Tighten the pressure plate fixing-bolt (3).
27 – 34 Nm {2.8 – 3.5 kgm}
4.Fix the pin (2) with the snap ring.
If any damage is found at the snap ring,
replace it with a new one.
5.Remove the pressure plate fixing-bolt.
6.Install the clutch case cover.
3
2
1
20-22AX50/BX50 Se ries
Page 49
TESTING AND ADJUSTING
TORQFLOW TRANSMISSION CASE
WARNING
The temperature of the oil is very high immediately
after stop operation of the truck. Be sure to start
inspection after cooling down completely
INSPECTION OF OIL LEVEL
1.Open the floor plate to check the oil level with the oil
lev el gau ge.
2.Refill the oil if necessary.
TORQFLOW TRANSMISSION CASE
Air breather
for transmission
Oil level gauge
Line filter
REPLACEMENR OF OIL, INSPECTION AND
CLEANING OF STRAINER
1.Remove the drain plug to drain the oil. Tighten the
drain plug af ter draining.
2.Remove the m ounti ng bolt to tak e ou t the st rain er f or
cleaning with flushing oil .
3.After cleaning, blow dry compressed air from inside
to outside of the s train er and i nst all when comp let ely
dry.
If any damage or clogs is found on the strainer,
replace it with a new one.
4.Refill the oil as specified.
5.Check the oil level after refilling.
Replacement Oil Level:
First Speed
(F1/R1) Model
IMPORTANT
Be sure to always use the Komatsu genuine oil
"FED10-CD" for the engine oil.
9.5 liters including torque
converter
REPLACEMENT OF LINE FILTER
1.Turn the line filter counterclockwise for removal.
2.Install a new line filter. When installing, check to
make sure that the seal of the line filter touched the
case fitting face and then tighten it by another threequarter turning.
Air breather for transmission
Strainer
Drain plug
Air breather
for differential
AX50/BX50 Series
20-23
Page 50
DIFFERENTIAL CASE
DIFFERENTIAL CASE
WARNING
The temperature of the oil is very high immediately
after stop operation of the truck. Be sure to start
inspection after it is cooled down completely
INSPECTION OF OIL LEVEL
1.Remove the oil level check plug to check that the oil
is nearly up to the lower level of the plug-hole. Refill
the oil, if necessary.
TESTING AND ADJUSTING
REPLACEMENR OF OIL
1.Remove the oil filler plug and drain the oil through
the drain plug.
2.After draining, tighten the drain plug and refill the oil
as specified.
3.Check the oil level after refilling.
Replacem ent Oil Level:
1.0 – 1.75
ton
2.0 – 3.0
ton
IMPORTANT
Be sure to always use the Komatsu genuine oil
"FG090" for the gear oil.
IMPORTANT
The same oil is being used at the differential case and
the transmission case for the clutch model, while the
specifications of the oil being used at those devices
differs for the TORQFLOW type.
Therefore, the TORQFLOW type requires inspection and
replacement of the TORQFLOW transmission case in
addition to those of the differential case.
10 liters for clutch model and 6 liters
for the TORQFLOW type.
12.5 liters for clutch model and 7
liters for the TORQFLOW type.
Oil level check and
Drain plug
oil filling combination plug
20-24AX50/BX50 Se ries
Page 51
TESTING AND ADJUSTING
HYDRAULIC TANK
HYDRAULIC TANK
REPLACEMENT OF HYDRALIC OIL
REPLACEMENT OF LINE FILTER
CLEANING OF STRAINER
CLEANING OF INSIDE HYDRAULIC TANK
WARNING
The temperature of the oil is very high immediately
after stop operation of the truck. Be sure to start
inspection after cooling down completely.
1.Remove the drain plug located at the bottom of the
hydraulic tank for draining. Then, uncover the
hydraulic tank and remove the strainer. Clean the
strainer up with flushing oil.
2.After cleaning inside hydraulic tank, install the drain
plug.
3.After cleaning the strainer, blow dry compressed air
from inside to outside of the strainer until it is completely dry.
Breather
Cover
Strainer
Line filter
Drain plug
4.Remove the line filter and replace it with a new one.
Then, install the tank cover.
5.Refill the hydraulic oil through the breather hole.
Check the oil level with the oil level gauge.
Replacement Oil Level:
1.0 –
1.75 ton
2.0 – 3.0
ton
6.Start the engine and operate the mast with lifting
and tilting until stroke-end for several times so as to
bleed the air.
IMPORTANT
Always be sure t o use the Komatsu genui ne hydraulic oil.
52 for the standard models and
34 for the compact models.
34
AX50/BX50 Series
20-25
Page 52
h
MEASUREMENT OF HYDRAULIC DRIFT OF LIFT AND TILT CYLINDERS
TESTING AND ADJUSTING
MEASUREMENT OF HYDRAULIC DRIFT OF LIFT AND TILT CYLINDERS
PRECAUTIONS
1.Never allow anyone to stand or pass under the raised forks or the load.
2.Keep your hands and legs away form the lifting mechanism including the mast stay or the dashboard area, which will
keep your hands and legs safe from harm or injury caught in the mast. Always prepare a ladder or a stand that is
strong enough to use for your inspection.
3.Check to make sure that the hydraulic oil level is normal, not dirty and not mixed with any other kind of oil.
4.Park the truck on an even surface. The me as urem en t m u st be carried out in front of a l oad ing pl atform strong enough
to support the truck even if it should tip over to the front.
METHOD OF MEASUREMENT
1.Hold the forklift truck at 500 mm in front of the plat-
form.
2.Repeat lifting and tilting to set the hydraulic oil temperature to 50 °C.
1: Keep mast uprig
3.Set the rated load on the forks and secure it to the
fork ca r riage with wire.
4.Lift the forks about 1, 500 mm and keep the mast
upright.
[Hydraulic Drift of Lift Cylinder]
5.Wait for 3 minutes and place a ruler against the pis-
ton rod of the lift cylinder. Then, make a mark "A" on
it.
6.Measure the hydraulic drift over the next 15 minutes.
Hydraulic
Drift of Lift
Cylinder For
15 Minutes
[Hydraulic Drift of Tilt Cylinder]
7.Wait for 3 minutes and place a ruler against the pis-
ton rod of the tilt cylinder. Then, make a mark "B" on
it.
8.Measure the hydraulic drift over the next 15 minutes
Hydraulic Drift of Tilt
Cylinder For 15 Minutes
1.0 – 1.75 ton: within 75 mm
2.0 – 3.0 ton: within 50 mm
within 45 mm
H
Approx.
1,500 mm
A
Ruler
B
Ruler
2: Lift cylinder
3: Tilt cylinder
20-26AX50/BX50 Se ries
Page 53
TESTING AND ADJUSTING
ADJUSTMENT OF CLUTCH AND BRAKE PEDAL
ADJUSTMENT OF CLUTCH AND BRAKE PEDAL (CLUTCH MODEL)
Stop lamp switch
2
c
Clutch pedal
Brake pedal
153 mm
1.PROCEDURE FOR ADJUSTMENT OF CLUTCH AND BRAKE PEDAL (CLUTCH MODEL)
1)Brake pedal stroke
1 – 1.8 ton51 ±10 mm
2 – 3 ton65 ±10 mm
If the brake pedal stroke is more than the standard, check the brake shoe for wear.
2)Adjust the height of the brake pedal with the stopper bolt (1) to make it approximately 137 mm from the floor
plate.
3)Adjust the height of the clutch pedal with the stopper bolt (2) to make it approximately 153 mm from the floor
plate.
1
137 mm
2.PROCEDURE FOR ADJUSTMENT OF STOP LAMP SWITCH
Set the measurement "C" at the range of 0.5 mm through 1.5 mm after adjustment of the brake pedal height.
AX50/BX50 Series
20-27
Page 54
ADJUSTMENT OF INCHING AND BRAKE PEDAL
TESTING AND ADJUSTING
ADJUSTMENT OF INCHING AND BRAKE PEDAL (TORQFLOW MODEL)
Stop lamp switch
2
3
c
159 mm
1
Inching pedal
Brake pedal
137 mm
1.PROCEDURE FOR ADJUSTMENT OF INCHING AND BRAKE PEDAL (TORQFLOWMODEL)
1)Brake pedal stroke
1 – 1.8 ton51 ±10 mm
2 – 3 ton65 ±10 mm
If the brake pedal stroke is more than the standard, check the brake shoe for wear.
2)Adjust the height of the brake pedal with the stopper bolt (1) to make it approximately 137 mm from the floor
plate.
3)Adjust the height of the inching pedal with the stopper bolt (2) to make it approximately 159 mm from the floor
plate.
4) Adjust the bolt (3) so that it can gear with the brake pedal with the inching pedal stroke in the range of 55 mm
through 61 mm accordingly.
2.PROCEDURE FOR ADJUSTNENT OF STOP LAMP AWITCH
Set the measurement "C" in the range of 0.5 mm through 1.5 mm after adjustment of the brake pedal height.
20-28AX50/BX50 Se ries
Page 55
TESTING AND ADJUSTING
ADJUSTMENT OF ACCELERATOR PEDAL
K15/K21/K25 ENGINE MODEL
ADJUSTMENT OF ACCELERATOR PEDAL
1
PROCEDURE FOR ADJUSTMENT OF ACCELERATOR
PEDAL
1.Set the stopper bolt (1) tempor arily with the heig ht of
65 mm.
2.After assembling the cable, adjust the outer casing
mount of the ca ble to allow the pedal play of 2 to 3
mm.
3.Adjust the height of stopper bolt (1) again to allow
the engine full throttle when flooring the accelerator
pedal.
AX50/BX50 Series
20-29
Page 56
ADJUSTMENT OF ACCELERATOR PEDAL
4D92E/4D94LE/4D98E ENGINE MODEL
1
TESTING AND ADJUSTING
PROCEDURE FOR ADJUSTMENT OF ACCELERATOR
PEDAL
1.Set the stopper bolt (1) tem pora rily with the height of
65 mm.
2.After asse mbling the cable, ad just the outer c asing
mount of the cable to al lo w the ped al pla y betwee n 2
to 3 mm.
3.Adjust the height of stopper bolt (1) again to allow
the engine full throttle when flooring the accelerator
pedal.
20-30AX50/BX50 Se ries
Page 57
TESTING AND ADJUSTING
ADJUSTMENT OF PARKING BRAKE LEVER
ADJUSTMENT OF PARKING BRAKE LEVER
Before starting adjustment, check to make sure
that all of both front and rear wheels of the forklift
truck has locked with stoppers respectively
1.Release the parking brake by pushing the parking
brake lever (2) forward to the release position (B)
while pressing the push button (1).
2.Turn the adjustment bolt (3) and adjust the lever
control force at the initial extension of the cable to be
set as follows:
•For standard brake147 – 196N {15 – 20 kgf}
•For power brake: 245 – 294N {25 – 30 kgf}
B
3
1
A
2
AX50/BX50 Series
20-31
Page 58
WHEEL BRAKE
WHEEL BRAKE
PROCEDURE FOR ADJUSTMENT OF BRAKE SHOE
CLEARANCE
1.Release the parking brake while floating the wheels
up above the grou nd.
2.Remove the rubber cap.
3.Tur n the gear (1) in the direction (A) or toward the
brake shoes repeatedly with a screwdriver until the
brake shoes should touch the brake drum. Turning
of every notch makes sound of clicks.
IMPORTANT:
Turn the wheels by hands to feel braking a little bit.
4.Prepare two screwdrivers. The first screwdriver
should be used for mildly pushing the lever (2) and
have it miss each gear notch. Be careful not to push
strongly. The second one should be used for turning
the gear (1) toward the direction (B) counting by
twenty-one (21) notches while the fist one is still on
duty. It counts 30 notches for one turning of the
gear.
IMPORTANT:
Since no clicks are made available here, count the
number of notches watching through the hole of the
rubber c ap (3) for carrying out the adjustment.
TESTING AND ADJUSTING
5.Install the rubber cap (3).
6.Tur n the wheels by hands and check to make sure
that there is no brake dragging.
IMPORTANT:
The clearance between the brake shoe and brake
drum can be adjusted approximately to 0.55 mm
(clearance of diameter) with this adjustment.
20-32AX50/BX50 Se ries
Page 59
TESTING AND ADJUSTING
BLEEDING AIR
BRAKE PIPING
WARNING
• Before starting bleeding air, adjust the brake shoe
clearance to the specified 0.40 to 0.56 mm (diameter of the space).
• From time to time, refill the brake fluid to prevent
the brake fluid in the reserve tank from empty for
carrying out air bleeding. You should carry out the
inspection again just from the beginning because
air could be mixed in once the tank becomes
empty.
1.Remove the cap from the air bleed plug (1) of the
brake wheel cylinder. Install one end of a plastic
hose for air bleedin g to the plug and put t he othe r
end of the hose in a container of the brake fluid.
The color of the plastic hose should be transparent as much as possible.
BLEEDING AIR
2.If inspector is only one, connect a string or a wire to
the upper arm of brake pedal (2) and let the other
end of string or wire loose free in approximately
300 mm through the space between the frame (3)
and the dashboard (4).
3.Slowly pull out the string or the wire connected
with the brake pedal (2) arm from the front of the
forklift so as to compress the air inside the brake
piping and hold it as is.
If inspector is more than two, one inspector
should press the brak e pedal .
4.Loosen the air bleed plug (1) of the brake wheel cyl-
inder approxim ate ly 3/4 turns to the left and depre ss
the brake pedal to bleed the air in the piping along
with the brake fluid. Then, tighten the bleed plug (1)
while bleeding the brake fluid.
In this stage, keep pulling the string or the wire
for a whil e.
2
2
5.After tightening the bleed plug, release the brake
pedal.
AX50/BX50 Series
20-33
Page 60
BLEEDING AIR
6.Repeat the step 3, 4, and 5 of the above until no
more bubbles come out from the hose.
7.After completing one side of brak e adjus tment, carry
out the other side of adjustment with the same
steps.
8.Then, repeat the air b le edi ng o f the brake and check
again to make sure that no more air left in the brake
piping.
9.Depress the brake pedal to check it for normal
response. Then, depress the brake pedal with
depressing force of 196 N or 20 kgf to measure the
pedal stroke (a). Check to make sure that the pedal
stroke (a) is within 55 mm to 75 mm when depressing the pedal.
Pedal Stroke:
TESTING AND ADJUSTING
b
a
Pedal stroke (a)
when depressed
Play:
Play (b)0 – 4 mm
10. Remove the hose from the air bleed plug (1).
Tighten again the both side of the air bleed plug and
install the cap.
Air bleed plug: 5 .9 – 8.8 Nm {0.6 – 0.9 kg m}
11. Refill the brake fluid up to the MAX line (C) on the
reserve tank (5) of upper master cylinder, which
shows the specifie d flui d level.
12. Remove the string or the wire connected with the
brake pedal arm.
1 – 1.8 ton41 – 61 mm
2 – 3 ton55 – 75 mm
20-34AX50/BX50 Se ries
Page 61
TESTING AND ADJUSTING
CLUTCH PIPING
1.Remove the cap from the air bleed plug. Then, fit
one end of the plastic hose to the plug and put the
other end of the hose in a container of the brake
fluid.
2.Loosen the air bleed plug approximately 3/4 turns
and depress the brake pedal.
3.Tighten the air bleed plug. Then, release the brake
pedal.
BLEEDING AIR
Release cylinderAir bleed plug
4.Repeat the step 2 an d 3 u nti l n o m ore bubbles come
out from the hose.
5.When all the air has been completely removed,
tighten the plug and install the cap.
LIFT CYLINDER
1.Start the engine and run it at low idling.
2.Lift up and down the mast.
Try to stop lifting at about 100 mm before
reaching to the maximum lifting and lowering
height.
3.Repeat the step 2 of the above four to five times.
4.Lift up and down the mast to the maximum lifting
and lowering height .
5.Repeat the step 4 of the above four to five times.
FUEL PIPING (Diesel Engine Forklift Truck)
1.Loosen th e plug (1) and move the knob (2) up and
down until no more bubbles come out with the fluid.
Clutch lever
2.Tighten the plug (1) after completely bleeding the
air.
Standard Type1,1311,4801,8752,272
Compact Type1,1701,5571,900–
663773969
Lift25
Tilt12
Power Steering16
3233
120
6290
27
AX50/BX50 Series
30-5
Page 72
MAST
MAST
REMOVAL
1.Put blocks under the front and the rear wheels
2.Lift the fork carriage with the crane to remove the
hydraulic piping.
3.Rem ove the forks.
4.Put blocks under the fork carriage.
5.Operate the work equipment control levers several
times to release remaining pressure in the hydraulic
piping. Then, the remove the piping.
After removing the piping, fit the blind plug
immediately to prevent the hydraulic oil from
flowing out and to prevent dirt or dust from getting in.
REMOVAL AND INSTALLATION
6.Lift up the fork carriage slightly with the crane and
remove the blocks.
7.Lift down the fork carriage.
8.Fit the crane to the mast.
9.Remove the tilt pin.
10. Tilt the mast forward slightly and remove the differ-
ential mounting cap bolt.
WARNING:
If the mast is kept being tilted backward, you are in
danger that the mast may fall over.
11. Remove the mast.
WARNING:
When carrying the removed mast horizontally,
secure the lower stay and the fork carriage by the
annealing wire with twisted (A).
Put blocks under the bottom of the mast and lay
the mast assembly horizontally so that the fork
carriage is at the top.
Carry out installation in the reverse orde r to removal.
30-6AX50/BX50 Series
Page 73
REMOVAL AND INSTALLATION
LIFT CYLINDER
REMOVAL
1.Upright the mast.
2.Remove the stopper bolt.
LIFT CYLINDER
3.Hoist the mast by the crane.
4.Put blocks unde r the inner mast.
5.Remove the cylinder clamp.
6.Operate the work equipment control levers several
times to release remaining pressure in the hydraulic
piping. Then, the remove piping.
After removing the piping, fit the blind plug
immediately to prevent the hydraulic oil from
flowing out and to prevent dirt or dust from getting in.
7.Crane the cylinder with sling belt to remove it.
INST ALLATION
1.Lift the mast up to the maximum lifting heigh t .
2.Check the mast for the play on both side.
3.Adjust the shims so that the both side of the cylin-
ders are synchronized with each other at the maximum lifting height.
Stopper bolt
Lift Cylinder
29.4 – 49 Nm
{3 – 5 kgm}
Inner
mast
Angled to leftInsert shims into the left cylinder
Angled to right Insert shims into the right cylinder
AX50/BX50 Series
Shim
Cylinder
rod
Outer
mast
30-7
Page 74
ENGINE
ENGINE
REMOVAL
1.Overhead Guard (Ceiling)
Engine Hood
Counterweight
Check to make sure that the mast including forks
and attachment must be lowered or lift down to
the ground or removed from the mast.
2.Wiring and Battery
The figure below shows a gasoline model.
REMOVAL AND INSTALLATION
Sheet Switch Wiring Harness
Starter B Terminal
Starter S Terminal
Fuse Box
Controller
Engine Wiring Harness
30-8AX50/BX50 Series
Page 75
REMOVAL AND INSTALLATION
3.Accelerator Wire
Remove the accelerator wire.
4.Piping and Hoses
Hydraulic Pump Piping, Torque Converter Piping, Radiator Hose, Air Cleaner Hose, Fuel Hose
•Diesel Engine Forklift Truck (TORQFLOW type equipped with 4D94LE)
ENGINE
•Gasoline Engine Forklift Truck (TORQFLOW type equipped with K15, K21 and K25)
AX50/BX50 Series
30-9
Page 76
ENGINE
5.Radiator, Shrou d and Exh aus t Pipe
4D92E, 4D94LE, 4D98EK15, K21, K25
REMOVAL AND INSTALLATION
6.Engine
1)Place a wooden block under the transmission
case.
2)Crane the engine and hold it.
3)For clutch type trucks, remove the bolts mount-
ing the clutch case.
For TORQFLOW type trucks, remove the bolts
mounting the torque converter case.
Clutch Type Forklift Truck
TORQFLOW Type Forklift Truck
4)Remove the left and right hand bolts mounting
the engine.
30-10AX50/BX50 Series
Page 77
REMOVAL AND INSTALLATION
INST ALLATION
1.Installation of Engine
1)Loosen the bolts mounting the engine located
at the transmission side
2)Mount the engine slowly to put it on the center
of the truck frame.
ENGINE
3)Check that the ga p A between fan and shroud
is even.
4)For torque converter models, remove the inching valv e and c heck the parallelis m w ith a level.
For clutch mo de ls, remov e the ba ck buzzer and
neutral switch, and then check the parallelism
of the surfaces with a level.
AA
AX50/BX50 Series
30-11
Page 78
ENGINE
2.Tightening Clutch Case Mounting Bolt (Clutch
Type)
Tightening Torque Converter Case Mounting Bolt
(TORQFLOW Type)
59 – 74 Nm {6 – 7.5 kgm}
Note: The illustration on the right is for clutch type.
3.Tightening Torque for Engine Mount Bolt at
Transmission Side
157 – 196 Nm {16 – 20 kgm}
REMOVAL AND INSTALLATION
Mounting bolt
4.Alignment of Power Train
See 30-00: Alignment of Power Train
5.Tightening Hydraulic Piping
See 10-22 STANDARD TIGHTENING TORQUE FOR PIPE JOINTS
6.Installation of Accelerator Wiring
See 20-29 ADJUSTMENT OF ACCELERATOR
PEDAL
7.Tightening Counterweight Mounting Bolts
441 – 639 Nm {45 – 65 kgm}
30-12AX50/BX50 Series
Page 79
REMOVAL AND INSTALLATION
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
CLUTCH AND TORQUE CONVER TER, TRANSMISSION AND DRIVE AXLE
When dismantling such devices as the clutch, the
toque converter, the tr a ns mi ssion a nd the drive axle,
remove the counterweight first to prevent the truck
from ove rturn. Then hoist the t ruc k frame in the front
with the crane
Check to make sure that the mast including forks
and attachment must be lowered or lift down to
the ground or removed from the mast.
2.Mast
See 30-6: Mast
AX50/BX50 Series
30-13
Page 80
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
5.Inching Cable (TORQFLOW type)
6.Pedal Assembly
AX50/BX50 Series
30-15
Page 82
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
7.Forward/Reverse Control Lever, High/Low Speed
Control Lever (Clutch Type)
High/Low Speed Cable
Forward/Reverse Cable
8.Torque Converter Cooler Piping
REMOVAL AND INSTALLATION
9.Piping
30-16AX50/BX50 Series
Page 83
REMOVAL AND INSTALLATION
10. Wiring
The figure below shows a gasoline model
Starter S Terminal
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
Sheet Switch Wiring Harness
Starter B Terminal
Controller
Fuse Box
Engine Wiring Harness
AX50/BX50 Series
30-17
Page 84
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
11. Drive Axle
1)Place blocks under the bottom of the truck
frame to keep the frame about 10 mm above
the ground.
2)Place a carriage as shown in the illustration on
the right to support the front axle.
3)Mark (A) (B) and (C) to match the differential
and the front axle both on the left and the right.
REMOVAL AND INSTALLATION
A
BC
C
30-18AX50/BX50 Series
Page 85
REMOVAL AND INSTALLATION
4)Remove the bolts mounting the propeller shaft
and remove the propeller shaft.
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
5)Remove the support for the front axle from the
frame and pull out the front axle placing on the
carriage.
AX50/BX50 Series
30-19
Page 86
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
12. Clutch, Torque Converter, Transmission and
Drive Axle
1)Hoist the engine with a crane and hold it.
2)Place a carriage as shown in the illustration on
the right and support two unit assemblies.
3)Remove the bolts mounting the clutch case.
(Clutch Type)
Remove the bolts mounting the torque converter case. (TORQFLOW Type)
4)Remove the bolts mounting the engine at the
transmission side and pull out the two unit
assemblies placing on the carriage.
REMOVAL AND INSTALLATION
30-20AX50/BX50 Series
Page 87
REMOVAL AND INSTALLATION
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
INST ALLATION
Apply the reverse order for removal. Pay attention on the
followings:
1.Tightening Torque for Clutch Case Mounting
Bolt (Clutch Type)
Tightening Torque for Torque Converter Case
Mounting Bolt (TORQFLOW Type)
Tightening Torque for Mounting Bolt:
59 – 74 Nm {6 – 7.5 kgm}
2.Tightening Torque for Engine Mounting Bolt
(Transmission side)
Tightening Torque for Mounting Bolt:
157 – 196 Nm {016 – 20 kg m}
Mounting bolt
Check the engine for placing on the center of
engine mounting both left and right at the
engine side properly. Then, tighten the bolt
mounting the engine at the transmission side.
AX50/BX50 Series
30-21
Page 88
CLUTCH AND TORQUE CONVERTER, TRANSMISSION AND DRIVE AXLE
3.Drive Axle
1)Install the dr ive axle following to th e matching
marks on the equipment marked at the time of
removal.
2)Remove the level plug, and check levelness
with a dedicated tool and a level
Tightening Torque for Front Axle Support Bolts
343 – 427 Nm {35 – 43.5 kgm}
Alignment of Power Train: See 30-28
If no matching marks can be found, tighten
temporarily the fro nt fix bo lts wit h the front axle.
Then tighten the two mounting bolts on the
support side and check the remaining two bolts
for the correct positioning toward the center
accordingly.
REMOVAL AND INSTALLATION
4.Propeller Shaft
Tightening Torque for Propeller Shaft Mounting
Bolts
32.4 – 38.2 Nm {3.3 – 3.6 kgm}
5.Pedal Assembly
Brake Piping
Bleeding Air: See 20-35
Adjustment of Pedal: See 20-26
6.Counterweight
Tightening Torque for Counterweight Mounting
Bolts
441 – 639 Nm {45 – 65 kgm}
7.Mast
Tightening Torque for Mast Cap Mounting Bolts
1.0 – 1.75 ton
2.5 ton
2.5 ton (Compact Type)
3.0 ton
3.5 ton
157 – 196 Nm
{16 – 20 kgm}
245 – 309 Nm
{25 – 31.5 kgm}
343 – 427 Nm
{35 – 43.5 kgm}
490 – 608 Nm
{50 – 62 kgm}
30-22AX50/BX50 Series
Page 89
REMOVAL AND INSTALLATION
ALIGNMENT OF POWER TRAIN
ALIGNMENT OF POWER TRAIN
When removing th e po w er trai n (f ront ax le or Transmission/ engine ), alw a y s be sure to tak e an alignm ent be tw een the
front axle and the transmission.
Measurement of Alignment
1.Prepare the tools as shown bellows.
(a) Special tool for remove/install back lamp/Neutral switch for manual transmission.
(b) Block for Water level meter for manual transmission
(c) L-Type block for Axle
(d) Electric Water level Meter
(a) Special tool for Neutral/back lamp switch
(c) L-Type block for Axle
(b) Block for Water level meter
(d) Electric Water Level Meter
AX50/BX50 Series
30-23
Page 90
ALIGNMENT OF POWER TRAIN
2.Remove Oil Level Plug from Front Axle and install
the L type block by Plug.
Then put Electric water level meter and measure
leaning angle of fron t axle.
3.Measure leaning angle of Engine/Transmission.
•Manual Transmission
Remove the Neutral switch/ Back lamp switch
from transmission.
•Automatic Transmission
Remove transmission control valve.
REMOVAL AND INSTALLATION
Then put electric wate r level meter on the machining
surface of transmission as above.
And reading the leaning angle of transmission.
4.Service limit of leaning angle of Transmission and
Front axle.
Maximum 0.5degree between Transmission/Axle
leaning.
5.When angle of leaning is more than 0.5 degree, its
shows wrong position in either the front axle or
engine/transmission.
Check he engine mounting and axle mounting.
(for Manual transmission)
30-24AX50/BX50 Series
Page 91
REMOVAL AND INSTALLATION
STEERING AXLE AND POWER STEERING
343 – 427 Nm
{35 – 43.5 kgfm}
STEERING AXLE AND POWER STEERING
157 – 245 Nm
{16 – 25 kgfm}
35 – 63 Nm
{3.6 – 6.4 kgfm}
AX50/BX50 Series
30-25
Page 92
WHEEL BRAKE
WHEEL BRAKE
REMOVAL
1.Front Axle and Torque Shaft
1)Apply the wheel stopper to the rear wheels.
2)Place the wooden blocks under the bottom of
the truck frame to lift the front wheels.
3)Apply the parking brake.
REMOVAL AND INSTALLATION
4)Remove the hub nut and then the torque shaft
(3).
5)Release the parking brake.
1.0 – 1.75 ton
2.0 – 3.0 ton
3
2
1
2
1
3
30-26AX50/BX50 Series
Page 93
REMOVAL AND INSTALLATION
2.Hub
1)Remove the bolt (4).
2)Remove the lock nut (5) with a special tool (80
mm double face box).
3)Remo v e th e hub no t to be twi sted u pside dow n.
WHEEL BRAKE
1.0 – 1.75 ton
4
5
2.0 – 3.0 ton
4
INST ALLATION
1.Back Plate (when removed)
Apply the Locti te to the m oun tin g b ol t (1) and tighten
it with tightening torque specified as follows:
176 – 196 Nm {18 – 20 kgm}
LOCTITE #271
5
1.0 – 1.75 ton
1
2.0 – 3.0 ton
AX50/BX50 Series
1
30-27
Page 94
WHEEL BRAKE
2.Hub
1)Install a new oil seal.
Apply the grease G2-L1 on the lip surface of
the oil seal.
2)Fill the grease G2-L1 in the bearing (7) and
install it to the hub (8).
3)Remove dirt or fat and oil in the inside face of
the brake drum (9) completely.
4)Install the hub to the shaft tube.
5)Tighten the locknut (5) so that the starting
torque of the hub can conform to the following.
1.0 – 1.75 ton
9
8
REMOVAL AND INSTALLATION
6
7
Starting
Torque
6) Tighten the bolt (4) after applying the Loctite.
6.1 – 15.7 Nm {62.5 – 160 kgm}
Loctite #271
2.0 – 3.0 ton
6
9
7
8
1.0 – 1.75 ton
4
5
2.0 – 3.0 ton
4
5
30-28AX50/BX50 Series
Page 95
REMOVAL AND INSTALLATION
WHEEL BRAKE
3.Front Axle and Torque Shaft
1)Install the torque shaft (3) and tighten the bolt
(2) with tightening torque specified as follows:
98 – 127 Nm {10 – 13 kgm}
2)Install the front axle and tighten the hub nut (1)
with tightening torque specified as follows.