SEBM032300

Machine model Serial number

D155C-1 31586 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.

• D155C-1 mounts the SA6D140E-2 engine.

For details of the engine, see the 6D140-2 Series Engine Shop Manual.

© 2004
All Rights Reserved 00-1
Printed in Japan 10-04 (01)
 Contents
No. of page
01 General .......................................................................................................................... 01-1

10 Structure and function ...................................................................................... 10-1

20 Testing and adjusting ........................................................................................ 20-1

30 Disassembly and assembly .......................................................................... 30-1

40 Maintenance standard.........................................................................................40-1

90 Others ............................................................................................................................. 90-1

00-2 D155C-1
Safety Safety notice

Safety
Safety notice

Important safety notice

Proper service and repair is extremely important for safe machine operation. The service and repair
techniques recommended by Komatsu and described in this manual are both effective and safe.
Some of these techniques require the use of tools specially designed by Komatsu for the specific
purpose.

To prevent injury to workers, the symbol k is used to mark safety precautions in this manual. The
cautions accompanying these symbols should always be followed carefully. If any dangerous situa-
tion arises or may possibly arise, first consider safety, and take the necessary actions to deal with the
situation.

General precautions
6. Decide a place in the repair workshop to keep
Mistakes in operation are extremely dangerous. tools and removed parts. Always keep the tools
Read the Operation and Maintenance Manual care- and parts in their correct places. Always keep
fully BEFORE operating the machine. the work area clean and make sure that there is
no dirt or oil on the floor. Smoke only in the
1. Before carrying out any greasing or repairs, read areas provided for smoking. Never smoke while
all the precautions given on the decals which working.
are fixed to the machine.
Preparations for work
2. When carrying out any operation, always wear
safety shoes and helmet. Do not wear loose 7. Before adding oil or making any repairs, park
work clothes, or clothes with buttons missing. the machine on hard, level ground, and block
• Always wear safety glasses when hitting the wheels or tracks to prevent the machine
parts with a hammer. from moving.
• Always wear safety glasses when grinding
parts with a grinder, etc. 8. Before starting work, lower blade, ripper, bucket
or any other work equipment to the ground. If
3. If welding repairs are needed, always have a this is not possible, insert the safety pin or use
trained, experienced welder carry out the work. blocks to prevent the work equipment from fall-
When carrying out welding work, always wear ing. In addition, be sure to lock all the control
welding gloves, apron, hand shield, cap and levers and hang warning signs on them.
other clothes suited for welding work.
9. When disassembling or assembling, support the
4. When carrying out any operation with two or machine with blocks, jacks or stands before
more workers, always agree on the operating starting work.
procedure before starting. Always inform your
fellow workers before starting any step of the 10. Remove all mud and oil from the steps or other
operation. Before starting work, hang UNDER places used to get on and off the machine.
REPAIR signs on the controls in the operator's Always use the handrails, ladders or steps when
compartment. getting on or off the machine. Never jump on or
off the machine. If it is impossible to use the
5. Keep all tools in good condition and learn the handrails, ladders or steps, use a stand to pro-
correct way to use them. vide safe footing.

00-3
Safety Safety notice

Precautions during work 19. Be sure to assemble all parts again in their origi-
nal places.
11. When removing the oil filler cap, drain plug or
Replace any damaged parts with new parts.
hydraulic pressure measuring plugs, loosen
• When installing hoses and wires, be sure
them slowly to prevent the oil from spurting out.
that they will not be damaged by contact with
Before disconnecting or removing components
other parts when the machine is being
of the oil, water or air circuits, first remove the
operated.
pressure completely from the circuit.
20. When installing high pressure hoses, make sure
12. The water and oil in the circuits are hot when the
that they are not twisted. Damaged tubes are
engine is stopped, so be careful not to get
dangerous, so be extremely careful when install-
burned.
ing tubes for high pressure circuits. Also, check
Wait for the oil and water to cool before carrying
that connecting parts are correctly installed.
out any work on the oil or water circuits.
21. When assembling or installing parts, always use
13. Before starting work, remove the leads from the
the specified tightening torques. When installing
battery. Always remove the lead from the nega-
protective parts such as guards, or parts which
tive (–) terminal first.
vibrate violently or rotate at high speed, be par-
ticularly careful to check that they are installed
14. When raising heavy components, use a hoist or
correctly.
crane.
Check that the wire rope, chains and hooks are
22. When aligning two holes, never insert your fin-
free from damage.
gers or hand. Be careful not to get your fingers
Always use lifting equipment which has ample
caught in a hole.
capacity.
Install the lifting equipment at the correct places.
23. When measuring hydraulic pressure, check that
Use a hoist or crane and operate slowly to pre-
the measuring tool is correctly assembled
vent the component from hitting any other part.
before taking any measurements.
Do not work with any part still raised by the hoist
or crane.
24. Take care when removing or installing the tracks
of track-type machines.
15. When removing covers which are under internal
When removing the track, the track separates
pressure or under pressure from a spring,
suddenly, so never let anyone stand at either
always leave two bolts in position on opposite
end of the track.
sides. Slowly release the pressure, then slowly
loosen the bolts to remove.

16. When removing components, be careful not to

break or damage the wiring. Damaged wiring
may cause electrical fires.

17. When removing piping, stop the fuel or oil from

spilling out. If any fuel or oil drips onto the floor,
wipe it up immediately. Fuel or oil on the floor
can cause you to slip, or can even start fires.

18. As a general rule, do not use gasoline to wash

parts. In particular, use only the minimum of gas-
oline when washing electrical parts.

00-4
Foreword General

Foreword
General
This shop manual has been prepared as an aid to improve the quality of repairs by giving the serviceman an
accurate understanding of the product and by showing him the correct way to perform repairs and make judge-
ments. Make sure you understand the contents of this manual and use it to full effect at every opportunity.

This shop manual mainly contains the necessary technical information for operations performed in a service
workshop. For ease of understanding, the manual is divided into the following chapters; these chapters are fur-
ther divided into the each main group of components.

Structure and function

This section explains the structure and function of each component. It serves not only to give an under-
standing of the structure, but also serves as reference material for troubleshooting.
In addition, this section may contain hydraulic circuit diagrams, electric circuit diagrams, and mainte-
nance standards.

Testing and adjusting

This section explains checks to be made before and after performing repairs, as well as adjustments to
be made at completion of the checks and repairs.
Troubleshooting charts correlating “Problems” with “Causes” are also included in this section.

Disassembly and assembly

This section explains the procedures for removing, installing, disassembling and assembling each com-
ponent, as well as precautions for them.

Maintenance standard
This section gives the judgment standards for inspection of disassembled parts.
The contents of this section may be described in “Structure and function”.

Others
This section mainly gives hydraulic circuit diagrams and electric circuit diagrams.
In addition, this section may give the specifications of attachments and options together.

Notice
The specifications contained in this shop manual are subject to change at any time and without any
advance notice. Use the specifications given in the book with the latest date.

00-5
Foreword General

How to read the shop manual Revised edition mark

W he n a m an ua l i s r ev i s e d, an e di t i on m a r k
Volumes ((1)(2)(3)....) is recorded on the bottom of the pages.
Shop manuals are issued as a guide to carrying out
repairs. They are divided as follows:
Revisions
Chassis volume: Issued for every machine model Revised pages are shown in the List of revised
Engine volume: Issued for each engine series pages next to the Contents page.
Each issued as one
Electrical volume:
volume to cover all
Attachments volume: Symbols
models
So that the shop manual can be of ample practical
use, important safety and quality portions are
These various volumes are designed to avoid dupli- marked with the following symbols.
cating the same information. Therefore, to deal with
all repairs for any model , it is necessary that chas-
Symbol Item Remarks
sis, engine, electrical and attachment volumes be

k
available. Special safety precautions
Safety are necessary when
performing the work.
Distribution and updating Special technical
Any additions, amendments or other changes will be precautions or other
sent to KOMATSU distributors. Get the most up-to- a Caution precautions for preserving
date information before you start any work. standards are necessary
when performing the work.
Filing method Weight of parts of systems.
1. See the page number on the bottom of the page. Caution necessary when
4
File the pages in correct order. Weight selecting hoisting wire, or
when working posture is
2. Following examples show how to read the page
important, etc.
number.
Places that require special
3
Example 1 (Chassis volume): Tightening
attention for the tightening
torque
10 - 3 torque during assembly.

2
Places to be coated with
Item number Coat adhesives and lubricants,
(10. Structure and Function) etc.
Consecutive page number for

5
each item. Places where oil, water or
Oil, water fuel must be added, and
Example 2 (Engine volume): the capacity.
12 - 5 Places where oil or water
6
Drain must be drained, and
Unit number (1. Engine) quantity to be drained.
Item number
(2. Testing and Adjusting)
Consecutive page number for
each item.

3. Additional pages: Additional pages are indi-

cated by a hyphen (–) and number after the
page number. File as in the example.
Example:
10-4 20-203
10-4-1 12-203-1
Added pages
10-4-2 12-203-2
10-5 12-204

00-6
Foreword Hoisting instructions

Hoisting instructions
Hoisting
Slinging near the edge of the hook may
k
cause the rope to slip off the hook during
Heavy parts (25 kg or more) must be lifted
hoisting, and a serious accident can result.
with a hoist, etc. In the Disassembly and
Hooks have maximum strength at the mid-
assembly section, every part weighing 25
dle portion.
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
part to the relative parts. 100% 88% 79% 71% 41%
2) Check for existence of another part causing SAD00479

interference with the part to be removed. 3) Do not sling a heavy load with one rope
alone, but sling with two or more ropes
Wire ropes symmetrically wound onto the load.
k
1) Use adequate ropes depending on the
Slinging with one rope may cause
weight of parts to be hoisted, referring to the
turning of the load during hoisting,
table below:
untwisting of the rope, or slipping of the
Wire ropes rope from its original winding position on
(Standard “Z” or “S” twist ropes the load, which can result in a dangerous
without galvanizing) accident.
Rope diameter Allowable load
mm kN tons 4) Do not sling a heavy load with ropes forming
10 9.8 1.0 a wide hanging angle from the hook.
11.5 13.7 1.4 When hoisting a load with two or more
12.5 15.7 1.6 ropes, the force subjected to each rope will
14 21.6 2.2 increase with the hanging angles. The table
16 27.5 2.8 below shows the variation of allowable load
18 35.3 3.6 kN {kg} when hoisting is made with two
20 43.1 4.4 ropes, each of which is allowed to sling up
22.4 54.9 5.6
to 9.8 kN {1000 kg} vertically, at various
30 98.1 10.0
hanging angles.
40 176.5 18.0
50 274.6 28.0 When two ropes sling a load vertically, up to
60 392.2 40.0 19.6 kN {2000 kg} of total weight can be
suspended. This weight becomes 9.8 kN
a The allowable load value is estimated to be {1000 kg} when two ropes make a 120?
one-sixth or one-seventh of the breaking hanging angle. On the other hand, two
strength of the rope used. ropes are subjected to an excessive force
as large as 39.2 kN {4000 kg} if they sling a
2) Sling wire ropes from the middle portion of 19.6 kN {2000 kg} load at a lifting angle of
the hook. 150°.

00-7
Foreword Method of disassembling, connecting push-pull type coupler

Method of disassembling, connecting push-pull type coupler

k Before carrying out the following work, release Type 1
the residual pressure from the hydraulic tank.
For details, see “Tes ting and adjus ting”,
Releasing residual pressure from hydraulic tank.

k Even if the residual pressure is released from

the hydraulic tank, some hydraulic oil flows out
when the hose is disconnected. Accordingly,
prepare an oil receiving container.

Disconnection
1) Release the residual pressure from the
hydraulic tank. For details, see “Testing and
adjusting”, Releasing residual pressure from
hydraulic tank.

2) Hold adapter (1) and push hose joint (2) into

mating adapter (3). (See Fig. 1)
a The adapter can be pushed in about 3.5 mm.
a Do not hold rubber cap portion (4).

3) After hose joint (2) is pushed into adapter (3),

press rubber cap portion (4) against (3) until it
clicks. (See Fig. 2)

4) Hold hose adapter (1) or hose (5) and pull it out.

(See Fig. 3)
a Since some hydraulic oil flows out, prepare
an oil receiving container.

Connection
1) Hold hose adapter (1) or hose (5) and insert it in
mating adapter (3), aligning them with each
other. (See Fig. 4)
a Do not hold rubber cap portion (4).

2) After inserting the hose in the mating adapter

perfectly, pull it back to check its connecting
condition. (See Fig. 5)
a When the hose is pulled back, the rubber cap
portion moves toward the hose about 3.5
mm. This does not indicate abnormality,
however.

00-8
Foreword Method of disassembling, connecting push-pull type coupler

Type 2 Type 3
1) Hold the mouthpiece of the tightening portion 1) Hold the mouthpiece of the tightening portion
and push body (2) in straight until sliding and push body (2) in straight until sliding
prevention ring (1) contacts contact surface a of prevention ring (1) contacts contact surface a of
the hexagonal portion at the male end. the hexagonal portion at the male end.

2) Hold in the condition in Step 1), and turn lever 2) Hold in the condition in Step 1), and push until
(4) to the right (clockwise). cover (3) contacts contact surface a of the
hexagonal portion at the male end.
Disassembly

3) Hold in the condition in Steps 1) and 2), and pull 3) Hold in the condition in Steps 1) and 2), and pull
out whole body (2) to disconnect it. out whole body (2) to disconnect it.

• Hold the mouthpiece of the tightening portion and • Hold the mouthpiece of the tightening portion and
push body (2) in straight until sliding prevention push body (2) in straight until sliding prevention
ring (1) contacts contact surface a of the ring (1) contacts contact surface a of the
hexagonal portion at the male end to connect it. hexagonal portion at the male end to connect it.
Connection

00-9
Foreword Coating materials

Coating materials
a The recommended coating materials such as adhesives, gasket sealants and greases used for disassembly
and assembly are listed below.
a For coating materials not listed below, use the equivalent of products shown in this list.

Category Komatsu code Part No. Q’ty Container Main applications, featuresr

• Used to prevent rubber gaskets, rubber

LT-1A 790-129-9030 150 g Tube
cushions, and cock plug from coming out.
• Used in places requiring an immediately
effective, strong adhesive.
20 g Polyethylene Used for plastics (except polyethylene,
LT-1B 790-129-9050
(2 pcs.) container polyprophylene, tetrafluoroethlene and
vinyl chloride), rubber, metal and non-
metal.
• Features:
Polyethylene Resistance to heat and chemicals
LT-2 09940-00030 50 g
container • Used for anti-loosening and sealant
purpose for bolts and plugs.
Adhesive: • Used as adhesive or sealant for metal,
790-129-9060
1 kg glass and plastic.
(Set of adhesive
LT-3 Hardening Can
and hardening
agent:
agent)
Adhesives 500 g
Polyethylene • Used as sealant for machined holes.
LT-4 790-129-9040 250 g
container
Holtz • Used as heat-resisting sealant for
790-126-9120 75 g Tube
MH 705 repairing engine.
• Quick hardening type adhesive
Three bond Polyethylene • Cure time: within 5 sec. to 3 min.
790-129-9140 50 g
1735 container • Used mainly for adhesion of metals,
rubbers, plastics and woods.
• Quick hardening type adhesive
• Quick cure type
Aron-alpha Polyethylene
790-129-9130 2g (max. strength after 30 minutes)
201 container
• Used mainly for adhesion of rubbers,
plastics and metals.
• Resistance to heat, chemicals
Loctite Polyethylene
79A-129-9110 50 cc • Used at joint portions subject to high
648-50 container
temperatures.
• Used as adhesive or sealant for gaskets
LG-1 790-129-9010 200 g Tube
and packing of power train case, etc.
• Used as sealant for various threads, pipe
joints, flanges.
LG-5 790-129-9080 1 kg Can
• Used as sealant for tapered plugs,
elbows, nipples of hydraulic piping.
• Features: Silicon based, resistance to
heat, cold
LG-6 790-129-9020 200 g Tube • Used as sealant for flange surface, tread.
• Used as sealant for oil pan, final drive
Gasket case, etc.
sealant • Features: Silicon based, quick hardening
type
LG-7 790-129-9070 1g Tube • Used as sealant for flywheel housing,
intake manifold, oil an, thermostat
housing, etc.
Three bond • Used as heat-resisting sealant for
790-129-9090 100 g Tube
1211 repairing engine.
• Features: Silicone type, heat resistant,
Three bond vibration resistant, and impact resistant
419-15-18131 100 g Tube
1207B sealing material
• Used as sealing material for transfer case

00-10
Foreword Coating materials

Category Komatsu code Part No. Q’ty Container Main applications, featuresr

• Used as lubricant for sliding portion (to

LM-G 09940-00051 60 g Can
prevent from squeaking).
Molybdenum
disulphide • Used to prevent seizure or scuffling of the
lubricant thread when press fitting or shrink fitting.
LM-P 09940-00040 200 g Tube
• Used as lubricant for linkage, bearings,
etc.
SYG2-400LI • General purpose type
SYG2-350LI
G2-LI SYG2-400LI-A Various Various
SYG2-160LI
SYGA-160CNLI
SYG2-400CA • Used for normal temperature, light load
SYG2-350CA bearing at places in contact with water or
G2-CA SYG2-400CA-A Various Various steam.
SYG2-160CA
SYGA-160CNCA
Molybdenum • Used for heavy load portion
SYG2-400M 400 g × 10 Bellows type
disulphide
Grease SYG2-400M-A 400 g × 20 Bellows type
grease
SYGA-16CNM 16 kg Can
LM-G (G2-M)
Hyper White • Seizure resistance and heat resistance
SYG2-400T-A
Grease G2-T higher than molybdenum disulfide grease
SYG2-16CNT 400 g Bellows type
G0-T (*) • Since this grease is white, it does not
SYG0-400T-A (*) 16 kg Can
*: For use in stand out against machine body.
SYG0-16CNT (*)
cold district
Biogrease G2B • Since this grease is decomposed by
SYG2-400B
G2-BT (*) bacteria in short period, it has less effects
SYGA-16CNB 400 g Bellows type
*: For high on microorganisms, animals, and plants.
SYG2-400BT (*) 16 kg Can
temperature
SYGA-16CNBT (*)
and large load
SUNSTAR • Used as primer for cab side
Glass
PAINT PRIMER 20 ml (Using limit: 4 months)
container
580 SUPER
Primer
SUNSTAR • Used as primer for glass side
Glass
GLASS PRIMER 20 ml (Using limit: 4 months)
container
580 SUPER 417-926-3910
Adhesive for cab glass

SUNSTAR • “S” is used for high-temperature

PENGUINE season (April - October) and “W” for
Polyethylene
SEAL 580 320 ml low-temperature season (November -
container
Adhesive SUPER “S” or April) as adhesive for glass.
“W” (Using limit: 4 months)
Sika Japan, Polyethylene • Used as adhesive for glass.
20Y-54-39850 310 ml
Sikaflex 256HV container (Using limit: 6 months)
SUNSTAR • Used to seal joints of glass parts.
Polyethylene
PENGUINE 417-926-3920 320 ml (Using limit: 4 months)
container
Caulking SEAL No. 2505
material SEKISUI • Used to seal front window.
Polyethylene
SILICONE 20Y-54-55130 333 ml (Using limit: 6 months)
container
SEALANT

00-11
Foreword Standard tightening torque

Standard tightening torque

Standard tightening torque table (when using torque wrench)
a In the case of metric nuts and bolts for which there is no special instruction, tighten to the torque given in the
table below.
Tightening torque
Thread diameter Width across
of bolt flats

mm mm Nm kgm
6 10 11.8 – 14.7 1.2 – 1.5
8 13 27 – 34 2.8 – 3.5
10 17 59 – 74 6 – 7.5
12 19 98 – 123 10 – 12.5
14 22 153 – 190 15.5 – 19.5

16 24 235 – 285 23.5 – 29.5

18 27 320 – 400 33 – 41
20 30 455 – 565 46.5 – 58
22 32 610 – 765 62.5 – 78
24 36 785 – 980 80 – 100

27 41 1150 – 1440 118 – 147

30 46 1520 – 1910 155 – 195
33 50 1960 – 2450 200 – 250
36 55 2450 – 3040 250 – 310
39 60 2890 – 3630 295 – 370

Tightening torque
Thread diameter Width across
of bolt flats

mm mm Nm kgm
6 10 5.9 – 9.8 0.6 – 1.0
8 13 13.7 – 23.5 1.4 – 2.4
10 14 34.3 – 46.1 3.5 – 4.7
12 27 74.5 – 90.2 7.6 – 9.2

Sealing surface

Table of tightening torques for flared nuts

a In the case of flared nuts for which there is no
special instruction, tighten to the torque given in
the table below.
SAD00483

Thread diameter Width across flats Tightening torque

mm mm Nm kgm
14 19 24.5 ± 4.9 2.5 ± 0.5
18 24 49 ± 19.6 5±2
22 27 78.5 ± 19.6 8±2
24 32 137.3 ± 29.4 14 ± 3
30 36 176.5 ± 29.4 18 ± 3
33 41 196.1 ± 49 20 ± 5
36 46 245.2 ± 49 25 ± 5
42 55 294.2 ± 49 30 ± 5

00-12
Foreword Standard tightening torque

Table of tightening torques for flared nuts

a In the case of flared nuts for which there is no special instruction, tighten to the torque given in the table
below.

Thread diameter Width across flats Tightening torque

mm mm Nm kgm
10 14 59 – 74 6 – 7.5
12 17 98 – 123 10 – 12.5
16 22 235 – 285 23.5 – 29.5

Table of tightening torques for o-ring boss piping joints

a Unless there are special instructions, tighten the O-ring boss piping joints to the torque below.

Thread diameter Width across flats Tightening torque

Norminal No.
mm mm Nm kgm
02 14 35 – 63 {3.5 – 6.5} 44 {4.5}
03, 04 20 Varies depending 84 – 132 {8.5 – 13.5} 103 {10.5}
05, 06 24 on type of 128 – 186 {13.0 – 19.0} 157 {16.0}
10, 12 33 connector. 363 – 480 {37.0 – 49.0} 422 {43.0}
14 42 746 – 1010 {76.0 – 103} 883 {90.0}

Table of tightening torques for o-ring boss plugs

a Unless there are special instructions, tighten the O-ring boss plugs to the torque below.

Thread diameter Width across flats Tightening torque

Norminal No.
mm mm Nm kgm
08 08 14 5.88 – 8.82 {0.6 – 0.9} 7.35 {0.75}
10 10 17 9.8 – 12.74 {1.0 – 1.3} 11.27 {1.15}
12 12 19 14.7 – 19.6 {1.5 – 2.0} 17.64 {1.8}
14 14 22 19.6 – 24.5 {2.0 – 2.5} 22.54 {2.3}
16 16 24 24.5 – 34.3 {2.5 – 3.5} 29.4 {3.0}
18 18 27 34.3 – 44.1 {3.5 – 4.5} 39.2 {4.0}
20 20 30 44.1 – 53.9 {4.5 – 5.5} 49.0 {5.0}
24 24 32 58.8 – 78.4 {6.0 – 8.0} 68.6 {7.0}
30 30 32 93.1 – 122.5 {9.5 – 12.5} 107.8 {11.0}
33 33 — 107.8 – 147.0 {11.0 – 15.0} 124.4 {13.0}
36 36 36 127.4 – 176.4 {13.0 – 18.0} 151.9 {15.5}
42 42 — 181.3 – 240.1 {18.5 – 24.5} 210.7 {21.5}
52 52 — 274.4 – 367.5 {28.0 – 37.5} 323.4 {33.0}

00-13
Foreword Standard tightening torque

Tightening torque for 102 engine series

1) Bolt and nuts
Use these torques for bolts and nuts (unit: mm) of Cummins Engine.
Thread diameter Tightening torque
mm Nm kgm
6 10 ± 2 1.02 ± 0.20
8 24 ± 4 2.45 ± 0.41
10 43 ± 6 4.38 ± 0.61
12 77 ± 12 7.85 ± 1.22

2) Eye joints
Use these torques for eye joints (unit: mm) of Cummins Engine.
Thread diameter Tightening torque
mm Nm kgm
6 8±2 0.81 ± 0.20
8 10 ± 2 1.02 ± 0.20
10 12 ± 2 1.22 ± 0.20
12 24 ± 4 2.45 ± 0.41
14 36 ± 5 3.67 ± 0.51

3) Tapered screws
Use these torques for tapered screws (unit: inch) of Cummins Engine.
Thread diameter Tightening torque
inch Nm kgm
1 / 16 3±1 0.31 ± 0.10
1/8 8±2 0.81 ± 0.20
1/4 12 ± 2 1.22 ± 0.20
3/8 15 ± 2 1.53 ± 0.41
1/2 24 ± 4 2.45 ± 0.41
3/4 36 ± 5 3.67 ± 0.51
1 60 ± 9 6.12 ± 0.92

Tightening torque table for hoses (taper seal type and face seal type)
a Tighten the hoses (taper seal type and face seal type) to the following torque, unless otherwise specified.
a Apply the following torque when the threads are coated (wet) with engine oil.
Taper seal
Tightening torque (Nm {kgm}) Face seal type
Nominal type
Width
size of Nominal thread size
across flats Thread size Root diameter
hose Range Target – Threads per inch,
(mm) (mm) (Reference)
Thread series
9
02 19 34 – 63 {3.5 – 6.5} 44 {4.5} 14 – 18UNF 14.3
16
11
22 54 – 93 {5.5 – 9.5} 74 {4.5} — – 16UN 17.5
16
03
24 59 – 98 {6.0 – 10.0} 78 {8.0} 18 — —
13
04 27 84 – 132 {8.5 – 13.5} 103 {10.5} 22 1 – 16UN 20.7
16
05 32 128 – 186 {13.0 – 19.0} 157 {16.0} 24 1 – 14UNS 25.4
3
06 36 177 – 245 {18.0 – 25.0} 216 {22.0} 30 1 – 12UNF 30.3
16
(10) 41 177 – 245 {18.0 – 25.0} 216 {22.0} 33 — —

(12) 46 197 – 294 {20.0 – 30.0} 245 {25.0} 36 — —

(14) 55 246 – 343 {25.0 – 35.0} 294 {30.0} 42 — —

00-14
Foreword Electric wire code

Electric wire code

In the wiring diagrams, various colors and symbols are employed to indicate the thickness of wires.
This wire code table will help you understand WIRING DIAGRAMS.
Example: 5WB indicates a cable having a nominal number 5 and white coating with black stripe.

Classification by thickness
Copper wire
Norminal Cable O.D. Current rating
Number of Dia. of Cross section Applicable circuit
number (mm) (A)
strands strands (mm2) (mm2)

0.85 11 0.32 0.88 2.4 12 Starting, lighting, signal etc.

2 26 0.32 2.09 3.1 20 Lighting, signal etc.

5 65 0.32 5.23 4.6 37 Charging and signal

15 84 0.45 13.36 7.0 59 Starting (Glow plug)

40 85 0.80 42.73 11.4 135 Starting

60 127 0.80 63.84 13.6 178 Starting

100 217 0.80 109.1 17.6 230 Starting

Classification by color and code

Circuits
Priority Charging Ground Starting Lighting Instrument Signal Other
Classification

Code W B B R Y G L
1 Primary
Color White Black Black Red Yellow Green Blue

Code WR — BW RW YR GW LW
2
White & White & Red & Rellow & Green & Blue &
Color —
Red Black White Red White White

Code WB — BY RB YB GR LR
3
White & Black & Red & Yellow & Green & Blue &
Color —
Black Yellow Black Black Red Yellow

Code WL — BR RY YG GY LY
4 Auxiliary
White & Black & Red & Yellow & Green & Blue &
Color —
Blue Red Yellow Green Yellow Yellow

Code WG — — RG YL GB LB
5
White & Red & Yellow & Green & Blue &
Color — —
Green Green Blue Black Black

Code — — — RL YW GL —
6
Yellow & Green &
Color — — — Red & Blue —
White Blue

00-15
 Foreword Conversion table

Conversion table
Method of using the conversion table
The Conversion Table in this section is provided to enable simple conversion of figures. For details of the
method of using the Conversion Table, see the example given below.

Example
• Method of using the Conversion Table to convert from millimeters to inches
1. Convert 55 mm into inches.
1) Locate the number 50 in the vertical column at the left side, take this as (A), then draw a horizontal line
from (A).
2) Locate the number 5 in the row across the top, take this as (B), then draw a perpendicular line down
from (B).
3) Take the point where the two lines cross as (C). This point (C) gives the value when converting from
millimeters to inches. Therefore, 55 mm = 2.165 inches.
2. Convert 550 mm into inches.
1) The number 550 does not appear in the table, so divide by 10 (move the decimal point one place to the
left) to convert it to 55 mm.
2) Carry out the same procedure as above to convert 55 mm to 2.165 inches.
3) The original value (550 mm) was divided by 10, so multiply 2.165 inches by 10 (move the decimal point
one place to the right) to return to the original value. This gives 550 mm = 21.65 inches.

Millimeters to inches (B)

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
(C)

(A) 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

00-16
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
Foreword Conversion table

Liter to U.S. Gallon

1l = 0.2642 U.S. Gal
0 1 2 3 4 5 6 7 8 9
0 0 0.264 0.528 0.793 1.057 1.321 1.585 1.849 2.113 2.378
10 2.642 2.906 3.170 3.434 3.698 3.963 4.227 4.491 4.755 5.019
20 5.283 5.548 5.812 6.076 6.340 6.604 6.869 7.133 7.397 7.661
30 7.925 8.189 8.454 8.718 8.982 9.246 9.510 9.774 10.039 10.303
40 10.567 10.831 11.095 11.359 11.624 11.888 12.152 12.416 12.680 12.944

50 13.209 13.473 13.737 14.001 14.265 14.529 14.795 15.058 15.322 15.586
60 15.850 16.115 16.379 16.643 16.907 17.171 17.435 17.700 17.964 18.228
70 18.492 18.756 19.020 19.285 19.549 19.813 20.077 20.341 20.605 20.870
80 21.134 21.398 21.662 21.926 22.190 22.455 22.719 22.983 23.247 23.511
90 23.775 24.040 24.304 24.568 24.832 25.096 25.361 25.625 25.889 26.153

Liter to U.K. Gallon

1l = 0.21997 U.K. Gal
0 1 2 3 4 5 6 7 8 9
0 0 0.220 0.440 0.660 0.880 1.100 1.320 1.540 1.760 1.980
10 2.200 2.420 2.640 2.860 3.080 3.300 3.520 3.740 3.950 4.179
20 4.399 4.619 4.839 5.059 5.279 5.499 5.719 5.939 6.159 6.379
30 6.599 6.819 7.039 7.259 7.479 7.969 7.919 8.139 8.359 8.579
40 8.799 9.019 9.239 9.459 9.679 9.899 10.119 10.339 10.559 10.778

50 10.998 11.281 11.438 11.658 11.878 12.098 12.318 12.528 12.758 12.978
60 13.198 13.418 13.638 13.858 14.078 14.298 14.518 14.738 14.958 15.178
70 15.398 15.618 15.838 16.058 16.278 16.498 16.718 16.938 17.158 17.378
80 17.598 17.818 18.037 18.257 18.477 18.697 18.917 19.137 19.357 19.577
90 19.797 20.017 20.237 20.457 20.677 20.897 21.117 21.337 21.557 21.777

00-18
Foreword Conversion table

kgm to ft. lb
1 kgm = 7.233 ft. lb
0 1 2 3 4 5 6 7 8 9
0 0 7.2 14.5 21.7 28.9 36.2 43.4 50.6 57.9 65.1
10 72.3 79.6 86.8 94.0 101.3 108.5 115.7 123.0 130.2 137.4
20 144.7 151.9 159.1 166.4 173.6 180.8 188.1 195.3 202.5 209.8
30 217.0 224.2 231.5 238.7 245.9 253.2 260.4 267.6 274.9 282.1
40 289.3 296.6 303.8 311.0 318.3 325.5 332.7 340.0 347.2 354.4

50 361.7 368.9 376.1 383.4 390.6 397.8 405.1 412.3 419.5 426.8
60 434.0 441.2 448.5 455.7 462.9 470.2 477.4 484.6 491.8 499.1
70 506.3 513.5 520.8 528.0 535.2 542.5 549.7 556.9 564.2 571.4
80 578.6 585.9 593.1 600.3 607.6 614.8 622.0 629.3 636.5 643.7
90 651.0 658.2 665.4 672.7 679.9 687.1 694.4 701.6 708.8 716.1

100 723.3 730.5 737.8 745.0 752.2 759.5 766.7 773.9 781.2 788.4
110 795.6 802.9 810.1 817.3 824.6 831.8 839.0 846.3 853.5 860.7
120 868.0 875.2 882.4 889.7 896.9 904.1 911.4 918.6 925.8 933.1
130 940.3 947.5 954.8 962.0 969.2 976.5 983.7 990.9 998.2 1005.4
140 1012.6 1019.9 1027.1 1034.3 1041.5 1048.8 1056.0 1063.2 1070.5 1077.7

150 1084.9 1092.2 1099.4 1106.6 1113.9 1121.1 1128.3 1135.6 1142.8 1150.0
160 1157.3 1164.5 1171.7 1179.0 1186.2 1193.4 1200.7 1207.9 1215.1 1222.4
170 1129.6 1236.8 1244.1 1251.3 1258.5 1265.8 1273.0 1280.1 1287.5 1294.7
180 1301.9 1309.2 1316.4 1323.6 1330.9 1338.1 1345.3 1352.6 1359.8 1367.0
190 1374.3 1381.5 1388.7 1396.0 1403.2 1410.4 1417.7 1424.9 1432.1 1439.4

00-19
Foreword Conversion table

kg/cm2 to lb/in2
1kg/cm2 = 14.2233 lb/in2
0 1 2 3 4 5 6 7 8 9
0 0 14.2 28.4 42.7 56.9 71.1 85.3 99.6 113.8 128.0
10 142.2 156.5 170.7 184.9 199.1 213.4 227.6 241.8 256.0 270.2
20 284.5 298.7 312.9 327.1 341.4 355.6 369.8 384.0 398.3 412.5
30 426.7 440.9 455.1 469.4 483.6 497.8 512.0 526.3 540.5 554.7
40 568.9 583.2 597.4 611.6 625.8 640.1 654.3 668.5 682.7 696.9

50 711.2 725.4 739.6 753.8 768.1 782.3 796.5 810.7 825.0 839.2
60 853.4 867.6 881.8 896.1 910.3 924.5 938.7 953.0 967.2 981.4
70 995.6 1010 1024 1038 1053 1067 1081 1095 1109 1124
80 1138 1152 1166 1181 1195 1209 1223 1237 1252 1266
90 1280 1294 1309 1323 1337 1351 1365 1380 1394 1408

100 1422 1437 1451 1465 1479 1493 1508 1522 1536 1550
110 1565 1579 1593 1607 1621 1636 1650 1664 1678 1693
120 1707 1721 1735 1749 1764 1778 1792 1806 1821 1835
130 1849 1863 1877 1892 1906 1920 1934 1949 1963 1977
140 1991 2005 2020 2034 2048 2062 2077 2091 2105 2119

150 2134 2148 2162 2176 2190 2205 2219 2233 2247 2262
160 2276 2290 2304 2318 2333 2347 2361 2375 2389 2404
170 2418 2432 2446 2460 2475 2489 2503 2518 2532 2546
180 2560 2574 2589 2603 2617 2631 2646 2660 2674 2688
190 2702 2717 2731 2745 2759 2773 2788 2802 2816 2830

200 2845 2859 2873 2887 2901 2916 2930 2944 2958 2973
210 2987 3001 3015 3030 3044 3058 3072 3086 3101 3115
220 3129 3143 3158 3172 3186 3200 3214 3229 3243 3257
230 3271 3286 3300 3314 3328 3343 3357 3371 3385 3399
240 3414 3428 3442 3456 3470 3485 3499 3513 3527 3542

00-20
Foreword Conversion table

Temperature
Fahrenheit-Centigrade Conversion ; a simple way to convert a Fahrenheit temperature reading into a Centi-
grade temperature reading or vice versa is to enter the accompanying table in the center or boldface col-
umn of figures.
These figures refer to the temperature in either Fahrenheit or Centigrade degrees.
If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table of
Fahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left.
If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table of
Centigrade values, and read the corresponding Fahrenheit temperature on the right.
1°C = 33.8°F
°C °F °C °F °C °F °C °F
–40.4 –40 –40.0 –11.7 11 51.8 7.8 46 114.8 27.2 81 117.8
–37.2 –35 –31.0 –11.1 12 53.6 8.3 47 116.6 27.8 82 179.6
–34.4 –30 –22.0 –10.6 13 55.4 8.9 48 118.4 28.3 83 181.4
–31.7 –25 –13.0 –10.0 14 57.2 9.4 49 120.2 28.9 84 183.2
–28.9 –20 –4.0 –9.4 15 59.0 10.0 50 122.0 29.4 85 185.0

–28.3 –19 –2.2 –8.9 16 60.8 10.6 51 123.8 30.0 86 186.8

–27.8 –18 –0.4 –8.3 17 62.6 11.1 52 125.6 30.6 87 188.6
–27.2 –17 1.4 –7.8 18 64.4 11.7 53 127.4 31.1 88 190.4
–26.7 –16 3.2 –7.2 19 66.2 12.2 54 129.2 31.7 89 192.2
–26.1 –15 5.0 –6.7 20 68.0 12.8 55 131.0 32.2 90 194.0

–25.6 –14 6.8 –6.1 21 69.8 13.3 56 132.8 32.8 91 195.8

–25.0 –13 8.6 –5.6 22 71.6 13.9 57 134.6 33.3 92 197.6
–24.4 –12 10.4 –5.0 23 73.4 14.4 58 136.4 33.9 93 199.4
–23.9 –11 12.2 –4.4 24 75.2 15.0 59 138.2 34.4 94 201.2
–23.3 –10 14.0 –3.9 25 77.0 15.6 0 140.0 35.0 95 203.0

–22.8 –9 15.8 –3.3 26 78.8 16.1 61 141.8 35.6 96 204.8

–22.2 –8 17.6 –2.8 27 80.6 16.7 62 143.6 36.1 97 206.6
–21.7 –7 19.4 –2.2 28 82.4 17.2 63 145.4 36.7 98 208.4
–21.1 –6 21.2 –1.7 29 84.2 17.8 64 147.2 37.2 99 210.2
–20.6 –5 23.0 –1.1 30 86.0 18.3 65 149.0 37.8 100 212.0

–20.0 –4 24.8 –0.6 31 87.8 18.9 66 150.8 40.6 105 221.0

–19.4 –3 26.6 0 32 89.6 19.4 67 152.6 43.3 110 230.0
–18.9 –2 28.4 0.6 33 91.4 20.0 68 154.4 46.1 115 239.0
–18.3 –1 30.2 1.1 34 93.2 20.6 69 156.2 48.9 120 248.0
–17.8 0 32.0 1.7 35 95.0 21.1 70 158.0 51.7 125 257.0

–17.2 1 33.8 2.2 36 96.8 21.7 71 159.8 54.4 130 266.0

–16.7 2 35.6 2.8 37 98.6 22.2 72 161.6 57.2 135 275.0
–16.1 3 37.4 3.3 38 100.4 22.8 73 163.4 60.0 140 284.0
–15.6 4 39.2 3.9 39 102.2 23.3 74 165.2 62.7 145 293.0
–15.0 5 41.0 4.4 40 104.0 23.9 75 167.0 65.6 150 302.0

–14.4 6 42.8 5.0 41 105.8 24.4 76 168.8 68.3 155 311.0

–13.9 7 44.6 5.6 42 107.6 25.0 77 170.6 71.1 160 320.0
–13.3 8 46.4 6.1 43 109.4 25.6 78 172.4 73.9 165 329.0
–12.8 9 48.2 6.7 44 111.2 26.1 79 174.2 76.7 170 338.0
–12.2 10 50.0 7.2 45 113.0 26.7 80 176.0 79.4 175 347.0

00-21
Foreword Units

Units
In this manual, the measuring units are indicated with Internatinal System of units (SI).
As for reference, conventionally used Gravitational System of units are indicated in parentheses { }.

Example:
N {kg}
Nm {kgm}
MPa {kg/cm2}
kPa {mmH2O}
kPa {mmHg}
kW/rpm {HP/rpm}
g/kWh {g/HPh}

00-22
 01 General

General assembly drawing.............................01- 2

Specifications .................................................01- 3
Weight table ...................................................01- 8
Table of fuel, coolant and lubricants ...............01- 10

D155C-1 01-1
General General assembly drawing

General assembly drawing

a The data in ( ) are for 7.3 m boom.

01-2 D155C-1
General Specifications

Specifications

Model name of machine D155C-1

Serial No. 31586 and up

Operating weight 6.2-m boom 7.3-m boom

Weight

• Boom + Counterweight + Cab + Side cover with kg

45,800 45,930
710-mm wide shoe
Max. lifting load kN {kg} 686 {70,000} 686 {70,000}

Overhang of boom m 1.2 – 6.1 1.3 – 7.1

Gradeability deg. 30

Stability (Forward, reverse, right, and left) deg. 35

1st km/h 3.6

Forward
Performance

2nd km/h 6.6

Transmission
gear speed

3rd km/h 11.2

1st km/h 4.4

Reverse

2nd km/h 7.8

3rd km/h 12.4

length pressure
Overall Overall Ground

Boom + Counterweight + Cab + Side cover MPa {kg/cm2} 0.09 {0.92}

Overall length mm 5,840

Retraction of counterweight mm 3,760

width

Extraction of counterweight mm 5,575

6.2-m boom 7.3-m boom

Dimensions

Overall
height

Up to boom top pin (With boom retracted) mm 6,780 7,955

Up to top of counterweight
(With counterweight extracted) mm 3,020

Track gauge mm 2,380

Length of track on ground mm 3,620

Width of track shoe (Standard) mm 710

Minimum ground clearance mm 460

(Up to underside of undercover)

D155C-1 01-3
General Specifications

Model name of machine D155C-1

Serial No. 31586 and up

Name SA6D140E-2

Type 4-cycle, water-cooled, in-line, direction injection,

with turbocharger and aftercooler

Number of cylinders – Bore x Stroke mm 6 – 140 x 165

Total displacement l {cc} 15.24 {15,240}

Rated output kW {HP}/rpm 239 {320}/2,000

Max. torque Nm {kgm}/rpm 1,412 {144}/1,400

Performance
Engine

High idling speed rpm 2,130 ± 50

Low idling speed rpm 600 ± 50

Min. fuel consumption ratio g/kW•h 202 {149}

{g/HP• h}

Starting motor 24 V, 11 kW

Alternator 24 V, 50 A

Battery 12 V, 170 Ah

Type of radiator core D-6

Torque converter 3 elements, 1 stage, 1 phase

Planetary gear, hydraulic, forced lubrication type,

Transmission
3 forward gear speeds and 3 reverse gear speeds
Power train

Bevel gear shaft Spiral bevel gear, splash lubrication type

Clutch and

Steering clutch Wet, multiple-disc, spring pressure, manual type

brake

Steering brake Wet, band, foot-operated, hydraulic booster type

Spur gear, 1-stage planetary gear,

Final drive
splash lubrication type
Suspension Rigid
Undercarriage

Carrier roller 2 pieces on each side

Track roller 8 pieces on each side

Assembly-type, single grouser,

Track shoe (710 mm)
41 pieces on each side, Pitch: 228.6 mm

Transmission pump Gear type (FAL045)

Scavenging pump Gear type

Steering pump Gear type (BAR(3)140)

01-4 D155C-1
General Specifications

Model name of machine D155C-1

Serial No. 31586 and up

Counterweight Segment plate type, hydraulically controlled

Counterweight pump Gear type (PAL063)

Hydraulically controlled, double drum,

Type
reversible type

Hydroshift, wet, multi-disc, multi-shaft,

Transmission
clutch type

Wet, multi-disc, spring pressure, hydraulic

Brake
release type
Winch

Pump Gear type (FAL100)

Work equipment

Hook speed (with bare drum)

Winding-in: 1st gear speed m/min 5.5

2nd gear speed m/min 12.7

Winding-out: 1st gear speed m/min 4.5

2nd gear speed m/min 10.2

Type Double acting, piston type
counterweight cylinder
Hydraulic cylinder

Cylinder bore mm 120

Dimensions of

Outside diameter of piston rod mm 50

Max. piston stroke mm 873

Max. distance between pins mm 2,118

Min. distance between pins mm 1,245

D155C-1 01-5
General Specifications

Lifting performance curve

Equipment
• Wire rope: 20 mm in diameter, having minimum breaking load of 27,600 kg
• Number of wire ropes for the hook: 6
• Number of wire ropes for the boom: 5
• Counterweight pushed out: 9,230 kg
Pulley efficiency is included.

01-6 D155C-1
General Weight table

Weight table
k This weight table is a guide for use when transporting or handling components.

Unit: kg

Model name of machine D155C-1

Serial No. 31586 and up

Engine and torque converter assembly 1,985

• Engine 1,750

• Torque converter 235

Radiator and radiator guard assembly 735

• Radiator assembly 400

• Radiator guard 335

Fuel tank assembly 138

Universal joint 25

TORQFLOW transmission 950

• Transmission control valve 35

Bevel gear shaft and steering clutch

• Steering clutch and brake band assembly (1 side) 160

• Bevel gear shaft unit 35

• Bevel gear unit 40

Steering control valve assembly 60

Brake cover link assembly (1 side) 50

Final drive case (1 side) 185

Sprocket assembly (1 side) 350

Main frame and steering case assembly

• Steering case and main frame 3,030

• Sprocket shaft unit (1 side) 152

assembly

Single shoe (710 mm, 1 side) 5,670

Track

Single shoe (760 mm, 1 side) 5,920

01-8 D155C-1
General Weight table

Unit: kg

Model name of machine D155C-1

Serial No. 31586 and up

Track frame

• Idler assembly (1 side, including yoke) 500

• Track roller (Single, 1 piece) 110

• Track roller (Double, 1 piece) 120

• Carrier roller 65

• Recoil spring assembly (1 side) 330

• Track frame (1 side) 1,440

Cross bar 780

Engine underguard 190

Bumper 160

Transmission underguard 150

Front: 200
Floor frame assembly
Rear: 430

PTO assembly 165

• Counterweight pump 24

• Transmission pump 21

• Steering pump 26

• Winch pump 29

Hydraulic tank 360

• Control valve assembly 9

Counterweight cylinder assembly (1 side) 50

D155C-1 01-9
General Table of fuel, coolant and lubricants

Table of fuel, coolant and lubricants

Standard

01-10 D155C-1
General Table of fuel, coolant and lubricants

–50°C Specification

D155C-1 01-11
General Table of fuel, coolant and lubricants

Note
1) When fuel sulphur content is less than 0.5 %,
c h a n g e o i l i n t h e o i l pa n e v e r y p e r i o d i c
maintenance hours described in this manual.
Change oil according to the following table if fuel
sulphur content is above 0.5 %.
Change interval of oil
Fuel sulphur content
in engine oil pan
0.5 to 1.0% 1/2 of regular interval
Above 1.0% 1/4 of regular interval

2) When starting the engine in an atmospheric

temperature of lower than 0°C, be sure to use
e n g i n e o i l o f S A E 1 0 W, S A E 1 0 W- 3 0 a n d
SAE15W-40 even though an atmospheric
temperature goes up to 10°C more or less in the
day time.
3) Use API classification CD as engine oil and if
API classification CC, reduce the engine oil
change interval to half.
4) There is no problem if single grade oil is mixed
with multigrade oil (SAE10W-30, 15W-40), but
be sure to add single grade oil that matches the
temperature in the table on the left.
5) We recommend Komatsu genuine oil which has
been specifically formulated and approved for
use in engine and hydraulic work equipment
applications.
ASTM: American Society of Testing and Material
SAE: Society of Automotive Engineers
API: American Petroleum Institute
Specified capacity:
Total amount of oil including oil for compo-
nents and oil in piping.
Refill capacity:
Amount of oil needed to refill system during
normal inspection and maintenance.

01-12 D155C-1
 10 Structure and function

Radiator fan .................................................. 10- 2 Recoil spring ..................................................10- 56

Radiator shutter ............................................ 10- 4 Suspension ....................................................10- 57
PTO (Power Take-Off)................................... 10- 5 Winch control .................................................10- 58
Oil cooler ....................................................... 10- 6 Hydraulic circuit diagram for winch ................10- 61
Power train diagram...................................... 10- 8 Winch.............................................................10- 62
TORQFLOW hydraulic circuit........................ 10- 10 Detailed working circuit diagram for clutch
Hydraulic circuit diagram............................... 10- 11 and brake of winch..................................10- 67
Torque converter ........................................... 10- 12 Power train on winch .....................................10- 69
Transmission control ..................................... 10- 17 High-Low valve ..............................................10- 75
Transmission................................................. 10- 19 PPC valve......................................................10- 76
Transmission control valve............................ 10- 27 Flow divider valve ..........................................10- 78
Transmission lubrication relief valve ............. 10- 34 Counterweight hydraulic tank ........................10- 80
Steering and brake control ............................ 10- 35 Counterweight piping .....................................10- 81
Axle, steering clutch...................................... 10- 36 Counterweight control....................................10- 82
Steering brake hydraulic piping..................... 10- 39 Counterweight hydraulic circuit diagram........10- 83
Steering and brake hydraulic circuit Counterweight................................................10- 84
diagram .................................................. 10- 40 Counterweight control valve ..........................10- 87
Steering brake............................................... 10- 42 Boom .............................................................10- 88
Steering control valve.................................... 10- 48 Safety device .................................................10- 89
Final drive ..................................................... 10- 53 Cab ................................................................10- 95
Track group ................................................... 10- 55 Actual electric wiring diagram ........................10- 96

D155C-1 10-1
Structure and function Radiator fan

Radiator fan

1. Upper tank 10. Fin

2. Cap 11. Tube
3. Plug (for measuring water temperature) 12. Drain valve
4. Tube 13. Outlet tube
5. Inlet tube 14. Lower tank
6. Boss 15. Shield
7. Pulley 16. Core
8. Shaft 17. Fan
9. Tube

10-2 D155C-1
Structure and function Radiator fan

The radiator is composed of three parts, upper tank After its temperature has been lowered, the cooling
(1), radiator core (16) and lower tank (14). water in the lower tank is forced by the water pump
The cooling water passes the engine thermostat and back to the engine cylinder block.
goes to the upper tank where it stays for a short time The upper tank is equipped with a vacuum valve
to remove the air contained in it. The cooling water which keeps the pressure in the upper tank within 74
then flows from the upper tank to the lower tank, kPa {0.75 kg/cm2}. This is to prevent cooling water
passing through the radiator core. Here, heat is dis- from boiling at more than 100°C and forming air bub-
persed by radiation to reduce the temperature of the bles in the cooling water.
cooling water to 85 – 95°C, the most suitable tem- In addition, there is a tube (11) between the upper
perature for the engine. tank and the inlet tube of water pump. The function
The core consists of a number of flat drawn tubes (9) of tube (11) is to supply cooling water from the upper
and fins (10) which increase the heat dispersal effi- tank to prevent the formation of air bubbles at the
ciency. There are two types, D type and G type, inlet of the water pump.
divided according to the arrangement of the tubes. Radiator fan (17) is driven by the V-belts round the
The radiator of the D155C is of the in-line type (D pulleys attached to the engine, and forces air to the
type). core to increase the heat dispersal efficiency of the
core.
The D155C employs the air push-type to send air to
the radiator.

D155C-1 10-3
Structure and function Radiator shutter

Radiator shutter

1. Control lever Lever position

2. Lock lever A: CLOSE
3. Rod B: OPEN
4. Radiator shutter C: Lever “FREE”
D: Lever “LOCK”

10-4 D155C-1
Structure and function PTO (Power Take-Off)

PTO (Power Take-Off)

The PTO device is attached to the upper part of the The transmission pump is attached to the front face
engine flywheel. It is composed of main shaft (3) of the flywheel housing.
(which fits to the spline of the gear meshed with the The oil flowing through the oil cooler return hose is
external teeth of the engine flywheel), drive gear (2) divided to lubrication tubes (12) and (13) by block
assembled to main shaft (3), and three driven gears (11) to lubricate the gears and bearing of the PTO.
(1), (5), (8) and planetary gear (7).
Shaft (9) is attached to the boss spline of driven gear
(8), and the steering pump is attached to the boss
spline of gear (1).

1. Driven gear (for steering pump) 8. Driven gear

2. Drive gear 9. Shaft
3. Main shaft 10. Case
4. Flywheel housing 11. Block
5. Driven gear (for counterweight pump) 12. Lubrication tube
6. PTO case 13. Lubrication tube
7. Planetary gear

D155C-1 10-5
Structure and function Oil cooler

Oil cooler

1. Tube 7. Oil cooler A. Oil inlet

2. Tube 8. Drain plug B. Oil outlet
3. Tube 9. Tube C. Water inlet
4. Hose 10. Tube D. Water outlet
5. Tube 11. Cover (R.H.)
6. Case 12. Cover (L.H.)

10-6 D155C-1
Structure and function Power train diagram

Power train diagram

10-8 D155C-1
Structure and function Power train diagram

1. Engine (SA6D140E-2) • Power generated by engine (1) is transmitted to

2. Torque converter torque converter (2) via the flywheel. In the
3. Universal joint torque converter, power from the engine turns
4. TORQFLOW transmission the output shaft (turbine shaft) by the oil in
5. Steering case accordance with load fluctuations.
6. Steering brake • The power from the torque converter output
7. PTO shaft is transmitted through universal joint (3) to
8. Steering clutch the input shaft of transmission (4).
9. Sprocket A clutch in the transmission is selected by the
10. Final drive transmission control valve mounted on the
11. Track transmission case. Power is then transmitted to
12. Coupling bevel pinion A at the rear end of the transmis-
sion.
A. Bevel pinion (21 teeth) The steering clutches and brakes are used to
B. Bevel gear (49 teeth) change machine traveling direction or stop the
C. Final drive No. 1 pinion (12 teeth) machine.
D. Final drive No. 1 gear (45 teeth) • The power thus transmitted by way of engine o
E. Final drive No. 2 pinion (12 teeth) torque converter o transmission is directed to
F. Final drive No. 2 gear (55 teeth) left and right steering clutches (8) (perpendicular
to the power train) by bevel pinion A, and bevel
P1: Steering pump gear B.
P2: Scavenging pump The direction of the machine is changed by
P3: Transmission pump operating the steering control valve on the steer-
P4: Hydraulic pump ing case and disengaging the steering clutch on
the side intended to turn. In this case the
machine turns at a large radius. For a sharp
turning, steering brake (6) mounted on the
periphery of the steering clutch brake drum, is
applied.
Power from the steering clutch is transmitted to
the final drive flange, being transmitted under
sequential speed reduction by way of final drive
pinion C o final drive gear D. Furthermore,
power is transmitted to sprocket (9) reducing the
speed by the planetary gear mechanism. The
sprocket drives track (11) to cause the machine
travel.

D155C-1 10-9
Structure and function TORQFLOW hydraulic circuit

TORQFLOW hydraulic circuit

1. Oil cooler A. Plug for R.H. clutch pressure (PT1/8)

2. Torque converter B. Plug for L.H. clutch pressure (PT1/8)
3. Regulator valve C. Plug for brake booster pressure (PT1/8)
4. Transmission pump (FAL045) D. Plug for R.H. brake pressure (PT1/8)
5. Transmission lubrication relief valve E. Plug for L.H. brake pressure (PT1/8)
6. Transmission control valve
7. R.H. brake booster
8. Brake relief valve
9. L.H. brake booster
10. Magnetic strainer
11. Oil filter
12. Relief valve
13. Steering pump (FAR100)
14. Oil strainer

10-10 D155C-1
Structure and function Hydraulic circuit diagram

Hydraulic circuit diagram

1. Steering case 14. Brake relief valve

2. Magnet strainer 15. Transmission valve
3. Steering pump (FAR100) 16. Modulating relief valve
4. Transmission pump (FAL045) 17. Torque converter
5. Oil filter 18. Regulator valve
6. Oil filter 19. Oil cooler
7. Flow divider valve 20. Torque converter relief valve
8. Modulating valve 21. Transmission lubrication
9. Steering clutch control valve (L.H.) 22. Orifice
10. Steering clutch control valve (R.H.) 23. PTO lubrication
11. Main relief valve 24. Torque converter case
12. Brake flow divider valve 25. Scavenging pump
13. Brake booster 26. Transmission lubrication relief valve

D155C-1 10-11
Structure and function Torque converter

Torque converter

1. Drive gear 12. Stator 23. Relief valve spring

2. Drive case 13. Scavenging pump 24. Regulator valve spool
3. Turbine 14. Drive gear 25. Regulator valve spring
4. Torque converter housing 15. Strainer
5. Pump 16. Drain plug A. To lubricating circuit
6. Drive gear 17. Turbine boss B. From transmission
7. Stator shaft 18. Holder modulating valve
8. Housing 19. Pilot C. To oil cooler
9. Coupling 20. Relief valve D. Oil temperature sensor
10. Turbine shaft 21. Regulator valve mounting port
11. Stator boss 22. Relief valve spool E. To steering case

10-12 D155C-1
Structure and function Torque converter

D155C-1 10-13
Structure and function Torque converter

Operation of torque converter

1. Transmission of power
The power generated by the engine is transmit-
ted to pump (5). This pump, drive gear (1), and
drive case (2) are made in 1 unit rotated
together.
The power transmitted to the pump rotates tur-
bine (3) with the oil. Accordingly, the power is
transmitted to turbine shaft (10) and coupling (9)
which is made together with the turbine in 1 unit.
The power transmitted to the coupling is trans-
mitted through the universal joint to the input
shaft of the transmission.

2. Flow of oil
The oil pressure is regulated to 0.85 MPa {8.7
kg/cm 2 } by the torque converter relief valve.
Then, the oil flows through port A and the oil
hole in stator shaft (7) into pump (5). Since the
pump is constantly rotated by the engine power,
the oil in it is given centrifugal force and flows in
turbine (3), which is rotated by the centrifugal
force of the oil.
Since the turbine and turbine shaft (10) are
made in 1 unit, the power received by the tur-
bine is transmitted to the transmission.
The oil flowing out of turbine (3) is sent to stator
(12) and flows in pump (5) again. A part of it is
sent from stator shaft (7) through port B to the
oil cooler, however.

10-14 D155C-1
Structure and function Torque converter

Outline
Model D155C is equipped with a three-element, one
stage, single phase torque converter which uses
fluid to carry out automatic torque conversion,
depending upon machine load, while transmitting
power from the engine. The principle components of
the torque converter are pump (5) for converting
mechanical energy from the engine into kinetic
energy of fluid, turbine (3) for reconverting the trans-
mitted kinetic energy into mechanical energy, and
stator (12) for guiding the fluid flow.
When drive gear (1), meshing with the internal teeth
of the flywheel, is rotated by engine starting, pump
(5), constituting a unit with the drive gear and drive
case (2), and mounted on stator shaft (7) with the
bearing, is rotated.
By this rotation, the fluid is thrown outward from the
pump along the pump blades by centrifugal force,
and flows helically to the turbine.
The fluid is impelled with force against the blades of
the turbine and changes its direction toward stator
(12).
The reaction developed at the blades by this action
causes the turbine to rotate, and power is transmit-
ted by turbine shaft (10).
The fluid at the turbine is directed from the central
part of the turbine to the stator where its direction is
changed, and finally returned to the central part of
the pump.
In short, while the fluid flows in the order of pump o
turbine o stator o pump, power is continuously
delivered from the pump to the turbine shaft, from
which it is then transmitted to the universal joint.
The stator used in model D155C is fixed securely on
the stator shaft spline, and does not rotate.
The torque converter (comprising, as already men-
tioned, one pump, one turbine, and one fixed stator)
is referred to as three-element, one stage, single
phase torque converter.

Torque converter relief valve

This relief valve controls the hydraulic pressure of
the fluid so that abnormally high pressure is not
applied to the torque converter. The hydraulic pres-
sure, which is at 2.0 ± 0.2 MPa {20 ± 2 kg/cm2} when
relieved from the modulating relief valve of the trans-
mission valves, is further reduced to 0.85 +0.03
+0 MPa
+0.3
{8.7 +0 kg/cm } by this relief valve.
2

The fluid from the transmission control valve flows

through port A and the passage in the torque con-
verter housing to the pump.
When port A is filled up and hydraulic pressure to
the pump reaches 0.69 ± 0.01 MPa {7 ± 0.1 kg/cm2},
the fluid compresses spring (1), pushing up spool
(2), and flows through port B into the flow circuit of
the transmission lubrication relief valve.
a Cracking pressure:
0.85 +0.03
+0 MPa {8.7 +0.3
+0 kg/cm2}

D155C-1 10-15
Structure and function Torque converter

Torque converter regulator valve

This regulator valve, incorporated into the outlet cir-
cuit of the torque converter, maintains hydraulic
pressure inside the torque converter below 0.44 ±
0.05 MPa {4.5 ± 0.5 kg/cm2 } to protect the torque
converter and ensure optimum performance.
Fluid from the torque converter flows through the
passage in the torque converter housing to port C
until the port is filled up.
When hydraulic pressure in port C reaches 0.44 ±
0.05 MPa {4.5 ± 0.5 kg/cm2}, the fluid compresses
spring (3), pushing up spool (4), and flows through
port D into the oil cooler circuit.
a Set pressure
0.25 ± 0.1 MPa {2.5 ± 1.0 kg/cm2} at 60 l/min.
0.34 ± 0.05 MPa {3.5 ± 0.5 kg/cm2} at 100 l/min.
0.44 ± 0.05 MPa {4.5 ± 0.5 kg/cm2} at 200 l/min.

Scavenging pump
Oil oozing out from between contacting faces of
pump, turbine, and stator and PTO lubricating oil is
drained into the torque converter housing after lubri-
cating each sliding part.
Oil collected in the torque converter housing is recir-
culated through strainer (15) to the steering case by
means of scavenging pump (13) which is driven by
gears (14) provided on the back face of the torque
converter pump.

14. Drive gear

20. Cover
21. Driven gear
22. Pump case
23. Drive gear

10-16 D155C-1
Structure and function Transmission control

Transmission control

1. Transmission control valve

2. Lock lever
3. Shift lever

Lever position
N: Neutral
A: Forward 1st
B: Forward 2nd
C: Forward 3rd
D: Reverse 1st
E: Reverse 2nd
F: Reverse 3rd
G: Free
H: Lock

D155C-1 10-17
Structure and function Transmission

Transmission

1. Transmission control valve cover A. From transmission pump

2. Transmission lubrication relief valve B. To torque converter
3. Transmission case C. From torque converter oil cooler
4. Transfer case D. To No. 1 (forward) clutch
5. Transmission control valve cover E. To No. 2 (reverse) clutch
F. To No. 5 (1st speed) clutch
G. To No. 4 (2nd speed) clutch
H. To No. 3 (3rd speed ) clutch
J. Reducing pressure detection port

D155C-1 10-19
Structure and function Transmission

10-20 D155C-1
Structure and function Transmission

6. Input coupling 32. No. 4 (2nd speed) gear

7. Input shaft (21 teeth) 33. No. 5 (1st speed) clutch drum
8. Front cover 34. No. 5 (1st speed) gear (105 teeth)
9. Cage 35. No. 5 (1st speed) piston housing
10. No. 1 (forward) sun gear (33 teeth) 36. Valve seat
11. No. 1 (forward) piston housing 37. Ball check valve
12. No. 1 (forward) clutch piston 38. No. 5 (1st speed) clutch piston
13. No. 1 (forward) planetary pinion (24 teeth) 39. Rear housing
14. No. 1 (forward) ring gear (81 teeth) 40. Collar
15. No. 1, 2 (forward, reverse) clutch plate 41. Output shaft
16. No. 2 (reverse) planetary pinion (24 teeth) 42. Transfer drive gear (29 teeth)
17. Pinion shaft 43. Cage
18. No. 2 (reverse) ring gear (81 teeth) 44. Bevel pinion (21 teeth)
19. No. 2 (reverse ) clutch piston 45. Cover
20. No. 2 (reverse) piston housing 46. Cage
21. No. 1, 2, 3 (forward, reverse, 3rd speed) 47. Transfer driven gear (24 teeth)
carrier 48. Retainer
22. No. 3 (3rd speed ) ring gear (81 teeth) 49. No. 5 (1st speed) piston return spring
23. No. 3 (3rd speed ) clutch piston 50. Wave spring
24. No. 3 (3rd speed) planetary pinion (24 teeth) 51. No. 4 (2nd speed) piston return spring
25. No. 3, 4 (3rd speed, 2nd speed) piston 52. No. 3 (3rd speed) piston return spring
housing 53. No. 2 (reverse) planetary pinion (23 teeth)
26. No. 3, 4 (3rd speed, 2nd speed) sun gear 54. No. 2 (reverse) piston return spring
(33 teeth, 42 teeth) 55. No. 1 (forward) piston return spring
27. No. 4 (2nd speed) clutch piston 56. Washer spring
28. No. 4 (2nd speed) clutch plate 57. Clutch plate
29. No. 4 (2nd speed) ring gear (81 teeth) 58. Clutch disc
30. Pinion shaft 59. Pin
31. No. 4 (2nd speed) planetary pinion (19 teeth) 60. Tie-bolt

D155C-1 10-21
Structure and function Transmission

Outline
Model D155C is equipped with planetary type trans-
mission (F3, R3) and is a combination of planetary
gear system and disc clutch.
For each revolution direction and rpm, two of 5 disc
clutches of the planetary gear system are hydrauli-
cally locked by actuating the control valve.
No. 1 clutch is for Forward, No. 2 for Reverse, No. 3
for 3rd speed, No. 4 for 2nd speed, and No. 5 for 1st
speed.

Speeds and operation clutches

Speed Operating clutch
Neutral No. 5 clutch
1st speed No. 1 and No. 5 clutches
Forward
2nd speed No. 1 and No. 4 clutches
3rd speed No. 1 and No. 3 clutches
Neutral No. 5 clutch
1st speed No. 2 and No. 5 clutches
Reverse
2nd speed No. 2 and No. 4 clutches
3rd speed No. 2 and No. 3 clutches

Number of discs and plates on each clutch

Clutch No. Number of discs Number of plates
No. 1 clutch 4 3
No. 2 clutch 4 3
No. 3 clutch 3 2
No. 4 clutch 2 1
No. 5 clutch 5 4

10-22 D155C-1
Structure and function Transmission

Operation of disc clutch

• The disc clutch is composed of piston (12), plate
(57), disc (58), pin (59), piston return spring (55)
and washer spring (56) to return spring (55) and
washer spring (56) to fix ring gear (14).
• Disc (58) internal teeth are engaged with ring
gear (14) external teeth.
• Plate (57) is engaged with pin (59) fixed to the
protruding cut-out portion outside plate (57) and
piston housing (11).

Clutch "engage" (locking)

• Oil from the control valve is forced to the rear
side of piston (12) through the port on piston
housing (11).
• Piston (12) crimps plate (57) and disc (58), and
the frictional force stops rotating disc (58) and
locks ring gear (14) engaged with the internal
teeth.

Clutch "release" (opening)

• When oil from the control valve is cut off, piston
return spring (55) returns piston (12) to the origi-
nal position, the frictional force between plate
(57) and disc (58) is released, and ring gear (14)
comes to the neutral position.
• Pin plate (57) and washer spring (56) fitted
between plates (57) are intended to return pis-
ton (12) quickly and to separate plate (57) from
disc (58) so as to prevent drag turning when the
clutch is released.

D155C-1 10-23
Structure and function Transmission

Operation of No. 5 clutch (ball check valve)

• No. 5 clutch is rotary one.
• When the clutch is released, the pressure oil on
the rear side of the piston generates centrifugal
force due to the rotation, and piston return
spring (49) force is not sufficient to return piston
(38) to the original position. So, the clutch
remains half engaged.
• Even if the gear shift lever is set to the neutral
position from the operator's seat, the clutch
remains engaged and the gear comes not to be
shifted.
• To prevent this situation, ball check valve (37) is
installed in rotary clutch piston housing (35).

Clutch "engage" (locking)

• Oil from the control valve is forced to the rear
side of piston (38) through the port on piston
housing (35).
• Then, ball check valve (37) closes the hole on
the valve seat. The piston crimps plate (57) and
disc (58) and engages the internal teeth of disc
(58) with the external teeth of gear (34) and the
external teeth of plate (57) with the internal teeth
of clutch drum (33). And gear (34) and clutch
drum (33) rotate together.

Clutch "release" (opening)

• When oil from the control valve is cut off, ball
check valve (37) is forced to the outer side by
centrifugal force due to rotation. Oil on the rear
side of piston (38) passes through the clearance
of ball check valve (37) and is drained from
valve seat (36). Piston return spring (49) returns
piston (38) to the original position without affect
of oil centrifugal force.
• On the other hand, when piston (38) returns to
the original position and the clutch is released,
plate (57) and wave spring (50) fitted between
plates (57) separate plate (57) from disc (58)
smoothly and prevents drag turning.

10-24 D155C-1
Structure and function Transmission

Operation of transmission

Forward 1st speed

• In the forward 1st speed, No. 1 clutch and No. 5 • When No. 5 clutch is connected, ring gear (22),
clutch are connected, ring gear (14) is fixed and carrier (32), clutch drum (33) and gear (34) are
gear (34) and output shaft (41) are directly con- combined like a unit.
nected to output power. • As the carrier rotates, the power rotates all of
• Power from the torque converter is transmitted ring gear (22), carrier (32), clutch drum (33),
to input coupling (6) and then to input shaft (7), gear (34) and sun gear (26). Output shaft (41)
sun gear (10) and planetary pinion (13). rotates in the same direction with sun gear (10)
• Since ring gear (14) is fixed, planetary pinion to transmit the power.
(13) rotates on its own axis and moves around • The rotation of output shaft (41) is transmitted to
sun gear (10) along ring gear (14). transfer drive gear (42), transfer driven gear (47)
• And carrier (21) transmits power rotating in the and is output from bevel pinion (44) as a rotation
same direction with sun gear (10). in reverse direction from the input direction.

D155C-1 10-25
Structure and function Transmission

Reverse 1st speed

• In the forward 1st speed, No. 2 clutch and No. 5

clutch are engaged, ring gear (18) is fixed and
gear (34) and output shaft (41) are directly con-
nected to output power.
• Power from the torque converter is transmitted
to input coupling (6) and then to input shaft (7),
planetary pinion (53) and planetary pinion (16).
• Since ring gear (18) is fixed, planetary pinion
(16) and planetary pinion (53) rotate on their
own axes and move around input haft (7) along
ring gear (18).
• At the time, the power that rotates input shaft (7)
is transmitted as power to rotate the carrier.
Since the power is transmitted through planetary
pinion (53), the carrier rotates in the reverse
direction from input shaft (7).
• So, the power to output shaft (41) is transmitted
in the reverse direction. Thereafter, the power
transmission routes of the 1st, 2nd and 3rd
speeds are the same as those for the above for-
ward 1st speed, forward 2nd speed and forward
3rd speed.

10-26 D155C-1
Structure and function Transmission control valve

Transmission control valve

D155C-1 10-27
Structure and function Transmission control valve

10-28 D155C-1
Structure and function Transmission control valve

A. Reducing pressure detection port

B. To torque converter
C. From transmission pump
D. To speed valve H port
E. To speed valve L port
F. To No. 1 (forward) clutch
G. To No. 2 (reverse) clutch
H. From reducing valve D port
J. To No. 5 (1st speed ) clutch
K. To No. 4 (2nd speed) clutch
L. From reducing valve E port
M. To No. 3 (3rd speed) clutch

1. Upper valve
2. Lower valve
3. Valve set
4. Stopper cover
5. Spring
6. Spring
7. Spring seat
8. Spring
9. Upper valve body
10. Modulating relief valve spool
11. Modulating relief valve sleeve
12. Piston
13. Spring
14. Piston
15. Stopper
16. Cover
17. Quick return valve sleeve
18. Quick return valve
19. Piston
20. Spring
21. Piston
22. Reducing valve
23. Spring
24. Stopper
25. Stopper
26. Directional valve spool
27. Lower valve body
28. Speed valve spool

D155C-1 10-29
Structure and function Transmission control valve

Modulating valve

Outline
• The modulating valve consists of a modulating
relief valve and a quick return valve and is
intended for pressure modulating and main
relief.
• When the gear shift lever is changed over, the
clutch is crimped with the piston. When a high
pressure is applied suddenly, the piston will con-
nect the clutch quickly and the machine will start
immediately or be subjected to an excessive
shock.
So, the modulating valve is installed to rise the
oil pressure applied to the piston slowly to the
set pressure when the gear shift lever is
changed over. It helps to engage the clutch
smoothly without shock at the time of starting, to
improve durability of the power train and to
make the operation comfortable.
Set pressure: 2.26 +0.2 +2
–0.1 MPa {23 –1 kg/cm }
2

• The right figure shows oil pressure rise and time

elapse in modulating. When forward 1st speed
is changed to forward 2nd speed, for example,
oil from the pump flows in the 2nd speed clutch
through the speed valve and fills the circuit up to
the clutch piston port.
The time that elapses until oil fills the circuit up
to the clutch piston port is called the filling time,
and the oil pressure is 0 – 0.49 MPa {0 – 5 kg/
cm2}. The time that elapses from pressure rise to
arrival to the set pressure after the circuit was
filled with oil is called the build-up time. The fill-
ing time and the build-up time compose the
modulating time.

10-30 D155C-1
Structure and function Transmission control valve

Operation
1. Right after gear shift
• When the gear shift lever is changed over to
engage the clutch, the passage from the pump
to the clutch piston will open and oil will flow in
the clutch piston. This oil flow moves quick
return valve (18) to the left, and the passage
from chamber A to drain port B opens to release
the back pressure of modulating relief valve
sleeve (11).
Then, the reaction force of springs (5), (6) and
(8) return modulating relief valve spool (10) and
modulating relief valve sleeve (11) to the right
and closes the passage to the torque converter.

2. Start and on the way of oil pressure rise

• When oil forced from the pump fills the circuit up
to the clutch piston, the oil pressure will start ris-
ing. Oil passed through orifice "a" of quick
return valve (18) moves the quick return valve to
the right and closes the passage between cham-
ber A and drain port B. Also, the oil flows
through orifice "b" of modulating relief valve
spool (10) and flows in chamber C to push pis-
ton (14). Then, the reaction force makes modu-
lating relief valve spool (10) compress springs
(5) and (8) and move them to the left. So, the
passage of port D between modulating relief
valve spool (10) and modulating relief valve
sleeve (11) opens and the oil pressure is
relieved to the torque converter.
On the other hand, oil passed through the center
port of quick return valve (18) flows in chamber
A through orifice "c" and turns into the back
pressure of modulating relief valve sleeve (11).
The back pressure moves valve sleeve (11) to
the left and compresses spring (6).

D155C-1 10-31
Structure and function Transmission control valve

3. On the way and end of oil pressure rise

As the oil pressure in the circuit rises, the back
pressure of modulating relief valve sleeve (11)
rises. When valve sleeve (11) moves to the left,
the passage of port D to modulating relief valve
spool (10) will close. Also, the oil pressure push-
ing piston (14) rises, the reaction force moves
valve spool (10) to the left and open the pas-
sage of port D to modulating relief valve sleeve
(11).
A s t he a bo v e o pe r a t io n i s i nt e r m i tt en t l y
repeated, the loads to springs (5), (6) and (8)
increase, the oil pressure rises gradually and
modulating relief valve sleeve (11) comes to the
stopper cover at last and does not move any
more.
At the time, modulating relief valve spool (10)
opens the passage of part D to modulating relief
valve sleeve (11) and stops there.
The oil from the pump flows in modulating relief
valve spool (1) and modulating relief valve
sleeve (11) and is relieved from port D to the
torque converter.
Then, the rise of oil pressure ends.

10-32 D155C-1
Structure and function Transmission control valve

Reducing valve

Outline
• The reducing valve is located in the circuit
between the modulation valve and the speed
valve and reduces the oil pressure applied to the
1st speed clutch below the set pressure of the
modulation valve.
• A rotary clutch is adopted as the 1st speed
clutch of the transmission of a machine on which
the reducing valve is installed.
If the same oil pressure applied to other clutches
is applied to the 1st speed clutch and the clutch
is engaged, an excessive oil pressure much
higher than the clutch capacity will be applied to
the 1st speed clutch. Therefore, the clutch disc
and the clutch plate will be damaged and the
seal ring will be overloaded. As a result, the
clutch will easily come to slip due to oil leak.
So, the reducing valve is installed mainly to pro-
tect the 1st speed clutch (rotary clutch).

Operation
1. Valve "Open"
When oil from the pump fills the whole circuit
and closes the ball check valve of the 1st speed
piston housing, the oil pressure in the whole cir-
cuit including the 1st speed clutch circuit will
start rising.
The modulating valve lets the oil pressure rise
slowly, but the oil passed through orifice "a" of
reducing valve (22) pushes piston (19). As the
oil pressure rises, the reaction force moves
reducing valve (22) gradually to the left and
starts throttling the 1st speed clutch circuit.

2. Valve "Close"
When the modulating valve lets the oil pressure
in the whole circuit rise further, reducing valve
(22) will move more to the left, keep throttling
the 1st speed clutch circuit, come to the stopper
and will not move any more. At the time, the 1st
speed clutch circuit closes the passage from the
modulating valve, and the oil pressure in the cir-
cuit comes not to rise.
When the oil pressure drops due to lubrication of
the transmission or oil leak from the seal ring,
the reaction force of spring (23) will open the 1st
speed clutch circuit, raise the dropped oil pres-
sure to the set pressure of reducing valve (22)
and will maintain the oil pressure at the set pres-
sure.
Set pressure: 1.27 +0.2 +2
–0.1 MPa {13 –1 kg/cm }
2

The oil pressures in the other clutch circuits

except the 1st speed clutch circuit rise further to
the set pressure of the modulating valve.

D155C-1 10-33
Structure and function Transmission lubrication relief valve

Transmission lubrication relief valve

A. To steering case Outline

B. From oil cooler • Oil from the torque converter flows through the
C. To transmission lubrication oil cooler and the transmission lubrication relief
D. To transmission lubrication valve and lubricates the transmission, the brake
and the PTO.
1. Valve body • The transmission lubrication relief valve is
2. Cover installed to the transmission case and maintains
3. Valve guide the lubricating oil pressure at the set pressure.
4. Valve spring Set pressure: 0.12 MPa {1.24 kg/cm2}
5. Lubricating valve
6. Cover
7. O-ring
8. Sleeve
9. Sleeve
10. Gasket

10-34 D155C-1
Structure and function Steering and brake control

Steering and brake control

1. Steering lever Positions of levers and pedals

2. Lock lever N: Neutral F: Right brake RELEASED
3. Brake pedal A: Right clutch DISENGAGED G: Right brake APPLIED
4. Steering brake B: Right clutch DISENGAGED, H: Left brake RELEASED
5. Steering control valve Right brake APPLIED J: Left brake APPLIED
C: Neutral K: Free
D: Left clutch DISENGAGED L: Lock
E: Left clutch DISENGAGED,
Left brake APPLIED

D155C-1 10-35
Structure and function Axle, steering clutch

Axle, steering clutch

1. Outer drum (brake drum) 7. Breather 13. Cover

2. Pressure plate 8. Axle hub 14. Drain plug
3. Clutch plate (each 11 pieces) 9. Bearing cage 15. Hub nut
4. Clutch disc (each 12 pieces) 10. Taper roller bearing 16. Clutch spring (large)
5. Inner drum (clutch drum) 11. Axle 17. Clutch spring (small)
6. Clutch piston 12. Bevel gear (49 teeth) 18. Collar

10-36 D155C-1
Structure and function Axle, steering clutch

1. Axle 2. Steering clutch

The rear axle system is installed which converts The steering clutches, mounted on both ends of
the power transmitted in the order of engine o the axle, control machine steering by transmit-
torque converter o transmission to right and left ting or shutting off the torque delivered to the
at right angles by engaging the bevel pinion at axle; that is, by supplying or stopping the power
the end of the transmission output shaft with to the final drive.
bevel gear (12) on the rear axle. In model D155C, the wet type, multi-plate,
The skew bevel gears are used for the bevel spring clutch is employed.
pinion and the bevel gear. Rear axle shaft (11) is The steering clutch is made up of clutch inner
connected to the steering case by taper roller drum (5) bolted to axle hub (8) which is locked
bearing (10) and bearing cage (9), with adjust- on axle (11) by taper spline, clutch outer drum
ing shims placed between the shaft and the (1) bolted to final drive primary pinion flange,
case to enable adjustment of the tooth bearing plate (3) meshing with the inner drum, disc (4)
with the bevel pinion. meshing with the outer drum, pressure plate (2)
Axle hubs (8) for mounting the steering clutch for pressing the plate and the disc, piston (6),
are pressed in both ends of the axle by means clutch springs (16) and (17), and bolt for mount-
of the taper serration. On the axle hub and the ing the piston and the pressure plate.
bearing cage, the oil port for the clutch operation In the steering clutch, the plate drives and the
is grooved. disc is driven.
Splash lubrication is employed by rotation of the
bevel gear in the oil tank.
Adjustment of the backlash and the teeth bear-
ing of the bevel pinion and the bevel gear con-
sists in the axial adjustment in which shims
provided to the bevel pinion bearing cage
mounting face on the side of the transmission is
reduced or increased and in the transverse
adjustment in which right and left shims pro-
vided to the axle bearing cage mounting face
are increased or reduced.

D155C-1 10-37
Structure and function Axle, steering clutch

Left steering clutch engaged

Basically, pressure plate (2) under force of clutch
springs (16) and (17), presses plate (3) and discs (4)
against inner drum (5), and the frictional force devel-
oped by this transmits power from the inner drum to
the outer drum.

Left steering clutch disengaged

When the steering lever is pulled, fluid from the
steering control valve is forced to flow through bear-
ing cage (9), and axle hub (8) to the right half of
piton (6) and pushes the piston leftward, compress-
ing clutch springs (16) and (17). Thus, pressure
plate (2) is moved leftward, bringing the pressing
force onto plate (3) and disc (4) to zero. As a result,
the power supply to the final drive is stopped. When
the steering lever is released, the discharge circuit
of the steering control valve is opened, and the pis-
ton returns to the initial position under the force of
the clutch spring. Thus the clutch engaged condition
is attained, as shown in the above picture. When the
left steering clutch is disengaged, power is delivered
only to the right steering clutch, achieving the right
turn.

10-38 D155C-1
Structure and function Steering brake hydraulic piping

Steering brake hydraulic piping

1. Oil strainer Outline

2. Steering pump (FAR100) The oil inside the steering case passes through oil
3. Steering filter strainer (1) and is sucked up by steering pump (2). It
4. Steering main relief valve and flow divider the passes through oil filter (3) and is sent to main
5. Steering control valve relief and flow divider valve (4).
6. Brake relief valve In the flow divider valve there is a piston which
7. Brake booster divides the flow into oil for steering circuit 3 and
brake circuit 1. After the oil is divided, it is set to a
A. Plug for R.H. clutch pressure (PT1/8) pressure of 1.23 MPa {12.5 kg/cm 2 } by the main
B. Plug for L.H. clutch pressure (PT1/8) relief valve, and flows to steering valve (5). The oil
C. Plug for brake booster pressure (PT1/8) relieved by the main relief valve flows to torque con-
D. Plug for R.H. brake pressure (PT1/8) verter circuit.
E. Plug for L.H> brake pressure (PT1/8) The oil in the brake circuit flows to the left and right
brake boosters (7) and when the brake is applied the
maximum pressure is set to 2.45 MPa {25 kg/cm2}
by brake relief valve (6).

D155C-1 10-39
Structure and function Steering and brake hydraulic circuit diagram

Steering and brake hydraulic circuit diagram

Steering

1. Magnet strainer 9. Modulating valve

2. Steering pump (FAR100) 10. L.H. clutch spool
3. Steering filter 11. R.H. clutch spool
4. Flow divider valve 12. Steering case
5. Piston
6. Steering main relief valve A. Main relief pressure take-off plug (PT1/8)
7. L.H. clutch spool B. L.H. clutch pressure take-off plug (PT1/8)
8. R.H. clutch spool C. R.H. clutch pressure take-off plug (PT1/8)

10-40 D155C-1
Structure and function Steering and brake hydraulic circuit diagram

Brake

1. Magnet strainer 10. Spool

2. Steering pump (FAR100) 16. Steering brake
3. Steering filter 17. L.H. brake pressure take-off port (PT1/8)
4. Flow divider valve 18. R.H. brake pressure take-off port (PT1/8)
7. Flow divider valve for brake 19. Steering case
8. Brake relief valve 20. Brake booster pressure take-off port (PT1/8)
9. Brake booster

D155C-1 10-41
Structure and function Steering brake

Steering brake

1. Brake cover 9. Cover 17. Rod

2. Lever 10. Rod 18. End
3. Lever 11. Return spring 19. Brake lining
4. Booster spring 12. Cover 20. Brake band
5. Booster spool 13. Adjustment bolt 21. Relief spring
6. Booster body 14. Bracket 22. Bushing
7. Booster piston 15. Lever 23. Retainer
8. Lever 16. Block

10-42 D155C-1
Structure and function Steering brake

The steering brake employed in model D155C is an

anchor type, contracting band brake, in which the
band clamps the outer surface of the brake drum.
This brake is a wet type using an oil bath.
Steering brake interlocks with steering lever and
functions by brake pedals.
When parking machine, depress in the middle of
right and left brake pedals and engage brake lock to
lock brake pedals.

D155C-1 10-43
Structure and function Steering brake

Steering brake engaged

When the steering lever on the turning side is pulled,
the steering clutch on the turning side is disen-
gaged.
However, the power remains partially on the clutch
and drives the track shoe on the turning side, result-
ing in a wide turning radius.
In order to improve on this, it is so designed as to
apply a brake on the outer drum (brake drum) by
pulling the lever further in order to shorten the turn-
ing radius.
Depressing the brake pedal causes lever (2) to
press spool (6), thus closing the oil circuit from
selector valve (23) at the position between the valve
and piston (8).
With increasing pressure in the port connecting
booster body (7) and the piston, the piston is moved
to open the drain port.
Then, the brake pedal is further depressed by the
amount corresponding to the opening of the drain
port to press the spool. When this procedure is con-
tinuously carried out, lever (24) at the front end of
the piston is pressed, pulling rod (11) in the direction
of the arrow, and the brake is applied by lever (13).

Brake operation during forward turning

Brake band (10) is supported at one end by A of
lever (13) while another end is supported by B of rod
(15).
Depressing the brake pedal causes rod (11) to be
shifted, and pulling lever, as shown by arrows.
One end of the brake band moves downward while
the other end moves upward, with C of the lever act-
ing as a supporting point.
As the drum is rotating in the forward direction, the
brake band clamps the drum, with A acting as a sup-
porting point, while supporting point C at the oppo-
site position is shifted from the drum.

Brake operation during reverse turning

Depressing the brake pedal causes A to move
upward and B downward.
As the drum is rotating in the reverse direction, the
brake band clamps the drum, with B acting as a sup-
porting point, while supporting point A at the oppo-
site position is shifted from the drum.

10-44 D155C-1
Structure and function Steering brake

Brake booster valve

• In the D155C, a brake booster is used for the
steering brake to reduce the operating force of
the steering lever and steering brake pedal.
• The flow divider valve divides the oil from the
steering pump at the rate of 3 parts for the steer-
ing circuit and 1 part for the brake circuit. In
addition, the oil in the brake circuit is divided into
left and right lines by the flow divider valve, and
enters port A of the brake booster.

• When the brake pedal is depressed, lever (2)

pushes spool (5) and the passage between the
spool and piston (7) is shut off.
When the passage is shut off, the oil pressure to
port A starts to rise.
When the oil pressure at port A rises, the piston
moves to the right and the passage to the drain
port is opened.
When this drain port is opened and brake pedal
is pushed further, it pushes the spool and shuts
off the passage.
By repeating this operation, the tip of the piton
pushes lever (8) and pulls rod (10) to the left.
The brake is then actuated by lever (15).

D155C-1 10-45
Structure and function Steering brake

• The brake is fully applied and the passage to the

drain port is kept shut off. When the oil pressure
inside the circuit rises, the oil pushes open
plunger (24) of the brake relief valve and is
drained from the drain port to the steering case.
The set pressure of the relief valve at this point
is 2.5 MPa {25 kg/cm2}.
When the oil pressure rises, a pressure differ-
ence is generated at the left and right ports of
the free piston of the flow divider valve in the
brake circuit. The free piston moves to the circuit
on the side where the brake pedal is not being
depressed, and increases the flow of oil to the
high pressure port.

10-46 D155C-1
Structure and function Steering control valve

Steering control valve

The steering control valve consists of flow divider

(25) for distributing the fluid to the steering circuit
and to the brake circuit, main relief valve (21) for
adjusting the steering circuit at the set pressure
(1.23 MPa {12.5 kg/cm2}), the brake relief valve for
adjusting the brake circuit at the set pressure (2.5
MPa {25 kg/cm2}), valve spools (2) and (9) for direct-
ing the fluid flow to either the right or left steering
clutch and valves (4), (7) for modulating steering
clutch pressure.

10-48 D155C-1
Structure and function Steering control valve

1. Piston F. Plug (for right steering clutch pressure PT 1/8)

2. Spool (right) G. Plug (for left steering clutch pressure PT 1/8)
3. Spring H. Plug (for brake main relief pressure PT 1/8)
4. Modulating valve I. Plug (for right brake pressure PT 1/8)
5. Valve body J. Plug (for left brake pressure PT 1/8)
6. Brake valve assembly
7. Spool
8. Spring
9. Spool (left)
10. Spring
11. Piston
12. Lever (right)
13. Lever (left)
14. Valve body
15. Plate
16. Seat
17. Tube
18. Tube (right)
19. Stopper
20. Spring
21. Main relief valve
22. Piston
23. Stopper
24. Stopper
25. Flow divider

D155C-1 10-49
Structure and function Steering control valve

Main relief valve

• Fluid from the steering pump is directed into port
A then distributed to the steering circuit and the
brake circuit in the proportion of 3:1 by flow
divider (28).

• As the fluid from the control valve fills the port up

to the clutch piston, the pressure in the steering
circuit increases and the fluid in port B flows
through orifice a of relief valve (24) into piston
(25) to push it.
The pressure on the piston works as a reaction
force on relief valve (24) and moves it to the left.
Thus, the fluid is drawn from port B to port C
and then into the torque converter circuit.
This relieving pressure of the circuit is wet pres-
sure (1.23 MPa {12.5 kg/cm 2 }) of the steering
circuit.

Right and left clutch "ON"

(control valve "HOLD")
• Pressurized oil from pump passes through main
relief valve (24) and enters port D in valve body.
Pressurized oil in port D flows into port L pass-
ing through port M and port N.
Pressurized oil in port L flows to TORQFLOW
circuit.

10-50 D155C-1
Structure and function Steering control valve

Left clutch "OFF", right clutch "ON"

(left lever pulled)
• When left steering lever is pulled, left spool (9)
and spool (7) are moved in the direction o with
lever (13). When valve is moved, pressurized oil
enters from orifice d of valve and reaction force
pushing piston (1), together with lever control
force, moves spool in the direction o only stroke
of left spool and push modulating valve (4) in the
direction o with the aid of spring (8) and guide.
Pressurized oil from pump enters port D of valve
body through main relief valve and flows into
port E and port G passing through clearance b
between modulating valve and valve body.
• As in modulating valve reaction force pushing
piston (11) with pressurized oil flowing from port
G after passing through orifice e balances with
reaction force of spool side, pressurized oil in
port E flows to left clutch from port F, thus left
clutch is released.
When left spool is moved halfway instead of to
its stroke end, modulating valve pumps due to
difference of pressure between port D and ports
E, G and clearance b is opened and closed
i ntermittently, thus c lutch becomes half-
engaged. When left steering lever is released,
passage for pressurized oil in port D is closed
and flow to left clutch is cut.
• On the other hand oil in left clutch piston circuit
is returned with clutch piston spring and enters
drain port H via clearance c between left spool
and valve body and is drained there.
At the same time, modulating valve and valve
return to "HOLD" position and pressurized oil
enters drain port J via piping of seat (17) and is
drained there.

D155C-1 10-51
Structure and function Steering control valve

Left clutch "ON", Right clutch "OFF"

(right lever pulled)
• When right steering lever is pulled, right spool
(2) and spool (7) are moved in the direction o
with lever (12).
When valve is moved, pressurized oil enters
from orifice d of valve and reaction force push-
ing piston (1), together with lever control force,
moves spool in the direction o only stroke of
right spool and push modulating valve (4) in
direction o through the side of spring (8) and
guide.
Pressurized oil from pump enters port D of valve
body through main relief valve and flows into
port E and port G passing through clearance b
between modulating valve and valve body.
• As in modulating valve reaction force pushing
piston (11) with pressurized oil flowing from port
G after passing through orifice e balances with
reaction force of spool side, pressurized oil in
port G flows to right clutch from port K, thus right
clutch is released.
• When right spool is moved halfway instead of to
its stroke end, modulating valve pumps due to
the difference of pressure between port D and
ports E, G and clearance b is opened and
closed intermittently, thus clutch becomes half-
engaged.
• When right steering lever is released, passage
for pressurized oil in port D is closed and flow to
right clutch is cut.
On the other hand, oil in right clutch piston cir-
cuit is returned with clutch piston spring and
enters drain port H via clearance between right
spool and valve body and is drained there.
At the same time modulating valve and valve
return to respective "HOLD" position and pres-
surized oil enters drain port J via piping of seat
(17) and is drained there.

Left clutch "OFF", right clutch "OFF"

(right and left levers are pulled)
• When both right and left clutches are pulled,
above operations of pulling right and left levers
are performed at the same time, pressurized oil
flows from port F and port K to left and right
steering clutch pistons, thus both right and left
clutches are released.

10-52 D155C-1
Structure and function Final drive

Final drive

1. Final drive flange 11. Sprocket support 21. Sprocket shaft

2. No. 1 pinion (12 teeth) 12. Cover 22. Nut
3. Cover 13. Nut 23. Sprocket hub
4. Final drive case 14. Bushing 24. Holder
5. Cover 15. Collar 25. No. 2 pinion (12 teeth)
6. Segment teeth 16. Floating seal 26. No. 1 gear (45 teeth)
7. Seal guard 17. Retainer 27. Flange nut
8. Sprocket boss 18. Floating seal 28. Spacer
9. Stopper 19. Guard
10. Sprocket nut 20. No. 2 gear (55 teeth)

D155C-1 10-53
Structure and function Final drive

Model D155C employes the two-step reduction

method using spur gears, and splash lubrication the
gear rotation is used.
• Power from the axle and steering system is
transmitted through the clutch outer drum (brake
drum) to final drive flange (1), rotating No. 1 pin-
ion (2) on the flange.
No. 1 pinion engages with No. 1 gear (26), rotat-
ing No. 2 pinion (25) on the gear shaft.
Power is further transmitted from the No. 2 pin-
ion to No. 2 gear (20) engaging with the No. 2
pinion, with speed reduction effected at the
same time.
Due to the construction in which the No. 2 gear
is bolted on final drive hub (23), into which
sprocket boss (8) is pressed in by the taper ser-
ration the rotation of the No. 2 gear turns itself
into the rotation of the sprocket boss.

• Final drive case (4) functions as a lubricating oil

tank for each gear. The rotating sliding parts of
the sprocket are equipped with floating seals
(16) and (18) in order to prevent entry of dust or
mud, and oil leakage.

10-54 D155C-1
Structure and function Track group

Track group

1. Idler
2. Rod
3. Carrier roller
4. Recoil spring
5. Carrier roller
6. Track roller guard
7. Track roller (D)
8. Track roller (S)

D155C-1 10-55
Structure and function Recoil spring

Recoil spring

1. Rod 11. Piston ring

2. Piston 12. Front cover
3. Front pilot 13. Spacer
4. Recoil spring (large) 14. Bolt
5. Recoil spring (small) 15. Rear pilot
6. Sleeve 16. Stopper
7. Nut 17. Lubricator
8. Cover 18. Grease fitting
9. Cylinder 19. Plug
10. Packing

10-56 D155C-1
Structure and function Suspension

Suspension

1. Bar
2. Shim
3. Washer

D155C-1 10-57
Structure and function Winch control

Winch control
Winch

1. High-low valve General

2. Winch assembly • The winch control has three control levers linked to
3. PPC valve a total of seven valves (six pressure proportional
4. Winch control box control valves and a high-low selector valve).
5. High-low control lever This control system facilitates such crane opera-
6. Hook control lever tions as simultaneous operation, inching operation,
7. Lock lever and free-fall operation.

Lever position
Winch high-low control lever
N: NEUTRAL
A: LOW
B: HIGH
Hook control lever
C: LOWER
N: NEUTRAL
D: RAISE
E: FREE FALL
Lock lever
F: FREE
L: LOCK

10-58 D155C-1
Structure and function Winch control

Boom

1. PPC valve • Make sure that the interlock mechanism is in

2. Winch control box action with the high-low control lever in neutral
3. Boom control lever (N). If the boom or hook control lever cannot be
4. Lock lever moved to RAISE or LOWER position when the
5. Dumper high-low control lever is in neutral, it indicates
that the interlock mechanism is positively in
Lever position action.
A: LOWER • When the high-low control lever is in LOW or
N: NEUTRAL HIGH position, make sure that the boom or hook
B: RAISE control lever can be moved smoothly to RAISE
F: FREE or LOWER position without actuation of the
L: LOCK interlock mechanism.

D155C-1 10-59
Structure and function Winch control

Winch control lever mechanism

1. Hook lever Lever position

2. Winch control box A: Hook RAISE
3. Boom lever B: Hook LOWER
4. PPC valve C: Boom RAISE
5. Boom raise spool D: Boom LOWER
6. Boom lower spool N: NEUTRAL
7. Boom brake spool
8. Hook lower spool
9. Hook brake spool
10. Hook raise spool

10-60 D155C-1
Structure and function Hydraulic circuit diagram for winch

Hydraulic circuit diagram for winch

1. Winch case 7. Low clutch

2. Winch pump (FAL100) 8. High clutch
3. Oil filter (set pressure: 0.14 MPa {1.4 kg/cm2}) 9. Gear lubrication
4. Flow divider valve 10. Bushing lubrication
5. High-low valve 11. Hook raise clutch
5A. Pressure adjustment valve 12. Hook brake
(set pressure: 1.5 – 2.2 MPa {15 – 22.5 kg/cm2}) 13. Hook lower clutch
5B. Oil cooler bypass valve 14. Boom raise clutch
(set pressure: 0.74 – 1.2 MPa {7.5 – 12 kg/cm2}) 15. Boom brake
5C. Lubrication valve 16. Boom lower clutch
(set pressure: 0.4 – 1.01 MPa {4 – 10.3 kg/cm2}) 17. Solenoid valve
6. Oil cooler bypass valve 18. PPC valve

D155C-1 10-61
Structure and function Winch

Winch

1. Boom case General

2. Flow divider valve • The important unit for assuring full pipelayer per-
3. High-low valve formance, it employs various new methods and
4. Hook case new mechanisms to realize improved perfor-
5. Winch strainer mance and durability. Power train is separated
6. Boom case into two lines: one for controlling the boom, the
7. Winch control box other for the hook. Two lines are each provided
8. PPC valve with individual wet, multiple plate type lifting
9. Winch filter clutches, lowering clutch and brake. Hydrauli-
10. Hook case cally controlled clutches and brakes allow two
11. Filter tube winch drums to rotate independently or simulta-
neously in desired direction.
A. Drum shaft
B. Intermediate shaft
C. Brake shaft
D. Lowering shaft
E. Lifting shaft
F. High-low shaft
G. Input shaft

10-62 D155C-1
Structure and function Winch

D155C-1 10-63
Structure and function Winch

1. Hook brake assembly 5. High clutch assenbly 9. Boom drum

2. Hook raise clutch assembly 6. Boom lower clutch assembly 10. Hook drum
3. Hook lower clutch assembly 7. Boom raise clutch assembly 11. Drum shaft
4. Low clutch assembly 8. Boom brake aseembly

10-64 D155C-1
Structure and function Winch

Winch clutch

1. Drum
2. Piston
3. Drum (inner)
4. Disc
5. Plate
6. Drum (outer)
7. Plate
8. Drum (outer)
9. Shaft
10. Plate
11. Bolt

D155C-1 10-65
Structure and function Winch

Winch brake

1. Drum (inner)
2. Cover
3. Disc
4. Plate
5. Drum (outer)
6. Piston
7. Cover
8. Shaft

10-66 D155C-1
Structure and function Detailed working circuit diagram for clutch and brake of winch

Detailed working circuit diagram for clutch and brake of winch

D155C-1 10-67
Structure and function Detailed working circuit diagram for clutch and brake of winch

Operation
• Oil from oil pump is distributed by flow divider to
two oil circuits: The control circuit which includes
the PPC valve, and the lubrication circuit for var-
ious component parts. Oil distributed to control
circuit flows to individual clutches and brakes.
The direction of oil flow to a clutch or brake is
varied depending on operation of PPC valve.
• When a PPC valve spool is moved to the left, oil
pressure actuates the corresponding clutch pis-
ton to engage clutch. At the same time, oil pres-
sure releases the corresponding brake.
• When clutch piston reaches its stroke end, PPC
valve spool is returned to neutral position, open-
ing the oil drain port, so that oil pressure in cir-
cuit leading to clutch piston is prevented from
increasing further.
Spring-loaded brakes are normally actuated,
clutches are normally disengaged.
• When releasing a brake, it is necessary to push
the brake piston by hydraulic pressure against
return spring force. When engaging a clutch,
clutch disc is compressed by hydraulic pressure.

10-68 D155C-1
Structure and function Power train on winch

Power train on winch

1. Neutral position of the Hi-Low lever

Operation
• The PTO input shaft (winch No. 1 shaft) is con-
nected to the Hi-Low clutch first. Since each
lever is in neutral, however, the hydraulic oil
from the PPC valve is drained and the power is
not transmitted.

D155C-1 10-69
Structure and function Power train on winch

2. Low position of the Hi-Low lever

Operation
• Since the Hi-Low lever is in the "Low" position,
the hydraulic oil from the PPC valve flows in the
Low clutch.

10-70 D155C-1
Structure and function Power train on winch

3. High position of the Hi-Low lever

Operation
• Since the Hi-Low lever is in the "Hi" position, the
hydraulic oil from the PPC valve flows in the Hi
clutch.

D155C-1 10-71
Structure and function Power train on winch

4. Low position of the Hi-Low lever and hook Raise operation

Operation
• Since the winch Hi-Low lever is in the "Low"
position and the hook lever is in the "Raise"
position, the hydraulic oil from the PPC valve
flows in the hook raise clutch and hook brake to
release the hook drum. Accordingly, the hook
drum rotates.

10-72 D155C-1
Structure and function Power train on winch

5. High position of the Hi-Low lever and boom Raise, hook Lower operation

Operation
• Since the winch Hi-Low lever is in the "Hi" posi-
tion and the boom lever is in the "Raise" position
and the hook lever is in the "Lower" position, the
hydraulic oil from the PPC valve flows in the
hook brake and boom brake to release the hook
drum and boom drum. Accordingly, the hook
drum and boom drum rotate.

D155C-1 10-73
Structure and function Power train on winch

6. Hook lever (Free fall)

Operation
• The hook lever is in the “Free fall“ position, sole-
noid valve for hook lower clutch stops oil flow to
hook lower clutch, and release the hook brake.
Accordingly, the hook drum rotates.

10-74 D155C-1
Structure and function High-Low valve

High-Low valve

1. Spring Structure
2. Detent ball • High-low selector valve is combined with lubri-
3. Spool (for selector valve) cation valve, cooler bypass valve and pressure
4. Spool (For pressure adjustment valve) adjustment valve.
5. Spool (for cooler bypass valve)
6. Spool (for lubrication valve)

D155C-1 10-75
Structure and function PPC valve

PPC valve

1. Spring Structure
2. Piston • PPC valve consists of six spools which control
3. Spring boom raising clutch, boom brake, boom lower-
4. Shaft ing clutch, hook lowering clutch, hook brake and
raising clutch.
• Each spool is a directional control spool which
changes the direction of oil flow by moving to
right or left.

10-76 D155C-1
Structure and function PPC valve

Operation
• The figure shows PPC valve in neutral where
pressurized oil in a clutch is drained out.
• Spring force in valve is increased according to
stroke of valve spool (1). If spool (1) is moved to
left, drain port C will be closed. At same time,
passage of oil from inlet port A to clutch port B
will be opened, allowing oil to flow into clutch,
which will, in turn, increase the oil pressure.
• Under increased oil pressure, spool will be
moved to right, closing the passage to clutch
port, which will, in turn, result in oil flow from
drain port. In this manner, spring force applied
to spool is dependent on spool stroke.

D155C-1 10-77
Structure and function Flow divider valve

Flow divider valve

1. Spool Structure
2. Body • Flow divider valve properly distributes oil from
3. Plug an oil pump to two hydraulic systems, and is
operated independently.
A. From winch pump • Oil must be sent at a certain flow ratio to two
B. To high-low valve separate points from a single pipe. This is
C. To high-low valve accomplished by routing oil through a flow
divider containing a free piston which automati-
cally moves back and forth in response to pres-
sure changes, and thus regulates the flow.
• Some flow dividers are used for dividing oil flow
into two circuits at the rate of 1 : 1. (Division of
oil flow can be adjusted as required by changing
the size and number of holes provided in the
flow divider for distributing oil to two circuits.)

10-78 D155C-1
Structure and function Flow divider valve

Operation
• A hollow piston capable of moving left or right is
provided in the valve and its center has holes
drilled sideways. Oil flows from port A into cen-
ter of hollow piston through holes and is divided
into L.H. and R.H. chambers B and C leading to
boosters. The hollow piston forms small and
long hole.

• In normal conditions where flow amounts in L.H.

and R.H. chambers B and C are equal, piston
(1) does not move because it is pushed under
equal oil pressure from both ends.
• If oil pressure is increased in L.H. chamber B,
amount of oil flow on left side will be reduced.
• If there were no flow divider, oil from the pump
will escape through the R.H. booster giving less
resistance, resulting in no oil pressure rise in
L.H. booster.
In flow divider, if amount of oil flow on left side is
reduced by more pressure, and piston (1) will be
pushed to right, increasing pressure and resis-
tance on the right. Thus, resistance and pres-
sure will be built up on both left and right sides,
and actuate the flow divider sleeve to control
flow quantity in proper amount for both sides
and actuate the flow devider piston to control the
flow quantity in proper amount for both sides.

• If oil pressure is reduced in L.H. chamber B,

amount of oil flow on left side will be increased
due to less resistance. Then, piston (1) in the
valve will be pushed to left by the oil pressure
from R.H. chamber C.
As described above, the oil flow is divided into
L.H. and R.H. chambers at the ratio of 1 : 1, irre-
spective of oil pressure.

• Effect of orifice
This orifice a was purposed to prevent the chat-
tering of spool by the damping effect of oil kept
in the left side chamber B.

D155C-1 10-79
Structure and function Counterweight hydraulic tank

Counterweight hydraulic tank

1. Cap Specification
2. Screen Tank capacity: 47 l
3. Sight gauge (When counterweight is retracted)
4. Counterweight control valve
5. Hydraulic tank

A: Counterweight cylinder bottom side

B: Counterweight cylinder head side
C: To counterweight pump
D: From counterweight pump

10-80 D155C-1
Structure and function Counterweight piping

Counterweight piping

1. Counterweight cylinder (front) General

2. Counterweight • Counterweight (2) is smoothly operated by the
3. Counterwight cylinder (rear) hydraulic system. This system is established by
4. Slow return valve counterweight control valve (6) and slow return
5. Oil filter valve (4).
6. Counterweight control valve • Counterweight control valve (6) is located on
7. Hydraulic tank (for counterweight) hydraulic tank (7) and slow return valve (4) is
8. Counterweight pump (SAL(2)-040) located in the piping.
9. PTO case

D155C-1 10-81
Structure and function Counterweight control

Counterweight control

1. Hydraulic tank (for counterweight) Lever position

2. Control valve A: RETRACT
3. Control lever B: EXTEND
4. Lock lever F: FREE
H: HOLD
L: LOCK

10-82 D155C-1
Structure and function Counterweight hydraulic circuit diagram

Counterweight hydraulic circuit diagram

1. Hydraulic tank
2. Counterweight pump (PAL063)
3. Main relief valve (Set pressure: 13.7 MPa {140 kg/cm2})
4. Spool
5. Oil filter (Set pressure: 0.22 MPa {2.2 kg/cm2})
6. Slow return valve
7. Counterweight cylinder

D155C-1 10-83
Structure and function Counterweight

Counterweight

1. Counterweight cylinder Function

2. Link • Counterweight (4) suspended by a counter-
3. Frame weight cylinder (1) is used for relocating the
4. Counterweight machine center of gravity. Necessary machine
balance can be maintained even when the
heavy weight of a pipe is loaded on opposite
side of machine. Link (2) mechanism for pro-
truding counterweight outside of machine is
designed so that a large moment can be
obtained from a relatively light weight.
• The easy-to-assemble segment plate type coun-
terweight (4) facilitates transportation and
makes it possible to vary the number of segment
plates assembled together as a counterweight
to meet the requirements for hoisting capacity.

10-84 D155C-1
Structure and function Counterweight

Operation
Retraction of counterweight
• The counterweight is retracted by extracting cyl-
inder (7). Spool (4) of the changeover valve is
set to the "RETRACT" position.
• The oil flows through port A and port C of slow
return valve (6) to the cylinder bottom side. The
oil on the cylinder head side returns through the
orifice of port D of the slow return valve. The
counterweight is operated smoothly by this sys-
tem.

1. Hydraulic tank 4. Spool

2. Counterweight pump (PAL063) 5. Oil filter (Set pressure: 0.22 MPa {2.2 kg/cm2})
3. Main relief valve 6. Slow return valve
(Set pressure: 13.7 MPa {140 kg/cm2}) 7. Counterweight cylinder

D155C-1 10-85
Structure and function Counterweight

Extention of counterweight
• The counterweight is extended by retracting cyl-
inder (7). Spool (4) of the changeover valve is
set to the "EXTEND" position.
• The oil flows through port B and port D of slow
return valve (6) to the cylinder head side. The
oil on the cylinder bottom side returns through
port C of the slow return valve. Since the oil
flow is reduced by port D, the counterweight is
extracted smoothly.

1. Hydraulic tank 4. Spool

2. Counterweight pump (PAL063) 5. Oil filter (Set pressure: 0.22 MPa {2.2 kg/cm2})
3. Main relief valve 6. Slow return valve
(Set pressure: 13.7 MPa {140 kg/cm2}) 7. Counterweight cylinder

10-86 D155C-1
Structure and function Counterweight control valve

Counterweight control valve

A. To counterweight cylinder
B. To counterweight cylinder
P. From counterweight pump
T. To counterweight tank

D155C-1 10-87
Structure and function Boom

Boom

1. Sheave block (lower) Structure

2. Wedge • The simple gate type boom, the main parts of
3. Wedge pocket which are made of high-tension steel or high-ten-
4. Sheave block (upper) sion steel casting, is strong enough to suspend
5. Boom heavy loads handled by large size pipelayers.
6. Boom cable Box cross-section boom assures high durability.

10-88 D155C-1
Structure and function Safety device

Safety device
Boom kick-out system
• This is a safety device. If boom should collide 1. Boom
against machine body because of overwinding 2. Damper
of wire rope or any other reason, it will cause 3. Shaft
loss of balance or damage to machine body. 4. Spring
Collisions are eliminated by the boom kick-out 5. Rod
system. 6. Boom control lever
• As shown in the figure below, damper spring (4)
is actuated when point A of boom (1) comes into Lever position
contact with point B of shaft (3). A: Boom RAISE
The shock given to the shaft (3) is transmitted to N: NEUTRAL
the rod (5) which automatically moves the boom B: Boom LOWER
control lever (6) from RAISE position to NEU-
TRAL position. As a result, winch is braked by
function of PPC valve.

D155C-1 10-89
Structure and function Safety device

Overwind caution system

• This system prevents overwind of the hook to
protect the wire, rope, hook, and pulley.
• The overwind caution system works not only
when the hook is raised but also when the boom
is lowered.
• While the machine is traveling without operating
the hook control lever and boom control lever,
even if the hook sheave block swings and switch
(5) is turned ON, horn (6) does not sound.

Function
• Switch (5) is turned ON and OFF with the lever.
Normally, since the weight is hanging in the free
state, the switch is kept turned OFF.
• If the hook is wound in more than a certain point,
the weight rises together with hook sheave
block. Then, cable (3) is slackened, switch lever
(4) turns (operates), the switch is turned ON,
and horn (6) sounds.
• If the hook is raised or the boom is lowered, the
positive (+) power of the battery is supplied
through the oil pressure switch to switch (5). If
switch (5) is turned ON at this time, horn (6)
sounds.
If the hook or boom is stopped under this condi-
tion, the oil pressure switch is turned OFF.
Since relay (7) is turned ON, however, the posi-
tive (+) power is supplied through the relay to
switch (5), thus horn (6) keeps sounding.
If the hook or boom is raised and the weight
hangs in the free state, switch (5) is turned OFF
and horn (6) stops sounding.

1. Hook sheave block

2. Weight
3. Cable
4. Lever
5. Switch
6. Horn
7. Relay

A: To winch PPC valve oil pressure switch

B: To winch PPC valve oil pressure switch

10-90 D155C-1
Structure and function Safety device

Winch brake release device

• This system is used when abnormal conditions,
such as engine trouble, arise. It enables the
brake to be released manually and the load to
be lowered safely.

1. Lever Lever position

2. Valve A: OPEN
3. Drain hose B: CLOSE
4. Elbow
5. Shim
6. Gasket
7. Oil pump
8. Hose

D155C-1 10-91
Structure and function Safety device

Operation
1. When lowering boom
1) Remove elbow (4), install shim (5) and
gasket (6) as shown in the figure, then
install elbow (4) again.
2) Install oil pump (7) and hose (8) as shown in
the figure.
3) Fill pump (7) with engine oil, operate lever
(1) as shown in the figure to generate
hydraulic power. Release the brake and
lower the load.
When doing this, check that valve (2) is in
the CLOSE position.
The lever must be operated 30 to 40 times
to generate hydraulic power. (This is to fill
the brake chamber with oil to make up for
the oil lost during disassembly.)
4) To stop the load, set valve (2) to the OPEN
position to release the hydraulic pressure
and apply the brake.
When valve (2) is set to the OPEN position,
oil will spurt out from drain hose (3).
a Use the same engine oil as used for the
winch.

2. When lowering hook

1) Remove elbow (4), install shim (5) and
gasket (6) as shown in the figure, then
install elbow (176-76-62320) again.
2) All other procedures are the same as for
lowering the hook.

k Precautions:
Always use engine oil to fill the pump of this
release device. Never use grease, or any pump
which may allow grease to mix with the oil. If
grease gets in, it may become impossible to
operate the winch.

10-92 D155C-1
Structure and function Safety device

Moment limiter

• The moment limiter is installed between the

winch and boom. It is an alarm to prevent a roll-
over of the machine caused by a load.

1. Sheave block A. To yellow lamp (Wiring harness: Different color)

2. Cable B. To red lamp (Wiring harness: Red)
3. Mounting late C. To O-terminal of fuse (Wiring harness: White)
4. Mounting bracket
5. Deviation pulley
6. Control box
7. Cam control rod
8. Anchor bracket

D155C-1 10-93
Structure and function Safety device

• Cam standard angle positioner

1. Cam reference angle setting plate Function

2. Cam control lever The lifting performance (moment) at each overhang
3. Locknut reaches about 87% of the set limit (71 ton•m), the
4. Cam control rod yellow lamp which is a preliminary alarm lights up
5. Winch case (fixed) (when the moment is above 63.6 ton•m). If the
6. Yoke moment increases further and reaches the limit, the
7. Locknut boom control lever and hook control lever are forc-
8. Positioning hole ibly returned to the neutral position and the red lamp
9. Cam dowel pin hole lights up and the alarm (buzzer) sounds. In this
10. Control box case, the operator must decrease the moment by
increasing the hoisting angle or lowering the load to
the ground.

10-94 D155C-1
Structure and function Cab

Cab
Cab assembly

1. Door
2. Rear window
3. Top window
4. Right glass
5. Rear glass
6. Rear wiper
7. Front glass
8. Front wiper

D155C-1 10-95
Structure and function Actual electric wiring diagram

Actual electric wiring diagram

1. Side lamp 8. Horn switch

2. Horn 9. Limit switch
3. R.H. front lamp 10. Rear head lamp
4. Alternator 11. Electric power source for cab
5. Starting motor 12. Horn
6. Engine coolant temperature 13. Fuse box
7. Engine oil pressure caution lamp

10-96 D155C-1
 20 Testing and adjusting

Standard value table for engine related parts ............................................................................................. 20- 2

Standard value table for chassis ................................................................................................................. 20- 4
Testing and adjusting .................................................................................................................................. 20-101
Troubleshooting .......................................................................................................................................... 20-201

a Note the following when making judgements using the standard value tables for testing, adjusting, or
troubleshooting.
1. The standard value for a new machine given in the table is the value used when shipping the machine from
the factory and is given for reference. It is used as a guideline for judging the progress of wear after the
machine has been operated, and as a reference value when carrying out repairs.
2. The service limit value given in the tables is the estimated value for the shipped machine based on the
results of various tests. It is used for reference together with the state of repair and the history of operation
to judge if there is a failure.
3. These standard values are not the standards used in dealing with claims.

k When carrying out testing, adjusting, or troubleshooting, park the machine on level ground, insert the safety
pins, and use blocks to prevent the machine from moving.
k When carrying out work together with other workers, always use signals and do not let unauthorized people
near the machine.
k When checking the water level, always wait for the water to cool down. If the radiator cap is removed when
the water is still hot, the water will spurt out and cause burns.
k Be careful not to get caught in the fan, fan belt or other rotating parts.

D155C-1 20-1
Testing and adjusting Standard value table for engine related parts

Standard value table for engine related parts

Standard

Engine SA6D140E-2

Standard value for

Item Measurement conditions Unit Service limit value
new machine
High idling 2,170 2,170
Engine speed Low idling upm 625 625
Rated speed 2,000 —
Exhaust temperature
Whole speed range
(turbocharger inlet port °C Max. 680 Max. 700
(ambient temperaturea: 20°C)
temperature)
kPa Min. 85.3 Min. 67.9
Air supply pressure At rated output
{mmHg} {Min. 640} {Min. 510}
At sudden acceleration Bosch Max. 6.0 Max. 8.0
Exhaust gas color
At high idling index Max. 1.0 Max. 2.0
Valve clearance Intake valve 0.43 —
mm
(normal temperature) Exhaust valve 0.8 —
Compression pressure Oil temperature: 40 – 60°C MPa Min. 3.14 Min. 2.16
(SAE30 oil) Engine speed: 200 – 250 rpm {kg/cm2} {Min. 32} {Min. 22}
(Water temperatrue:
Blow-by pressure kPa Max. 0.98 Max. 1.96
Operating range)
(SAE30 oil) {mmH2O} {Max. 100} {Max. 200}
At rated output
(Water temperatrue:
Operating range)

0.29 – 0.49 Min. 0.2

At rated output (SAE30)
{3.0 – 5.0} {Min. 2.0}

MPa Min. 0.1 Min. 0.07

Oil pressure At low idling (SAE30)
{kg/cm2} {Min. 1.0} {Min. 0.7}

0.25 – 0.44 Min. 0.18

At rated output (SAE10W)
{2.5 – 4.5} {Min. 1.8}

Min. 0.1 Min. 0.07

At low idling (SAE10W)
{Min. 1.0} {Min. 0.7}

Whole speed range

Oil temperature °C 80 – 110 120
(inside oil pan)
+0.2 +0.2
Fuel injection timing Before top dead center °(deg) 12 –0.19 12 –0.19

Deflection when pressed with fin-

Alternator belt tension mm 15 —
ger force of approx. 59 N {6 kg}

20-2 D155C-1
Testing and adjusting Standard value table for engine related parts

–50°C spec.

Engine SA6D140E-2

Standard value for

Item Measurement conditions Unit Service limit value
new machine
High idling 2,130 ± 50 2,130 ± 50
Engine speed Low idling upm 600 ± 50 600 ± 50
Rated speed 2,000 —
Exhaust temperature
Whole speed range
(turbocharger inlet port °C Max. 680 Max. 700
(ambient temperaturea: 20°C)
temperature)
kPa Min. 85.3 Min. 67.9
Air supply pressure At rated output
{mmHg} {Min. 640} {Min. 510}
At sudden acceleration Bosch Max. 6.0 Max. 8.0
Exhaust gas color
At high idling index Max. 1.0 Max. 2.0
Valve clearance Intake valve 0.43 —
mm
(normal temperature) Exhaust valve 0.8 —
Compression pressure Oil temperature: 40 – 60°C MPa Min. 3.14 Min. 2.16
(SAE30 oil) Engine speed: 200 – 250 rpm {kg/cm2} {Min. 32} {Min. 22}
(Water temperatrue:
Blow-by pressure kPa Max. 0.98 Max. 1.96
Operating range)
(SAE30 oil) {mmH2O} {Max. 100} {Max. 200}
At rated output
(Water temperatrue:
Operating range)

0.29 – 0.49 Min. 0.2

At rated output (SAE30)
{3.0 – 5.0} {Min. 2.0}

MPa Min. 0.1 Min. 0.07

Oil pressure At low idling (SAE30)
{kg/cm2} {Min. 1.0} {Min. 0.7}

0.25 – 0.44 Min. 0.18

At rated output (SAE10W)
{2.5 – 4.5} {Min. 1.8}

Min. 0.1 Min. 0.07

At low idling (SAE10W)
{Min. 1.0} {Min. 0.7}

Whole speed range

Oil temperature °C 80 – 110 120
(inside oil pan)
+0.2 +0.2
Fuel injection timing Before top dead center °(deg) 12 –0.19 12 –0.19

Deflection when pressed with fin-

Alternator belt tension mm 15 —
ger force of approx. 59 N {6 kg}

D155C-1 20-3
Testing and adjusting Standard value table for chassis

Standard value table for chassis

Category

Permissible
Item Measurement conditions Unit Standard value
value

• Engine oil pressure: Within operating range

• Engine oil temperature: Within operating range
Engine

• Power train oil temperature: 70 – 80°C

Stall speed • Hydraulic oil temperature: 45 – 55°C rpm 1,570 ± 50 Max. 1,500
• Gear speed: F3
• ASTM No. 2: Used
Engine: Slow o Full 181 ± 30 181 ± 30
Fuel control lever Center of lever knob
Engine: Slow o Stop 91 ± 15 91 ± 15
Decelerator pedal Center of pedal Engine: Full o Stopper 44 ± 10 44 ± 10

• Engine: Stopped Between gear speeds 41 ± 5 41 ± 5

Gearshift lever
• Center of knob F R 74 ± 10 74 ± 10

All stroke 160 ± 10 160 ± 10

Steering lever • Engine: Slow
• Center of lever knob Until clutch is disen-
90 ± 5 90 ± 5
gaged completely
• Engine: Slow
Stroke of control lever

Brake pedal • Center of pedal All stroke 160 ± 10 160 ± 10

• Pressing force: 15 kg

• Engine: Slow Neutral LOW 63 ± 10 63 ± 10

• Center of lever knob mm
HI-LOW lever • Hydraulic oil temperature:
45 – 55°C Low HI 63 ± 10 —

• Engine: Slow Neutral Lower 140 ± 21

• Center of lever knob
Hook lever • Hydraulic oil temperature: Neutral Raise 140 ± 21
45 – 55°C Neutral Lower quickly 70 ± 10

• Engine: Slow Neutral Lower 140 ± 21

Boom lever • Center of lever knob
• Hydraulic oil temperature:
45 – 55°C Neutral Raise 140 ± 21

• Engine: Slow Neutral Retract 50 ± 10

• Center of lever knob
Counterweight lever • Hydraulic oil temperature: Neutral Extend 50 ± 10
45 – 55°C Push out Float 50 ± 10

20-4 D155C-1
Testing and adjusting Standard value table for chassis

Category

Permissible
Item Measurement conditions Unit Standard value
value

78.4 ± 58.8
Engine: Slow o Full
{8 ± 6}
Fuel control lever • Center of lever knob Engine: Full o Slow —
156.9 ± 19.6
Engine: Slow o Stop
{16 ± 2}
Engine: Full o 122.6 ± 24.5
• Engine speed: Deceleration Slow {12.5 ± 2.5}
Decelerator pedal 900 – 950 rpm
• Center of pedal

29.9 ± 4.4
Between gear speeds
• Engine: Stopped {3.05 ± 0.45}
Gearshift lever
• Center of lever knob 31.9 ± 4.4
F R
{3.25 ± 0.45}
Until clutch is disen- 42.2 ± 9.8
• Engine: Slow gaged completely {4.3 ± 1}
Steering lever • Center of lever knob Apply brake and measure 48.1 ± 9.8
Operating effort of control lever

until machine turns {4.9 ± 1}

• Engine: Slow
• Center of pedal 132.4 ± 14.7
Brake pedal • Apply either brake and {13.5 ± 1.5}
measure until torque converter stalls N
{kg} 49 – 88.2
Neutral LOW
• Engine: Slow {5 – 9}
HI-LOW lever
• Center of lever knob 49 – 88.2
Low HI
{5 – 9}
49 – 78.5
Neutral Lower
{5 – 8}
• Engine: Slow 49 – 78.5
Hook lever Neutral Raise
• Center of lever knob {5 – 8}
9.8 – 49
Neutral Lower quickly
{1 – 5}
49 – 78.5
Neutral Lower
• Engine: Slow {5 – 8}
Boom lever • Center of lever knob 49 – 78.5
Neutral Raise
{5 – 8}
19.6 – 39.2
Neutral Retract
{2 – 4}
• Engine: Slow 19.6 – 39.2
Counterweight lever • Center of lever knob Neutral Extend
{2 – 4}
19.6 – 39.2
Push out Float
{4 – 6}

D155C-1 20-5
Testing and adjusting Standard value table for chassis
Category

Permissible
Item Measurement conditions Unit Standard value
value

Torque converter relief • Engine speed: Full 0.8 ± 0.1 0.8 ± 0.1
pressure (Inlet) • Power train oil tempera- {8 ± 1} {8 ± 1}
ture: 70 – 80°C
Torque converter 0.4 ± 0.1 0.4 ± 0.1
outlet pressure {4 ± 1} {4 ± 1}
Transmission 2.2 ± 0.3 2.2 ± 0.3
modulating pressure {22.5 ± 2.5} {22.5 ± 2.5}
Transmission 1.2 ± 0.1 1.2 ± 0.1
reducing pressure {12.5 ± 1} {12.5 ± 1}
Transmission lubricat- 0.1 0.1
ing oil pressure {1.24} {1.24}
Steering clutch 1.4 ± 0.3 1.4 ± 0.3
actuating pressure {14.5 ± 2.5} {14.5 ± 2.5}
Brake actuating 2.5 ± 0.3 2.5 ± 0.3
pressure {25.5 ± 3.5} {25.5 ± 3.5}
13 – 13.7
Engine: Slow {133 – 140} —
Counterweight relief • Hydraulic oil tempera-
pressure ture: 45 – 55°C 13.5 – 14.4
Engine: Full —
{138 – 147}
1.9 – 2.3
Engine: Slow {19 – 23} —
Hydraulic pressure

Winch pump outlet • Hydraulic oil tempera-

pressure ture: 60 – 70°C 2.5 – 2.9
Engine: Full {25 – 30} —
MPa
{kg/cm2} 1.7 – 2.3
Engine: Slow —
Boom clutch • Hydraulic oil tempera- {17 – 23}
actuating pressure ture: 60 – 70°C 1.9 – 2.5
Engine: Full {19 – 25} —

Engine: Slow 1.7 – 2.3 —

Boom brake actuat- • Hydraulic oil tempera- {17 – 23}
ing pressure ture: 60 – 70°C 1.9 – 2.5
Engine: Full {19 – 25} —

1.7 – 2.3
Engine: Slow {17 – 23} —
Hook clutch actuating • Hydraulic oil tempera-
pressure ture: 60 – 70°C 1.9 – 2.5
Engine: Full —
{19 – 25}
1.7 – 2.3
Engine: Slow {17 – 23} —
Hook brake actuating • Hydraulic oil tempera-
pressure ture: 60 – 70°C 1.9 – 2.5
Engine: Full {19 – 25} —

Engine: Slow 1.5 – 2.3 —

HI-LOW clutch • Hydraulic oil tempera- {15 – 23}
actuating pressure ture: 60 – 70°C 1.6 – 2.5
Engine: Full {16 – 25} —

Winch lubricating oil 0.4 – 1.0 —

pressure {4 – 10.5}

20-6 D155C-1
Testing and adjusting Standard value table for chassis

Category

Permissible
Item Measurement conditions Unit Standard value
value
Counterweight

• Engine speed: Full Extend 6.1 ± 0.6

Operating speed • Hydraulic oil
of counterweight temperature: 45 – 55°C
• Cylinder operating speed Retract 7.3 ± 0.7

• Run engine at full throttle Hi-Low valve:

and measure time 7.7 ± 0.8
No-load required to raise boom Low range
operating speed from 40° to 60° with bare sec
• Boom RAISE drum. Hi-Low valve:
• Hydraulic oil 3.4 ± 0.4
Hi range
temperature: 60 – 70°C

• Measure time required to Hi-Low valve: 9.6 ± 1.0

lower boom from 60° to Low range
• Boom LOWER 40° with bare drum.
• Hydraulic oil Hi-Low valve:
temperature: 60 – 70°C 4.2 ± 0.4
Hi range

• Moving distance at full Hi-Low valve:

5.5 ± 0.6
engine speed (with bare Low range
Work equipment

• Hook RAISE drum)

• Hydraulic oil Hi-Low valve:
12.7 ± 1.3
temperature: 60 – 70°C Hi range
m/min
Hi-Low valve:
• Moving distance at full 4.5 ± 0.5
engine speed Low range
Boom

• Hook LOWER • Hydraulic oil Hi-Low valve:

temperature: 60 – 70°C 10.2 ± 1.0
Hi range
Vertical direction 8
mm
Horizontal direction 8
• Run engine at 800 rpm and raise boom by inching from 45° to 50°.
Then, calculate average inching distance of 1 operation of lever.
• Lifting load: 39.4 – 73.6 kN {4 – 7.5 ton}

• Oil temperature: 60 – 70°C

Inching A (or B)
Inching distance =
• Boom Number of inching times

W = Load of 4 – 7.5 ton

A = Vertical moving distance
B = Horizontal moving distance

D155C-1 20-7
 Testing and adjusting

Tools for testing, adjusting, and troubleshooting ......................................................................................... 20-102

Adjusting valve clearance ........................................................................................................................... 20-103
Measuring compression pressure ............................................................................................................... 20-104
Testing and adjusting fuel injection timing................................................................................................... 20-105
Measuring engine oil pressure .................................................................................................................... 20-106
Measuring exhaust color ............................................................................................................................. 20-107
Measuring exhaust temperature ................................................................................................................. 20-108
Testing and adjusting alternator belt tension............................................................................................... 20-109
Measuring blow-by ...................................................................................................................................... 20- 110
Measuring air supply pressure (boost pressure)......................................................................................... 20- 111
Measuring engine speed............................................................................................................................. 20- 112
Measuring torque converter stall speed ...................................................................................................... 20- 113
Bleeding air from counterweight cylinder .................................................................................................... 20- 114
Adjusting winch control interlock mechanism ............................................................................................. 20- 115
Measuring oil pressure................................................................................................................................ 20- 116
Measuring counterweight oil pressure ........................................................................................................ 20- 118
Measuring winch oil pressure ..................................................................................................................... 20- 119
Hydraulic circuit diagram for winch ............................................................................................................. 20-120
Measuring leakage inside cylinder .............................................................................................................. 20-121
Reinstallation (if moment limiter was removed) and adjusting .................................................................... 20-122
Adjustment procedure for moment limiter performance .............................................................................. 20-123

k When carrying out testing, adjusting, or troubleshooting, park the machine on level ground, insert the safety
pins, and use blocks to prevent the machine from moving.
k When carrying out work together with other workers, always use signals and do not let unauthorized people
near the machine.
k When checking the water level, always wait for the water to cool down. If the radiator cap is removed when
the water is still hot, the water will spurt out and cause burns.
k Be careful not to get caught in the fan, fan belt or other rotating parts.

D155C-1 20-101
Testing and adjusting Tools for testing, adjusting, and troubleshooting

Tools for testing, adjusting, and troubleshooting

Check or measurement Sym-
Part No. Part name Q'ty Remarks
item bol
799-203-8001 Multi-tachometer 1
1
Engine speed A
6210-81-4110 Adapter 1 Digital display L : 60 – 2,000 rpm
H : 60 – 19,999 rpm
799-203-8901 Clamp set 1
2 Kit Part No. : 799-203-9000
6210-81-4111 Gear box 1
Adjusting fuel injection
AA 795-471-1200 Gauge assembly 1 0.01 – 10 mm (meter)
timing
Coolant and oil
B 799-101-1502 Thermometer 1 -99.9 – 1299°C (sensor)
temperature
Pressure gauge: 2.5, 5.9, 39.2, 58.8 MPa
799-101-5002 Hydraulic tester 1
1 {25, 60, 400, 600 kg/cm2}
790-261-1203 Digital hydraulic tester 1 Pressure gauge: 71.4 MPa {700 kg/cm2}
2 799-401-2320 Hydraulic gauge 1 1.0 MPa {10 kg/cm2}
Both male and female 14 x 1.5
790-261-1311 1
(female PT 1/8)
Oil pressure C 3 Adapter
Both male and female 18 x 1.5
790-261-1321 1
(female PT 1/8)
Both male and female 18 x 1.5
790-261-1360 Adapter 1
(female PT 1/8)
4
790-261-1370 Nut 1 14 x 1.5 blind
07003-31419 Gasket 1 For blind
1 795-502-1590 Gauge assembly 1 0 – 6.9 MPa {0 – 70 kg/cm2}
795-502-1500 Adapter assembly 1 (Kit Par No. : 795-502-1205)
Compression pressure D
2 • 795-502-1510 • Adapter 1 —
• 795-502-1520 • Plate 1 —
1 799-201-1504 Blow-by checker 1 —
Blow-by pressure E
2 799-201-1590 Gauge 1 0 – 9.8 kPa {0 – 1000 mmH2O}
Commercially
Valve clearance F Feeler gauge 1 —
available
1 799-201-9000 Handy smoke checker 1 Discoloration 0 – 70 % (with standard
Exhaust color G color)
2 Commercially Smoke meter 1 (Discoloration x 1/10 C Bosch index)
available
Air supply pressure
H 799-201-2201 Boost gauge KIT 1 -101.3 – 199.9 kPa {-760 – 1,500 mmHg}
(boost pressure)
79A-264-0020 1 0 – 294 N {0 – 030 kg}
Operating force I Push-pull scale
79A-264-0090 1 0 – 490 N {0 – 50 kg}
Commercially
Stroke, hydraulic drift J Scale 1 —
available
Commercially
Work equipment speed K Stop watch 1 —
available
Measuring voltage and
L 79A-264-0210 Tester 1 —
resistance values
Measuring wear of sprocket
P 791-627-1160 Wear gauge 1 —
tooth

20-102 D155C-1
Testing and adjusting Adjusting valve clearance

Adjusting valve clearance 4. Rotate the crankshaft int the normal cirection by
one revolution and adjust the valve clearance
a Adjusting instrument for valve clearance for the remaining valves marked Q.
a To adjust the valve clearance, loosen lock nut
Symbol Part. No. Name (5) on adjustment screw (4), insert feeler
F Commercially available Feeler gauge gauge F corresponding to the specified
clearance between crosshead (6) and rocker
1. Remove the rocker arm housing cover. arm (7), and adjust the clearance with the
adjustment screw until the thickness gauge
2. Rotate the crankshaft in the normal direction. can slide lightly.
While watching the movement of the intake
valve of the No. 6 cylinder, bring the No. 1 cylin-
der into the top dead center position of the com-
pression stroke and align the "1.6 TOP" mark on
vibration damper (1) with pointer (2).
a When the No. 1 cylinder comes near the top
dead center of the compression stroke, the
No. 6 intake valve will start to move (open).

5. After the clearance is properly adjusted, tighten

the lock nut to secure the adjustment screw.
3 Lock nut:
58.8 ± 5.9 Nm {6.0 ± 0.6 kgm}
a The engine firing order is 1 – 5 – 3 – 6 – 2 – 4.
a Intake and exhasut valve clearances may be
adjusted for each cylinder in the firing order
by rotating the crankshaft 120° at a time in
3. Adjust the valve clearance for valves marked q the normal direction.
in the valve arrangement diagram.

D155C-1 20-103
Testing and adjusting Measuring compression pressure

Measuring compression 4. Install adapter D2 to the nozzle holder mounting

section of the cylinder to be measured, and
pressure tighten the adapter with plate D2 to the specified
torque:
3 Adapter: 66.7 ± 7.3 Nm {6.8 ± 0.75 kgm}
a Measuring instruments for compression pressure

Symbol Part. No. Name

1 795-502-1590 Compression gauge
795-502-1500 Adapter assemblly
D
2 • 795-502-1510 • Adapter
• 795-502-1511 • Plate

Measurement procedure
k While measuring the compression pressure,
take care not burn yourself on the exhaust
manifold or muffler, and be careful not to get
caught in any revolving part of the engine.
a Measure the compression pressure while
the engine is warm. 5. Connect compression gauge D1 to the adapter.
(Oil temperature: 40 – 60°C)
1. Adjust the valve clearance property. For details, 6. Place the fuel control lever in NO INJECTION
see Adjusting valve clearance. position, crank the engine with the starting
motor, and read the gauge when the pointer is
2. Disconnect fuel injection tube (1). stabilized.
a When the No. 1 cylinder comes near the top k If you do not put the fuel control lever in NO
dead center of the compression stroke, the INJECTION position, fuel will blow out.
No. 6 intake valve will start to move (open). a Most compression leakage can be prevented
by applying a small amount of oil to the
mounting section of the adapter.
a For the reference values of the compression
pressure, see Standard value table for en-
gine related parts.

3. Remove inlet connector (2) and nozzle holder

assembly (3) for each cylinder.

20-104 D155C-1
Testing and adjusting Testing and adjusting fuel injection timing

Testing and adjusting fuel 7. Rotate the crankshaft again slowly in the normal
direction and set to specified dimension c.
injection timing a Specified dimension c: 2.36 +0.2 mm
–0.19
(BTDC: 22°)
a Adjusting instrument for fuel injection timing a Always rotate the crankshaft in the normal
Symbol Part. No. Name direction to align the position.
a Continue to rotate in the normal direction,
AA 795-471-1200 Dial gauge and when the No. 1 cylinder reaches the
TOP (top dead center) position (the indicator
1. Remove No. 1 nozzle holder assembly (1). on the dial gauge rotates in reverse), check
For details, see Removal of nozzel holder assem- that the dial gauge reading is 0 +0.2 mm. If
bly. –0.19
it is not within 0 +0.2
–0.19
mm, carry out Steps 4
and 5 again.

2. Remove injection pump coupling cover.

8. Check that fuel injection timing line a on the fuel
3. Align No. 1 cylinder with the compression top injection pump is aligned with line b on the cou-
dead center line (1:6). pling.
a When doing this, check that the fuel injection
timing line on the fuel injection pump is near 9. After adjusting fuel injection timing, install nozzle
the line on the fuel injection pump body. holder assmbly.
For details, see Removal of nozzel holder assem-
4. Set dial gauge AA to the nozzle holder hole bly.
where the nozzle holder assembly has been
removed. (See the diagram.)
a Set the magnet stand of dial guage AA in a
stable place where installation can be
carried out.

5. Set the scale on dial gauge AA to 0 when the

piston is at the top dead center.
a Rotate the crankshaft in the normal direction
and in the reverse direction in turn to align
the top dead center. b a
a Record the vaue indicated by the short
TLD00141
indicator on dial gauge.

6. Rotate the crankshaft approx. 45° in the reverse

direction from the No. 1 cylinder TOP position.

D155C-1 20-105
Testing and adjusting Measuring engine oil pressure

Measuring engine oil pressure

a Measuring instruments for engine oil pressure

Symbol Part. No. Name

799-101-5002 Hydraulic tester
1
C 790-261-1203 Digital hydraulic tester
2 799-401-2320 Hydraulic gauge

a Measure the engine oil pressure under the

following conditions.
• Coolant temperature: Within operating range
1. Remove engine pressure pickup plug (1) (PT 1/
8), then install the adapter of oil pressure gauge
kit C1 and oil pressure gauge C2 (1.0 MPa {10
kg/cm2}).

2. Start the engine, and measure the oil pressure

at low idling and high idling.

TLD00023

C1

TLD00024

C2

TLD00025

20-106 D155C-1
Testing and adjusting Measuring exhaust color

Measuring exhaust color 2. Measuring with smoke meter G2

1) Insert the probe [1] of smoke meter G2 into
a Measuring instruments for exhasut color the outlet port of the exhaust pipe, and
tighten the clip to secure it to the exhaust
Symbol Part. No. Name pipe.
1 799-201-9000 Handy smoke checker
G
2 Commercially availaable Smoke meter 1

• When measuring in the field where there is no

air or electric power supply, use handy smoke
checker G1; when recording formal data, use
smoke meter G2.
a Raise the coolant temperature to the operating
range before measuring.
k Be careful not to touch any hot parts when
removing or installing the measuring tools.
TLD00012

1. Measuring with handy smoke checker G1.

1) Install filter paper to handy smoke checker 2) Connect the air hose and the socket of the
G1. probe hose and accelerator switch to smoke
2) Insert the exhaust gas suction port into the meter G2.
exhaust pipe, accelerate the engine a Keep the pressure of the air supply
suddenly, and operate the handle of handy below 1.5 MPa {15 kg/cm2}.
smoke checker G1 at the same time to 3) Connect the power cord to the AC100V
collect the exhaust gas on the filter paper. socket.
3) Remove the filter paper and compare it with a When connecting the cord, check that
the scale supplied to judge the condition. the power switch of smoke meter G2 is
OFF.
4) Loosen the cap nut of the suction pump, and
fit the filter paper.
G1 a Fit the filter paper securely so that the
exhaust gas cannot leak.
5) Turn the power switch of smoke meter G2
OFF.
6) Accelerate the engine suddenly, and depress
the accelerator pedal of smoke meter G2 at
the same time to collect the exhaust gas color
on the filter.
7) Place the filter paper used to catch the
TLD00011 exhaust gas color on top of at least 10
sheets of unnused filter paper inside the
filter paper holder, and read the value
shown.

G2

TLD00140

D155C-1 20-107
Testing and adjusting Measuring exhaust temperature

Measuring exhaust temperature

a Measuring instruments for exhasut temperature

Symbol Part. No. Name

B 799-101-1502 Thermometer

k The temperature sensor must be installed to the

exhaust manifold, so if the machine has been
operated, wait for the manifold temperature to
drop before installing the sensor.
a Raise the coolant temperature to the operating
range before measuring.
Measurement procedure
1. Remove plug (1) from the exhaust manifold, and • When measuring the maximum value for the
install thermometer sensor B. exhaust temperature.
• Thermometer sensor B: 6215-11-8180 Carry out actual work and measure the
(cable length 610 mm) maximum value during operation.
or a Use the PEAK mode (it can store the
: 6215-11-8170 maximum value in memory) of the
(cable length 490 mm) temperature gauge function.
Note:
2. Connect to digital thermometer B with the wiring The exhaust temperature varies greatly accord-
harness. ing to the ambient temperature (temperature of
the engine intake air), so if any abnormal value
is obtained, carry out temperature compensa-
tion.
a Compensation value = Measured value + 2 x
(20°C – ambient temperature)

TLD00030

20-108 D155C-1
Testing and adjusting Testing and adjusting alternator belt tension

Testing and adjusting

alternator belt tension
1. Testing
• Measure the deflection of the belt when it is
pressed at a force of approx. 59 N {6 kg} at a
point midway between the alternator and fan
pulley.
a Dflection (standard value) a : 15 mm

TLD00026

2. Adjusting
1) Loosen alternator mount bolt (1).
2) Loosen locknut (2), then turn adjustment nut
(3) and adjust the belt tension.
3) After adjusting the belt tension to the standard
value, tighten lock (2), then tighten alternator
mount bolt (1).

TLD00027

D155C-1 20-109
Testing and adjusting Measuring blow-by

Measuring blow-by 2. Run the engine at near rated output, and mea-
sure the blow-by pressure.
k When measuring, be careful not to touch
a Measuring instruments for blow-by pressure.
any hot parts or rotating parts.
Symbol Part No. Name a The blow-by should be measured with the
1 799-201-1504 Blow-by checker engine running at rated output. However,
E when measuring in the field, a similar value
2 799-201-1590 Gauge can be obtained at torque converter stall
speed.
a Raise the coolant temperature to the operating • If it is impossible to check at rated output or
range before measuring. stall speed, measure at high idling.
In this case, the blow-by value will be about
1. Install blow-by checker E1 to the end of engine 80% of the value at rated output.
breather hose (1), then connect it to gauge E2. a Blow-by varies greatly according to the
condition of the engine. Therefore, if the blow-
by value is considered abnormal, check for
E1 problems connected with defective blow-by,
such as excessive oil consumption, defective
exhaust gas color, and prematurely dirty or
deteriorated oil.

1
TLD00020

E2

TLD00021

20-110 D155C-1
Testing and adjusting Measuring air supply pressure (boost pressure)

Measuring air supply pressure 3. Run the engine at full throttle to stall the torque
conveter, and read the pressure indicated by the
(boost pressure) gauge.

a Measuring instruments for air supply pressure. a The air supply pressure (boost pressure) should
Symbol Part No. Name be measured with the engine running at rated
output. However, when measuring in the field, a
H 799-201-2201 Boost gauge KIT similar value can be obtained at torque conerter

k
stall speed.
Be careful not to touch any hot parts or get
caught in any rotating parts when measuring or
when removing or installing the measuring tools.
1. Remove air supply pressure measurement plug
(1) (PT1/8), then install the coupler inside oil
pressure gauge kit C1.

TLD00033

2. Connect the oil pressure measurement hose to

the coupler and pressure gauge H (199 kPa
{1,500 mmHg}.

TLD00034

Note: Operate the engine speed at midrange or

above, and use the self-seal portion of the
gauge to bleed the oil inside the hose.
• Insert the gauge about half way, repeat the
action to open the self-seal portion, and
bleed the oil.
a If there is oil inside the hose, the gauge will
not work, so always bleed the oil.

D155C-1 20-111
Testing and adjusting Measuring engine speed

Measuring engine speed

a Measuring instruments for engine speed

Symbol Part No. Name

799-203-8001 Multi-tachometer
A
6210-81-4110 Adapter

k Be careful not to touch any hot parts when

removing or installing the measuring tools.
a Measure the engine speed under the following
conditions.
• Coolant temperature: Within operating range
• Hydraulic temperature: 45 – 55°C
• Power train oil temperature: 70 – 90°C

1. Install sensor [1] of multi-tachometer A to the

speed pickup port then connect to multi-tachom-
eter A.

2. Start the engine and measure the engine speed

at high idling and low idling.

a When measuring items other than above, see

the measurement procedure for each item.

TLD00010

20-112 D155C-1
Testing and adjusting Measuring torque converter stall speed

Measuring torque converter 6. Repeat Steps 2 – 4 to stall the torque converter

again.
stall speed
7. Measure the engine speed immediately the torque
a Measuring instruments for conveter stall speed. converter oil temperature gauge enters the red
Symbol Part No. Name range.
a After completion of the measurement, return
799-203-8001 Multi-tachometer the gear shift lever swiftly to neutral, and run
A
6210-81-4110 Adapter the engine at full throttle to lower the oil
temperature.
a Measuring the stall speed under the following
conditions.
• Coolant temperature: Within operating range
• Power train oil temperature: 70 – 90°C
• Hydraulic oil temperature: Min. 50°C

k Make sure that there is no one near the machine

before starting measurements.

1. Install multi-tachometer A.
For details, see Measuring engine speed.

TLD00010

2. Depress the steering brake firmly and move the

gear shift lever to F3.

3. Depress the decelerator pedal, set the fuel con-

trol lever to FULL , run the engine at full throut-
tle, and stall the torque converter.
k Precautions when relieving the torque
converter.
1) Depress the decelerator pedal before
pulling the fuel control lever to the FULL
position.
2) Release the decelerator pedal to run the
engine at full throttle. However, for
safety reasons, always keep your right
foot on the decelerator pedal until the
completion of the measurement
operation.

4. When the torque converter oil temperature gauge

enters the red range, immediately return the gear
shift lever to neutral and lower the oil tempera-
ture.

5. Repeat Steps 2 – 4 three times.

D155C-1 20-113
Testing and adjusting Bleeding air from counterweight cylinder

Bleeding air from counterweight

cylinder
a If the counterweight cylinder has been replaced
or has been removed and installed again, or if
the hydraulic piping has been removed, bleed
the air from the counterweight cylinder as
follows.
1) Start the engine and run at idling for approx.
5 minutes.
2) Run the engine at low idling and operate the
counterweight EXTEND and RETRACT 4 –
5 times.
a Stop the piston rod approx. 100 mm
before the end of its stroke. Do not relieve
the cylinder under any circumstances.
3) Run the engine at high idling and repeat
Step 2). After this, run the engine at low
idling and operate the piston rod to the end
of its stroke to relieve the circuit.

20-114 D155C-1
Testing and adjusting Adjusting winch control interlock mechanism

Adjusting winch control interlock mechanism

1. Adjust the length of the rod so that the center of 1. High-low lever
the interlock spool pin of the control box will be 2. Rod
at 30 mm from the top of the cover when winch 3. Spool
control high-low lever (1) is set in the "N" posi- 4. Cover
tion. 5. PPC valve
a When the high-low valve spool is pushed in, 6. High-low valve
the high-low lever is set in the "N" position.

2. Check that the interlock mechanism operates

when the high-low lever is set in the "N" position.
When the high-low lever is set in the "N" posi-
tion, if the boom and hook raise/lower levers
cannot be set in the RAISE position or LOWER
position, the interlock mechanism is operating
normally.

3. Set the high-low lever in the "Lo" or "Hi" position

and check that the interlock mechanism does
not operate and you can set the raise/lower
levers smoothly.

D155C-1 20-115
Testing and adjusting Measuring oil pressure

Measuring oil pressure

k Park the machine on a level surface and land the
work equipment securely before pulling up the
parking brake.
k Be sure to stop the engine before removing
plugs and installing oil pressure gauges.
a When measuring the oil pressure, thoroughly re-
move mud, sand and any other foreign sub-
stance from the plug of the pressure measuring
port and its neighborhood in advance and always
measure when the oil temperature is within the
specified range.

1. Measuring the power train oil pressure

a Measure the pressure setting the speed shift
lever to the “N“ position.
• When measuring the torque converter relieving
pressure:
1) Remove the plug (1) and install the oil
pressure gauge C1 (2.5 MPa {25 kg/cm2}).
2) Measure the oil pressure running the engine
at the Hi-Idling revolution.

• When measuring the torque converter regulator

pressure:
1) Remove the plug (2) and install the oil
pressure gauge C1 (2.5 MPa {25 kg/cm2}).
2) Measure the oil pressure running the engine
at the Hi-Idling revolution.

• When measuring the transmission reducing pres-

sure:
1) Remove the plug (3) and install the oil
pressure gauge C1 (2.5 MPa {25 kg/cm2}).
2) Measure the oil pressure running the engine
at the Hi-Idling revolution.

• When measuring the transmission modulating

pressure:
1) Remove the plug (4) and install the oil
pressure gauge C1 (5.9 MPa {60 kg/cm2}).
2) Measure the oil pressure running the engine
at the Hi-Idling revolution.

20-116 D155C-1
Testing and adjusting Measuring oil pressure

• When measuring the steering clutch activation

pressure:
1) Remove the plug of the measuring side and
install the oil pressure gauge C1 (2.5 MPa
{25 kg/cm2}).
2) Drawing the steering lever of the measuring
side as far as the clutch becomes disen-
gaged, measure the oil pressure running the
engine at the Hi-Idling revolution.
a RH clutch: (5)
LH clutch: (6)

• When measuring the brake activation pressure:

1) Remove the plug of the measuring side and
install the oil pressure gauge C1 (2.5 MPa
{25 kg/cm2}).
2) Stepping on the brake pedal of the measur-
ing side to its full stroke, measure the oil
pressure running the engine at the Hi-Idling
revolution.
a RH brake: (7)
LH brake: (8)

D155C-1 20-117
Testing and adjusting Measuring counterweight oil pressure

Measuring counterweight oil Adjusting

1. Drain the oil from the hydraulic tank and remove
pressure the tank cover.
a Measuring instrument for counterweight oil pressure. 2. Loosen locknut (3) of main relief valve (2) and
Symbol Part. No. Name turn adjustment screw (4) to adjust the oil pres-
sure.
C1 799-101-5002 Hydraulic tester
a If the adjustment screw is
• Turned to the right, the oil pressure is
a When measuring the oil pressure, remove all dirt increased.
and sand from the nipple and plug. • Turned to the left, the oil pressure is
a When measuring the oil pressure, increase the decreased.
hydraulic oil temperature to 45 – 55 °C. a Quantity of adjustment per turn of adjustment
screw: Approx. 2.9 MPa {Approx. 29.4 kg/cm2}
a Stop the vehicle on level ground and apply the
parking brake. Before removing or installing the 3. After adjusting the oil pressure, add hydraulic oil
plug and oil pressure gauge, stop the engine. to the specified level and check again that the oil
pressure is in the standard range.
Measuring
1. Disconnect plug (1) and install tool C1 (Gauge:
39.2 MPa {400 kg/cm2}).

2. Run the engine at full throttle, operate the coun-

terweight control lever to relieve the oil, and
measure the oil pressure.

20-118 D155C-1
Testing and adjusting Measuring winch oil pressure

Measuring winch oil pressure Oil pressure pickup port

[1] Pump intake pressure
a When measuring the oil pressure, remove all dirt [2] Filter inlet (Pump outlet pressure)
and sand from the nipple and plug. [3] Low clutch pressure
a When measuring the oil pressure, increase the [4] High clutch pressure
hydraulic oil temperature to 45 – 55°C. [5] Hook lower clutch pressure
[6] Hook raise clutch pressure
k Stop the vehicle on level ground and apply the [7] Hook brake pressure
parking brake. [8] Boom lower clutch pressure
k Before removing or installing the plug and oil [9] Boom raise clutch pressure
pressure gauge, stop the engine. [10] Boom brake pressure
[11] Hi-low clutch lubrication oil pressure
1. Remove each plug ([1] – [16]) and install tool C [12] Lower clutch lubrication oil pressure
(Gauge: 2.5 MPa {25 kg/cm2} or 5.9 MPa {60 kg/ [13] Raise clutch lubrication oil pressure
cm2}). [14] Hook brake lubrication oil pressure
2. Run the engine at low idling or full throttle and [15] Boom brake lubrication oil pressure
measure the oil pressure. [16] Oil cooler intake pressure

D155C-1 20-119
Testing and adjusting Hydraulic circuit diagram for winch

Hydraulic circuit diagram for winch

1. Winch case 7. Low clutch

2. Winch pump (FAL063) 8. High clutch
3. Oil filter (set pressure 0.14 MPa {1.4 kg/cm2}) 9. Gear lubrication
4. Low divider valve 10. Bushing lubrication
5. Hi-low valve 11. Hook raise clutch
5A. Pressure adjustment valve 12. Hook brake
(set pressure : 1.8 – 2.5 MPa {18 – 25.5 kg/ 13. Hook lower clutch
cm2}) 14. Boom raise clutch
5B. Oil cooler bypass valve (set pressure 0.74 – 15. Boom brake
1.2 MPa {7.5 – 12 kg/cm2}) 16. Boom lower clutch
5C. Lubrication valve (set pressure 0.4 – 1.04 17. Solenoid valve
MPa {4 – 10.6 kg/cm2}) 18. PPC valve
6. Oil cooler

20-120 D155C-1
Testing and adjusting Measuring leakage inside cylinder

Measuring leakage inside

cylinder
• If the hydraulic drift exceeds the standard value,
check if the cause of the hydraulic drift is in the
cylinder or in the control valve.
a Oil temperature when measuring: 45 – 55°C

1. Measurement posture
• Fully extend the rod of the cylinder and
retract the counterweight.

2. Measuring
1) Disconnect the head piping, and block the
piping at the chassis end with a blind plug.
k Be careful not to disconnect the piping
at the bottom end.
2) Start the engine, run the engine at high
idling, and apply the relief pressure to the
bottom end of the cylinder.
3) Wait for 30 seconds, then measure the
amount of leakage over the next 1 minute.

Disconnect hose
End of stroke

Hose
Relief pressure

TAD00148

D155C-1 20-121
Testing and adjusting Reinstallation (if moment limiter was removed) and adjusting

Reinstallation (if moment

limiter was removed) and
adjusting
If the moment limiter was removed, adjust it accord-
ing to the following procedure, since the position of
the cam is a little different from the length of the rod.

1. Adjusting cam control rod

Stop the vehicle on level ground as shown in the
figure at right, and then set angle β (the angle
between the level and moment limit) to 10°
accurately with a level.
Then, adjust the position of control lever (9) with
cam position adjustment jig plate (10) shown in
the figure. Adjust length of rod (7), too.
After adjusting, tighten locknuts (4) and (8).
Then, be sure to remove all the adjusting tools.

1. Control box
2. Position of cam dowel pin
3. Matching hole
4. Locknut
5. Connection
6. Fixing (Winch case)
7. Cam control rod
8. Locknut
9. Cam control lever
10. Plate (Cam positioning jig)

20-122 D155C-1
Testing and adjusting Adjustment procedure for moment limiter performance

Adjustment procedure for

moment limiter performance
Adjust the moment limiter according to the fol-
lowing procedure.

1. Check
The operation characteristics diagram in the
next page shows the lifting performance curves
of 71 ton-m. The moment limiter operates and
the red lamp on the instruments panel in the
operator's cab lights up according to these
curves.

1) Adjust the performance of the moment limiter

at point A, B, or C.
2) When adjusting at point B, for example, lift
up a load of 13.3 ton at the boom overhang
of 5 m.
i) If the red lamp lights up at this time, the
moment limiter operates inside the
performance curve of 71 ton-m and it is
set under the standard.
ii) If the red lamp does not light up at all,
the moment limiter operates outside the
performance curve and it is set over the
standard.

D155C-1 20-123
Testing and adjusting Adjustment procedure for moment limiter performance

Lifting performance curve

Equipment
• Wire rope: 20 mm in diameter, having minimum breaking load of 27,600 kg
• Number of wire ropes for the hook: 6
• Number of wire ropes for the boom: 5
• Counterweight pushed out: 9,230 kg
Pulley efficiency is included.

20-124 D155C-1
Testing and adjusting Adjustment procedure for moment limiter performance

2. Adjustment method

1) Loosen 4 lock bolts D (6) of the primer block

by 2 turns as shown in the figure at right.
(Do not loosen the lock bolts more than 2
turns for safety. If they are loosened exces-
sively, the pulley may fall.)

2) When the moment limiter operates inside

the performance curve
i) Loosen locknuts C (2) and (4) and bolt
B (5).
ii) Turn bolt A (1) to move primer block E
(3) toward front F of the vehicle.
iii) The red lamp lights up at point B of the
102 ton-m curve.
iv) After checking point B, tighten bolt B (5)
and lock it and bolt (A) (1) with locknuts
C (2) and (4), and then tighten 4 lock
bolts D (6).

3) When the moment limiter operates outside

the performance curve
i) Loosen locknuts C (2) and (4) and bolt
A (1).
ii) Referring to 2) above, move the primer
block toward the rear of the vehicle.

Note: The yellow lamp lights before the red lamp.

Since the yellow lamp gives only information, 1. Bolt A
check the operation by the red lamp. 2. Locknut C
3. Primer block E
4. Locknut C
5. Bolt B
6. Lock bolt D (4 pieces)
F. Front of vehicle
R. Rear of vehicle

D155C-1 20-125
 Troubleshooting

Points to remember when troubleshooting.................................................................................................. 20-202

Sequence of events in troubleshooting ....................................................................................................... 20-203
Points to remember when carrying out maintenance.................................................................................. 20-204
Checks before troubleshooting ................................................................................................................... 20-212
Troubleshooting of engine system (S mode) .............................................................................................. 20-301
Troubleshooting of hydraulic, mechanical system (H mode) ...................................................................... 20-401

D155C-1 20-201
Testing and adjusting Points to remember when troubleshooting

Points to remember when troubleshooting

k Stop the machine in a level place, and check that the safety pin, blocks, and parking brake are securely fitted.
k When carrying out the operation with two or more workers, keep strictly to the agreed signals, and do not
allow any unauthorized person to come near.
k If the radiator cap is removed when the engine is hot, hot water may spurt out and cause burns, so wait for
the engine to cool down before starting troubleshooting.
k Be extremely careful not to touch any hot parts or to get caught in any rotating parts.
k When disconnecting wiring, always disconnect the negative (–) terminal of the battery first.
k When removing the plug or cap from a location which is under pressure from oil, water, or air, always release
the internal pressure first. When installing measuring equipment, be sure to connect it properly.

The aim of troubleshooting is to pinpoint the basic cause of the failure, to carry out repairs swiftly, and to
prevent reoccurrence of the failure.
When carrying out troubleshooting, and important point is of course to understand the structure and func-
tion.
However, a short cut to effective troubleshooting is to ask the operator various questions to form some idea
of possible causes of the failure that would produce the reported symptoms.

1. When carrying out troubleshooting, do not hurry 5) Other maintenance items can be checked
to disassemble the components. ex t e r n al l y, s o c h e c k an y i te m th a t i s
If components are disassembled immediately considered to be necessary.
any failure occurs:
• Parts that have no connection with the failure 4. Confirming failure
or other unnecessary parts will be • Confirm the extent of the failure yourself, and
disassembled. judge whether to handle it as a real failure or
• It will become impossible to find the cause of as a problem with the method of operation,
the failure. etc.
It will also cause a waste of manhours, parts, or a When operating the machine to reenact
oil or grease, and at the same time, will also lose the troubleshooting symptoms, do not
the confidence of the user or operator. carry out any investigation or
For this reason, when carrying out troubleshoot- me a s ur em e nt t h at m ay m ak e t h e
ing, it is necessary to carry out thorough prior problem worse.
investigation and to carry out troubleshooting in
accordance with the fixed procedure. 5. Troubleshooting
• Use the results of the investigation and
2. Points to ask user or operator inspection in Items 2 – 4 to narrow down the
1) Have any other problems occurred apart causes of failure, then use the
from the problem that has been reported? troubleshooting flowchart to locate the
2) Was there anything strange about the position of the failure exactly.
machine before the failure occurred? a The basic procedure for troubleshooting
3) Did the failure occur suddenly, or were there is as follows.
problems with the machine condition before 1) Start from the simple points.
this? 2) Start from the most likely points.
4) Under what conditions did the failure occur? 3) Investigate other related parts or
5) Had any repairs been carried out before the information.
failure?
When were these repairs carried out? 6. Measures to remove root cause of failure
6) Has the same kind of failure occurred • Even if the failure is repaired, if the root
before? cause of the failure is not repaired, the same
failure will occur again.
3. Check before troubleshooting To prevent this, always investigate why the
1) Check the oil level problem occurred. Then, remove the root
2) Check for any external leakage of oil from cause.
the piping or hydraulic equipment.
3) Check the travel of the control levers.
4) Check the stroke of the control valve spool.

20-202 D155C-1
Testing and adjusting Sequence of events in troubleshooting

Sequence of events in troubleshooting

D155C-1 20-203
Testing and adjusting Points to remember when carrying out maintenance

Points to remember when carrying out maintenance

To maintain the performance of the machine over a long period, and to prevent failures or other troubles before
they occur, correct operation, maintenance and inspection, troubleshooting, and repairs must be carried out.
This section deals particularly with correct repair procedures for mechatronics and is aimed at improving the
quality of repairs. For this purpose, it gives sections on "Handling electric equipment" and "Handling hydraulic
equipment" (particularly gear oil and hydraulic oil).

1. Points to remember when handling electric

equipment

1) Handling wiring harnesses and connectors

Wiring harnesses consist of wiring connecting
one component to another component, connec-
tors used for connecting and disconnecting one
wire from another wire, and protectors or tubes
used for protecting the wiring.
Compared with other electrical components fit-
ted in boxes or cases, wiring harnesses are
more likely to be affected by the direct effects of
rain, water, heat, or vibration. Furthermore, dur-
ing inspection and repair operations, they are
frequently removed and installed again, so they
are likely to suffer deformation or damage. For
this reason, it is necessary to be extremely care-
ful when handling wiring harnesses.

Main failures occurring in wiring harness

1) Defective contact of connectors (defective
contact between male and female)
Problems with defective contact are likely to
occur because the male connector is not
properly inserted into the female connector,
or because one or both of the connectors is
deformed or the position is not correctly
aligned, or because there is corrosion or
oxidization of the contact surfaces.

2) Defective crimping or soldering of

connectors
The pins of the male and female connectors
are in contact at the crimped terminal or sol-
dered portion, but if there is excessive force
brought to bear on the wiring, the plating at
the joint will peel and cause improper con-
nection or breakage.

20-204 D155C-1
Testing and adjusting Points to remember when carrying out maintenance

3) Disconnections in wiring
If the wiring is held and the connectors are
pulled apart, or components are lifted with a
crane with the wiring still connected, or a
heavy object hits the wiring, the crimping of
the connector may separate, or the solder-
ing may be damaged, or the wiring may be
broken.

4) High-pressure water entering connector

The connector is designed to make it diffi-
cult for water to enter (drip-proof structure),
but if high-pressure water is sprayed directly
on the connector, water may enter the con-
nector, depending on the direction of the
water jet.
As already said, the connector is designed
to prevent water from entering, but at the
same time, if water does enter, it is difficult
for it to be drained. Therefore, if water
should get into the connector, the pins will
be short-circuited by the water, so if any
water gets in, immediately dry the connector
or take other appropriate action before
passing electricity through it.

5) Oil or dirt stuck to connector

If oil or grease are stuck to the connector
and an oil film is formed on the mating sur-
face between the male and female pins, the
oil will not let the electricity pass, so there
will be defective contact.
If there is oil or grease stuck to the connec-
tor, wipe it off with a dry cloth or blow it dry
with compressed air and spray it with a con-
tact restorer.
a When wiping the mating portion of the
connector, be careful not to use
excessive force or deform the pins.
a If there is oil or water in the compressed
air, the contacts will become even dirtier,
so remove the oil and water from the
compressed air completely before
cleaning with compressed air.

D155C-1 20-205
Testing and adjusting Points to remember when carrying out maintenance

2) Removing, installing, and drying connectors

and wiring harnesses

• Disconnecting connectors
1) Hold the connectors when disconnecting.
When disconnecting the connectors, hold
the connectors and not the wires. For con-
nectors held by a screw, loosen the screw
fully, then hold the male and female connec-
tors in each hand and pull apart. For con-
nectors which have a lock stopper, press
down the stopper with your thumb and pull
the connectors apart.
a Never pull with one hand.

2) When removing from clips

When removing a connector from a clip, pull
the connector in a parallel direction to the
clip.
a If the connector is twisted up and down
or to the left or right, the housing may
break.

3) Action to take after removing connectors

After removing any connector, cover it with a
vinyl bag to prevent any dust, dirt, oil, or
water from getting in the connector portion.
a If the machine is left disassembled for a
long time, it is particularly easy for
improper contact to occur, so always
cover the connector.

20-206 D155C-1
Testing and adjusting Points to remember when carrying out maintenance

• Connecting connectors
1) Check the connector visually.
1) Check that there is no oil, dirt, or water
stuck to the connector pins (mating por-
tion).
2) Check that there is no deformation,
defective contact, corrosion, or damage
to the connector pins.
3) Check that there is no damage or break-
age to the outside of the connector.
a If there is any oil, water, or dirt stuck to
the connector, wipe it off with a dry cloth.
If any water has got inside the
connector, warm the inside of the wiring
with a dryer, but be careful not to make it
too hot as this will cause short circuits.
a If there is any damage or breakage,
replace the connector.

2) Fix the connector securely.

Align the position of the connector correctly,
then insert it securely.
For connectors with lock stopper, push in
the connector until the stopper clicks into
position.

3) Correct any protrusion of the boot and any

misalignment of the wiring harness.
For connectors fitted with boots, correct any
protrusion of the boot. In addition, if the wir-
ing harness is misaligned, or the clamp is
out of position, adjust it to its correct posi-
tion.
a If the connector cannot be corrected
easily, remove the clamp and adjust the
position.

4) If the connector clamp has been removed,

be sure to return it to its original position.
Check also that there are no loose clamps.

• Connecting connectors (DT type connector)

Since the DT 8-pole and 12-pole DT type con-
nectors have 2 latches respectively, push them
in until they click 2 times.
1. Male connector, 2. Female connector
• Normal locking state (Horizontal): a, b, d
• Incomplete locking state (Diagonal): c

D155C-1 20-207
Testing and adjusting Points to remember when carrying out maintenance

• Drying wiring harness

If there is any oil or dirt on the wiring harness,
wipe it off with a dry cloth. Avoid washing it in
water or using steam. If the connector must be
washed in water, do not use high-pressure
water or steam directly on the wiring harness.

If water gets directly on the connector, do as fol-

lows:
1) Disconnect the connector and wipe off the
water with a dry cloth.
a If the connector is blown dry with
compressed air, there is the risk that oil
in the air may cause defective contact,
so remove all oil and water from the
compressed air before blowing with air.

2) Dry the inside of the connector with a dryer.

If water gets inside the connector, use a
dryer to dry the connector.
a Hot air from the dryer can be used, but
regulate the time that the hot air is used
in order not to make the connector or
related parts too hot, as this will cause
deformation or damage to the
connector.

3) Carry out a continuity test on the connector.

After drying, leave the wiring harness dis-
connected and carry out a continuity test to
check for any short circuits between pins
caused by water.
a After completely drying the connector,
b l o w i t wi th c o n t ac t r e s t o r e r a n d
reassemble.

20-208 D155C-1
Testing and adjusting Points to remember when carrying out maintenance

3) Handling control box

1) The control box contains a microcomputer
and electronic control circuits. These control
all of the electronic circuits on the machine,
so be extremely careful when handling the
control box.
2) Do not open the cover of the control box
unless necessary.

3) Do not place objects on top of the control

box.
4) Cover the control connectors with tape or a
vinyl bag.
Never touch the connector contacts with
your hand.
5) During rainy weather, do not leave the
control box in a place where it is exposed to
rain.

6) Do not place the control box on oil, water, or

soil, or in any hot place, even for a short
time.
(Place it on a suitable dry stand)
7) Precautions when carrying out arc welding
When carrying out arc welding on the body,
disconnect all wiring harness connectors
connected to the control box. Fit an arc
welding ground close to the welding point.

2. Points to remember when troubleshooting electric circuits

1) Always turn the power OFF before disconnecting or connecting connectors.
2) Before carrying out troubleshooting, check that all the related connectors are properly inserted.
a Disconnect and connect the related connectors several times to check.
3) Always connect any disconnected connectors before going on to the next step.
a If the power is turned ON with the connectors still disconnected, unnecessary abnormality displays
will be generated.
4) When carrying out troubleshooting of circuits (measuring the voltage, resistance, continuity, or current),
move the related wiring and connectors several times and check that there is no change in the reading
of the tester.
a If there is any change, there is probably defective contact in that circuit.

D155C-1 20-209
Testing and adjusting Points to remember when carrying out maintenance

3. Points to remember when handling hydraulic

equipment

With the increase in pressure and precision of

hydraulic equipment, the most common cause of
failure is dirt (foreign material) in the hydraulic cir-
cuit. When adding hydraulic oil, or when disassem-
bling or assembling hydraulic equipment, it is
necessary to be particularly careful.

1) Be careful of the operating environment

Avoid adding hydraulic oil, replacing filters, or
repairing the machine in rain or high winds, or
places where there is a lot of dust.

2) Disassembly and maintenance work in the

field
If disassembly or maintenance work is carried
out on hydraulic equipment in the field, there is
danger of dust entering the equipment. It is also
difficult to confirm the performance after repairs,
so it is desirable to use unit exchange. Disas-
sembly and maintenance of hydraulic equip-
ment should be carried out in a specially
prepared dustproof workshop, and the perfor-
mance should be confirmed with special test
equipment.

3) Sealing openings
After any piping or equipment is removed, the
openings should be sealed with caps, tapes, or
vinyl bags to prevent any dirt or dust from enter-
ing. If the opening is left open or is blocked with
a rag, there is danger or dirt entering or of the
surrounding area being made dirty by leaking oil
so never do this.
Do not simply drain oil out on to the ground, col-
lect it and ask the customer to dispose of it, or
take it back with you for disposal.

4) Do not let any dirt, or dust get in during

refilling operations.
Be careful not to let any dirt or dust get in when
refilling with hydraulic oil. Always keep the oil
filler and the area around it clean, and also use
clean pumps and oil containers. If an oil clean-
ing device is used, it is possible to filter out the
dirt that has collected during storage, so this is
an even more effective method.

20-210 D155C-1
Testing and adjusting Points to remember when carrying out maintenance

5) Change hydraulic oil when the temperature

is high.
When hydraulic oil or other oil is warm, it flows
easily. In addition, the sludge can also be
drained out easily from the circuit together with
the oil, so it is best to change the oil when it is
still warm. When changing the oil, as much as
possible of the old hydraulic oil must be drained
out. (Do not drain the oil from the hydraulic tank;
also drain the oil from the filter and from the
drain plug in the circuit.) If any old oil is left, the
contaminants and sludge in it will mix with the
new oil and will shorten the life of the hydraulic
oil.

6) Flushing operations
After disassembling and assembling the equip-
ment, or changing the oil, use flushing oil to
remove the contaminants, sludge, and old oil
from the hydraulic circuit.
Normally, flushing is carried out twice: primary
flushing is carried out with flushing oil, and sec-
ondary flushing is carried out with the specified
hydraulic oil.

7) Cleaning operations
After repairing the hydraulic equipment (pump,
c o n tr o l v a lv e , e t c .) o r wh e n r u n ni n g t he
machine, carry out oil cleaning to remove the
sludge or contaminants in the hydraulic oil cir-
cuit.
The oil cleaning equipment is used to remove
the ultrafine (about 3µ) particles that the filter
built into the hydraulic equipment cannot
remove, so it is an extremely effective device.

D155C-1 20-211
Testing and adjusting Checks before troubleshooting

Checks before troubleshooting

Judgement
Item Action
Value
1. Check fuel level, type of fuel — Add fuel
2. Check for impurities in fuel — Clean, drain
3. Check hydraulic oil level — Add oil
Lubricating oil, coolant

4. Check hydraulic strainer — Clean, drain

5. Check power train oil level — Add oil
6. Check engine oil level — Add oil
7. Check coolant level — Add water
8. Check dust indicator for clogging — Clean or replace
9. Check power train oil filter — Replace
10. Check hydraulic filter — Replace
11. Check final drive oil level — Add oil
12. Check for looseness, corrosion of battery terminal, wiring — Tighten or replace
equipment
Electrical

13. Check for looseness, corrosion of alternator terminal, wiring — Tighten or replace
14. Check for looseness, corrosion of starting motor terminal, wiring — Tighten or replace
15. Check operation of gauges — Repair or replace
mechanical
equipment
Hydraulic,

16. Check for abnormal noise, smell — Repair

17. Check for oil leakage — Repair
18. Carry out air bleeding — Bleed air

19. Check battery voltage (engine stopped) 24 – 26 V Replace

20. Check battery electrolyte level — Add or replace
Electrics, electrical equipment

21. Check for discolored, burnt, exposed wiring — Replace

22. Check for missing wiring clamps, hanging wiring — Repair
23. Check for water leaking on wiring (pay particularly careful atten- Disconnect
—
tion to water leaking on connectors or terminals) connector and dry
24. Check for blown, corroded fuses — Replace
After running
for several
25. Check alternator voltage (engine running at 1/2 throttle or above) Replace
minutes:
27.5 – 29.5 V
26. Check operating sound of battery relay (starting switch ON, OFF) — —

20-212 D155C-1
 Troubleshooting of engine system
(S mode)
Method of using troubleshooting charts ...................................................................................................... 20-302
S-1 Starting performance is poor (starting always takes time)................................................................ 20-306
S-2 Engine does not start ....................................................................................................................... 20-307
(1) Engine does not turn................................................................................................................... 20-307
(2) Engine turns but no exhaust smoke comes out (fuel is not being injected) ................................ 20-308
(3) Exhaust smoke comes out but engine does not start (Fuel is being injected) ............................ 20-309
S-3 Engine does not pick up smoothly (follow-up is poor) ...................................................................... 20-310
S-4 Engine stops during operations........................................................................................................ 20- 311
S-5 Engine does not rotate smoothly (hunting)....................................................................................... 20-312
S-6 Engine lacks output (no power)........................................................................................................ 20-313
S-7 Exhaust smoke is black (incomplete combustion) ........................................................................... 20-314
S-8 Oil consumption is excessive (or exhaust smoke is blue) ................................................................ 20-315
S-9 Oil becomes contaminated quickly................................................................................................... 20-316
S-10 Fuel consumption is excessive ........................................................................................................ 20-317
S-11 Oil is in cooling water, or water spurts back, or water level goes down ........................................... 20-318
S-12 Oil pressure caution lamp lights up (drop in oil pressure) ................................................................ 20-319
S-13 Oil level rises (water, fuel in oil)........................................................................................................ 20-320
S-14 Water temperature becomes too high (overheating)........................................................................ 20-321
S-15 Abnormal noise is made................................................................................................................... 20-322
S-16 Vibration is excessive....................................................................................................................... 20-323

D155C-1 20-301
Troubleshooting Method of using troubleshooting charts

Method of using troubleshooting charts

This troubleshooting chart is divided into three sec-
tions: questions, check items, and troubleshoot-
ing. The questions and check items are used to
pinpoint high probability causes that can be located
from the failure symptoms or simple inspeciton with-
out using troubleshooting tools.
Next, troubleshooting tools or direct inspection are
used to check the high probability causes to make
final confirmation.

[Questions]
Sections [A] + [B] in the chart on the right corre-
sponds to the items where answers can be obtained
from the user. The items in [B] are items that can be
obtained from the user, depending on the user's
level.
[Check items]
The serviceman carries out simple inspection to nar-
row down the causes. The items under [C] in the
chart on the right correspond to this.
The serviceman narrows down the causes from
information [A] that he has obtained from the user
and the results of [C] that he has obtained from his
own inspection.
[Troubleshooting]
Troubleshooting is carried out in the order of proba-
bility, starting with the causes that have been
marked as having the highest probability from infor-
mation gained from [Questions] and [Check
items].

20-302 D155C-1
Troubleshooting Method of using troubleshooting charts

The basic method of using the troubleshooting chart

is as follows.
Items listed for [Questions] and [Check items] that
have a relationship with the Cause items are marked
with Q, and of these, causes that have a high proba-
bility are marked with w.
Check each of the [Questions] and [Check items]
in turn, and marked the Q or w in the chart for items
where the problem appeared. The vertical column
(Causes) that has the highest number of points is the
most probable cause, so start troubleshooting for
that item to make final confirmation of the cause.
*1. For [Confirm recent repair history] in
the [Questions] Section, ask the user,
and mark the Cause column with E to
use as reference for locating the cause
of the failure. However, do not use this
when making calculations to narrow
down the causes.
*2. Use the E in the Cause column as ref-
erence for [Degree of use (Operated
for long period)] in the [Questions]
section as reference. As a rule, do not
use it when calculating the points for
locating the cause, but it can be
included if necessary to determine the
order for troubleshooting.

D155C-1 20-303
Troubleshooting Method of using troubleshooting charts

• Example of troubleshooting when exhaust gas is black

Let us assume that [Clogged air cleaner] is taken to be the cause of black exhaust gas. Three symptoms
have causal relationship with this problem: [Exhaust gas slowly became black], [Power slowly became
weaker], and [Dust indicator is red].
If we look from these three symptoms to find the causes, we find that there is a relationship with five causes.
Let us explain here the method of using this causal relationship to pinpoint the most probable cause.

S-7 Exhaust gas is black (incomplete combustion)

General causes why exhaust gas is black
• Insufficient intake of air
• Improper condition of fuel injection
• Excessive injection of fuel

20-304 D155C-1
Troubleshooting Method of using troubleshooting charts

D155C-1 20-305
Troubleshooting S-1

S-1 Starting performance is poor (starting always takes time)

a Check that the monitor panel does not display any Legend
Q : Possible causes (judging from Questions and
abnormality in the governor control system.
check items)
General causes why exhaust smoke comes out but w : Most probable causes (judging from Questions
engine takes time to start and Check items)
• Defective electrical system E : Possible causes due to length of use (used for a
long period)
• Insufficient supply of fuel q : Items to confirm the cause
• Insufficient intake of air
Causes
• Improper selection of fuel

Defective injection pump (rack, plunger stuck)

(At ambient temperature of 10°C or below, use ASTM D975 No. 1)
a Battery charging rate

Clogged air breather hole in fuel tank cap

Defective contact of valve, valve seat

Defective electrical intake air heater

Leakage, clogging, air in fuel piping

Charging rate

Defective or deteriorated battery

Ambient 100 % 90 % 80 % 75 % 70 %
temperature

Clogged air cleaner element

Clogged feed pump strainer

Clogged fuel filter, strainer

Defective injection nozzle

Worn piston ring, cylinder

Defective injection timing

20°C 1.28 1.26 1.24 1.23 1.22
0°C 1.29 1.27 1.25 1.24 1.23

Defective alternator
Defective regulator
–10°C 1.30 1.28 1.26 1.25 1.24
• The specific gravity should exceed the value for the
charging rate of 70% in the above table.
• In cold areas the specific gravity must exceed the value for
the charging rate of 75% in the above table.
Confirm recent repair history
Degree of use of machine Operated for long period E E E E
Gradually became worse w w Q Q Q
Ease of starting
Starts when warm w w
Questions

Indicator lamp does not light up w

Engine oil must be added more frequently w
Replacement of filters has not been carried out according to Operation Manual w w w Q Q
Dust indicator is red w
Non-specified fuel is being used Q Q Q Q
Battery charge lamp is ON w w
Starting motor cranks engine slowly w
When exhaust manifold is touched immediately after starting engine, temperature of
w
some cylinders is low
Engine does not pick up smoothly, and combustion is irregular Q Q w
w
Check items

Blow-by gas is excessive

Match marks on fuel injection pump are out of alignment w
Mud is stuck to fuel tank cap Q
When engine is cranked with starting motor,
w
1) Little fuel comes out even when injection pipe sleeve nut is loosened
2) Little fuel comes out even when fuel filter air bleed plug is loosened w w w
Leakage from fuel piping Q w
There is hunting from engine (rotation is irregular) Q Q w Q

When compression pressure is measured, it is found to be low q q

When air cleaner element is inspected directly, it is found to be clogged q
When fuel filter, strainer are inspected directly, they are found to be clogged q q
When feed pump strainer is inspected directly, it is found to be clogged q
q
Troubleshooting

Heater mount does not become warm

Is voltage 26 - 30V between alternator terminal B and terminal E with engine Yes q
at low idling? No q
Either specific gravity of electrolyte or voltage of battery is low q
Speed does not change when operation of certain cylinders is stopped q
When check is made using delivery method, injection timing is found to be incorrect q
When control rack is pushed, it is found to be heavy or does not return (when blind cover
q
at rear of pump is removed, it can be seen that plunger control sleeve does not move)
When fuel cap is inspected directly, it is found to be clogged q
Replace

Replace
Replace
Replace
Replace
Replace

Replace
Correct

Correct
Adjust
Clean
Clean
Clean

Clean

Remedy

20-306 D155C-1
Troubleshooting S-2

S-2 Engine does not start

(1) Engine does not turn

General causes why engine does not turn

• Internal parts of engine seized
a If internal parts of the engine are seized, carry out
troubleshooting for "Engine stops during operations".
• Failure in power train
Causes
• Defective electrical system

Defective adjustment of engine stop motor wire

Defective safety relay or safety switch

Defective battery terminal conncetion

Defective wiring of starting circuit
Defective or deteriorated battery

Defective engine stop motor

Defective fuel cut solenoid

Defective starting switch

Defective starting motor

Defectinve battery relay

Broken ring gear
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

E E
Questions

Degree of use Operated for long period

Horn does not sound w Q Q
Condition of horn when starting switch is turned ON
Horn sound level is low w
Roaing speed is slow w
When starting switch is turned to START, pinion moves Makes grating noise w w
out, but Soon disengages again w
Makes rattling noise and does not turn Q Q Q
When starting switch is turned to START, pinion does not move out Q Q
w
Check items

When starting switch is turned to ON, there is no clicking sound Q w

Carry out troubleshooting for defective wiring of starting circuit

Battery terminal is loose w

When starting switch is turned to ON, linkage dose not move w w w
When battery is checked, battery electrolyte is found to be low w

Specific gravity of electrolyte, voltage of battery is low q

For the following conditions 1) – 5), turn the starting switch OFF, connect the cord, and carry out
troubleshooting at ON q
1) When terminal B and terminal C of starting switch are connected, engine starts
Troubleshooting

2) When terminal B and terminal C of starting motor are connected, engine starts q
3) When terminal B and terminal C of safety relay are connected, engine starts q
4) When terminal of safety switch and terminal B of starting motor are connected, engine starts q
5) There is no 24V voltage between battery relay terminal b and terminal E q
When ring gear is inspected directly, tooth surface is found to be chipped q
Does not move even when fuel cut solenoid linkage is disconnected q
Does not move even when engine stop motor linkage is disconnected q q
Replace
Replace
Replace
Replace
Replace
Replace
Replace

Replace
Replace
Adjust

Remedy —

D155C-1 20-307
Troubleshooting S-2

(2) Engine turns but no exhaust smoke comes out

(fuel is not being injected)

General causes why engine turns but no exhaust smoke comes out
• Supply of fuel impossible
• Supply of fuel is extremely small
• Improper selection of fuel (particularly in winter)
Causes

a Standards for use of fuel

Defective injection pump (rack, plunger seized)

Broken injection pump drive shaft, key

Clogged fuel tank air breather hole

Seized, broken feed pump piston

Defective engine stop motor

Clogged feed pump strainer

Clogged, leaking fuel piping

Clogged fuel filter, strainer

Defective fuel cut solenoid

Improper fuel used

Lack of fuel
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
Confirm recent repair history
Degree of use Operated for long period E E E
w w w
Questions

Exhaust smoke suddenly stops coming out (when starting again)

Replacement of filters has not been carried out according to operation manual w w
Fuel tank is found to be empty w
There is leakage from fuel piping w
Mud is stuck to fuel tank cap w
When starting switch is turned ON, linkage does not move w w
When fuel filter is drained, fuel does not come out w
Check items

When engine is cranked with starting motor,

w
1) Injection pump coupling does not rotate
2) No fuel comes out even when fuel filter air bleed plug is loosened w Q Q Q
3) No fuel spurts out even when injection pipe sleeve nut is loosened w w w
Rust and water are found when fuel tank is drained Q Q

Check injection pump directly q

When control rack is pushed, it is found to be heavy, or does not return q
Troubleshooting

Check feed pump directly q

When fuel filter, strainer are inspected directly, they are found to be clogged q q
When feed pump strainer is inspected directly, it is found to be clogged q
When fuel cap is inspected directly, it is found to be clogged q
Does not move even when fuel cut solenoid linkage is disconnected q
Does not move even when engine stop motor linkage is disconnected q
Replace
Replace
Replace

Replace
Replace
Replace
Repair
Repair
Clean
Clean

Remedy
Add

20-308 D155C-1
Troubleshooting S-2

(3) Exhaust smoke comes out but engine does not start
(Fuel is being injected)

a General causes why exhaust smoke comes out but engine

does not start
• Lack of rotating force due to defective electrical system
Causes
• Insufficient supply of fuel
• Insufficient intake of air

Defective, broken valve system (valve, rocker lever, etc.)

• Improper selection of fuel and oil

Defective injection pump (rack, plunger stuck)

Clogged air breather hole in fuel tank cap

Clogged injection nozzle, defective spray
Leakage, clogging, air in fuel system
Defective electrical intake air heater
Defective or deteriorated battery
Worn piston ring, cylinder liner

Clogged air cleaner element

Clogged feed pump strainer
Clogged fuel filter, strainer

Improper fuel used

Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Degree of use of machine Operated for long period E E E E
Suddenly failed to start w w
When engine is cranked, abnormal noise is heard from around head w
Questions

Engine oil must be added more frequently w

Non-specified fuel is being used Q Q
Replacement of filters has not been carried out according to Operation Manual w w w
Rust and water are found when fuel tank is drained w
Dust indicator is red w w
Preheating indicator lamp does not light up w
Starting motor cranks engine slowly w
Mud is stuck to fuel tank cap Q
When fuel lever is placed at FULL position, it does not contact stopper Q
When engine is cranked with starting motor,
w
1) Little fuel comes out even when injection pipe sleeve nut is loosened
Check items

2) No fuel comes out even when fuel filter air bleed plug is loosened w w Q
There is leakage from fuel piping w
When exhaust manifold is touched immediately after starting engine, temperature of some
w
cylinders is low
When fuel filter is drained, no fuel comes out w

Remove head cover and check directly q

When control rack is pushed, it is found to be heavy, or does not return q
When compression pressure is measured, it is found to be low q
q q
Troubleshooting

When fuel filter, strainer are inspected directly, they are found to be clogged
When feed pump strainer is inspected directly, it is found to be clogged q
When air cleaner element is inspected directly, it is found to be clogged q
Heater mount does not become warm q
Either specific gravity of electrolyte or voltage of battery is low q
When feed pump is operated, operation is too light or too heavy q
Speed does not change when operation of certain cylinders is stopped q
When fuel cap is inspected directly, it is found to be clogged q
Replace
Replace
Replace

Replace
Replace

Replace
Correct
Clean
Clean
Clean

Clean
Clean

Remedy

D155C-1 20-309
Troubleshooting S-3

S-3 Engine does not pick up smoothly (follow-up is poor)

a Check that the monitor panel does not display any abnormality in
the governor control system.
General causes why engine does not pick up smoothly
• Insufficient intake of air
• Insufficient supply of fuel
• Improper condition of fuel injection
• Improper fuel used
Causes

Clogged air breather hole in fuel tank cap

Defective contact of valve and valve seat

Clogged injection nozzle, defective spray

Seized turbocharger, interference

Worn piston ring, cylinder liner
Seized injection pump plunger
Clogged air cleaner element

Clogged feed pump strainer

Clogged, leaking fuel piping

Clogged fuel filter, strainer

Improper valve clearance

Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

Degree of use of machine Operated for long period E E E E E
Replacement of filters has not been carried out according to Operation Manual w w w
Questions

Non-specified fuel is being used w w w w

Engine oil must be added more frequently w
Rust and water are found when fuel tank is drained w w
Dust indicator is red w
Noise of interference is heard from around turbocharger w
Engine pick-up suddenly became poor Q w Q Q
Blue under light load w
Color of exhaust gas
Black w w w Q
Clanging sound is heard from around cylinder head w
Mud is stuck to fuel tank cap w
There is leakage from fuel piping w
Check items

High idling speed under no load is normal, but speed suddenly drops when load is applied w w Q
There is hunting from engine (rotation is irregular) Q w Q Q
When exhaust manifold is touched immediately after starting engine, temperature of some cylinders
w Q
is low
Blow-by gas is excessive w

When air cleaner element is inspected directly, it is found to be clogged q

When fuel filter, strainer are inspected directly, they are found to be clogged q
When feed pump strainer is inspected directly, it is found to be clogged q
Troubleshooting

Speed does not change when operation of certain cylinders is stopped q

When control rack is pushed, it is found to be heavy, or does not return q
When compression pressure is measured, it is found to be low q q
When turbocharger is rotated by hand, it is found to be heavy q
When valve clearance is checked directly, it is found to be outside standard value q
When fuel cap is inspected directly, it is found to be clogged q
When feed pump is operated, operation is too light or too heavy q
Replace
Replace
Replace

Replace
Correct

Correct
Adjust
Clean
Clean
Clean

Clean

Remedy

20-310 D155C-1
Troubleshooting S-4

S-4 Engine stops during operations

General causes why engine stops during operations

• Seized parts inside engine
• Insufficient supply of fuel
• Overheating
a If there is overheating and insufficient output, carry
out troubleshooting for overheating.
• Failure in power train
Causes
a If the engine stops because of a failure in the power
train, carry out troubleshooting for the chassis.

Broken valve system (valve, rocker lever, etc.)

Defective injection pump (rack, plunger stuck)

Broken, seized piston, connecting rod

Clogged fuel tank air breather hole

Broken, seized crankshaft bearing

Broken fuel pump drive shaft, key

Broken pump auxiliary equipment

Broken, seized feed pump piston

Failure in chassis power train

Clogged feed pump strainer

Clogged, leaking fuel piping

Clogged fuel filter, strainer
Broken, seized gear train
Legend
Q : Possible causes (judging from Questions and check items)

Lack of fuel
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

Degree of use Operated for long period E E
Abnormal noise was heard and engine
w w w w w w Q Q w
stopped suddenly
Questions

Condition when engine stopped Engine overheated and stopped w Q Q

Engine stopped slowly w Q Q
There was hunting and engine stopped w Q Q Q Q
Fuel gauge lamp lights up w
Fuel tank is found to be empty w
Replacement of filters has not been carried out according to operation manual w w
Non-specified fuel is being used Q Q Q Q
When feed pump is operated, there is no response or it is heavy Q Q w
Mud is stuck to fuel tank cap w
Engine turns, but stops when transmission control lever is operated w
Does not turn at all w w
Check items

Turns in opposite direction w

Try to turn by hand using barring tool
Carry out troubleshooting in chassis volume

Moves amount of backlash w w

Shaft does not turn w
Rust and water are found when fuel is drained w w
Metal particles are found when oil is drained w w Q Q

Remove oil pan and check directly q q

Remove head cover and check directly q
Troubleshooting

When gear train is inspected, it does not turn q

Turns when pump auxiliary equipment is removed q
When fuel filter, strainer are inspected directly, they are found to be clogged q
When feed pump strainer is inspected directly, it is found to be clogged q
Check feed pump directly q
When control rack is pushed, it is found to be heavy or does not return q
Replace
Replace
Replace
Replace
Replace
Replace

Replace

Replace
Repair
Clean
Clean

Clean

Remedy —
Add

D155C-1 20-311
Troubleshooting S-5

S-5 Engine does not rotate smoothly (hunting)

General causes why engine does not rotate smoothly

• Air in fuel system
• Defective governor mechanism
• Defective electric governor mechanism
a If hunting does not occur when the rod between the governor
motor and the injection pump is disconnected, troubleshoot by
using the electrical system troubleshooting (E mode).
Causes

Clogged, air in circuit between feed pump and injection nozzle

Clogged, air in circuit between fuel tank and feed pump

Clogged air breather hole in fuel tank cap

Defective operation of control rack
Defective adjustment of governor
Defective operation of governor

Clogged feed pump strainer

Low idling speed is too low

Clogged fuel filter, strainer

Legend
Q : Possible causes (judging from Questions and check items)

Lack of fuel
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Degree of use of machine Operated for long period E E
Occurs at a certain speed range w w w Q
Q w Q Q Q Q
Questions

Occurs at low idling

Condition of hunting
Occurs even when speed is raised Q Q Q Q
Occurs on slopes w
Fuel tank is found to be empty w
Replacement of filters has not been carried out according to Operation Manual w w
Rust, water are found when fuel tank is drained Q Q
Leakage from fuel piping w w
When feed pump is operated,
w w
1) No response, light, return is quick
Check items

2) No response, light, return is normal w

Engine speed sometimes rises too far w w
Engine is sometimes difficult to stop w w
Seal on injection pump has come off w w

When governor lever is moved it is found to be stiff q q

Troubleshooting

When injection pump is tested, governor is found to be improperly adjusted q

When control rack is pushed, it is found to be heavy, or does not return q
When fuel cap is inspected directly, it is found to be clogged q q
When feed pump strainer is inspected directly, it is found to be clogged q
When fuel filter, strainer are inspected directly, they are found to be clogged q
Correct
Correct
Adjust
Adjust
Adjust
Adjust

Clean
Clean

Clean

Remedy
Add

20-312 D155C-1
Troubleshooting S-6

S-6 Engine lacks output (no power)

General causes why engine lacks output

• Insufficient intake of air
• Insufficient supply of fuel
• Improper condition of fuel injection
• Improper fuel used Causes
(if non-specified fuel is used, output drops)
• Lack of output due to overheating
a If there is overheating and insufficient output, carry out

Bent fuel control linkage, defective adjustment

troubleshooting for overheating.

Clogged air breather hole in fuel tank cap

Defective contact of valve and valve seat
Clogged injection nozzle, defective spray
Seized turbocharger, interference
Worn piston ring, cylinder liner

Seized injection pump plunger

Clogged air cleaner element

Clogged feed pump strainer

Clogged, leaking fuel piping

Clogged fuel filter, strainer

Improper valve clearance

Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

Degree of use of machine Operated for long period E E E E E
Questions

Suddenly w
Power was lost
Gradually Q Q Q Q Q Q
Engine oil must be added more frequently w
Replacement of filters has not been carried out according to Operation Manual w w w
Non-specified fuel is being used w w w w
Dust indicator is red w
Black w
w

Color of exhaust gas

Blue under light load w
Noise of interference is heard from around turbocharger w
Blow-by gas is excessive w
Check items

Engine pickup is poor and combustion is irregular w w Q Q

High idling speed under no load is normal, but speed suddenly drops when load is applied w w Q
When exhaust manifold is touched immediately after starting engine, temperature of some
w Q
cylinders is low
There is hunting from engine (rotation is irregular) Q Q Q Q
Clanging sound is heard from around cylinder head w
High idling speed of engine is low Q w
Leakage from fuel piping w

When air cleaner element is inspected directly, it is found to be clogged q

When turbocharger is rotated by hand, it is found to be heavy q
When compression pressure is measured, it is found to be low q q
When fuel filter, strainer are inspected directly, they are found to be clogged q
Troubleshooting

When feed pump strainer is inspected directly, it is found to be clogged q

Speed does not change when operation of certain cylinders is stopped q
When control rack is pushed, it is found to be heavy, or does not return q
When valve clearance is checked directly, it is found to be outside standard value q
When lever is placed at FULL position, it does not contact stopper q
When feed pump is operated, operation is too light or too heavy q
When fuel cap is inspected directly, it is found to be clogged q
Replace
Replace

Replace

Replace
Correct

Correct
Adjust

Adjust
Clean

Clean
Clean

Clean

Remedy

D155C-1 20-313
Troubleshooting S-7

S-7 Exhaust smoke is black (incomplete combustion)

General causes why exhaust smoke is black

• Insufficient intake of air
• Improper condition of fuel injection
• Excessive injection of fuel
Causes

Leakage of air between turbocharger and cylinder head

Defective injection pump (rack, plunger seized)

Defective injection pump (excessive injection)
Clogged injection nozzle, defective spray

Defective contact of valve and valve seat

Seized turbocharger, interference

Worn piston ring, cylinder liner

Clogged air cleaner element

Improper valve clearance

Crushed, clogged muffler
Improper injection timing
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Degree of use of machine Operated for long period E E E E
Suddenly became black w Q Q
Color of exhaust gas Gradually became black w Q Q
Questions

Blue under light load w

Engine oil must be added more frequently w
Suddenly w Q Q
Power was lost
Gradually Q Q Q Q
Non-specified fuel is being used Q Q
Noise of interference is heard from around turbocharger w
Dust indicator is red w
Blow-by gas is excessive w
Engine pickup is poor and combustion is irregular Q w Q Q Q Q
When exhaust manifold is touched immediately after starting engine, temperature of some cylinders is low w Q
Match marks on fuel injection pump are out of alignment w
Check items

Seal on injection pump has come off w

Clanging sound is heard from around cylinder head w
Exhaust noise is abnormal Q Q w
Muffler is crushed w
Leakage of air between turbocharger and cylinder head, loose clamp w

When turbocharger is rotated by hand, it is found to be heavy q

When air cleaner is inspected directly, it is found to be clogged q
When compression pressure is measured, it is found to be low q q
Troubleshooting

Speed does not change when operation of certain cylinders is stopped q

When check is made using delivery method, injection timing is found to be incorrect q
Injection pump test shows that injection amount is incorrect q
When valve clearance is checked directly it is found to be outside standard value q
When muffler is removed, exhaust color returns to normal q
When control rack is pushed, it is found to be heavy, or does not return q
Replace

Replace
Replace

Replace

Replace
Replace
Correct
Adjust
Adjust
Adjust
Clean

Remedy

20-314 D155C-1
Troubleshooting S-8

S-8 Oil consumption is excessive (or exhaust smoke is blue)

a Do not run the engine at idling for more than 20 minutes

continuously. (Both low and high idling)
General causes why oil consumption is excessive
• Abnormal combustion of oil
• External leakage of oil
• Wear of lubrication system
Causes

Turbocharger

Worn valve (stem, guide), broken seal

Leakage from oil pan or cylinder head

Worn, broken rear seal, seal surface

Clogged breather or breather hose

Dust sucked in from intake system

Leakage from oil filter or oil cooler
Worn piston ring, cylinder liner

Leakage from oil drain plug

Worn seal at turbine end

Worn seal at blower end
Leakage from oil piping
Broken piston ring

Broken oil cooler

Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

E E E E
Questions

Degree of use of machine Operated for long period

Oil consumption suddenly increased w Q
Engine oil must be added more frequently w Q
Engine oil becomes contaminated quickly Q w Q
Exhaust smoke is blue under light load w w
Excessive w w Q Q
Amount of blow-by gas
None w
Area around engine is dirty with oil w w w w
There is oil in engine cooling water w
Check items

When exhaust pipe is removed, inside is found to be dirty with oil w Q

When turbocharger air supply pipe is removed, inside is found to be dirty with oil w
Oil level in clutch or TORQFLOW transmission damper chamber rises w
Clamps for intake system are loose w

When compression pressure is measured, it is found to be low q q

When breather element is inspected, it is found to be clogged with dirty oil q
Troubleshooting

There is external leakage of oil from engine q q q q

Pressure-tightness test of oil cooler shows there is leakage q
Excessive play of turbocharger shaft q q
Inspect rear seal directly q
When intake manifold is removed, dust is found inside q
When intake manifold is removed, inside is found to be dirty with oil q
Replace
Replace

Replace
Replace
Replace
Correct
Correct
Correct
Correct

Correct
Correct
Correct
Clean

Remedy

D155C-1 20-315
Troubleshooting S-9

S-9 Oil becomes contaminated quickly

General causes why oil becomes contaminated quickly

• Intake of exhaust gas due to internal wear
• Clogging of lubrication passage
• Improper fuel
• Improper oil used
• Operation under excessive load
Causes

Defective seal at turbocharger turbine end

Clogged breather, breather hose

Clogged turbocharger drain tube

Worn piston ring, cylinder liner

Worn valve, valve guide

Exhaust smoke is black

Defective safety valve
Clogged oil cooler
Clogged oil filter
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

Questions

Degree of use of machine Operated for long period E E E

Engine oil must be added more frequently w
Non-specified oil is being used Q
Blue under light load w
Color of exhaust gas
Black w
Excessive w Q Q Q

Carry out troubleshooting for "Exhaust smoke is black".

Amount of blow-by gas
None w
Check items

Oil filter caution lamp stays on even when oil pressure rises w Q
When oil filter is inspected, metal particles are found Q w Q
When exhaust pipe is removed, inside is found to be dirty with oil w
Engine oil temperature rises quickly w

When compression pressure is measured, it is found to be low q q

When breather element is inspected directly, hose is broken or is found to be clogged with dirty oil q
Troubleshooting

When oil filter is inspected directly, it is found to be clogged q

When oil cooler is inspected directly, it is found to be clogged q
Turbocharger drain tube is clogged q
Excessive play of turbocharger shaft q

When safety valve is directly inspected, spring is found to be catching or broken q

Replace

Replace
Replace

Replace
Replace
Clean

Clean
Clean

Remedy —

20-316 D155C-1
Troubleshooting S-10

S-10 Fuel consumption is excessive

General causes why fuel consumption is excessive

• Leakage of fuel
• Improper condition of fuel injection
• Excessive injection of fuel

Causes

Defective injection pump (excessive injection)

Defective oil seal inside feed pump (piston)

Defective adjustment of fuel control linkage
External leakage from fuel piping, fuel filter
Leakage of fuel inside head cover
Defective injection pump plunger
Defective nozzle holder spray

Defective fuel injection timing

Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

E E E
Questions

Degree of use of machine Operated for long period

More than for other machines of same model w Q
Condition of fuel consumption Gradually increased Q Q
Suddenly increased Q Q
Black w Q Q Q
Exhaust smoke color
White Q
Seal on injection pump has come off w
There is irregular combustion w
When exhaust manifold is touched immediately after starting engine, temperature of some cylinders is low w Q
Check items

Match mark on injection pump is misaligned w

There is external leakage of fuel from engine w
Engine oil level rises and smells of diesel fuel Q w w
Engine low idling speed is high Q w

Injection pump measurement shows that injection amount is excessive q

Speed does not change when operation of certain cylinders is stopped q
Troubleshooting

When control rack is pushed, it is found to be heavy, or does not return q

When check is made using delivery method, injection timing is found to be incorrect q
Remove head cover and inspect directly q
Remove feed pump and inspect directly q
When engine speed is measured, low idling speed is found to be high q
Replace
Replace

Correct
Correct
Correct
Adjust

Adjust

Adjust

Remedy

D155C-1 20-317
Troubleshooting S-11

S-11 Oil is in cooling water, or water spurts back, or water level goes down

General causes why oil is in cooling water

• Internal leakage in lubrication system
• Internal leakage in cooling system

Causes

Broken liner O-ring, holes caused by pitting

Broken cylinder head, head gasket

Broken oil cooler for power train

Internal cracks in cylinder block

Broken oil cooler core, O-ring

Insufficient protrusion of liner

Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause

Confirm recent repair history

E E
Questions

Degree of use of machine Operated for long period

Suddenly increased Q Q Q
Oil level
Gradually increased Q Q
Hard water is being used as cooling water Q Q
Engine oil level has risen, oil is cloudy white w Q Q
Check items

Excessive air bubbles inside radiator, spurts back w w

Hydraulic oil, torque converter, transmission oil is cloudy white w
When hydraulic oil, torque converter, transmission oil is drained, water is found w

Pressure-tightness test of oil cooler shows there is leakage q q

Troubleshooting

Pressure-tightness test of cylinder head shows there is leakage q

Remove cylinder head and inspect directly q
Remove oil pan and inspect directly q q
Replace
Replace
Replace
Replace
Replace
Replace

Remedy

20-318 D155C-1
Troubleshooting S-12

S-12 Oil pressure caution lamp lights up (drop in oil pressure)

General causes why oil pressure monitor lights up

• Leakage, clogging, wear of lubricating system

• Defective oil pressure control
• Improper oil used (improper viscosity)
• Deterioration of oil due to overheating

a Standards for engine oil selection

Causes

Leaking, crushed hydraulic piping

Clogged strainer inside oil pan
Clogged oil pipe inside oil pan

Defective oil pressure sensor

Broken suction pipe brazing

Defective oil level sensor

Defective regulator valve
Worn bearing, journal

Defective relief valve

Lack of oil in oil pan
Defective oil pump

Water, fuel in oil

Clogged oil filter
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Questions

Degree of use of machine Operated for long period E E E

Replacement of filters has not been carried out according to Operation Manual w
Caution lamp lights up w Q
Non-specified oil is being used Q Q
Lights up at low idling w Q
Lights up at low, high idling w w w w Q Q Q
Condition when oil pressure lamp lights up
Lights up on slopes w
Check items

Sometimes lights up w w Q Q
There is clogging, leakage from hydraulic piping (external) w
Oil level sensor lamp lights up w w
When oil level in oil pan is checked, it is found to be low w
Metal particles are found when oil is drained w
Metal particles are stuck to oil filter element w Q
Oil is cloudy white or smells of diesel oil w
Carry out troubleshooting

When oil filter is inspected directly, it is found to be clogged q q

Troubleshooting

Remove oil pan and inspect directly q q q

for "Oil level rises".

Oil pump rotation is heavy, there is play q

There is catching of relief valve or regulator valve, spring or valve guide is broken q q
When oil level sensor is replaced, oil pressure sensor lamp goes out q
When oil pressure is measured, it is found to be within standard value q
Replace

Replace
Replace
Correct

Correct
Adjust
Adjust
Clean
Clean
Clean
Clean

Remedy —
Add

D155C-1 20-319
Troubleshooting S-13

S-13 Oil level rises (water, fuel in oil)

a If there is oil in the cooling water, carry out

troubleshooting for "Oil is in cooling water".
General causes why oil level rises
• Water in oil
• Fuel in oil (diluted, and smells of diesel fuel)
• Entry of oil from other component
Causes

Broken cylinder head, head gasket (precombustion chamber)

Damaged cylinder liner O-ring, holes made by pitting

Clogged water pump breather hole, defective seal

Defective part inside injection pump (flange type)

Leakage of fuel inside head cover
Worn, damaged rear seal surface

Defective thermostat seat portion

Defective nozzle holder sleeve
Broken oil cooler core, O-ring

Cracks inside cylinder block

Defective main pump seal
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Questions

Degree of use of machine Operated for long period E E E E E

When engine is first started, drops of water come from muffler w
Exhaust smoke is white w Q Q
There is oil in radiator cooling water w Q Q Q Q
Leave radiator cap open. When engine is run at idling, an abnormal number of bubbles appear, or
w Q
water spurts back
Water pump breather hole is clogged with mud w
Check items

When water pump breather hole is cleaned, water comes out w

Oil level goes down in clutch, TORQFLOW transmission or damper chamber w
Oil level goes down in hydraulic tank w
Engine oil smells of diesel fuel w w w
Fuel must be added more frequently w w w

Pressure-tightness test of oil cooler shows there is leakage q

Pressure-tightness test of cylinder head shows there is leakage q
When compression pressure is measured, it is found to be low q
Troubleshooting

Remove water pump and inspect directly q

Remove rear seal and inspect directly q
When main pump is removed, seal is found to be damaged q
Remove head cover and inspect directly q
Remove injection pump and inspect directly q
Defective contact of thermostat seal valve q
Remove oil pan and check directly q q
Replace
Replace
Replace
Replace

Replace

Replace
Replace
Replace
Replace
Correct

Correct

Remedy

20-320 D155C-1
Troubleshooting S-14

S-14 Water temperature becomes too high (overheating)

General causes why water temperature becomes too high

• Lack of cooling air (deformation, damage of fan)
• Drop in heat dissipation efficiency
• Defective cooling circulation system
• Power train oil temperature rises excessively
a Carry out troubleshooting for chassis.
Causes

Damaged liner O-ring, holes made by pitting

Torque converter oil temperature too high
Defective thermostat (does not open)
Defective water temperature gauge

Defective radiator pressure valve

Fan belt slipping, worn fan pulley
Clogged, crushed radiator fins

Broken head, head gasket

Clogged, broken oil cooler
Insufficient cooling water
Clogged radiator core
Broken water pump
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Degree of use of machine Operated for long period E E E E
w Q Q
Questions

Suddenly overheated
Condition of overheating
Always tends to overheat w w Q Q
Rises quickly w Q
Water temperature gauge
Does not go down w
Radiator water level sensor lights up w
Fan belt whines under sudden load w
Cloudy white oil is floating on cooling water w
Cooling water flows out from overflow hose w
Excessive air bubbles inside radiator, water spurts back w
Engine oil level has risen, oil is cloudy white Q w
Check items

There is play when fan pulley is rotated w

Radiator shroud, inside of underguard are clogged with dirt or mud w w
When light bulb is held behind radiator, no light passes through w
Water is leaking because of cracks in hose or loose clamps w
When belt tension is inspected, it is found to be loose w
Power train oil temperature enters red range before engine water temperature w

Temperature difference between top and bottom radiator tanks is excessive q

Carry out troubleshooting for chassis.

Temperature difference between top and bottom radiator tanks is slight q

When water filler port is inspected, core is found to be clogged q
Troubleshooting

When function test is carried out on thermostat, it does not open even at cracking temperature q
When water temperature is measured, it is found to be normal q
When oil cooler is inspected directly, it is found to be clogged q
When measurement is made with radiator cap tester, set pressure is found to be low q
When compression pressure is measured, it is found to be low q
Remove oil pan and inspect directly q
Replace

Replace
Replace

Replace
Replace
Replace
Replace
Correct
Correct

Correct

Remedy —
Add

D155C-1 20-321
Troubleshooting S-15

S-15 Abnormal noise is made

a Judge if the noise is an internal noise or an external noise.

General causes why abnormal noise is made
• Abnormality due to defective parts
• Abnormal combustion Causes
• Air sucked in from intake system

Leakage of air between turbocharger and cylinder head

Broken dynamic valve system (valve, rocker lever, etc.)

Defect inside muffler (dividing board out of position)

Defective injection pump (rack, plunger seized)
Defective injection pump (excessive injection)
Excessive wear of piston ring, cylinder liner

Defective adjustment of valve clearance

Deformed fan, fan belt interference
Seized turbocharger, interference

Clogged, seized injection nozzle

Improper gear train backlash

Missing, seized bushing
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Degree of use of machine Operated for long period E
Questions

Gradually occurred Q Q
Condition of abnormal noise
Suddenly occurred Q Q Q
Non-specified fuel is being used Q Q
Engine oil must be added more frequently w
Blue under light load w
Color of exhaust gas
Black w Q Q
Metal particles are found in oil filter w w
Blow-by gas is excessive w
Noise of interference is heard from around turbocharger w
Engine pickup is poor and combustion is abnormal w
When exhaust manifold is touched immediately after starting engine, temperature of some
Check items

w Q
cylinders is low
Seal on injection pump has come off w
Abnormal noise is loud when accelerating engine Q Q Q Q Q Q
Clanging sound is heard from around cylinder head w w
Leakage of air between turbocharger and cylinder head, loose clamp w
Vibrating noise is heard from around muffler w

When compression pressure is measured, it is found to be low q

When turbocharger is rotated by hand, it is found to be heavy q
Remove gear cover and inspect directly q q
Troubleshooting

Speed does not change when operation of certain cylinders is stopped q

When control rack is pushed, it is found to be heavy, or does not return q
Injection pump test shows that injection amount is incorrect q
Fan is deformed, belt is loose q
When valve clearance is checked, it is found to be outside standard value q
Remove cylinder head cover and inspect directly q
When muffler is removed, abnormal noise disappears q
Replace
Replace
Replace
Replace

Replace

Replace

Replace
Replace
Replace
Correct

Correct

Correct

Remedy

20-322 D155C-1
Troubleshooting S-16

S-16 Vibration is excessive

a If there is abnormal noise together with the vibration, carry out trouble-
shooting for "Abnormal noise is made".
General causes why vibration is excessive
• Defective parts (abnormal wear, breakage)
• Improper alignment
• Abnormal combustion
Causes

Defective dynamic valve system (valve, rocker lever, etc.)

Misalignment between engine and power train

Defective injection pump (excessive injection)

Loose engine mounting bolts, broken cushion
Broken part inside output shaft (damper)
Worn connecting rod, main bearing

Improper gear train backlash

Worn cam bushing
Worn support pilot
Legend
Q : Possible causes (judging from Questions and check items)
w : Most probable causes (judging from Questions and Check items)
E : Possible causes due to length of use (used for a long period)
q : Items to confirm the cause
Confirm recent repair history
Degree of use of machine Operated for long period E E E E
Questions

Suddenly increased Q Q
Condition of vibration
Gradually increased Q Q Q Q
Non-specified oil is being used Q Q
Metal particles are found in oil filter w w
Metal particles are found when oil is drained w w
Oil pressure is low at low idling Q Q
Vibration occurs at mid-range speed Q Q
Check items

Vibration follows engine speed Q Q Q Q Q

Exhaust smoke is black w Q
Seal on injection pump has come off w

Remove oil pan and inspect directly q

Remove side cover and inspect directly q
Check directly for worn support pilot, play q
Troubleshooting

Inspect directly for loose engine mounting bolts, broken cushion q

Inspect inside of output shaft (damper) directly q
When radial runout, face runout are measured, they are found to be outside standard value q
Remove front cover and inspect directly q
Remove head cover and inspect directly q
Injection pump test shows that injection amount is incorrect q
Replace
Replace
Replace
Replace
Replace

Replace
Correct
Correct

Adjust

Remedy

D155C-1 20-323
 Troubleshooting of hydraulic,
mechanical system
(H mode)
H-1 Torque converter oil temperature is too high .................................................................................... 20-402
H-2 Machine does not move ................................................................................................................... 20-403
H-3 Machine lacks power or speed......................................................................................................... 20-404
H-4 Machine moves when engine is started ........................................................................................... 20-405
H-5 Excessive time lag when starting machine or shifting gear.............................................................. 20-405
H-6 Excessive shock when starting off or shifting gear........................................................................... 20-406
H-7 Machine moves in only one direction (FORWARD or REVERSE) ................................................... 20-407
H-8 Steering clutch is not disengaged .................................................................................................... 20-408
H-9 Steering clutch slips ......................................................................................................................... 20-409
H-10 Steering brake does not work........................................................................................................... 20-410
H-11 Lack of power, speed when retract counterweight ........................................................................... 20- 411
H-12 Impossible to retract counterweight ................................................................................................. 20-412
H-13 Excessive hydraulic drift of counterweight cylinder .......................................................................... 20-413
H-14 Defective boom RAISE, LOWER (speed, raising force, lowering force) .......................................... 20-414
H-15 Defective hook RAISE, LOWER (speed, raising force, lowering force) ........................................... 20-415
H-16 Excessive hydraulic drift of boom..................................................................................................... 20-416
H-17 Excessive hydraulic drift of hook ...................................................................................................... 20-417
H-18 Play when operating hook ................................................................................................................ 20-418
H-19 Play when operating boom............................................................................................................... 20-419
H-20 Excessive time lag when operating hook ......................................................................................... 20-420
H-21 Excessive time lag when operating boom ........................................................................................ 20-421
H-22 Excessive inching amount................................................................................................................ 20-422
H-23 Winch free fall does not work ........................................................................................................... 20-423
H-24 Winch overheats............................................................................................................................... 20-424
H-25 Excessive noise when operating winch clutch, brake ...................................................................... 20-425
H-26 Control lever is heavy....................................................................................................................... 20-426
H-27 Hook overwind horn does not sound................................................................................................ 20-427

D155C-1 20-401
Troubleshooting H-1

H-1 Torque converter oil temperature is too high

The result of checking with the operator

• The oil temperature go up when the torque converter is
stalled, and down when it is not stalled.
o Normal (wrong selection of gear speed)

Checks before troubleshooting

• Is oil level in transmission and steering case correct?

Oil leaking inside torque converter (seal ring defective, plug loose)
Torque converter relief valve malfunction
Air leaking in at suction side of pump

Scavenging pump strainer clogged

Scavenging pump defective
Oil cooler element clogged
Causes

Stainer clogged

Pump defective
Filter clogged
Tank to pump

Scavenging
converter
Torque

pump

a b c d e f g h i
Remedy E E E C
C × × C ×
No. Diagnosis × × × ×
1 Pump makes abnormal noise when oil is cold Q Q
2 High idling, low idling speeds too low Q Q Q
3 Hydraulic pressure at outlet port of torque converter too low Q
4 Hydraulic pressure at inlet port of torque converter too low Q
5 Transmission modulating pressure too low Q Q Q
6 Excessive leakage of oil inside torque converter Q
7 Hydraulic pressure at outlet port of torque converter too high Q
If all checks show no problem,
a The following symbols are used to indicate the action to this is the cause.
be taken when a cause of failure is located.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-402 D155C-1
Troubleshooting H-2

H-2 Machine does not move

The result of checking with the operator

• The problem suddenly started.
o Seized, broken part
• Abnormal noise was heard when this happened.
(From where?)
o Broken part

Checks before troubleshooting

• Is oil level in transmission and steering case correct?

Restrictor hole of quick return valve clogged or spool defective

• Is stroke of valve spool correct?
• Is it normal, that is, there is no defect universal joint?

Restrictor hole of safety valve clogged, or spool defective

• Is brake lock lever released?

Seal ring or its groove of transmission clutch defective

Reducing valve spring deteriorated, or spool defective

Shaft seal ring in rotating clutch circuit defective

Rotating clutch defective (oil sealing defective)

Damage to internal part of torque converter

Damage to internal part of transmission
Air leaking in at suction side of pump

Modulating valve spool malfunction

No drive for pump (PTO defective)

Transmission clutch seized

Causes

Stainer clogged

Pump defective
Tank to pump

Transmission
Control valve

a b c d e f g h i j k l m n
Remedy E E E E C
C × C × × × × E ×
No. Diagnosis × × × × ×
1 Pump makes abnormal noise when oil is cold Q Q
2 Machine does not move in any speed range Q Q Q Q Q Q Q Q Q
3 Machine moves normally in certain speed ranges Q Q Q
4 As in item 3; in particuler, machine fails to move only in 1st Q Q Q Q
5 When gear shift lever is in neutral, torque converter output shaft does not rotate Q
6 Output shaft rotates in neutral, but not when gear shift lever is in travel position Q Q
7 Machine will not move when oil temperature rises Q Q Q Q
8 Transmission modulating pressure too Low at every speed range Q Q Q Q Q
9 low Normal at certain speed ranges Q

a If all checks show no problem, the steering clutch is slipping.

a If the transmission modulating pressure is low, but the cause cannot be found in
the above table, a possible cause is cracks in the valve or transmission.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-403
Troubleshooting H-3

H-3 Machine lacks power or speed

a If the travel speed is low and the torque

converter oil temperature gauge indicated red
range, go to Troubleshooting Item H-1,
Torque converter oil temperature too high.

The result of checking with the operator

• The operator has had previous experience of operating
this machine.

Oil leaking inside torque converter (Seal ring defective, plug loose)
• The performance lower than before.
o Some part is probably defective.

Modulating valve spring deteriorated, or operation defective

• The performance is lower than on other

Reducing valve spring deteriorated, or operation defective

machines (particularly when compared to large

Seal ring, or groove of transmission clutch defective

machines.)
o There is probably no defect.

Shaft seal ring in rotating clutch circuit defective

Rotating clutch defective (oil sealing defective)

Damage to internal part of torque converter

Checks before troubleshooting
• Is oil level in transmission and steering case correct?
• Is it normal, that is, there is no leakage of oil from

Brake, steering system defective

connections of piping and valve?

Transmission clutch seized

Causes

• Is brake lock lever released?

• Is track tension correct?

Engine defective
Transmission

Other system
Control valve

converter
Torque

a b c d e f g h i j
Remedy E E E
× × × × ×
No. Diagnosis × × ×
1 Speed and power normal in certain speed ranges Q Q Q Q
2 Torque converter stall speed too low Q Q
Low at every speed range Q Q
3 Transmission modulating pressure too low
Normal at certain speed ranges Q
4 Reducing pressure too low Q
Iron or aluminium particles stuck to strainer or drain plug of torque converter
5 Q
case

If all checks show

a If the check shows cause “Engine defective”, refer S-Mode of engine no problem, this
troubleshooting. is the cause.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-404 D155C-1
Troubleshooting H-4, H-5

H-4 Machine moves when engine is started

1. When engine is started with gear shift lever in NEUTRAL, machine moves.
o Transmission clutch seized.
2. As above, but machine operation returns to normal when engine is warmed up for 10 – 15 minutes.
o Transmission rotated by high viscosity of oil (is proper oil being used?)

H-5 Excessive time lag when starting machine or shifting gear

Checks before troubleshooting

• Is oil level in transmission and steering case correct?
• Is it normal, that is, there is no leakage of oil from
connections of piping and valve?

Modulating valve spring deteriorated, operation of spool defective

Seal ring, and groove of transmission clutch defective

Shaft seal ring in rotating clutch circuit defective

Rotating clutch defective (oil sealing defective)
Restrictor hose of quick return valve clogged
Operation of quick return valve defective
Air leaking in at suction side of pump
Causes

Strainer clogged

Pump defective
Tank to pump

Transmission
Control valve

a b c d e f g h i
Remedy E E E
C × × × × ×
No. Diagnosis × × ×
1 Pump makes abnormal noise when oil is cold Q Q
2 Excessive time lag in every speed ranges Q Q Q Q Q Q
3 Machine moves normally in certain speed ranges Q Q Q
As in item 3; in particular, machine fails to move or moves with excessive time
4 Q Q
lag only in 1st speed
5 Transmission modulating pressure too low in every speed range Q Q Q Q Q
6 Torque converter oil temperature is above operating range Q Q Q

a If all checks show no problem, the steering clutch is slipping.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-405
Troubleshooting H-6

H-6 Excessive shock when starting off or shifting gear

Checking for abnormalities

There is some shock, but it is difficult to measure if it is
excessive or not. The shock can be considered excessive
under the following conditions.
• The shock has clearly become large
suddenly.
• The shock is larger than on other machines
of the same type.

Restriction hole of quick return valve clogged or operation defective

Restriction hole of modulating valve clogged or operation defective
Causes

Quick return valve

Modulating valve

a b
C C
Remedy
E E
No. Diagnosis
× ×
1 Excessive shock when starting machine or shifting gear Q Q

a The following symbols are used to indicate the action to

be taken when a cause of failure is located.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-406 D155C-1
Troubleshooting H-7

H-7 Machine moves in only one direction (FORWARD or REVERSE)

The result of checking with the operator

• This problem suddenly occur
o Seizure or damage inside transmission
• There was abnormal noise when this happened
o Component broken

Checking for abnormalities

• Is oil level in transmission and steering case correct?
• Is adjustment of transmission control linkage correct?
• Is it normal, that is, there is no defect, such as bent or
twisted transmission control linkage?

Seizure or damage of FR clutch inside transmission

FR spool stuck, defective detent
Causes

FR valve

a b
Remedy E E
No. Diagnosis × ×
If gear shift lever does not move in F or R
Machine travels in one direction only Q
1 direction
(FORWARD or REVERSE)
If above is normal Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-407
Troubleshooting H-8

H-8 Steering clutch is not disengaged

The result of checking with the operator

• The steering clutch suddenly become impossible to
disengage.
o Component sized or damaged.
• There was abnormal noise when this happened.
o Component broken.

Drop in relief valve set pressure or sealing defective

Checks before troubleshooting
• Is oil level in transmission and steering case correct?

Seal ring portion of bevel gear shaft defective

• Is stroke of valve spool correct?

Seal ring portion of clutch piston defective

• Is steering control linkage properly adjusted?
• Do brakes work properly?

Air leaking in at suction side of pump

Operation of valve spool defective

Causes

Braking effect defective

Steering clutch seized
Strainer clogged

Pump defective

Steering clutch
Tank to pump

Control valve

a b c d e f g h i
A A
Remedy E E
C × E × × × E
No. Diagnosis × ×
× ×
1 Oil pressure tool low Q Q Q Q Q Q
2 Pump makes abnormal noise when oil is cold Q Q
3 Clutch does not disengage when oil temperature rises Q Q Q
4 Oil pressure normal, but clutch does not disengage Q
Sometimes disengages, sometimes does not disengage, and sometimes
5 Q
remains disengaged
6 Clutch on one side (left or right) only does not disengage (oil pressure normal) Q Q
7 Turning ability poor on flat surfaces or downhill slopes Q
8 Normal in item 6, but clutch does not disengage with oil temperature rises Q
Oil pressure becomes normal when relief valve is disassembled and cleaned, or
9 Q
shims are added

a In item 7, with cause "i", even if the clutch disengages, the machine will snake on
slopes. If the brakes do not work, the machine will not turn.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-408 D155C-1
Troubleshooting H-9

H-9 Steering clutch slips

The result of checking with the operator

• The clutch suddenly start slipping.
o Component seized or damaged.
• There was abnormal noise when this happened.
o Component broken.

Checks before troubleshooting

• Is oil level in transmission and steering case correct?
• Is stroke of valve spool correct?
• Is steering control linkage properly adjusted?

Operation of steering valve spool defective

Clutch spring deteriorated or damaged

Steering clutch Driven disc of clutch worn or twisted
Drive plate of clutch worn or twisted
Causes

Control valve

a b c d
Remedy E
× × ×
No. Diagnosis ×
1 Clutch slips on only one side (L.H. or R.H.) Q Q Q
Sometimes disengages, sometimes does not disengage, and sometimes
2 Q
remains disengaged

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-409
Troubleshooting H-10

H-10 Steering brake does not work

The result of checking with the operator

• The steering brake suddenly stop working
o Component sized or damaged.
• There was abnormal noise when this happened.
o Component broken.

Checks before troubleshooting

• Is oil level in transmission and steering case correct?

Drop in relief valve set pressure, seating defective

• Is brake control linkage properly adjusted?
• Is brake lining clearance properly adjusted?
(Check by measuring travel of brake pedal.)

Brake lining worn, peeling, or deformed

• Is it normal, that is, there is no defect, such as bent or

Valve to brake Operation of booster piston defective

Air leaking in at suction side of pump
Pump is not driven. (PTO defective)
twisted linkage?

Causes

Strainer clogged

Pump defective
Tank to pump

a b c d e f g
A
Remedy E E E
C × E ×
No. Diagnosis × × ×
×
1 Relief pressure too low Q Q Q Q Q
No oil comes out even when plug is removed from pressure pick-up port, and
2 Q
engine is cranked
Pump makes abnormal noise when oil is cold (also may happen with engine at
3 Q Q
full throttle)
4 Brake does not work when oil temperature rises Q
5 Oil pressure normal, but brake does not work Q Q
6 Brake on only side (left or right) does not work Q
Oil pressure becomes normal when relief valve is disassembled and cleaned, or
7 Q
shims are added

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-410 D155C-1
Troubleshooting H-11

H-11 Lack of power, speed when retract counterweight

a If there is lack of power and speed when retract the counterweight, and there is excessive hydraulic drift of the
counterweight cylinder, go to H-13 Excessive hydraulic drift of counterweight cylinder.

Checks before troubleshooting

• Is the level of oil in the counterweight tank correct?
• Is the travel of the control lever and control valve spool
correct?

Drop in set pressure of pilot relief valve, hole clogged, defective sealing
• Is it normal, that is, there is no leakage of oil from the
piping between the pump and control valve?
• Is it normal, that is, there is no leakage of oil from the
piping between the control valve and the counterweight
cylinder?

Defective opening of pilot relief valve

Air sucked in at pump suction side
Causes

Clogged cartridge filter

Fatigued spool spring

Defective pump

Spool stuck
Tank to pump

Control valve

a b c d e f g
A
Remedy E E C
C × C ×
No. Diagnosis × × ×
×
When engine is run at full throttle, relief pressure is tool low when pulling in
1 Q Q Q Q
counterweight
2 When condition is normal with engine is running at low idling Q Q
3 When item 1 is normal Q Q
4 Hydraulic pump makes abnormal noise Q Q
5 When lever is operated, speed is slow but circuit pressure is too high Q
6 Hydraulic drift of counterweight is normal when lever is at HOLD Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-411
Troubleshooting H-12

H-12 Impossible to retract counterweight

The result of checking with the operator

• The problem suddenly started.
o Seized, broken part
• Abnormal noise was heard when this happened.

Oil leakage from piping between control valve and counterweight cylinder head
(From where?)
o Broken part

Drop in set pressure of pilot relief valve, hole clogged, defective sealing
• There was no problem before, such as drop in speed.
o Worn parts, fatigued spring

Checks before troubleshooting

Oil leakage from piping between pump and control valve

Defective sealing of counterweight cylinder piston valve

• Is the level of oil in the counterweight tank correct?
• Is the travel of the control lever and control valve spool
correct?

Defective counterweight cylinder packing

Pump does not drive (defective PTO)
Causes

Defective slow return valve

Fatigued spool spring

Defective pump

Spool stuck
Control valve

Control valve
Valve to
cylinder
Pump

a b c d e f g h i j
A
Remedy E E E C C C
× C × ×
No. Diagnosis × × × × × ×
×
1 When pressure pickup plug is removed and engine is cranked, no oil comes out Q
When engine is run at full throttle, pressure at counterweight retract side rises
2 Q Q Q Q Q Q Q Q Q
only a little
When piping at counterweight cylinder head end is removed, then engine is run
3 at low idling and control lever is operated to RETRACT, cylinder does not move Q Q Q
but oil comes out.

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-412 D155C-1
Troubleshooting H-13

H-13 Excessive hydraulic drift of counterweight cylinder

The result of checking with the operator

• The problem suddenly started.
o Dirt caught in valve, broken part
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Hydraulic drift is within standard value when control
lever rod is disconnected at control valve end.
o Bent, twisted rod

Defective sealing of counterweight cylinder piston valve

• Is it normal, that is, there is no leakage of oil from the
piping between the control valve and the counterweight
cylinder bottom?

Defective counterweight cylinder packing

Damage, defective oil tightness of spool

Defective slow return valve

Causes

Control valve

Valve to
cylinder

a b c d
Remedy E C C
×
No. Diagnosis × × ×
Hydraulic drift is excessive even when blind plug is fitted in piping at
1 Q Q Q
counterweight cylinder bottom
2 When item 1 is normal Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-413
Troubleshooting H-14

H-14 Defective boom RAISE, LOWER (speed, raising force, lowering force)

The result of checking with the operator

• The operator has had long experience of operating this
machine.
• Performance has dropped compared with before.
o High probability of defect
• The problem suddenly started.
o Seized, damaged parts

Drop in set pressure of main relief valve or defective sealing

• There was abnormal noise when this happened.
o Broken parts

Defective operation, slipping of LOWER clutch

Defective operation, slipping of HI-LOW clutch
Checks before troubleshooting

Defective operation, slipping of RAISE clutch

Defective operation of HI-LOW valve spool

• Is winch oil level correct?

Defective operation of flow divider valve

Defective operation of PPC valve spool
• Is it normal, that is, there is no leakage of oil from

Causes
connections of piping and valve?

Oil leakage from seal ring, O-ring

• Is it normal, that is, there is no defect, such as bent or

Defective operation of brake

Drop in engine performance
twisted work equipment (hook, pulley)?

Drop in pump performance

• Is operating force, travel of control lever normal?

Checks for abnormalities

• Measure speed (wind in, wind out)
• Measure actuating pressure of each clutch, brake

a b c d e f g h i j k
Remedy C E E
A × × × × × × ×
No. Diagnosis A × ×
1 Nothing works (RAISE, LOWER, HI, LOW) Q Q Q Q Q Q Q Q Q
2 Defective actuation of HI or LOW clutch Q Q
3 Defective operation of HI-LOW valve for RAISE, LOWER Q Q Q Q
When boom and hook are operated together, hook speed is far slower than
4 Q Q Q Q Q
when hook is operated independently
Actuating pressures do not rise to relief pressure when engine is run at full
5 Q Q Q Q Q
throttle
6 Excessive drop in pressure from above when engine is run at low idling Q Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-414 D155C-1
Troubleshooting H-15

H-15 Defective hook RAISE, LOWER (speed, raising force, lowering force)

The result of checking with the operator

• The operator has had long experience of operating this
machine.
• Performance has dropped compared with before.
o High probability of defect
• The problem suddenly started.
o Seized, damaged parts
• There was abnormal noise when this happened.
o Broken parts

Drop in set pressure of main relief valve or defective sealing

Checks before troubleshooting
• Is winch oil level correct?
• Is it normal, that is, there is no leakage of oil from

Defective operation, slipping of LOWER clutch

Defective operation, slipping of HI-LOW clutch
connections of piping and valve?

Defective operation, slipping of RAISE clutch

Defective operation of HI-LOW valve spool

• Is it normal, that is, there is no defect, such as bent or

Defective operation of flow divider valve

Defective operation of PPC valve spool
twisted work equipment (hook, pulley)?

Causes
• Is operating force, travel of control lever normal?

Oil leakage from seal ring, O-ring

Defective operation of brake
Drop in engine performance
Checks for abnormalities

Drop in pump performance

Defective solenoid valve

• Measure speed (wind in, wind out)
• Measure actuating pressure of each clutch, brake

a b c d e f g h i j k l
Remedy C E E
A × × × × × × ×
No. Diagnosis A × ×
1 Nothing works (RAISE, LOWER, HI, LOW) Q Q Q Q Q Q Q Q Q
2 Defective actuation of HI or LOW clutch Q Q
3 Defective operation of HI-LOW valve for RAISE, LOWER Q Q Q
When boom and hook are operated together, hook speed is far slower than
4 Q Q Q Q Q
when hook is operated independently
Actuating pressures do not rise to relief pressure when engine is run at full
5 Q Q Q Q Q
throttle
6 Excessive drop in pressure from above when engine is run at low idling Q Q Q Q
7 Defective operation only at LOWER of HI and LOW Q Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-415
Troubleshooting H-16

H-16 Excessive hydraulic drift of boom

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Damaged brake
• The problem gradually appeared.
o Worn brake parts

Checks before troubleshooting

• Operating effort, travel of control lever is not correct.
o Bent, twisted rod
• Is end of wire fixed securely?

Checks for abnormality

• Hydraulic drift of boom

Causes

Defective PPC valve

Slipping brake

a b
Remedy
× ×
No. Diagnosis
1 Hydraulic drift occurs when engine is stopped Q
2 Hydraulic drift increases when engine speed is increased Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-416 D155C-1
Troubleshooting H-17

H-17 Excessive hydraulic drift of hook

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Damaged brake
• The problem gradually appeared.
o Worn brake parts

Checks before troubleshooting

• Operating effort, travel of control lever is not correct.
o Bent, twisted rod
• Is end of wire fixed securely?

Checks for abnormality

• Hydraulic drift of boom

Causes

Defective PPC valve

Slipping brake

a b
Remedy
× ×
No. Diagnosis
1 Hydraulic drift occurs when engine is stopped Q
2 Hydraulic drift increases when engine speed is increased Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-417
Troubleshooting H-18

H-18 Play when operating hook

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Dirt caught in valve, broken part
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is it normal, that is, there is no defect, such as bent or
twisted work equipment (hook, pulley)?
• Is operating force, travel of control lever normal?

Drop in set pressure of relief valve, defective sealing

• Is it normal, that is, engine is not hunting?
• Is type of oil correct?

Slipping, defective operation of RAISE clutch

Checks for abnormalities

Defective operation of PPC valve spool

Slipping, defective operation of brake

• Measure speed (wind in, wind out)
• Measure actuating pressure of each clutch, brake Causes

Oil leakage from seal ring, O-ring

Clogged strainer

a b c d e f
Remedy C E
× × C ×
No. Diagnosis A ×
1 Problem occurs for both RAISE and LOWER Q Q Q Q Q
2 Problem occurs for only RAISE or LOWER Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-418 D155C-1
Troubleshooting H-19

H-19 Play when operating boom

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Dirt caught in valve, broken part
• The problem gradually operated.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is it normal, that is, there is no defect, such as bent or
twisted work equipment (hook, pulley)?
• Is operating force, travel of control lever normal?

Drop in set pressure of relief valve, defective sealing

• Is it normal, that is engine is not hunting?
• Is type of oil correct?

Slipping, defective operation of RAISE clutch

Checks for abnormalities

Defective operation of PPC valve spool

Slipping, defective operation of brake

• Measure speed (wind in, wind out)

Causes
• Measure actuating pressure of each clutch, brake

Oil leakage from seal ring, O-ring

Clogged strainer

a b c d e f
Remedy C E
× × C ×
No. Diagnosis A ×
1 Problem occurs for both RAISE and LOWER Q Q Q Q Q
2 Problem occurs for only RAISE or LOWER Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-419
Troubleshooting H-20

H-20 Excessive time lag when operating hook

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Dirt caught in valve, broken part
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is operating force, travel of control lever normal?
• Is it normal, that is, there is no leakage of oil from
connections of piping and valve?

Drop in set pressure of relief valve, defective sealing

• Is type of oil correct?

Checks for abnormalities

• Measure time lag

Defective operation of flow divider valve

Defective operation of PPC valve spool

Slipping, defective operation of clutch

Slipping, defective operation of brake
Causes

Oil leakage from seal ring, O-ring

Clogged throttle of PPC valve
Drop in engine performance
Drop in pump performance
Clogged strainer

a b c d e f g h i j
Remedy E C
A × C C × × × ×
No. Diagnosis × A
1 Excessive for both RAISE and LOWER Q Q Q Q Q Q Q Q Q
2 Excessive for only RAISE or LOWER Q Q Q
3 Time lag excessive when engine is run at low idling Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-420 D155C-1
Troubleshooting H-21

H-21 Excessive time lag when operating boom

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Dirt caught in valve, broken part
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is operating force, travel of control lever normal?
• Is it normal, that is, there is no leakage of oil from
connections of piping and valve?

Drop in set pressure of relief valve, defective sealing

• Is type of oil correct?

Checks for abnormalities

• Measure time lag

Defective operation of flow divider valve

Defective operation of PPC valve spool

Slipping, defective operation of clutch

Slipping, defective operation of brake
Causes

Oil leakage from seal ring, O-ring

Clogged throttle of PPC valve
Drop in engine performance
Drop in pump performance
Clogged strainer

a b c d e f g h i j
Remedy E C
A × C C × × × ×
No. Diagnosis × A
1 Excessive for both RAISE and LOWER Q Q Q Q Q Q Q Q Q
2 Excessive for only RAISE or LOWER Q Q Q
3 Time lag excessive when engine is run at low idling Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-421
Troubleshooting H-22

H-22 Excessive inching amount

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Dirt caught in valve, broken part
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is operating force, travel of control lever normal?
• Is it normal, that is, there is no leakage of oil from
connections of piping and valve?

Drop in set pressure of relief valve, defective sealing

• Is type of oil correct?

Checks for abnormalities

• Measure inching amount

Defective operation of flow divider valve

Defective operation of PPC valve spool

Slipping, defective operation of clutch

Slipping, defective operation of brake
• Measure actuating pressure of each clutch, brake
Causes

Oil leakage from seal ring, O-ring

Clogged throttle of PPC valve
Drop in engine performance
Drop in pump performance

a b c d e f g h i
Remedy E C
A × C × × × ×
No. Diagnosis × A
1 Problem occurs for both RAISE and LOWER Q Q Q Q Q Q Q Q
2 Problem occurs for only RAISE or LOWER Q Q
3 Operating pressures do not rise to relief pressure Q Q Q Q Q Q
4 Pressure remaining at each clutch, brake Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-422 D155C-1
Troubleshooting H-23

H-23 Winch free fall does not work

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Broken parts
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is it normal, that is, there is no leakage of oil from
connections of piping and valve?
• Is operating force, travel of control lever normal?
• Is it normal, that is, there is no defect, such as bent or
twisted work equipment (hook, pulley)?
• Is there any disconnection?
• Is type of oil correct?

Causes
Checks for abnormality

Defective connection of wiring

• Measure each actuating pressure

Defective operation of brake

• Check continuity

Defective solenoid valve

Defective limit switch

Blown fuse

a b c d e
Remedy
× × × E ×
No. Diagnosis
1 When brake actuating pressure normal Q
2 Pressure remains at LOWER clutch Q
3 Solenoid valve pilot lamp lights up Q Q Q Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-423
Troubleshooting H-24

H-24 Winch overheats

The result of checking with the operator

• The operator has had previous experience of operating
this machine.

Checks before troubleshooting

• Is winch oil level correct?
• Is level of cooling water in radiator correct?
• Is type of oil correct?

Checks for abnormality

• Measure winch oil temperature
• Measure cooler oil pressure
• Measure engine water temperature

Defective winch oil cooler bypass valve

Causes

Clogged winch oil cooler piping

Clogged winch oil cooler core

a b c
Remedy
× C C
No. Diagnosis
1 Winch oil cooler oil pressure is high Q Q
2 Winch oil cooler oil pressure is low Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-424 D155C-1
Troubleshooting H-25

H-25 Excessive noise when operating winch clutch, brake

The result of checking with the operator

• The operator has had previous experience of operating
this machine.
• The problem suddenly started.
o Broken parts
• The problem gradually appeared.
o Worn parts

Checks before troubleshooting

• Is winch oil level correct?
• Is normal, that is, there is no leakage of oil from
connections of piping and valve?
• Is type of oil correct?
• Is operating effort, travel of control lever correct?

Defective operation of RAISE, LOWER clutch

Checks for abnormality

Defective operation of HI-LOW valve spool

• Measure actuating pressure of each clutch, brake

Defective operation of flow divider valve

Defective main relief valve set pressure

Defective operation of PPC valve spool

Defective operation of HI-LOW clutch

• Measure winch oil temperature

Causes

Defective HI-LOW valve throttle

Defective pump performance

Defective operation of brake

Defective PPC valve throttle

a b c d e f g h i j
Remedy C E E
× × C C × × ×
No. Diagnosis A × ×
1 Excessive noise for all of RAISE, LOWER, HI, LOW Q Q Q
2 Excessive noise when shifting between HI and LOW Q Q Q
3 Excessive noise when operating RAISE, LOWER Q Q Q Q
Excessive difference between condition when engine is at low idling and full
4 Q Q Q Q Q
throttle

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-425
Troubleshooting H-26

H-26 Control lever is heavy

Distortion of control valve caused by uneven tightening of mounting

Defective clearance between control valve body and spool

Defective roundness of control valve body and spool

Distortion of control valve body caused by pressure
Rotating portion of control lever, link is interfering
Causes

Bent control valve spool

Control valve
Link

a b c d e f
Remedy E E E
× × ×
No. Diagnosis × × ×
1 Becomes heavy when oil pressure is high Q Q
2 Becomes heavy when oil temperature is high Q
3 Always heavy regardless of oil pressure or oil temperature Q Q Q
Does not become lighter even when control lever rod is disconnected at valve
4 Q
end and lever is operated

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

20-426 D155C-1
Troubleshooting H-27

H-27 Hook overwind horn does not sound

• When the alarm switch operating weight is lifted up and

the weight slinging table is loosened, if the alarm horn
does not sound, check Nos. 1 – 5.
• Under the above condition, if the alarm horn sounds but
stops sounding when the winch or boom control lever is
returned to the "HOLD" position, check Nos. 6 and 7.

Disconnection or defective connection of wire

Malfunction of limit switch operating linkage

Defective boom raise oil pressure sensor

Defective hook raise oil pressure sensor
Causes

Defective limit switch

Broken fuse (L)

Defective relay
Defective horn

a b c d e f g h
Remedy
× E E × × × × ×
No. Diagnosis
1 Voltage of +24 V is applied to horn terminal. Q
2 Voltage of +24 V is applied to limit switch. Q Q Q
3 Horn sounds when boom is raised but does not sound when hook is raised. Q Q
4 Horn sounds when hook is raised but does not sound when boom is raised. Q Q
Voltage of +24 V is not applied to hook raise oil pressure sensor and boom
5 Q Q
lower oil pressure sensor.
6 When relay is replaced, horn sounds normally. Q
7 When relay is replaced, horn does not sound normally. Q

Legend
A : Adjust
C : Clean
E : Repair
× : Replace

D155C-1 20-427
 30 Disassembly and assembly

Method of using manual.................................30- 3 Disassembly and assembly of

Precautions when carrying out operation.......30- 5 torque converter relief valve assembly ... 30- 98
Special tool list ...............................................30- 7 Disassembly and assembly of
Removal and installation of torque converter regulator valve ............. 30- 98
starting motor assembly ..........................30- 10 Removal and installation of
Removal and installation of transmission control valve assembly ...... 30- 99
alternator assembly .................................30- 11 Disassembly and assembly of
Removal and installation of transmission control valve assembly ...... 30-102
engine oil cooler core assembly ..............30- 13 Removal and installation of
Removal and installation of transmission assembly............................ 30-106
fuel injection pump assembly ..................30- 15 Disassembly and assembly of
Removal and installation of TORQFLOW transmission assembly ...... 30-108
water pump assembly .............................30- 17 Removal and installation of transmission
Removal and installation of lubrication valve assembly ...................... 30-134
turbocharger assembly............................30- 20 Disassembly and assembly of transmission
Removal and installation of lubrication valve assembly ...................... 30-135
nozzle holder assembly...........................30- 22 Removal and installation of
Removal and installation of steering control valve assembly .............. 30-136
cylinder head assembly...........................30- 23 Disassembly and assembly of
Removal and installation of steering control valve assembly .............. 30-138
thermostat assembly ...............................30- 37 Removal and installation of
Removal and installation of brake safety valve assembly ................... 30-142
radiator assembly ....................................30- 38 Disassembly and assembly of
Removal and installation of brake safety valve assembly ................... 30-143
fuel tank assembly...................................30- 49 Removal and installation of
Removal and installation of torque steering pump assembly ......................... 30-144
converter and winch oil cooler assembly.30- 51 Removal and installation of
Removal and installation of steering clutch assembly......................... 30-145
engine assembly .....................................30- 53 Disassembly and assembly of
Removal and installation of PTO assembly ...30- 62 brake booster assembly .......................... 30-148
Disassembly and assembly of Disassembly and assembly of
PTO assembly .........................................30- 66 steering relief valve assembly ................. 30-149
Removal and installation of Disassembly and assembly of
transmission pump assembly ..................30- 73 steering clutch assembly......................... 30-150
Removal and installation of Disassembly and assembly of
floor frame assembly ...............................30- 74 bevel gear shaft assembly ...................... 30-152
Removal and installation of Disassembly and assembly of
torque converter assembly ......................30- 81 first pinion assembly ............................... 30-159
Disassembly and assembly of Disassembly and assembly of
torque converter assembly ......................30- 86 final drive assembly ................................ 30-162
Removal and installation of Removal and installation of track assembly... 30-173
torque converter relief valve assembly....30- 96 Removal and installation of
Removal and installation of torque converter carrier roller assembly............................. 30-176
regulating valve assembly .......................30- 97

D155C-1 30-1
Disassembly and assembly

Removal and installation of

track roller assembly................................30-178
Disassembly and assembly of
recoil spring assembly .............................30-180
Removal and installation of
track frame assembly ..............................30-182
Removal and installation of idler assembly ....30-186
Removal and installation of
winch control valve assembly ..................30-187
Disassembly and assembly of
winch control valve assembly ..................30-188
Removal and installation of high/low speed
selector valve assembly ..........................30-193
Disassembly and assembly of high/low speed
selector valve assembly ..........................30-194
Removal and installation of
towing winch pump assembly..................30-198
Removal and installation of
counterweight pump assembly ................30-199
Removal and installation of
counterweight cylinder assembly.............30-200
Disassembly and assembly of
counterweight cylinder assembly.............30-201
Removal and installation of
counterweight control valve assembly.....30-205
Disassembly and assembly of
counterweight control valve assembly.....30-206
Removal and installation of
gate frame assembly ...............................30-210
Removal and installation of
counterweight/frame ................................30-213
Removal and installation of boom/frame ........30-217
Removal and installation of
towing winch assembly............................30-218
Disassembly and assembly of
towing winch assembly............................30-222
Removal and installation of
heater assembly ......................................30-257

30-2 D155C-1
Disassembly and assembly Method of using manual

Method of using manual Installation of parts

• Except where otherwise instructed, install parts
is the reverse order of removal.
Removal and installation of assemblies • Instructions and precautions for installing parts
are shown with [*1] mark in the Installation Sec-
Special tools tion, identifying which step the instructions are
• Special tools that are deemed necessary for intended for.
removal or installation of parts are listed. • Marks shown in the Installation Section stand for
• List of the special tools contains the following the following.
kind of information.

1) Necessity k This mark indicates safety-related pre-

t: Special tools which cannot be substi- cautions which must be followed when
tuted, should always be used. doing the work.
q: Special tools which are very useful if
a This mark gives guidance or precau-
available, can be substituted with com-
tions when doing the procedure.
2 This mark stands for a specific coating
mercially available tools.
2) Distinction of new and existing special tools
N: Tools with new part numbers, newly agent to be used.
3 This mark
developed for this model.
R: Tools with upgraded part numbers, indicates the specified
remodeled from already available tools torque.
for other models. 5 This mark indicates an amount of oil or
Blank: Tools already available for other mod- water to be added.
els, used without any modification.
3) Circle mark (Q) in sketch column: Sketches of special tools
A circle mark means that a sketch of the • Various special tools are illustrated for the con-
special tool is presented in the section of venience of local manufacture.
Sketches for Special Tools.
a Part No. of special tools starting with 79*T means
that they are locally made parts and as such not
interchangeable with those made by Komatsu in
Japan e.g. 79*T--- xxx --- xxxx.

Removal of parts
• The removal section contains procedures, pre-
cautions and the amount of oil or water to be
drained.
• Various symbols used in the removal section are
explained and listed below.

k This mark indicates safety-related pre-

cautions which must be followed when
doing the work.
a This mark gives guidance or precau-
tions when doing the procedure.
[*1] This mark shows that there are instruc-
tions or precautions for installing parts.
6 This mark shows oil or water to be
drained.

D155C-1 30-3
Disassembly and assembly Method of using manual

Disassembly and assembly of assemblies Assembly

• Section titled Assembly contain procedures, pre-
Special tools cautions and the know-how for the work, as well
• Special tools which are deemed necessary for as the amount of oil or water to be added.
disassembly and assembly are listed in this sec- • Various symbols used in the Assembly Section
tion. are explained and listed below.
• List of the special tools contains the following
k
kind of information.
This mark indicates safety-related pre-
1) Necessity
cautions which must be followed when
t: Special tools which cannot be substi-
doing the work.
tuted, should always be used.
q: Special tools which are very useful if a This mark gives guidance or precau-
available, can be substituted with com- tions when doing the procedure.
2 This mark stands for a specific coating
mercially available tools.
2) Distinction of new and existing special tools
agent to be used.
3 This mark indicates the specified torque.
N: Tools with new part numbers, newly
developed for this model.

5
R: Tools with upgraded part numbers,
remodeled from already available tools This mark indicates an amount of oil or
for other models. water to be added.
Blank: Tools already available for other mod-
els, used without any modification. Sketches of special tools
3) Circle mark (Q) in sketch column: 1) Various special tools are illustrated for the
A circle mark means that a sketch of the convenience of local manufacture.
special tool is presented in the section of
Sketches for Special Tools.
4) Part No. of special tools starting with 79*T
means that they are locally made parts and
as such not interchangeable with those
made by Komatsu in Japan e.g. 79*T--- xxx
--- xxxx.

Disassembly
• The Disassembly Section contains procedures,
precautions and the amount of oil or water to be
drained.
• Various symbols used in the Disassembly Sec-
tion are explained and listed below.

k This mark indicates safety-related pre-

cautions which must be followed when
doing the work.
a This mark gives guidance or precau-
tions when doing the procedure.
[*1] This mark shows that there are instruc-
tions or precautions for installing parts.
6 This mark shows oil or water to be
drained.

30-4 D155C-1
Disassembly and assembly Precautions when carrying out operation

Precautions when carrying out operation

[When carrying out removal or installation (disassembly or assembly) of units, be sure to follow the general pre-
cautions given below when carrying out the operation.]
1. Precautions when carrying out removal work
• If the coolant contains antifreeze, dispose of it correctly.
• After disconnecting hoses or tubes, cover them or fit blind plugs to prevent dirt or dust from entering.
• When draining oil, prepare a container of adequate size to catch the oil.
• Confirm the match marks showing the installation position, and make match marks in the necessary places
before removal to prevent any mistake when assembling.
• To prevent any excessive force from being applied to the wiring, always hold the connectors when discon-
necting the connectors. Do not pull the wires.
• Fit wires and hoses with tags to show their installation position to prevent any mistake when installing.
• Check the number and thickness of the shims, and keep in a safe place.
• When raising components, be sure to use lifting equipment of ample strength.
• When using forcing screws to remove any components, tighten the forcing screws uniformly in turn.
• Before removing any unit, clean the surrounding area and fit a cover to prevent any dust or dirt from enter-
ing after removal.
a Precautions when handling piping during disassembly
Fit the following blind plugs into the piping after disconnecting it during disassembly operations.
1) Face seal type hoses and tubes
Nominal number Plug (nut end) Nut (elbow end)
02 07376-70210 02789-00210
03 07376-70315 02789-00315
04 07376-70422 02789-00422
05 07376-70522 02789-00522
06 07376-70628 02789-00628

2) Split flange type hoses and tubes

Nominal number Flange (hose end) Sleeve head (tube end) Split flange
04 07379-00400 07378-10400 07371-30400
05 07379-00500 07378-10500 07371-30500

3) If the part is not under hydraulic pressure, the following corks can be used.
Dimensions
Nominal number Part Number
D d L
06 07049-00608 6 5 8
08 07049-00811 8 6.5 11
10 07049-01012 10 8.5 12
12 07049-01215 12 10 15
14 07049-01418 14 11.5 18
16 07049-01620 16 13.5 20
18 07049-01822 18 15 22
20 07049-02025 20 17 25
22 07049-02228 22 18.5 28
24 07049-02430 24 20 30
27 07049-02734 27 22.5 34

D155C-1 30-5
Disassembly and assembly Precautions when carrying out operation

2. Precautions when carrying out installation work

• Tighten all bolts and nuts (sleeve nuts) to the specified (KES) torque.
• Install the hoses without twisting or interference.
• Replace all gaskets, O-rings, cotter pins, and lock plates with new parts.
• Bend the cotter pins and lock plates securely.
• When coating with adhesive, clean the part and remove all oil and grease, then coat the threaded portion
with 2 – 3 drops of adhesive.
• When coating with gasket sealant, clean the surface and remove all oil and grease, check that there is no
dirt or damage, then coat uniformly with gasket sealant.
• Clean all parts, and correct any damage, dents, burrs, or rust.
• Coat rotating parts and sliding parts with engine oil.
• When press fitting parts, coat the surface with anti-friction compound (LM-P).
• After fitting snap rings, check that the snap ring is fitted securely in the ring groove.
• When connecting wiring connectors, clean the connector to remove all oil, dirt, or water, then connect
securely.
• When using eyebolts, check that there is no deformation or deterioration, screw them in fully, and align the
direction of the hook.
• When tightening split flanges, tighten uniformly in turn to prevent excessive tightening on one side.

a When operating the hydraulic cylinders for the first time after reassembling cylinders, pumps and other
hydraulic equipment removed for repair, always bleed the air as follows:
1) Start the engine and run at low idling.
2) Operate the work equipment control lever to operate the hydraulic cylinder 4 – 5 times, stopping the
cylinder 100 mm from the end of its stroke.
3) Next, operate the hydraulic cylinder 3 – 4 times to the end of its stroke.
4) After doing this, run the engine at normal speed.
a When using the machine for the first time after repair or long storage, follow the same procedure.
• Precautions when completing the operation.
• If the coolant has been drained, tighten the drain valve, and add water to the specified level. Run the engine
to circulate the water through the system. Then check the water level again.
• If the hydraulic equipment has been removed and installed again, add engine oil to the specified level. Run
the engine to circulate the oil through the system. Then check the oil level again.
• If the piping or hydraulic equipment have been removed, always bleed the air from the system after reas-
sembling the parts.
a For details, see TESTING AND ADJUSTING, Bleeding air.
• Add the specified amount of grease (molybdenum disulphide grease) to the work equipment parts.

30-6 D155C-1
Disassembly and assembly Special tool list

Special tool list

a Tools with part number 79OT-QQQ-QQQQ cannot be supplied (they are items to be locally manufactured).
a New/remodel: N: Tools with new part numbers, newly developed for this model
R: Tools with upgraded part numbers, remodeled from items already available for
other models.
Blank: Tools already available for other models, used without any modification
a Tools marked Q in the Sketch column are tools introduced in special sketches (See SKETCHES OF
SPECIAL TOOLS).

New/remodel
Necessity

Sketch
Q'ty
Component Symbol Part No. Part Name Nature of work, remarks

Removal, installation of
nozzle holder ass’y
1 795-570-1100 Remover assembly t 1 Removal of nozzle holder
Removal, installation of
cylinder head ass’y A

Removal, installation of Wrench Tightening of cylinder head,

2 790-331-1110 t 1
engine cylinder head ass’y (for angle-tightening) bolt

Disassembly, assembly of 790-501-5000 Unit repair stand t 1 Disassembly, assembly of

B
torque converter 790-901-2110 Bracket t 1 torque converter

791-501-5000 Unit repair stand 1

Disassembly and assembly 1 790-901-3210 Bracket 1 Disassembly, assembly of

C
of transmission assembly 790-901-3220 Plate 1 transmission

2 799-301-1600 Oil leak tester kit 1 Air checker

791-465-5001 Compressor 1
Disassembly and assembly 790-101-1102 Pump 1
D —
of steering clutch assembly
Puller
790-101-2102 1
(294 kN {30 ton})
Removal and installation of
1 791-475-6000 Remover & installer 1
hub nut
791-480-3001 Remover D 1
790-101-1102 Pump 1
2 Pulling out hub
Disassembly and assembly Puller
E 790-101-3800 1
of bevel gear shaft (490 kN {50 ton})
790-480-4001 Installer C 1
790-101-1102 Pump 1
3 Press-fitting hub
Puller
790-101-3800 1
(490 kN {50 ton})
Removal and installation of
1 791-575-1301 Box 1
nut on shaft end
791-575-1400 Wrench 1
Removal and installation of
2 791-108-1370 Guide 1
hub holder nut
Disassembly and assembly
F 791-420-6130 Handle 1
of final drive assembly
791-576-1003 Remover A 1
791-101-1102 Pump 1
3 Pulling out sprocket
Cylinder
791-101-1600 1
(686 kN {70 ton})

D155C-1 30-7
Disassembly and assembly Special tool list

New/remodel
Necessity

Sketch
Q'ty
Component Symbol Part No. Part Name Nature of work, remarks

791-575-2003 Installer A 1
791-101-1102 Pump 1
4 Press-fitting sprocket
Cylinder
791-101-1600 1
(686 kN {70 ton})
5 791-575-1520 Installer 1
Installation of floating seal
6 791-580-1510 Installer 1
791-575-3003 Remover 1
790-101-1102 Pump 1 Pulling out second gear hub
7
assembly
Cylinder
790-101-1600 1
(686 kN {70 ton})
791-575-4003 Installer 1
790-101-1102 Pump 1 Press-fitting second gear
8
hub assembly
Puller
Disassembly and assembly 790-101-2102 1
F (294 kN {30 ton})
of final drive assembly
Removal and installation of
9 791-551-1300 Wrench 1
nut (inside body)
791-575-5500 Remover B 1
790-101-1102 Pump 1
10 Pulling out sprocket shaft
Cylinder
790-101-1600 1
(686 kN {70 ton})
791-575-6110 Plug 1
or
791-575-6501 Installer 1
11 Press-fitting sprocket shaft
790-101-1102 Pump 1
Cylinder
790-101-1160 1
(686 kN {70 ton})
Removal and installation of
12 790-401-1800 Lifting tool 1
final cover
Remover and Removal and installation of
1 791-475-6000 1
installer hub nut
791-480-3001 Remover D 1
790-101-1102 Pump 1
2 Pulling out hub
Disassembly and assembly Puller
G 790-101-3800 1
of first pinion assembly (490 kN {50 ton})
791-480-4001 Installer C 1
790-101-1102 Pump 1
3 Press-fitting hub
Puller
790-101-3800 1
(490 kN {50 ton})
791-681-5000 Remover & installer t 1
Removal, installation of 790-101-1102 Pump t 1 Removal, installation of
N
track shoe track shoe
Cylinder
790-101-4300 t 1
(1,471 kN {150 ton})

30-8 D155C-1
Disassembly and assembly Special tool list

New/remodel
Necessity

Sketch
Q'ty
Component Symbol Part No. Part Name Nature of work, remarks

Removal, installation of 790-401-1700 Lifting tool t 1 Removal, installation of

H
track roller 790-401-1760 Adapter t 1 track roller

1 791-685-8000 Compressor t 1
Disassembly, assembly of Cylinder Disassembly, assembly of
J 2 790-101-1300 t 1
recoil spring (981 kN {100 ton}) recoil spring
3 790-101-1102 Pump t 1

Disassembly, assembly of 1 790-102-3000 Repair stand t 1 Disassembly, assembly of

K
counterweight cylinder 2 790-102-1200 Power wrench t 1 counterweight cylinder

Removal, installation of Removal, installation of

L 790-102-1100 Wrench t 1
winch winch
1 791-780-1400 Wrench t 1
2 791-781-1330 Wrench t 1 Disassembly, assembly of
3 791-781-1310 Wrench t 1 winch

4 791-781-1320 Wrench t 1
5 791-781-1000 Compressor t 1 Assembly of winch brake
Disassembly, assembly of 791-100-2200 Installer t 1
M
winch
790-101-1102 Pump t 1
6
Puller
790-101-2102 t 1 Disassembly, assembly of
(294 kN {30 ton})
winch
790-101-1102 Pump t 1
7 Puller
790-101-2102 t 1
(294 kN {30 ton})

D155C-1 30-9
Disassembly and assembly Starting motor

Removal and installation of

starting motor assembly
Standard
Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Remove the engine right side cover.

2. Disconnect starting motor wires (1), (2), and (3).

3. Disconnect wire (4) and remove 3 bolts (5) and

starting motor assembly (6).

a Remove the lower side similarly to the above.

Standard
Installation

• Carry out installation in the reverse order to

removal.

–50°C specification
Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Remove the engine right side cover.

2. Disconnect starting motor wires (1), (2), and (3).

3. Disconnect heater wire (4).

4. Disconnect wiring connector (5).

5. Remove 3 bolts (6) and starting motor assembly

(7).

a Remove the lower side similarly to the above.

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

30-10 D155C-1
Disassembly and assembly Alternator

Removal and installation of

alternator assembly
Standard
Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Remove the engine right side cover.

2. Disconnect alternator wires (1) and (2).

3. Loosen locknut (3) and rotate adjustment nut (4)

to lower the tension of V-belt (5).

4. Remove bolts (6) and (7), alternator assembly

(8), and belt cover. [*1]

a While removing the V-belt, remove the pul-

ley.
8
Standard
Installation 6

• Carry out installation in the reverse order to 5

removal.

[*1] 3

4 7
a After installing the alternator, adjust the belt DED00004

tension. For details, see Testing and

adjusting, Testing and adjusting alternator
belt.

D155C-1 30-11
Disassembly and assembly Alternator

–50°C specification
Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Remove the engine right side cover.

2. Disconnect alternator wires (1) and (2).

3. Loosen locknut (3) and rotate adjustment nut (4)

to lower the tension of V-belt (5).

4. Remove bolts (6) and (7), alternator assembly

(8), and belt cover. [*1]

a While removing the V-belt, remove the pul-

ley.

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

[*1]

a After installing the alternator, adjust the belt

tension. For details, see Testing and
adjusting, Testing and adjusting alternator
belt.

30-12 D155C-1
Disassembly and assembly Engine oil cooler core

Removal and installation of

engine oil cooler core assembly
Standard
Removal

k Drain the coolant.

1. Remove muffler drain tube (1).

2. Remove heat insulation plate (2).

3. Disconnect turbocharger lubrication tube (3)

from the turbocharger and move it toward the
rear.

4. Disconnect hose (4).

5. Remove the oil cooler assembly.

6. Disconnect wire clamp (8).

7. Remove core assembly (7) from cover (6).

Standard
Installation

• Carry out installation in the reverse order to

removal.

• Refilling with coolant

Add coolant through the coolant filler to the
specified level. Run the engine to circulate the
coolant through the system. Then, check the
coolant level again.

D155C-1 30-13
Disassembly and assembly Engine oil cooler core

–50°C specification
Removal

k Drain the coolant.

1. Remove heater hose (1).

2. Remove heat insulation plate (2).

3. Disconnect turbocharger lubrication tube (3) from

the turbocharger and move it toward the rear.

4. Remove muffler drain tube (4).

5. Disconnect heater hose (5).

6. Disconnect water connector (6).

7. Remove core assembly (8) from cover (7).

8 7

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

DDD00006
• Refilling with coolant
Add coolant through the coolant filler to the
specified level. Run the engine to circulate the
coolant through the system. Then, check the
coolant level again.

30-14 D155C-1
Disassembly and assembly Fuel injection pump

Removal and installation of

fuel injection pump assembly
Removal

1. Close the valve of the fuel feed pipe.

2. Rotate the crankshaft forward to set the match

mark of the fuel injection pump.

a Perform this procedure to save the time for

checking the compression top dead center of
the No. 1 cylinder.

3. Open the engine left side cover (upper) and

remove the cover (lower).

4. Disconnect fuel control rod (1) and fuel hoses

(2), (3), and (4). [*1] 7
5. Remove boost pressure compensator tube (19).

6. Disconnect fuel hose (6) and tube (7).

7. Remove coupling cover (8). 6

8 DED00008

8. Remove lubrication tubes (9) and (10).

10
9 DED00009

9. Disconnect 6 delivery tubes (11). [*2]

11

DED00010

D155C-1 30-15
Disassembly and assembly Fuel injection pump

10. Loosen clamping bolt (12) on the drive shaft

side and remove 4 pump mounting bolts (13).

12
13
DED00011

11. Remove fuel injection pump assembly (14) and

coupling together. [*3] 14

13 13
DED00012

Installation 16

• Carry out installation in the reverse order to

removal.

[*1] 15
a Adjust the linkage. For details, see Testing
and adjusting, Adjusting control linkage.

[*2]
3 Sleeve nut: DED00013
23.5 ± 1.0 Nm {2.4 ± 0.1 kgm}

[*3]
a Install the fuel injection pump according to 18 17
the following procedure.
1) After installing the pump assembly,
accurately match mark (15) on the
damper (I.J) to pointer (16).
2) Loosen the bolt of coupling (18) and set
the match mark (17) on the injection
pump.

DED00014

30-16 D155C-1
Disassembly and assembly Water pump

Removal and installation of

water pump assembly
Standard
Removal
1
1. Drain the coolant

2. Push tension pulley (2) of fan belt (1) with an

adjustable wrench, etc. and remove fan belt (1).
3
4
3. Loosen locknut (3) and adjustment nut (4) and 2 5
remove V-belt (5). [*1]

DED00015 DED00016

4. Remove connectors (6) and (7).

5. Remove pulley (8).

6. Remove water pump assembly (9).

Standard
Installation 8
DED00018

• Carry out installation in the reverse order to

removal.

[*1]

a After installing the V-belt, adjust its tension.

For details, see Testing and adjusting,
Testing and adjusting alternator belt.

• Refilling with coolant

Add coolant through the coolant filler to the
specified level. Run the engine to circulate the
coolant through the system. Then, check the
coolant level again.

D155C-1 30-17
Disassembly and assembly Water pump

–50°C specification
Removal

1. Drain the coolant

2. Remove fan belt cover (1).

3. Remove heater hose (2).

4. Disconnect engine oil cooler hose (3).

5. Push tension pulley (5) of fan belt (4) with an

adjustable wrench, etc. and remove fan belt (4).

6. Loosen locknut (6) and adjustment nut (7) and

remove V-belt (8).

7. Remove connectors (9) and (10).

8. Remove pulley (11).

30-18 D155C-1
Disassembly and assembly Water pump

9. Remove water pump assembly (12).

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

[*1]

a After installing the V-belt, adjust its tension.

For details, see Testing and adjusting,
Testing and adjusting alternator belt.

• Refilling with coolant

Add coolant through the coolant filler to the
specified level. Run the engine to circulate the
coolant through the system. Then, check the
coolant level again.

D155C-1 30-19
Disassembly and assembly Turbocharger

Removal and installation of

turbocharger assembly
Standard
Removal

1. Remove the hood assembly. For details, see

Removal of hood assembly.

2. Remove heat insulation plates (2) and (3).

3. Disconnect tube (4) and hose (5) and lift off air
cleaner assembly (6).
4 Air cleaner assembly: 35 kg

4. Disconnect lubrication hose (7) and drain tube (8).

[*1]

5. Remove turbocharger assembly (9). [*1]

Standard
Installation

• Carry out installation in the reverse order to

removal.

[*1]
3 Hose mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}
7

8
DED00021

9
DED00020

30-20 D155C-1
Disassembly and assembly Turbocharger

–50°C specification
Removal

1. Remove the hood assembly. For details, see

Removal of hood assembly.

2. Remove heat insulation plates (2) and (3).

3. Disconnect tube (4) and hose (5) and lift off air
cleaner assembly (6).
4 Air cleaner assembly: 35 kg

4. Disconnect lubrication hose (7) and drain tube (8).

[*1]

5. Remove turbocharger assembly (9). [*2]

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

[*1]
3 Hose mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}
7

8
DED00021

9
DED00020

D155C-1 30-21
Disassembly and assembly Nozzle holder

Removal and installation of

nozzle holder assembly
Special tools

New/remodel
1

Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

2
Remover
A 1 795-570-1100 t 1
assembly

Removal
DBD00413
1. Remove the hood assembly. For details, see
Removal of hood assembly.

2. Remove cylinder head cover (1). [*1] 5

a When removing the head cover of the No. 4
or No. 5 cylinder, remove the air cleaner
assembly and air intake connector.
3
3. Disconnect delivery tube (2). [*2]
4
4. Loosen locknut (3) and remove connector (4).
[*3]

5. Remove holder (5). [*4] DBD00414

6. Using tool A1, remove nozzle holder assembly

(6). [*5]

Installation
• Carry out installation in the reverse order to
removal.
[*1]
4 Cylinder head cover mounting bolt:
24.5 ± 4.9 Nm {2.5 ± 0.5 kgm}
[*2]
4 Delivery tube sleeve nut:
23.5 ± 1.0 Nm {2.4 ± 0.1 kgm}
[*3]
4 Connector:
31.9 ± 2.5 Nm {3.25 ± 0.25 kgm}
4 Locknut: 39.2 ± 4.9 Nm {4.0 ± 0.5 kgm}
[*4]
4 Holder mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}
[*5]
a When installing the nozzle holder, clean its
mounting part and check that there is no
foreign matter in the sleeve.
Tighten the mounting bolts alternately so that
they will be tightened evenly.

30-22 D155C-1
Disassembly and assembly Cylinder head

Removal and installation of

cylinder head assembly
Standard
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

Remover
1 795-570-1100 t 1
assembly
A
Wrench (for angle-
2 790-331-1110 t 1
tightening)

Removal

k Disconnect the cable from the negative (–) terminal

of the battery.

1. Drain the coolant.

2. Close the valve of the fuel feed pipe.

3. Remove the hood assembly. For details, see

Removal of hood assembly.

4. Remove the engine side covers (right and left).

5. Remove heat insulation plates (2) and (3).

6. Disconnect tube (4), remove dust indicator (5),

and lift off air cleaner assembly (6).
4 Air cleaner assembly: 35 kg

7. Remove tube (7) and lift off muffler assembly (8).

4 Muffler assembly: 45 kg

8. Remove bracket (9).

9. Disconnect turbocharger lubrication hose (10)

and return tube (11).

10. Lift off the turbocharger and exhaust manifold

assembly (12). [*1]
4 Turbocharger and exhaust manifold
assembly: 50 kg

11. Remove aeration tube (13). [*3]

D155C-1 30-23
Disassembly and assembly Cylinder head

12. Disconnect hose (14) and tube (15) and remove

corrosion resistor (16) and fuel filter (17)
together with the bracket. [*4]

13. Remove engine oil filter (18).

14. Disconnect switch wires (19) and (20).

15. Disconnect wire clamp (21).

16. Remove oil tube (22), oil filler (23), and boost
pressure compensator tube (44).

17. Remove the clamping bolts of wires (24) and

(25), level gauge (26), fuel hose (27), and corro-
sion resistor hose (28). [*5]

a Since these bolts are also used to mount the

air intake manifold, check their lengths and
locations.

30-24 D155C-1
Disassembly and assembly Cylinder head

18. Remove aftercooler pipes (45) and (46).

19. Air intake connector (29). [*6]

20. Remove delivery tube clamp (30).

21. Remove the air intake manifold and aftercooler

assembly (32). [*5]

22. Remove spill tube (33). [*7]

23. Remove delivery tube (34). [*8]

24. Remove turbocharger lubrication hose (10). [*1]

a Perform this step for only the No. 3 cylinder.

25. Remove the head cover. [*9]

26. Remove rocker arm assembly (35). [*10]

a Loosen the locknut and then loosen the

adjustment screw by 2 – 3 turns.

D155C-1 30-25
Disassembly and assembly Cylinder head

27. Remove cross head (36). [*11]

28. Remove push rod (37).

29. Loosen locknut (38). [*12]

30. Remove connector (39). [*13]

31. Remove holder (40). [*14]

32. Using tool A1, remove nozzle holder assembly

(41).

33. Remove housing (42).

30-26 D155C-1
Disassembly and assembly Cylinder head

34. Remove cylinder head assembly (44). [*15]

4 Cylinder head assembly: 30 kg (1 piece)

D155C-1 30-27
Disassembly and assembly Cylinder head

Installation

• Carry out installation in the reverse order to

removal.

[*1]
3 Mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*2]
a Tighten the bolts in the order of [1] – [3], and
then tighten in the order of [4] – [24] as
shown in the figure at right.

3 Exhaust manifold mounting bolt:

1st time : 29.4 ± 4.9 Nm {3.0 ± 0.5 kgm}
2nd time: 66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*3]
3 Joint bolt:
29.4 ± 4.9 Nm {1.15 ± 0.15 kgm}

[*4]
a When installing the hose, take care not to
twist it.
3 Joint bolt: 29.4 ± 4.9 Nm {3.0 ± 0.5 kgm}
a Check that the ball of the adjustment screw
is fitted to the socket of the push rod.

[*5] a Adjust the valve clearance. For details, see

a Tighten the bolts in the order of [1] – [24] as Testing and adjusting, Adjusting valve
shown in the figure at right. clearance.
3 Air intake manifold mounting bolt:
1st time : 29.4 ± 4.9 Nm {3.0 ± 0.5 kgm} 3 Rocker arm assembly mounting bolt:
2nd time: 66.2 ± 7.4 Nm {6.75 ± 0.75 kgm} 98 ± 4.9 Nm {10 ± 0.5 kgm}

[*6] 3 Locknut:

3 Air intake connector mounting bolt:

48.0 ± 2.9 Nm {4.9 ± 0.3 kgm}

49 ± 0.8 Nm {5 ± 1 kgm} [*11]

a Adjust the cross head according to the
[*7] following procedure.
3 Joint bolt: 8.8 ± 1.0 Nm {0.9 ± 0.1 kgm}
1) Loosen the locknut and return the
adjustment screw.
2) Press the top of the cross head lightly
[*8]
3 Delivery tube sleeve nut:
and tighten the adjustment screw.
3) After the adjustment screw touches the
23.5 ± 1.0 Nm {2.4 ± 0.1 kgm} valve stem, tighten it further by 20°.
4) At this point, tighten the locknut.
[*9]
3 Head cover mounting bolt: 3 Locknut:
24.5 ± 9.8 Nm {2.5 ± 1.0 kgm} 58.8 ± 5.9 Nm {6.0 ± 0.6 kgm}

[*10] [*12]
3 Locknut: 39.2 ± 4.9 Nm {4.0 ± 0.5 kgm}
a When installing the mounting bolts, clean
their oil holes.

30-28 D155C-1
Disassembly and assembly Cylinder head

[*13]
3 Connector:
31.9 ± 2.5 Nm {3.25 ± 0.25 kgm}

[*14]
3 Holder mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*15]
a Check that the there is not dirt or foreign
matter on the cylinder head mounting face or
in the cylinder.
a When installing the gasket, check that the
grommet is not removed.
a Thoroughly apply molybdenum disulfide
(LM-P) to the threads and seat of the bolt.
a Tighten the cylinder head mounting bolts in
the order shown in the figure.

2 Mounting bolt:
Anti-friction compound (LM-P)

3 Cylinder head mounting bolt

1st time : Tighten to 147 ± 9.8 Nm
{15 ± 1 kgm}.
2nd time : Tighten to 215.6 ± 4.9 Nm
{22 ± 0.5 kgm}.
3rd time : 1) When using tool A2
Retighten the bolt by 90° +30
+0
with an angle tightening
wrench.
2) When not using tool A2
Make marks on the bolt and
cylinder head with a marker,
and then retighten the bolt by
90°.

a Tighten bolt [7] to 66.2 ± 7.4 Nm {6.75 ± 0.75

kgm} (Tighten only 1 time).
a After tightening each bolt, make a punch
mark on it to show the number of using
times.
• If there are 5 or more punch marks on a
bolt head, do not use that bolt again but
replace it.

• Refilling with coolant

Add coolant to the specified level. Run the
engine to circulate the coolant through the sys-
tem and raise its temperature. Then, check the
coolant level in the reserve tank.

D155C-1 30-29
Disassembly and assembly Cylinder head

–50°C specification
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

Remover
1 795-570-1100 t 1
assembly
A
Wrench (for angle-
2 790-331-1110 t 1
tightening)

Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Drain the coolant.

2. Close the valve of the fuel feed pipe.

3. Remove the hood assembly. For details, see

Removal of hood assembly.

4. Remove the engine side covers (right and left).

5. Remove heat insulation plates (2) and (3).

6. Disconnect tube (4), remove dust indicator (5),

and lift off air cleaner assembly (6).

4 Air cleaner assembly: 35 kg

7. Remove tube (7) and lift off muffler assembly (8).

4 Muffler assembly: 45 kg

8. Remove bracket (9).

9. Disconnect turbocharger lubrication hose (10)

and return tube (11). [*1]

30-30 D155C-1
Disassembly and assembly Cylinder head

10. Lift off the turbocharger and exhaust manifold

assembly (12). [*2]
4 Turbocharger and exhaust manifold
assembly: 50 kg

11. Remove aeration tube (13). [*3]

12. Disconnect hose (14) and tube (15) and remove

corrosion resistor (16) and fuel filter (17)
together with the bracket. [*4]

13. Remove engine oil filter (18).

14. Remove switch mounting bolt (19) and discon-

nect switch (20).

15. Disconnect wire clamp (21).

16. Remove oil tube (22), oil filler (23), and boost
pressure compensator tube (44).

17. Remove the clamping bolts of wires (24) and

(25), level gauge (26), fuel hose (27), and corro-
sion resistor hose (28). [*5]

a Since these bolts are also used to mount the

air intake manifold, check their lengths and
locations.

D155C-1 30-31
Disassembly and assembly Cylinder head

18. Remove aftercooler pipes (45) and (46).

19. Air intake connector (29). [*6]

20. Remove delivery tube clamp (30).

21. Remove the air intake manifold and aftercooler

assembly (32). [*5]

22. Remove spill tube (33). [*7]

23. Remove delivery tube (34). [*8]

24. Remove turbocharger lubrication hose (10). [*1]

a Perform this step for only the No. 3 cylinder.

25. Remove the head cover. [*9]

26. Remove rocker arm assembly (35). [*10]

a Loosen the locknut and then loosen the

adjustment screw by 2 – 3 turns.

30-32 D155C-1
Disassembly and assembly Cylinder head

27. Remove cross head (36). [*11]

28. Remove push rod (37).

29. Loosen locknut (38). [*12]

30. Remove connector (39). [*13]

31. Remove holder (40). [*14]

32. Using tool A1, remove nozzle holder assembly

(41).

33. Remove housing (42).

D155C-1 30-33
Disassembly and assembly Cylinder head

34. Remove cylinder head assembly (43). [*15]

4 Cylinder head assembly: 30 kg (1 piece)

30-34 D155C-1
Disassembly and assembly Cylinder head

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

[*1]
3 Mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*2]
a Tighten the bolts in the order of [1] – [3], and
then tighten in the order of [4] – [24] as
shown in the figure at right.

3 Exhaust manifold mounting bolt:

1st time : 29.4 ± 4.9 Nm {3.0 ± 0.5 kgm}
2nd time: 66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*3]
3 Joint bolt:
29.4 ± 4.9 Nm {1.15 ± 0.15 kgm}

[*4]
a When installing the hose, take care not to
twist it. a Check that the ball of the adjustment screw

3 Joint bolt: 29.4 ± 4.9 Nm {3.0 ± 0.5 kgm}

is fitted to the socket of the push rod.

a Adjust the valve clearance. For details, see

[*5] Testing and adjusting, Adjusting valve
a Tighten the bolts in the order of [1] – [24] as clearance.
shown in the figure at right.
3 Air intake manifold mounting bolt: 3 Rocker arm assembly mounting bolt:
1st time : 29.4 ± 4.9 Nm {3.0 ± 0.5 kgm} 98 ± 4.9 Nm {10 ± 0.5 kgm}
3 Locknut:
2nd time: 66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*6] 48.0 ± 2.9 Nm {4.9 ± 0.3 kgm}

3 Air intake connector mounting bolt: [*11]

49 ± 0.8 Nm {5 ± 1 kgm} a Adjust the cross head according to the
following procedure.
[*7] 1) Loosen the locknut and return the
3 Joint bolt: 8.8 ± 1.0 Nm {0.9 ± 0.1 kgm}
adjustment screw.
2) Press the top of the cross head lightly
and tighten the adjustment screw.
[*8]
3 Delivery tube sleeve nut:
3) After the adjustment screw touches the
valve stem, tighten it further by 20°.
23.5 ± 1.0 Nm {2.4 ± 0.1 kgm} 4) At this point, tighten the locknut.

3 Locknut:
[*9]
3 Head cover mounting bolt: 58.8 ± 5.9 Nm {6.0 ± 0.6 kgm}
24.5 ± 9.8 Nm {2.5 ± 1.0 kgm}
[*12]
3 Locknut: 39.2 ± 4.9 Nm {4.0 ± 0.5 kgm}
[*10]
a When installing the mounting bolts, clean
their oil holes.

D155C-1 30-35
Disassembly and assembly Cylinder head

[*13]
3 Connector:
31.9 ± 2.5 Nm {3.25 ± 0.25 kgm}

[*14]
3 Holder mounting bolt:
66.2 ± 7.4 Nm {6.75 ± 0.75 kgm}

[*15]
a Check that the there is not dirt or foreign
matter on the cylinder head mounting face or
in the cylinder.
a When installing the gasket, check that the
grommet is not removed.
a Thoroughly apply molybdenum disulfide
(LM-P) to the threads and seat of the bolt.
a Tighten the cylinder head mounting bolts in
the order shown in the figure.

2 Mounting bolt:
Anti-friction compound (LM-P)

3 Cylinder head mounting bolt

1st time : Tighten to 147 ± 9.8 Nm
{15 ± 1 kgm}.
2nd time : Tighten to 215.6 ± 4.9 Nm
{22 ± 0.5 kgm}.
3rd time : 1) When using tool A2
Retighten the bolt by 90° +30
+0
with an angle tightening
wrench.
2) When not using tool A2
Make marks on the bolt and
cylinder head with a marker,
and then retighten the bolt by
90°.

a Tighten bolt [7] to 66.2 ± 7.4 Nm {6.75 ± 0.75

kgm} (Tighten only 1 time).
a After tightening each bolt, make a punch
mark on it to show the number of using
times.
• If there are 5 or more punch marks on a
bolt head, do not use that bolt again but
replace it.

• Refilling with coolant

Add coolant to the specified level. Run the
engine to circulate the coolant through the sys-
tem and raise its temperature. Then, check the
coolant level in the reserve tank.

30-36 D155C-1
Disassembly and assembly Thermostat

Removal and installation of

thermostat assembly
Removal

1. Drain the coolant.

6 Coolant:
Below thermostat mounting position

2. Remove the alternator. For details, see Removal

of alternator assembly.

3. Disconnect radiator inlet hose (1).

4. Disconnect bypass tube (2).

5. Remove cover (3).

6. Remove 2 thermostats (4).

Installation

• Carry out installation in the reverse order to

removal.

• Refilling with coolant

Add coolant to the specified level. Run the
engine to circulate the coolant through the sys-
tem and raise its temperature. Then, check the
coolant level in the reserve tank.

D155C-1 30-37
Disassembly and assembly Radiator

Removal and installation of

radiator assembly
Standard
Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Drain the coolant.

2. Sling underguard (2), remove its mounting bolts,

and open it.

3. Remove air cleaner hood (3) and cover (4).

4. Remove exhaust pipe (5).

5. Remove right and left engine side covers (6).

6. Lift off engine hood (7).

7. Disconnect radiator inlet tube (8).

8. Disconnect aeration hose (9).

9. Disconnect bypass tube (10).

10. Remove plate (11).

30-38 D155C-1
Disassembly and assembly Radiator

11. Remove 3 radiator grilles (12).

12. Remove plate (13).

13. Disconnect side light wire (14).

14. Disconnect radiator shutter rod (15).

15. Disconnect radiator outlet tube (16).

16. Radiator assembly

1) Remove 4 radiator upper mounting bolts
(17).
2) Remove mounting bolts (18) and disconnect
the radiator and shroud.
3) Remove 2 radiator lower supports (19).
4) Gradually lift up and remove radiator
assembly (20), taking care that it will not
interfere with and break other parts.
a When removing the radiator assembly,
keep the radiator shutter closed.

4 Radiator assembly: 400 kg

D155C-1 30-39
Disassembly and assembly Radiator

Standard
Installation

1. Radiator assembly
1) Gradually lift up and set radiator assembly
(20) to the mounting position, taking care
that it will not interfere with and break other
parts.
a After positioning the radiator assembly,
lightly tighten the upper mounting bolts
and the bolts to connect the lower
support and shroud.
2) Tighten radiator upper mounting bolts (17).
3) Tighten bolts (18) to connect the radiator
and shroud.
4) Tighten radiator lower supports (19).

2. Radiator outlet tube

Stick the gasket and connect radiator outlet tube
(16).
2 Gasket: Gasket sealant (LG-1)

3. Rod
Connect radiator shutter rod (15).
a Bend the cotter pin securely.

4. Wiring
Connect side light wire (14).

5. Plate
Install plate (13).

6. Radiator grille
Install radiator grille (12).

30-40 D155C-1
Disassembly and assembly Radiator

7. Plate
Install plate (11)

8. Piping

1) Stick the gasket and connect bypass tube

(10).
2 Gasket: Gasket sealant (LG-1)
2) Connect aeration hose (9).
3) Stick the gasket and connect radiator inlet
tube (8).
2 Gasket: Gasket sealant (LG-1)

9. Hood and air cleaner

1) Sling and install hood (7).
2) Install right and left engine side covers (6).
3) Install exhaust pipe (5).
4) Install air cleaner cover (4) and hood (3).

10. Underguard
Sling underguard (2) and set it to the frame, and
then tighten the mounting bolts.

D155C-1 30-41
Disassembly and assembly Radiator

11. Refilling with coolant

1) Close the radiator drain valve.
2) Add coolant through coolant filler (21) to the
specified level.
a Run the engine to circulate the coolant
through the system. Then, check the coolant
level again.

30-42 D155C-1
Disassembly and assembly Radiator

–50°C specification
Removal

k Disconnect the cable from the negative (–)

terminal of the battery.

1. Drain the coolant.

2. Sling underguard (2), remove its mounting bolts,

and open it.

3. Remove air cleaner hood (3).

4. Remove bolts (4) and exhaust pipe (5).

5. Remove the right and left engine side covers.

6. Using sling [1], remove hood (7).

7. Disconnect radiator inlet tube (8).

8. Disconnect aeration hose (9).

9. Disconnect bypass tube (10).

D155C-1 30-43
Disassembly and assembly Radiator

10. Remove plate (11).

11. Remove 3 radiator grilles (12).

12. Remove plate (13).

13. Disconnect radiator shutter rod (14).

14. Remove radiator shutter rod bracket (15).

15. Disconnect radiator outlet tube (16).

30-44 D155C-1
Disassembly and assembly Radiator

16. Radiator assembly

1) Remove 4 radiator upper mounting bolts
(17).
2) Remove shroud mounting bolts (18) and
disconnect the radiator and shroud.
3) Remove 2 radiator lower supports (19).
4) Gradually lift up and remove radiator
assembly (20), taking care that it will not
interfere with and break other parts.
a When removing the radiator assembly,
keep the radiator shutter closed.
4 Radiator assembly: 400 kg

D155C-1 30-45
Disassembly and assembly Radiator

–50°C specification
Installation

1. Radiator assembly
1) Gradually lift up and set radiator assembly
(20) to the mounting position, taking care
that it will not interfere with and break other
parts.
a When installing the radiator assembly, keep
the radiator shutter closed.
a After positioning the radiator assembly,
lightly tighten the upper mounting bolts and
the bolts to connect the lower support and
shroud.
2) Tighten radiator upper mounting bolts (17).
3) Tighten bolts (18) to connect the radiator
and shroud.
4) Tighten radiator lower supports (19).

2. Radiator outlet tube

Stick the gasket and connect radiator outlet tube
(16).
2 Gasket: Gasket sealant (LG-1)

3. Rod
Connect radiator shutter rod (15).
a Bend the cotter pin securely.

4. Install radiator shutter rod bracket (15).

a Bend the cotter pin securely.

5. Plate
Install plate (13).

6. Radiator grille
Install radiator grille (12).

30-46 D155C-1
Disassembly and assembly Radiator

7. Plate
Install plate (11)

8. Piping
1) Stick the gasket and connect bypass tube
(10).
2 Gasket: Gasket sealant (LG-1)
2) Connect aeration hose (9).
3) Stick the gasket and connect radiator inlet
tube (8).
2 Gasket: Gasket sealant (LG-1)

9. Hood
1) Using sling [1], install hood (7).

10. Air cleaner

1) Install cover (3).
2) Position exhaust pipe (5) and tighten bolts
(4).

D155C-1 30-47
Disassembly and assembly Radiator

11. Underguard
Sling underguard (2) and set it to the frame, and
then tighten the mounting bolts.

12. Refilling with coolant

1) Close the radiator drain valve.
2) Add coolant through coolant filler (22) to the
specified level.
a Run the engine to circulate the coolant
through the system. Then, check the coolant
level again.

30-48 D155C-1
Disassembly and assembly Fuel tank

Removal and installation of

fuel tank assembly
Standard
Removal

1. Remove the chassis rear cover.

2. Close fuel feed valve (1).

3. Disconnect fuel feed hose (2).

4. Disconnect fuel return hoses (3) and (4).

5. Disconnect 6 fuel tank mounting bolts (5) and lift

off fuel tank assembly (6).

Standard
Installation

• Carry out installation in the reverse order to

removal.
3 Fuel feed hose mounting nut:
78 ± 19.6 Nm {8 ± 2 kgm}

D155C-1 30-49
Disassembly and assembly Fuel tank

–50°C specification
Removal

1. Remove chassis rear cover (1).

2. Remove fuel return hose (2) and clamp (3).

3. Close fuel feed valve (4).

4. Disconnect fuel feed hose (5).

5. Disconnect 6 fuel tank mounting bolts (6).

6. Lift off fuel tank assembly (7).

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.
3 Fuel feed hose mounting nut:
78 ± 19.6 Nm {8 ± 2 kgm}

30-50 D155C-1
Disassembly and assembly Torque converter and winch oil cooler

Removal and installation of

torque converter and winch
oil cooler assembly
Standard
Removal

1. Drain the coolant.

2. Remove engine right side covers (1) and (2).

3. Disconnect radiator outlet tube (3).

4. Remove hoses (4) and (5).

5. Remove cooler tubes (6) and (7).

6. Disconnect tube (8).

7. Loosen bolt (9) and lift off cooler assembly (10).

4 Cooler assembly: 120 kg

Standard
Installation

• Carry out installation in the reverse order to

removal.

• Refilling with coolant

a Close the drain valves of the radiator and oil
cooler. Add coolant through the coolant filler
to the specified level. Run the engine to
circulate the coolant through the system.
Then, check the coolant level again.

D155C-1 30-51
Disassembly and assembly Torque converter and winch oil cooler

–50°C specification
Removal

1. Drain the coolant.

2. Remove engine right side covers (1) and (2).

3. Remove heater hose (11).

4. Disconnect radiator outlet tube (3).

5. Remove hoses (4) and (5).

6. Remove cooler tubes (6) and (7).

7. Disconnect tube (8).

8. Loosen bolt (9) and lift off cooler assembly (10).

4 Cooler assembly: 120 kg

–50°C specification
Installation

• Carry out installation in the reverse order to

removal.

• Refilling with coolant

a Close the drain valves of the radiator and oil
cooler. Add coolant through the coolant filler
to the specified level. Run the engine to
circulate the coolant through the system.
Then, check the coolant level again.

30-52 D155C-1
Disassembly and assembly Engine

Removal and installation of

engine assembly
Standard
Removal

k Disconnect the cable from the negative (–) ter-

minal of the battery.
a Close the fuel tank valve.
a Drain the coolant.
a Drain the hydraulic oil.
• Remove the winch and gate-type frame. For
details, see Removal of gate-type frame as-
sembly and Removal of winch assembly.

1. Remove engine side covers (1) (right and left),

air cleaner hood (2), muffler pipe (3), and engine
hood (4).

2. Disconnect starting motor wires CN-51/52 and

CN-39/40 (5).

3. Disconnect alternator wire (6) and remove wire

clamps (7) and (8).

4. Disconnect oil cooler hose (9), water pump tube

(10), and hose (11).

5. Remove fan belt cover (12) and fan belt (13).

6. Disconnect left-hand wiring connector (14).

D155C-1 30-53
Disassembly and assembly Engine

7. Disconnect radiator outlet tube (15).

8. Disconnect radiator inlet hose (16), aeration

hose (17), and bypass hose (18).

9. Disconnect fuel feed hose (19) and fuel hose

(20).

10. Disconnect fuel control linkage (21).

11. Remove wire clamp (22) and disconnect wire

(23).

12. Remove the clamp and disconnect wire (24).

13. Disconnect switch wire (25).

14. Disconnect transmission pump tubes (26) and

(27).

15. Disconnect steering pump tube (28), hose (29),

hose (30), and clamp (31).

30-54 D155C-1
Disassembly and assembly Engine

16. Disconnect hydraulic pump tubes (32) and (33).

17. Disconnect torque converter regulator valve

tube (34), hose (35), and scavenging pump
hose (36).

18. Disconnect torque converter oil temperature

gauge sensor wire (37).

19. Disconnect torque converter relief valve tubes

(38) and (39).

20. Remove universal joint (40).

21. Remove breather tube (41).

22. Remove front mounting bolt (42) and rear

mounting bolt (43). [*1]

D155C-1 30-55
Disassembly and assembly Engine

23. While moving engine assembly (44) toward the

rear of the chassis, lift it off slowly.

a When removing the engine assembly, check that

all the wires, hoses, and tubes are disconnected
and take care not to damage them.
4 Engine assembly: 1,750 kg

Standard
Installation

• Carry out installation in the reverse order to re-

moval.

[*1]
3 Mounting bolt:
98.1 – 121.6 Nm {11.2 – 12.4 kgm}

• Refilling with coolant

Add coolant to the specified level. Run the en-
gine to circulate the coolant through the system.
Then, check the coolant level again.

• Refilling with oil

Add oil to the specified levels of the hydraulic
tank and steering case. Run the engine to circu-
late the oil through the system. Then, check the
oil level again.

a Check for coolant leakage and oil leakage.

• Bleeding air
Bleed air from the fuel system. For details, see
TESTING AND ADJUSTING, Bleeding air from
each part.

30-56 D155C-1
Disassembly and assembly Engine

–50°C specification
Removal

k Disconnect the cable from the negative (–) ter-

minal of the battery.
a Close the fuel tank valve.
a Drain the coolant.
a Drain the hydraulic oil.
• Remove the winch and gate-type frame. For
details, see Removal of gate-type frame as-
sembly and Removal of winch assembly.

1. Remove engine side covers (1) (right and left),

air cleaner hood (2), muffler pipe (3), and hood
(4).

2. Disconnect starting motor wires CN-408/39/40

(5).

3. Disconnect alternator wire (6) and remove the

wire clamp.

4. Remove fan belt cover (7) and fan belt (8).

5. Remove torque converter oil cooler hose (9) and

tube (10).

6. Disconnect radiator outlet tube (11).

7. Disconnect radiator inlet hose (12), aeration

hose (13), and bypass hose (14).

D155C-1 30-57
Disassembly and assembly Engine

8. Disconnect fuel feed hose (15) and fuel return

hose (16).

9. Disconnect wiring connector (17).

10. Disconnect all wire clamps (18) and wire (19).

11. Disconnect fuel control linkage (20).

12. Remove the clamp and disconnect wire (21).

13. Disconnect switch wire (22).

14. Disconnect transmission pump tubes (23) and

(24).

15. Disconnect hydraulic pump tubes (25) and (26).

30-58 D155C-1
Disassembly and assembly Engine

16. Remove steering pump tube (27) and hose (28).

17. Disconnect fuel control rod (29) and hose (30).

18. Disconnect torque converter regulator valve

tube (31), hose (32), and scavenging pump
hose (33).

19. Disconnect torque converter oil temperature

gauge sensor wire (34).

20. Remove breather tube (35).

21. Disconnect torque converter relief valve tube

(36).

22. Remove universal joint (37).

23. Disconnect heater hoses (38) and (39).

D155C-1 30-59
Disassembly and assembly Engine

24. Disconnect engine lower heater hose (40).

25. Remove front mounting bolt (41) and rear

mounting bolt (42). [*1]

26. While moving engine assembly (43) toward the

rear of the chassis, lift it off slowly.

a When removing the engine assembly, check that

all the wires, hoses, and tubes are disconnected
and take care not to damage them.
4 Engine assembly: 1,750 kg

30-60 D155C-1
Disassembly and assembly Engine

–50°C specification
Installation

• Carry out installation in the reverse order to re-

moval.

[*1]
3 Mounting bolt:
98.1 – 121.6 Nm {11.2 – 12.4 kgm}

• Refilling with coolant

Add coolant to the specified level. Run the en-
gine to circulate the coolant through the system.
Then, check the coolant level again.

• Refilling with oil

Add oil to the specified levels of the hydraulic
tank and steering case. Run the engine to circu-
late the oil through the system. Then, check the
oil level again.

a Check for coolant leakage and oil leakage.

• Bleeding air
Bleed air from the fuel system. For details, see
TESTING AND ADJUSTING, Bleeding air from
each part.

D155C-1 30-61
Disassembly and assembly PTO

Removal and installation of

PTO assembly
Removal
1. Oil draining
k Loosen hydraulic tank oil filler cap to relieve
pressure remaining in trank.
Remove drain plug (1) to drain oil from hydraulic
tank.
6 Hydraulic tank: Approx. 28 l

2. Gate type frame

Remove gate type frame (2) using procedure
stated in Removal of gate type frame assembly.

3. Hoses
1) Disconnect counterweight cylinder hose (3).
2) Disconnect heater hose (4).

4. Piping
1) Disconnect counterweight pump outlet tube
(9).
2) Remove counterweight pump inlet tube (10).
3) Disconnect steering pump outlet hose (11).
4) Remove steering pump inlet tube (12).

30-62 D155C-1
Disassembly and assembly PTO

5. Lubrication tube
Disconnect PTO lubrication tube (13) from en-
gine flange.

6. PTO assembly
Sling PTO assembly (14). Remove 11 bolts (15)
fastening assembly; lift out PTO assembly.
4 PTO assembly: 230 kg

D155C-1 30-63
Disassembly and assembly PTO

Installation
1. PTO assembly
1) Fit O-ring in place and lift PTO assembly
(14) into position so that its splines come
into alignment with those of flywheel hous-
ing.

2) Install and tighten 11 bolts (15) shown in fig-

ure below.

2. Lubrication tube
With gasket in place, connect lubrication tube
(13).

3. Piping
1) With O-ring in place, install steering pump
inlet tube (12).
2) Connect steering pump outlet hose (11).
3) With O-ring in place, install counterweight
pump inlet tube (10).
4) With O-ring in place, connect counterweight
pump outlet tube (9).

30-64 D155C-1
Disassembly and assembly PTO

4. Hoses
Fit O-ring in place and connect counterweight
cylinder hose (3).
a Make sure hoses are not twisted and do not
interfere with other parts.

5. Gate type frame

Install gate type frame (2) using procedure stat-
ed in Installation of gate type frame assembly.

6. Oil feeding
1) Tighten hydraulic tank drain plug.
2) Refill hydraulic tank at its oil filler (16) with
engine oil up to the specified level.
5 Hydraulic tank: Approx. 30 l
a Start and run engine to let oil circulate in
hydraulic piping.
Then, check oil level again.

D155C-1 30-65
Disassembly and assembly PTO

Disassembly and assembly of

PTO assembly
Disassembly
a With PTO assembly slung, remove drain plug to
drain oil.
k Take special care to prevent accident when
turning PTO assembly upside down.

1. Lubrication tube
1) Lay down PTO assembly (1) stably with a
block [1] wedged under the assembly.
2) Remove PTO lubrication tube (2).

2. Pumps
1) Turn PTO assembly upside down so that
pumps face upward.
Support PTO assembly on blocks [2] (200
mm high).
2) Remove counterweight pump (3).
3) Remove steering pump (4).

3. Covers
1) Remove flange (5).
2) Remove cover (6).
3) Remove cover (7); take out oil seal cage (8).

4) Turn PTO assembly upside down so that

coupling faces downward.
Support assembly on blocks [2].
5) Remove covers (9), (10) and (11).

30-66 D155C-1
Disassembly and assembly PTO

4. Case assembly
1) Remove mounting bolts.
2) Attach eyebolt [3] (10 mm P = 1.5) to case;
lift out case assembly (12).

5. Towing winch drive gear assembly

1) Remove holder (13).
2) Using gear puller [4], pull out bearing (14)
and towing winch drive gear (15).

6. Towing winch drive shaft assembly

1) Pull out towing winch drive shaft (16).
2) Remove oil seal cage (17).

7. Idle gear assembly

1) Turn case and gear assembly upside down.
Support the assembly on block [2] (200 mm
high).
2) Remove holder (18).
3) Using puller [5], pull out idle gear assembly
(19).

D155C-1 30-67
Disassembly and assembly PTO

8. Counterweight pump drive gear assembly

1) Remove nut (20).
2) Using the same procedure as used for re-
moving idle gear, pull out counterweight
pump drive gear assembly (21).

9. Steering pump drive gear assembly

1) Pry snap ring (22) out.
2) Using puller [5], pull out steering pump drive
gear assembly (23).

10. PTO drive gear and shaft assembly

1) Remove nut (24).
2) Using puller [5] or setting case and gear as-
sembly in press, pull out PTO drive gear and
shaft assembly (25).

11. Bearings
1) Remove bearings (27) from casing (26).
2) Remove bearing outer races (29) from cas-
ing (28).

30-68 D155C-1
Disassembly and assembly PTO

Assembly
k Take special care to prevent accidents when tur-
ing PTO assembly upside down.

1. Bearing
Using press-fit tool [6], press-fit bearings (27)
into casing (28).
a Be sure to install snap ring after press-fitting
steering pump drive gear bearings.

2. PTO drive gear and shaft assembly

1) Using press-fit tool (80 mm I.D.), press-fit
bearing (30) onto shaft (31).
2) Fit in key (32) to shaft; press-fit gear (33) in
place.
2 Gear press-fitting portion:
Anti-friction compound (LM-P)
3) Set casing in press and support bearing (34)
inner race on tool (70 mm I.D.). Press-fit
PTO drive gear and shaft assembly.

3. Steering pump drive gear assembly

1) Using press-fit tool (55 mm I.D.), press-fit
bearing (35) into gear (36). Install snap ring
(37).
2) Supporting bearing (38) inner race on tool
(55 mm I.D.), press-fit steering pump drive
gear assembly.

4. Counterweight pump drive gear assembly

1) Using press-fit tool (60 mm I.D.), press-fit
bearing (39) onto gear (40). Install snap ring
(41).
2) Supporting bearing (42) inner race on tool
(55 mm I.D.), press-fit counterweight pump
drive gear assembly.

D155C-1 30-69
Disassembly and assembly PTO

5. Idle gear assembly

1) Using press-fit tool (60 mm I.D.), press-fit
bearing (43) onto gear (44). Install snap ring
(45).
2) Supporting bearing (46) inner race on tool
(55 mm I.D.), press-fit idle gear assembly.

6. Towing winch drive shaft

1) Tie gears to casing with wires to prevent
them from slanting when case and gear as-
sembly is turned upside down. Special care
should be taken to lock idle gear and coun-
terweight pump drive gear securely since it
is very difficult to correct them if they are
once positioned slantwise.

2) Turn case and gear assembly upside down

and set in press.
3) Press-fit oil seal (48) into cage (47) using
push tool (105 mm OD). With O-ring in
place, install oil seal cage (17).
2 Oil seal lip: Fill 40 to 60% of
vacancy with grease (GLT2-Ll)
4) Supporting bearing inner race on tool (65
mm I.D.), press-fit shaft (16).

7. Nut, holder and snap ring

1) Support case and gear assembly on blocks
[2] (200 mm high).
2) Install snap ring (22).
3) Tighten nuts (24) and (20).
3 Nut:
392.3 ± 98.1 Nm {40 ± 10 kgm}
a Be sure to bend tangs on lockplates se-
curely.
4) Install holder (18).
a Be sure to bend tang on lock plate se-
curely.

30-70 D155C-1
Disassembly and assembly PTO

8. Towing winch drive gear

1) Turn case and gear assembly upside down
and support it on blocks [2].
2) Install gear (15). Press-fit bearing (14) using
push tool [7].
3) Install holder (13).
a Be sure to bend tang on lock plate se-
curely.

9. Case assembly
1) Set case in press. Press-fit all bearing outer
races (29) using press-fit tool.
a After installing steering pump drive gear
bearing outer race, lock it with snap ring.
a Press-fit PTO drive shaft bearing outer
race after fitting snap ring to case.

2) Attach eyebolts [3] (10 mm, P = 1.5) to case

assembly (12).
Lift the assembly into position.
2 Case matching surface:
Metal sealant (LG-4)

10. Cover
1) With O-rings in place, install covers (11),
(10) and (9).
2) Turn PTO assembly upside down and sup-
port it on blocks [2].

D155C-1 30-71
Disassembly and assembly PTO

3) Using push tool (82 mm OD), press-fit oil

seal (49) into cage (50).
2 Oil seal lip: Fill 40 to 60% of
vacancy with grease (GLT2-Ll)

4) With O-ring in place, install oil seal cage (8).

5) With gasket in place, install cover (7).
2 Gasket: Gasket sealant (LG-1)
6) With O-ring in place, install cover (6).
7) With O-ring in place, install flange (5).

11. Pumps
1) With O-ring in place, install steering pump
(4).
2) With O-ring in place, install counterweight
pump (3).

12. Lubrication tube

1) Lay down PTO assembly (1) stably by
wedging block [1] under the assembly.
2) With gasket in place, install PTO lubrication
tube (2).

30-72 D155C-1
Disassembly and assembly Transmission pump

Removal and installation of

transmission pump assembly
Removal
1. Remove left engine side covers (1) and (2).

2. Remove transmission pump inlet tube (3).

3. Remove transmission pump outlet tube (4).

4. Remove transmission pump assembly (5).

Installation
• Carry out installation in the reverse order to re-
moval.

D155C-1 30-73
Disassembly and assembly Floor frame

Removal and installation of

floor frame assembly
Removal

1. Plates
1) Remove floor plates (2), (3) and (4).
a Before removing floor plate (4), discon-
nect decelerator rod.

2) Remove plates (5), (6) and (7).

2. Counterweight control rod

1) Disconnect rod (8).
2) Open inspection cover and disconnect rod
(9).

3. Parking brake rod

Disconnect parking brake rod (10).

30-74 D155C-1
Disassembly and assembly Floor frame

4. Towing winch control rods

Disconnect towing winch control rods (14), (15)
and (16).

5. Wiring
Disconnect cable (17).

6. Transmission control rods

Disconnect transmission control rods (19) and
(20).

7. Steering and brake rods

Disconnect 4 rods (21).

8. Fuel control rods

Disconnect fuel control rods (22) and (23).

D155C-1 30-75
Disassembly and assembly Floor frame

9. Cover
Remove cover (24).

10. Compression release rod

Disconnect compression release rod (26).

11. Wiring and hose

1) Disconnect cable (28), remove intermediate
clamp, and keep cable forward.
2) Disconnect dust indicator hose (29).

12. Bracket
Disconnect upper and lower pipes (30) and (31).
Remove bracket (32).
a Attach identification tags to disconnected
pipes to prevent their erroneous connection.

13. Bracket
Remove bracket (33) from frame.

30-76 D155C-1
Disassembly and assembly Floor frame

14. Floor frame assembly

1) Remove floor frame assembly mounting
bolts (34).

2) Attach 4 eyebolts [1] (14 mm, P = 2.0) to

floor frame and lift out floor frame assembly
(35).
4 Floor frame assembly: 630 kg
a Be careful not to damage rods and wir-
ing when lifting out floor frame assembly.

Installation

a Be sure to bend cotter pins on the rods securely

and tighten lock nuts securely.

1. Floor frame assembly

1) Using 4 eyebolts [1] (14 mm, P = 2.0), lift
floor frame assembly (35) onto position in
machine.
a When positioning in machine, lower as-
sembly carefully and gradually so as not
to damage the rods and wiring.

2) Install and tighten mounting bolts (34).

D155C-1 30-77
Disassembly and assembly Floor frame

2. Bracket
Fit bracket (33) to frame

3. Bracket
Install bracket (32). Connect upper and lower
pipes (31) and (30).
a Be careful not to connect pipes erroneously.

4. Wiring and hose

1) Connect dust indicator hose (29).
2) Connect cable (28) and fix it with intermedi-
ate clamp.

5. Compression release rod

Connect compression release rod (26).

6. Cover
Install cover (24).

30-78 D155C-1
Disassembly and assembly Floor frame

7. Fuel control rod

Connect fuel control rods (23) and (22).

8. Steering/brake rods
Connect 4 rods (21).
a Be sure to bend cotter pins securely.

9. Transmission control rods

Connect transmission control rods (20) and (19).

10. Wiring
Connect cable (17).

11. Towing winch control rods

Connect towing winch control rods (16), (15)
and (14).

D155C-1 30-79
Disassembly and assembly Floor frame

12. Parking brake rod

Connect parking brake rod (10).

13. Counterweight control rods

1) Open inspection cover and connect rod (9).
2) Connect rod (8).

14. Plates
1) Install plates (7), (6) and (5).

2) Install floor plates (4), (3) and (2).

a After installing plate (4), connect decelerator
rod.

30-80 D155C-1
Disassembly and assembly Torque converter

Removal and installation of

torque converter assembly
Removal

1. Steering and transmission oil draining

Remove drain plug (1) to drain oil from steering
and transmission cases.
6 Steering and transmission oil:
Approx. 180 l

2. Plates
Remove plates (2) and (3).

3. Underguard
Using transmission jack [1], remove torque con-
verter underguard (4).
4 Underguard: 155 kg

k Support center of underguard stably on

transmission jack and remove underguard
carefully to prevent accidental falling.

4. Torque converter oil draining

Remove drain plug (5) to drain oil from torque
converter case.
6 Torque converter oil : Aprrox. 13 l

a After draining, install the drain plug.

D155C-1 30-81
Disassembly and assembly Torque converter

5. Piping
1) Disconnect scavenging pump outlet tube
(6).

2) Disconnect torque converter regulating

valve outlet tube (7).
3) Disconnect torque converter relief valve in-
let tube (8) and outlet tube (9).

6. Wiring
Disconnect torque converter oil temperature
gauge lead (10).

7. Universal joint
Sling universal joint (12), remove mounting
bolts, and lift out the joint.
4 Universal joint: 25 kg

30-82 D155C-1
Disassembly and assembly Torque converter

8. Torque converter breather tube

Remove torque converter breather tube (13).

9. Torque converter assembly

1) Sling torque converter assembly (14).
2) Remove mounting bolts.
3) Disconnect torque converter assembly from
flywheel housing by using jack bolts and
take down assembly.
4 Torque converter assembly: 235 kg

Installation

1. Torque converter assembly

1) Attach gasket to flywheel housing.
2) Turn in guide bolts (12 mm, P = 1.75, length
100 mm) to flywheel housing.
3) Lift torque converter assembly (14) into po-
sition on flywheel housing so that drive gear
meshes with flywheel gear.
4) Install and tighten mounting bolts.

2. Torque converter breather tube

Install torque converter breather tube (13).

D155C-1 30-83
Disassembly and assembly Torque converter

3. Universal joint
1) Lift universal joint (12) into position on cou-
pling.
2) Install and tighten mounting bolts.
2 Mounting bolt:
127.5 ± 3.9 Nm {13 ± 0.4 kgm}
a After installation, apply grease (GLT2-
LI).

4. Wiring
Connect the torque converter oil temperature
gauge lead (10).

5. Piping
1) With O-ring in place, connect torque con-
verter relief valve outlet tube (9) and inlet
tube (8).
2) With O-ring in place, connect torque con-
verter regulating valve outlet tube (7).

3) With O-ring in place, connect scavenging

pump outlet tube (6).

30-84 D155C-1
Disassembly and assembly Torque converter

6. Underguard
Using transmission jack [1] install torque con-
verter underguard (4).
k Support center of underguard stably on
transmission jack and install guard carefully
to prevent accidental falling.

7. Plates
Install plates (3) and (2).

8. Oil feeding
1) Tighten steering case drain plug.
2) Refill with engine oil at oil filler (15) up to
specified oil level.
5 Steering, transmission and torque
converter: Approx. 195 l
a Start and run engine to let oil to circulate
in piping. Then, check oil level again.

D155C-1 30-85
Disassembly and assembly Torque converter

Disassembly and assembly of

torque converter assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

790-501-5000 Unit repair stand t 1

B
790-901-2110 Bracket t 1

Disassembly
1. Torque converter assembly
1) Set torque converter assembly (1) on tool B.
2) Remove regulator valve assembly (2).
3) Remove relief valve assembly (3).
4) Remove strainer (4).
5) Remove scavenging pump assembly (5).
6) Remove coupling (6).

2. Drain plug
Remove the cover and remove 2 drain plugs (7)
to drain oil in the pump drive case.

3. Pump, drive case mounting bolts

Remove 30 mounting bolts (8).

4. Pilot
Using an forcing screw, remove pilot (9).

5. Drive case, turbine assembly

1) Remove holder (10).

30-86 D155C-1
Disassembly and assembly Torque converter

2) Using eyebolt [1], remove drive case and

turbine assembly (11).

3) Minute disassembly of drive case, turbine

assembly
i) Take out drive gear (12).

ii) Using forcing screw [2], remove turbine

(13) from the drive case.
iii) Remove bearing (14).

6. Stator
Remove stator (15).

7. Race
Remove snap ring (16), then remove race (17).

D155C-1 30-87
Disassembly and assembly Torque converter

8. Pump assembly
1) Remove pump assembly (18).

2) Minute disassembly of pump assembly

i) Remove mounting bolt (19) and take out
gear (20).
ii) Remove outer race (21).

9. Turbine shaft and stator shaft assembly

1) Using eyebolt [3], take out turbine shaft and
stator shaft assembly (22).

2) Fine disassembly of turbine shaft, stator

shaft assembly
i) Using a forcing screw, remove cover
(23).
ii) Remove oil seal (24) and dust seal (25).

30-88 D155C-1
Disassembly and assembly Torque converter

iii) Set the turbine shaft and stator shaft

assembly on the press and remove tur-
bine shaft assembly (26).

iv) Remove seal ring (28) and snap ring

(29) from turbine shaft (27), and remove
spacer (30), bearing (31), seat (32), and
O-ring (33).

v) Remove bearing (35) and seal ring (36)

from stator shaft (34).

10. Scavenging pump drive gear

1) Remove snap ring (37), then remove drive
gear (38).
a Strike the shaft out into the case.

D155C-1 30-89
Disassembly and assembly Torque converter

2) Remove bearing (39).

30-90 D155C-1
Disassembly and assembly Torque converter

Assembly
a Apply G2-Ll on the O-ring and oil seal.

1. Case
Set case (40) on tool B.

2. Scavenging drive gear

1) Using push tool [4], press-fit bearing (39).

2) Temporarily install scavenging pump as-

sembly (5) and secure bearing (39).
3) Install drive gear (38) by adjusting it to the
spline of the scavenging pump.

4) Remove the scavenging pump assembly

and install snap ring (37) to fix the drive gear
on the bearing.

D155C-1 30-91
Disassembly and assembly Torque converter

3. Turbine shaft, stator shaft assembly

1) Fine assembly of turbine shaft, stator shaft
assembly.
i) Mount seal ring (36) on stator shaft (34),
and use push tool [5] to press-fit bearing
(35).

ii) Mount O-ring (33) and seat (32) on the

turbine shaft, and use push tool [6] to
press-fit bearing (31).

iii) Mount spacer (30) and fix it with snap

ring (29), then install seal ring (28).

iv) Set the stator shaft assembly on the

press and use push tool [7] to press-fit
turbine shaft assembly (26).

30-92 D155C-1
Disassembly and assembly Torque converter

v) Mount dust seal (25) and use a push

tool to press-fit oil seal (24).
3 Oil seal press-fitting surface:
Liquid gasket (LG-5)
vi) Mount cover (23).

2) Using eyebolt [3], install turbine shaft and

stator shaft assembly (22).
2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

4. Pump assembly
1) Fine assembly of pump assembly
i) Using a push tool, press-fit outer race
(21).
ii) Mount gear (20) and tighten it with
mounting bolt (19).
2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
66.15 ± 7.35 Nm {6.75 ± 0.75 kgm}

iii) Mount pump assembly (18).

D155C-1 30-93
Disassembly and assembly Torque converter

5. Race
Mount race (17) and fix it with snap ring (16).

6. Stator
Mount stator (15).
2 Mounting bolt: Liquid adhesive (LT-2)
3 Mounting bolt:
66.15 ± 7.35 Nm {6.75 ± 0.75 kgm}

7. Drive case, turbine assembly

1) Fine assembly of drive case, turbine assem-
bly
i) Using a push tool, press-fit bearing (14).
ii) Using push tool [8], press-fit turbine (13)
into the drive case.

iii) Install drive gear (12).

2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

2) Use eyebolt [1] to install drive case and tur-

bine assembly (11).

30-94 D155C-1
Disassembly and assembly Torque converter

3) Install holder (10) and fix it with the lock

plate.
3 Mounting bolt:
95.55 ± 2.45 Nm {9.75 ± 0.25 kgm}

8. Pilot
Install pilot (9) and fix it with the lock plate.
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

9. Pump, drive case mounting bolt

Tighten 30 mounting bolts (8).
2 Mounting bolt: Liquid adhesive (LT-2)
3 Mounting bolt:
53.9 ± 4.9 Nm {5.5 ± 0.5 kgm}

10. Drain plug

Tighten 2 drain plugs (7) and install the cover.
3 Drain plug:
17.15 ± 2.45 Nm {1.75 ± 0.25 kgm}

11. Torque converter assembly

1) Install coupling (6).
2) Install scavenging pump assembly (5).
3) Install strainer (4).
4) Install relief valve assembly (3).
5) Install regulator valve assembly (2).
6) Remove torque converter assembly (1) from
tool B.

D155C-1 30-95
Disassembly and assembly Torque converter relief valve

Removal and installation of

torque converter relief valve
assembly
Removal

1. Using transmission jack [1], remove torque con-

verter underguard (1).
4 Underguard: 150 kg

k Support center of underguard stably on

transmission jack and remove guard care-
fully to prevent accidental falling.

2. Disconnect relief valve inlet tube (2).

3. Disconnect relief valve outlet tube (3).

4. Remove torque converter relief valve assembly

(4).

Installation

1. With O-ring in place, install torque converter

relief valve assembly (4).

2. With O-ring in place, connect relief valve outlet

tube (3).

3. With O-ring in place, connect relief valve inlet

tube (2).

4. Using transmission jack [1], install torque con-

verter underguard (1).
k Support center of underguard stably on
transmission jack and install guard carefully
to prevent accidental falling.

30-96 D155C-1
Disassembly and assembly Torque converter regulating valve

Removal and installation of

torque converter regulating
valve assembly
Removal

1. Using transmission jack [1], remove torque con-

verter underguard (1).
4 Underguard: 150 kg

k Support center of underguard stably on

transmission jack and remove guard care-
fully to prevent accidental falling.

2. Disconnect regulating valve outlet tube (2).

3. Remove torque converter regulating valve

assembly (3).

Installation

1. With O-ring in place, install torque converter reg-

ulating valve assembly (3).

2. With O-ring in place, connect regulating valve

outlet tube (2).

3. Using transmission jack [1], install torque con-

verter undeguard (1).
k Support center of underfuard stably on
transmission jack and install guard carefully
to prevent accidental falling.

D155C-1 30-97
 Torque converter relief valve
Disassembly and assembly Torque converter regulator valve

Disassembly and assembly of

torque converter relief valve
assembly
Disassembly
1. Remove the plug, then remove spacer (1), shim
(2), spring (3), and spool (4).

Assembly
1. Assemble spool (4), spring (3), shim (2), and
spacer (1) to the valve body, and install the O-
ring to tighten the plug.

Disassembly and assembly of

torque converter regulator
valve
Disassembly
1. Remove the plug, then remove spring (1) and
spool (2).

Assembly
1. Assemble spool (2) and spring (1) to the valve
body and install the O-ring to tighten the plug.

30-98 D155C-1
Disassembly and assembly Transmission control valve

Removal and installation of

transmission control valve
assembly
Removal

1. Floor plates
Remove floor plates (1), (2) and (3).
a Before removing floor plate (3), disconnect
decelerator rod.

2. Switch
Remove switch (4).

3. Transmission control rods

Disconnect transmission control rods (5) and
(6).

4. Wiring
Remove intermediate clamp of cable (7).

5. Steering rod
Disconnect steering rod (8).

6. Piping
Disconnect transmission control valve inlet and
outlet tubes (9) and (10).

7. Cover
Remove cover (11).

8. Cover assembly
1) Remove sleeve (12).
2) Loosen inspection plug (13).
a This is to facilitate removal of inspection
plug in the course of reassembly of
transmission control valve.
3) Remove cover assembly (14).

D155C-1 30-99
Disassembly and assembly Transmission control valve

9. Transmission control valve assembly

Remove the transmission control valve assem-
bly (15).
a Unscrew four bolts (marked*) to remove con-
trol valve assembly.
4 Transmission control valve assembly:
25 kg

Installation

1. Transmission control valve assembly

With O-ring in place, install transmission control
valve assembly (15).
a Be careful not to damage O-ring when posi-
tioning transmission control valve.
3 Mounting bolt:
41.2 ± 11.8 Nm {4.2 ± 1.2 kgm}

2. Cover assembly
1) Remove inspection plug (3).
2) With gasket in place, position spool yoke
properly to cover lever, and install cover as-
sembly (14).
a After installing cover assembly, check
inspection plug hole to see that lever is
fitting into yoke.
3) With O-ring in place, install and tighten in-
spection plug (13).
4) With O-ring in place, install sleeve (12).

3. Cover
With gasket in place, install cover (11).

4. Piping
With O-rings in place, connect transmission con-
trol valve inlet and outlet tubes (10) and (9).

30-100 D155C-1
Disassembly and assembly Transmission control valve

5. Steering rod
Connect steering rod (8).
a Be sure to bend cotter pin securely.

6. Piping
Install intermediate clamp of cable (7).

7. Transmission control rods

Connect transmission control rods (6) and (5).
a Be sure to bend cotter pins securely.
a After connecting rods, check for proper ad-
justment of transmission control lever. If nec-
essary, adjust length of rods.

8. Switch
Install switch (4) and connect lead.

9. Floor plates
Install floor plates (3), (2) and (1).
a After installing floor plate (3), connect decel-
erator rod and bend cotter pin securely.

D155C-1 30-101
Disassembly and assembly Transmission control valve

Disassembly and assembly of transmission control valve

assembly
Disassembly

30-102 D155C-1
Disassembly and assembly Transmission control valve

1. Remove the through bolt and disassemble mod-

ulating, reducing, and quick return valve assem-
blies (1) and speed and directional valve
assemblies (2).

2. Disassembly of modulating, reducing, quick

return valves
1) Disassembly of modulating valve
i) Remove cover (3), then remove springs
(4) and (5), seat (6), valve (7), washer
(8), and shim (9).
ii) Remove valve (10) together with spool
(11), then disassemble them.
iii) Remove valve (12) and spring (13) from
spool (11).
iv) Remove snap ring (14) from valve (10),
then remove stopper (15).
2) Disassembly of reducing valve
i) Remove cover (16).
ii) Remove spool (17) and spring (18).
iii) Remove piston (19) and spring (20)
from spool (17).
iv) Remove snap ring (21), then remove
retainer (22).
3) Disassembly of quick return valve
i) Remove cover (16)
ii) Remove sleeve (23) and valve (24).
iii) Remove snap ring (25), then remove
stopper (26).

3. Disassembly of speed and directional valve

assemblies
1) Disassembly of speed valve assembly
Pull out spool (27), then remove plug (28).
2) Disassembly of directional valve
Remove detent (29), then pull out spool
(30).

D155C-1 30-103
Disassembly and assembly Transmission control valve

Assembly

30-104 D155C-1
Disassembly and assembly Transmission control valve

1. Assembly of speed and directional valve

assemblies
1) Assembly of directional valve
i) Adjust dimension a from the surface of
the nut to the center of the yoke, then
tighten the lock nut.

3 Lock nut:
• Dimension a: 29 mm

66.15 ± 7.35Nm {6.75 ± 0.75 kgm}

ii) Assemble spool (30) to the body.
iii) Assemble detent (29) from the top and
bottom of the body.
2) Assembly of speed valve
i) Adjust dimension a from the surface of
the nut to the center of the yoke, then

3 Lock nut:
tighten the lock nut.

66.15 ± 7.35Nm {6.75 ± 0.75 kgm}

ii) Install plug (28) on spool (27) and

2 Plug: Liquid adhesive (LT-2)

assemble the spool to the body.

2. Assembly of modulating, quick return, reduc-

ing valve assemblies
1) Assembly of quick return valve
i) Assemble stopper (26) and fix it with
snap ring (25).
ii) Assemble valve (24) and sleeve (23) to
the body.
iii) Install cover (16).
2) Assembly of reducing valve
i) Assemble retainer (22) to the body and
fix it with snap ring (21).
ii) Assemble piston (19) an spring (20) to
spool (17).
iii) Assemble spring (18) and spool (17) to
the body.
iv) Install cover (16).
3) Assembly of modulating valve
i) Insert stopper (15) to valve (10) and fix
it with snap ring (14).
a Be careful not to insert the stopper
inversely.
a Check that the snap ring is surely
engaged in the ring groove.
ii) Assemble valve (12) and spring (13) to
spool (11).
iii) Assemble spool (11) to valve (10) and
assemble them to the body together.
iv) Assemble shim (9), washer (8), valve
(7), seat (6), and springs (4) and (5),
then install cover (3).

3. Install the O-ring on the contacting face, set

speed and directional valve assemblies (2), and
modulating, reducing, and quick return valve
assemblies (1), then tighten the through bolt.

D155C-1 30-105
Disassembly and assembly Transmission

Removal and installation of

transmission assembly
Removal
1. Drain the steering and transmission oil.
6 Steering and transmission case oil:
149 l

2. Remove transmission under-guard (1).

a Use transmission jack [1] to remove the un-
der-guard.
k When removing the under-guard, it inter-
feres with the diagonal brace, so push the
under-guard out toward the front side of the
body while gradually lowering the transmis-
sion jack.
4 Under-guard: 150 kg

3. See "Removal of cabin floor frame assembly" for

removal of the cabin floor frame assembly.

4. Disconnect tube (2).

5. Disconnect tube (3).

a Disconnect the tube together with the brack-
et.

6. Disconnect hose (4). [*1]

7. Disconnect rods (5) and (6). [*2]

8. Disconnect wiring connector (7).

9. Disconnect rod (8).

10. Disconnect transmission control cable (9).

11. Disconnect support (10).

12. Disconnect tube (11).

30-106 D155C-1
Disassembly and assembly Transmission

13. Disconnect hose (12).

14. Disconnect tube (13).

15. Disconnect tube (14).

16. Disconnect breather hose (15).

17. Remove universal joint assembly (18).

18. Disconnect hose (19).

19. Disconnect tube (20).

20. Disconnect tube (21).

21. Raise transmission assembly (22) to remove it.

a Temporarily raise the transmission assembly
leaving 2 or 3 mounting bolts installed, then
remove the remaining mounting bolts to re-
move the transmission assembly.
a When removing the transmission assembly,
gradually raise it to prevent interference with
other parts.
4 Transmission assembly: 950 kg

Installation
• Carry out installation in the reverse order to re-
moval.

[*1] [*2]
a Surely twist the cotter pin.

• Refilling with oil

a Tighten the drain plugs of the steering and trans-
mission case, refill with the engine oil to the
specified level, and run the engine to circulate
the oil through the system. Then check the oil
level again.
5 Steering and transmission case: 149 l

D155C-1 30-107
Disassembly and assembly TORQFLOW transmission assembly

Disassembly and assembly of

TORQFLOW transmission
assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

791-501-5000 Unit repair stand 1

1 790-901-3210 Bracket 1
C
790-901-3220 Plate 1
2 799-301-1600 Oil leak tester kit 1

Disassembly
a Store removed discs and plates on a flat place so
that they do not bend.

1. Set transmission assembly (1) on tool C1.

2. Sleeve, cover
1) Remove cover (2).
2) Remove sleeve (3).
3) Remove cover (4).

3. Control valve assembly

Remove mounting bolt (5), then remove valve
assembly (6) together with seat (7).

4. Bearing cage assembly

1) Using an extraction bolt [1], remove bearing
cage assembly (8).
2) Remove snap ring (9), then remove bearing
(10).

30-108 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

5. Transmission case
1) Remove mounting bolts (11) and (12).
2) Remove transmission case (13).

6. Coupling
1) Remove holder (14).
2) Using puller [2], remove coupling (15).

7. Bearing cage assembly

1) Remove the mounting bolt, then use eyebolt
[3] to remove bearing cage assembly (16).

2) Fine disassembly of bearing cage assembly

i) Remove snap ring (17).
ii) Using puller [4], remove bearing cage
(18).

D155C-1 30-109
Disassembly and assembly TORQFLOW transmission assembly

iii) Remove bearing (19).

iv) Remove oil seal (20), snap ring (21),
and spacer (22), then remove bearing
(23).

8. Shaft assembly
1) Remove spacer (24).
2) Using eyebolt [3], remove shaft assembly
(25).

3) Fine assembly of shaft assembly

i) Remove No. 1 sun gear (26).
ii) Remove snap ring (27).
iii) Remove inner race (28).

9. No. 1, 2, 3 carrier assembly

1) Using eyebolt [3], remove carrier assembly
(29).

30-110 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

2) Fine assembly of carrier assembly

i) Remove shaft (30).
a Using a copper hammer or other
tool, strike out the shaft.
a Be careful not to lose the ball when
storing.
ii) Remove gear (31), thrust washer (32),
and bearing (33).

iii) Remove shaft (34).

a Using a copper hammer or other
tool, strike out the shaft.
a Be careful not to lose the ball when
storing.
iv) Remove gear (35), thrust washer (36),
and bearing (37).

v) Remove snap ring (38), then remove

plate (39).
vi) Remove bearing (40).

10. Tie bolts

Remove tie bolts (41).
a Mark 2 short bolts of 14 tie bolts.

11. No. 1 housing, piston assembly

1) Using eyebolt [4], remove housing (42) to-
gether with piston (43).
a When removing the housing, hold the
piston with your hand so that it does not
drop.
2) Remove spring (44).

D155C-1 30-111
Disassembly and assembly TORQFLOW transmission assembly

12. No. 1 disc, plate, spring

Remove spring (45), disc (46), and plate (47) in
this order.

13. No. 1 ring gear

Remove ring gear (48).

14. Plate
Using an eyebolt, remove plate (49).

15. No. 2 disc, plate, spring

Remove spring (50), then remove spring (51),
disc (52), and plate (53) in this order.

16. No. 2 ring gear

Remove ring gear (54).

17. Guide pin

Remove guide pin (55).

30-112 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

18. No. 2 housing, piston assembly

Using eyebolt [4], remove housing (56) together
with piston (57).

19. No. 3 disc, plate, spring

Remove spring (58), then remove spring (59),
disc (60), and plate (61) in this order.

20. No. 3 ring gear

Remove snap ring (62), then remove ring gear
(63).

21. No. 3, 4 housing, piston assembly

Using eyebolt [4], remove housing (64) together
with piston (65).
a When removing the housing, hold No. 4 pis-
ton with your hand so that it does not drop.

D155C-1 30-113
Disassembly and assembly TORQFLOW transmission assembly

22. No. 4 disc, plate, spring

Remove spring (66), then remove spring (67),
disc (68), and plate (69) in this order.

23. No. 4 ring gear

Remove ring gear (70).

24. Plate
Using an eyebolt, remove plate (71).

25. Guide pin

Remove guide pin (72).

26. No. 3, 4 sun gear

Remove the snap ring, then remove sun gear
(73).

27. No. 5 housing, clutch assembly

1) Remove the mounting bolt, then use eyebolt
[4] to remove housing and clutch assembly
(74).

30-114 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

2) Fine assembly of housing assembly

i) Remove lock plate (75), then remove
pin (76).

ii) Using wrench [5], remove nut (77).

iii) Using puller [6], remove bearing (78)
together with gear (79).

iv) Use eyebolt [4], remove housing assem-

bly (80).
a Using a copper hammer or other
tool, strike the end of the shaft to re-
move the housing assembly.
v) Remove bearing (81).

vi) Using a push tool, remove outer race

(82) and collar (83).

D155C-1 30-115
Disassembly and assembly TORQFLOW transmission assembly

3) Fine assembly of No. 4 carrier assembly

i) Remove drum mounting bolts (84) leav-
ing 2 of them installed.

ii) Remove mounting bolts (85), then use

puller [6] to remove carrier assembly
(86).
a The carrier assembly is positioned
with 6 dowel pins.

iii) Remove shaft (87).

a Using a copper hammer or other
tool, strike the shaft to remove it.
a Be careful not to lose the ball when
storing.
iv) Remove gear (88), thrust washer (89),
and bearing (90).

4) Fine assembly of clutch assembly

i) Remove bolts left installed in i) of 3).
ii) Remove drum (91).

30-116 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

iii) Remove disc (92), spring (93), and plate

(94) in this order.

iv) Remove snap ring (95).

v) Using eyebolt [3] and puller [6], remove
ring gear (96) together with the bearing.

vi) Remove bearing (97).

vii) Set pusher [7], then use the press to

push the spring to remove snap ring
(98).
viii) Remove snap ring (99).
ix) Remove piston (100).

D155C-1 30-117
Disassembly and assembly TORQFLOW transmission assembly

x) Remove nut (101), then remove shaft

(103) from housing (102).

28. Bevel pinion assembly

1) Remove the mounting bolt, then remove
bevel pinion assembly (104).
2) Remove shim (105).
a Measure the distance between the end of
the case and end of the pinion gear before-
hand.
a Check the number and thickness of shims.

3) Fine assembly of bevel pinion gear.

i) Remove holder (106).

ii) Set the bevel pinion gear assembly on

base (8).
iii) Using push tool [9], push the pinion
shaft to remove inner race (107), spacer
(108), gear (109), spacer (110), and
bearing cage assembly (111).

30-118 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

iv) Remove cover (112) and shim (113).

v) Remove bearing (114).

29. Bearing
1) Remove bearing (115).
2) Remove outer race (116).

D155C-1 30-119
Disassembly and assembly TORQFLOW transmission assembly

Assembly
a Apply grease (G2-LI) to seal rings before instal-
lation.
a Install seal ring (a) for the piston with the pres-
sure receiving side (side "b") directed to housing
(c) as shown in the figure.

1. Transfer case
Set transfer case (117) on tool C1.

2. Bearing
1) Using a push tool, press-fit outer race (116).
2) Using a push tool, press-fit bearing (115).

3. Bevel pinion assembly

1) Set the bearing cage (118) on the press,
then use push tool [10] to press-fit bearing
(114).

30-120 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

i) Set cover (112) and measure distance a

between the bolt hole of the cover and
end face of bearing cage (118) with a
depth gauge. Measure thickness b of
the cover and obtain the value of a – b.
Insert shim (113) to adjust the clearance
between the cover and bearing cage to
the following value.
a Standard shim thickness: 0.5 mm
a Standard clearance between cover
and bearing cage: 0.05 – 0.15 mm

ii) Assemble shim (113), then install cover

(112) and fix it with temporary fixing bolt
[11].
a Sling bolt: M12 x P1.75, L = 25 mm

iii) Set the pinion shaft on the press, then

use push tool [12] to press-fit bearing
cage assembly (111).
iv) Set spacer (110), gear (109), spacer
(108), and inner race (107), then use
push tool [13] to press-fit the pinion
shaft.
v) Set holder (106) and measure dimen-
sion b between the bolt hole of the
holder and end face of the bevel pinion
with a depth gauge. Measure thickness
c of the holder and obtain the value of b
– c. Insert a shim to adjust the clear-
ance between the holder and bevel pin-
ion to the following value.
a Standard shim thickness: 1.1 mm
a Standard clearance between holder
and bevel pinion: 0.05 – 0.15 mm

3 Mounting bolt:
vi) Insert the shim and install holder (106).

157 – 196 Nm {16 – 20 kgm}

D155C-1 30-121
Disassembly and assembly TORQFLOW transmission assembly

2) Insert shim (105), remove temporary bolt

(11), and install the bevel pinion assembly.
a Standard shim thickness: 1.6 mm
a Tighten the mounting bolts to the speci-
fied torque without applying adhesive

3 Mounting bolt:
(LT-2)

98 – 122.5 Nm {10 – 12.5 kgm}

a Tighten the mounting bolts lightly at first.
Referring to Assembly of bevel gear
shaft assembly, adjust the backlash and
tooth contact. Then, tighten the mount-

2 Mounting bolt: Adhesive (LT-2)

ing bolts to the following torque.

3 Mounting bolt:
98 – 122.5 Nm {10 – 12.5 kgm}
a When tightening the mounting bolts per-
manently after adjusting the backlash
and tooth contact, check that the shim
has not fallen and take care not to drop
them.
a The mounting bolts for the spare trans-
mission assembly are not coated with
adhesive (LT-2). Referring to Assembly
of bevel gear shaft assembly, adjust the
backlash and tooth contact. Then, tight-
en the mounting bolts to the following

2 Mounting bolt: Adhesive (LT-2)

torque.

3 Mounting bolt:
98 – 122.5 Nm {10 – 12.5 kgm}
a Even if the shim on the bevel pinion side
does not need to be adjusted, apply ad-
hesive (LT-2) to the mounting bolts and
tighten them to the tightening torque.

30-122 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

4. No. 5 housing, clutch assembly

1) Fine assembly of clutch assembly
i) Assemble shaft (103) to housing (102)
and tighten nut (101).
3 Nut:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

ii) Install the seal ring, then install piston

(100).
iii) Install spring (99) and set pusher (7),
then use a press to push the spring, and
fix it with snap ring (98).

iv) Use a push tool to press-fit bearing (97).

D155C-1 30-123
Disassembly and assembly TORQFLOW transmission assembly

v) Use push tool [14] to press-fit ring gear

(96) together with the bearing.
vi) Install snap ring (95).

vii) Install plate (94), spring (93), and disc

(92) in this order.

viii) Install drum (91), then temporarily

tighten 2 or 3 mounting bolts.
ix) Tighten mounting bolts (84).
2 Mounting bolts:
Liquid adhesive (LT-2)
3 Mounting bolts:
107.8 ± 14.7 Nm {11.0 ± 1.5 kgm}

2) Fine assembly of No. 4 carrier assembly

i) Assemble bearing (90) to gear (88) and
install thrust washers (98) on both
sides, then set the gear in the carrier.
ii) Mount the ball, then install the shaft
(87).
a Be sure to install the ball on the
shaft.

30-124 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

iii) Mount the seal ring on the shaft.

iv) Mount carrier assembly (86) and tighten
it with mounting bolts (85).
2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
171.5 ± 24.5 Nm {17.5 ± 2.5 kgm}

3) Fine assembly of housing assembly

i) Using a push tool, press-fit collar (83)
and outer race (82).

ii) Install the seal ring on the shaft.

iii) Install bearing (81) on the housing, then
use an eyebolt to install housing assem-
bly (80).
a Be careful not to give damages to
the seal ring when mounting.
a Use a push tool to press-fit bearing
(81).

iv) Install gear (79), then use push tool [15]

to press-fit bearing (78).
v) Using wrench [5], tighten nut (77).

D155C-1 30-125
Disassembly and assembly TORQFLOW transmission assembly

vi) Install pin (76), then install lock plate

(75).

4) Use eyebolt [4] to install housing and clutch

assembly (74) and tighten them with bolts.

5. No. 3, 4 sun gear

Install sun gear (73) and fix it with the snap ring.

6. Guide pin
Install guide pin (72).

7. Plate
Use an eyebolt to install plate (71).
a Using a plastic hammer or other tool, strike in
the dowel pin until there is no more space left
in the contacting face.

8. No. 4 ring gear

Install ring gear (70).

30-126 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

9. No. 4 disc, plate, spring

Install plate (69), disc (68), and spring (67) in
this order, then install spring (66).
a Adjust the notches on the inner teeth of the
disc (4 parts on the circumference).
a Free length of spring: 59 mm

10. No. 3, 4 housing, piston assembly

1) Assemble the piston seal ring.
2) Using eyebolt [4], install piston (65) together
with housing (64).
a Hold No. 4 piston with your hand so it
does not drop at installation.
a Check that the spring is caught surely in
the hole on the piston.
a Using a plastic hammer or other tool,
strike in the dowel pin until there is no
more space left in the contacting face.
3) Install the sleeve in the through hole on the
tie bolt.

11. No. 3 ring gear

Install ring gear (63) to fix the snap ring (62).

12. No. 3 disc, plate, spring

Install plate (61), disc (60), and spring (59) in
this order, then install spring (58).
a Adjust the notches on the inner teeth of the
disc (4 parts on the circumference).
a Free length of spring: 59 mm

D155C-1 30-127
Disassembly and assembly TORQFLOW transmission assembly

13. No. 2 housing, piston assembly

1) Install the seal ring on the piston.
2) Use eyebolt [4] to install piston (57) together
with housing (56).
a Check that the spring is caught surely in
the hole on the piston.
a Using a plastic hammer or other tool,
strike in the dowel pin until there is no
more space left in the contacting face.

14. Guide pin

Install guide pin (55).

15. No. 2 ring gear

Install ring gear (54).
a Install the ring gear with inside notches fac-
ing up.

16. No. 2 disc, plate, spring

Install plate (53), disc (52), and spring (51) in
this order, then install spring (50).
a Adjust notches inside the disc (4 parts on the
circumference).
a Free length of spring: 66 mm

17. Plate
Using an eyebolt, install plate (49).
a Using a plastic hammer or other tool, strike in
the dowel pin until there is no more space in
the contacting face.

18. No. 1 ring gear

Install ring gear (48).
a Install the ring gear with inside notches fac-
ing up.

30-128 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

19. No. 1 disc, plate, spring

Install plate (47), disc (46), and spring (45) in
this order.
a Adjust notches inside the disc (4 parts on the
circumference)

20. No. 1 housing, piston assembly

1) Install spring (44).
a Free length of spring: 66 mm
2) Install the seal ring on the piston.
3) Using eyebolt [4], mount piston (43) togeth-
er with housing (42).
a Check that the spring is caught in the
hole on the piston.
a Using a plastic hammer or other tool,
strike in the dowel pin until there is no
more space in the contacting face.

21. Tie bolt

Tighten tie bolts (41)
3 Tie bolt:
166.6 ± 9.8 Nm {17.0 ± 1.0 kgm}
a Install 2 short bolts of 14 tie bolts on parts
marked at disassembly.

22. No. 1, 2, 3, carrier assembly

1) Fine assembly of carrier assembly
i) Using a push tool, press-fit bearing (40).
ii) Install plate (39) to fix snap ring (38).

D155C-1 30-129
Disassembly and assembly TORQFLOW transmission assembly

iii) Assemble bearing (37) to gear (35),

install thrust washers (36) on both
sides, and set the bearing in the carrier.
iv) Install the ball, then install shaft (34).
a Be sure to install the ball on the
shaft.

v) Assemble bearing (33) to gear (31),

install thrust washers (32) on both
sides, and set the bearing in the carrier.
vi) Install the ball, then install shaft (30).
a Be sure to install the ball on the
shaft.

2) Using eyebolt [3], install carrier assembly

(29).

23. Shaft assembly

1) Fine assembly of shaft assembly
i) Using a ring, press-fit the shaft to inner
race (28).
ii) Fix the shaft with snap ring (27).
iii) Install No. 1 sun gear (26).

30-130 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

2) Using eyebolt [3], install shaft assembly

(25).
3) Install spacer (24).
a Install the spacer with notches facing up.

24. Bearing cage assembly

1) Fine assembly of bearing cage assembly
i) Using a push tool, press-fit bearing (23),
then mount spacer (22), snap ring (21),
and oil seal (20).
ii) Using a push tool, press-fit bearing (19).

iii) Install the seal ring on the cage, then

install bearing cage (18).
iv) Fix the bearing cage with snap ring (17).

v) Using eyebolt [3], install bearing cage

assembly (16).
2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

D155C-1 30-131
Disassembly and assembly TORQFLOW transmission assembly

25. Coupling
1) Install coupling (15).
2) Install the O-ring, then install bolt (14).
3 Mounting bolt:
110.5 ± 12.25 Nm {11.25 ± 1.25 kgm)
(Applicable serial numbers:
50001 to 50900)
384.46 ± 41.65 Nm {39.25 ± 4.25 kgm}
(Applicable serial numbers:
50901 and up)

26. Measurement of piston stroke

Using tool C2, check stroke of each piston.
a Air pressure:
0.49 to 0.59 MPa {5 to 6 kg/cm2}
a Standard stroke: No. 1 clutch: 6 mm
No. 2 clutch: 4mm
No. 3 clutch: 4mm
No. 4 clutch: 4mm

27. Transmission case

1) Install the gasket, then install transmission
case (13).
2) Tighten mounting bolts (12) and (11).

28. Bearing cage assembly

1) Using push tool [16], press-fit bearing (10)
to fix snap ring (9).

30-132 D155C-1
Disassembly and assembly TORQFLOW transmission assembly

2) Using a push tool, press-fit bearing cage as-

sembly (8).

29. Control valve assembly

Install the O-ring, then install seat (7) together
with valve assembly (6) and tighten them with
mounting bolts (5).
3 Mounting bolt:
49 ± 4.9 Nm {5.0 ± 0.5 kgm}

30. Cover, sleeve

1) Install the gasket, then install cover (4).
2 Mounting bolt:
Liquid gasket (LG-1)
a Remove plug (118) and adjust the yoke
of the spool to the lever.

2) Install the O-ring, then install sleeve (3).

3) Install the gasket, then install cover (2).

D155C-1 30-133
Disassembly and assembly Transmission lubrication valve

Removal and installation of

transmission lubrication valve
assembly
Removal

1. Using transmission jack [1] remove torque con-

verter underguard (1).
k Support center of underguard stably on
transmission jack and remove underguard
carefully to prevent accidental falling.
4 Underguard: 150 kg

2. Disconnect lubrication valve outlet tube (2) and

inlet tube (3).

3. Remove lubrication valve assembly (4).

Installation

1. With gasket in place, install transmission lubri-

cation valve assembly (4).

2. With O-ring in place connect lubrication valve

inlet tube (3) and outlet tube (2).

3. Using transmission jack [1], install torque con-

verter underguard (1).
k Support center of underguard stably on
transmission jack and install underguard
carefully to prevent accidental falling.

30-134 D155C-1
Disassembly and assembly Transmission lubrication valve

Disassembly and assembly of

transmission lubrication valve
assembly
Disassembly
1. Remove cover (1), then remove guide (2),
spring (3), and valve (4).

Assembly
1. Assemble valve (4), spring (3), and guide (2) to
the valve body.

2. Install the O-ring, then install cover (1).

D155C-1 30-135
Disassembly and assembly Steering control valve

Removal and installation of

steering control valve assembly
Removal

1. Remove floor frame assembly (1) using proce-

dure started in Removal of floor frame assembly.

2. Remove steering control rods (2) and (3).

3. Remove tube (4) connecting valve to brake

valve.

4. Remove intermediate bracket and disconnect

steering valve outlet tube (5) and inlet tube (6).

5. Remove main relief valve (7).

6. Remove steering control valve assembly (8).

30-136 D155C-1
Disassembly and assembly Steering control valve

Installation

1. With O-ring in place, install steering control

valve assembly (8).

2. With O-ring in place, install main relief valve (7).

3. With O-ring in place, connect steering valve inlet

tube (6) and outlet tube (5). Attach intermediate
bracket.

4. With O-ring in place, install tube (4) to connect

steering valve to brake valve.

5. Install steering control rods (3) and (2).

a Be sure to bend cotter pins securely.

6. Install floor frame assembly (1) using the proce-

dure started in Removal of floor frame assembly.

D155C-1 30-137
Disassembly and assembly Steering control valve

Disassembly and assembly of

steering control valve assembly
Disassembly

• Disassembly of main relief valve assembly

1. Piston
Pry snap ring (1) out. Turn in jack bolt [1] (8 mm,
P = 1.25) to stopper (2) and pull jack bolt with
pliers to remove the stopper. Take out piston (3).

2. Relief valve
Pry snap ring (4) out. Turn in jack bolt (8 mm, P
= 1.25) to stopper (5) and pull jack bolt with pli-
ers to remove the stopper. Then, take out spring
(6), valve (7) and piston (8).

• Disassembly of steering control valve assembly

1. Cover
Remove cover (1).

2. R.H. lever shaft

1) Remove bolts (3) fastening lever (2).
2) Cut lock wire and remove lock bolt (5) from
bushing (4). Pull out R.H. lever shaft (6).
a When pulling lever shaft, remove key (7)
in housing.

30-138 D155C-1
Disassembly and assembly Steering control valve

3. L.H. lever shaft

Pull out L.H. lever shaft (8) using same proce-
dure mentioned for R.H. lever shaft.

4. Modulating valve
Remove plate (9) and take out spool (10), valve
(11), piston (12) and spring (13).

5. Right and left steering clutch spools

Remove L.H. spool (14), spring (15), R.H. spool
(16) and spring (17).

D155C-1 30-139
Disassembly and assembly Steering control valve

Assembly

a Coat sliding surfaces of parts with engine oil

before assembly.

• Assembly of main relief valve assembly

1. Main relief valve

1) Insert piston (8) into valve (7).
2) Install piston and valve assembly and spring
(6), in that order, in housing. Install stopper
(5) and lock with snap ring (4).

2. Piston
Install piston (3) in housing, fit stopper (2), and
lock with snap ring (1).
a Install piston so that the larger oil hole
faces pipe mounting side.

• Assembly of steering control valve assembly

1. Right and left steering clutch spools

Fit springs (17) and (15) to R.H. spool (16) and
L.H.spool (1), respectively. Install spools in
housing.

2. Modulating valve
1) Insert piston (12) into valve (11). Install
spring (13), valve (11) and spool (10), in that
order. in housing.
2) Fit plate (9) to housing.
a Install spool so that longer notch is posi-
tioned on right side as viewed from
housing.

30-140 D155C-1
Disassembly and assembly Steering control valve

3. Left lever shaft

1) Insert lever shaft (8) into housing, install
bushing on shaft, and tighten lock bolt.
a Lock lock bolt securely with a lock wire.
2) Install lever.

4. Right lever shaft

1) Insert lever shaft (6) into housing, install
bushing (4) on shaft, and tighten lock bolt
(5).
a Lock lock bolt securely with a lock wire.
2) Install lever (2).
a Install right and left levers so that center
of lever bolt hole is positioned 31 mm
apart from bushing end face.

5. Cover
With gasket in place, fit cover (1).

D155C-1 30-141
Disassembly and assembly Brake safety valve

Removal and installation of

brake safety valve assembly
Removal
1. Remove machine rear cover.

2. Disconnect hoses (1) and (2) connecting brake

booster to brake valve.

3. Remove tube (3) connecting steering valve to

brake valve.

4. Remove brake safety valve (4).

Installation

1. With O-ring in place, install brake safety valve

assembly (4).

2. With O-ring in place, install tube (3) to connect

steering valve to brake valve.

3. With O-rings in place, connect brake booster to

brake valve with hoses (2) and (1).

4. Install machine rear cover.

30-142 D155C-1
Disassembly and assembly Brake safety valve

Disassembly and assembly of

brake safety valve assembly
Disassembly

1. Safety valve
1) Remove capnut (1) and take out spring (2)
and plunger (3).
2) Loosen lock nut (4) and remove seat (5).

2. Piston
Pry snap ring (6) out, remove stopper (7), and
take out piston (8).

Assembly

1. Piston
Insert piston (8) into valve body. Install stopper
(7) and lock with snap spring (6).
a Coat piston with engine oil before assembly.

2. Safety valve
1) Install seat (5) in valve body and tighten
locknut (4).
2) Install plunger (3) and spring (2). Tighten
capnut (1).

a To set the standard of 1.67 MPa{17 kg/cm2},

adjust reference size a (from valve body end
face to plunger seat assembly end face) to
27 mm.

D155C-1 30-143
Disassembly and assembly Steering pump

Removal and installation of

steering pump assembly
Removal

1. Remove floor plate.

2. Disconnect heater hose clamp (1).

3. Disconnect starting engine high/low changeover

rod (2).

4. Disconnect pump outlet hose (3).

5. Disconnect pump inlet tube (4).

6. Remove steering pump assembly (5).

Installation

1. With O-ring fitted to housing, install steering

pump assembly (5) so that splines on pump
shaft align with splines in housing.

2. With O-ring in place, install pump inlet tube (4).

3. Connect pump outlet hose (3).

a Install hose without twists or interference.

4. Connect starting engine high/low changeover

rod (2).
a Be sure to bend cotter pins securely.

5. Connect heater hose clamp (1).

6. Install floor plate.

30-144 D155C-1
Disassembly and assembly Steering clutch

Removal and installation of

steering clutch assembly
Removal
1. Drain the steering oil.
6 Steering and transmission case: 149 l

2. See "Removal of fuel tank assembly" for removal

of the fuel tank assembly.

3. Disconnect rod (1). [*1]

4. Disconnect hose (2).

5. Disconnect tube (3).

6. Disconnect hose (4).

7. Remove cover (5).

8. Remove cap (6).

9. Remove alignment bolt (7).

a Fully loosen the brake alignment bolt.

10. Remove anchor rod (8). [*2]

11. Raise brake booster assembly (9) to remove it.

a Using forcing screw [1], remove the brake
booster assembly.
4 Brake booster assembly: 50 kg

a When removing the right steering clutch as-

sembly, remove the auxiliary brake cylinder
assembly.

D155C-1 30-145
Disassembly and assembly Steering clutch

12. Remove return spring (10).

13. Raise bracket assembly (11) to remove it. [*3]

a Raise the bracket assembly and remove pin
(12).
4 Bracket assembly: 45 kg

14. Disconnect hose (13).

15. Remove mounting bolts (14) and (15). [*4]

a Apply jack [2] to the grouser of the track shoe
and remove mounting bolts while turning the
track shoe.
a Leave 2 mounting bolts.

16. Raise steering clutch assembly (16) to remove

it. [*5]
a Mount the pin on the brake band to tempo-
rarily raise it, then remove remaining mount-
ing bolts and slide the inner drum to the
inside to install the clutch assembly.
4 Steering clutch assembly: 150 kg

30-146 D155C-1
Disassembly and assembly Steering clutch

Installation
• Carry out installation in the reverse order to re-
moval.

[*1] [*2]
a Surely bend the cotter pin.

[*3]
3 Mounting bolt:
548.8 ± 58.8 Nm {56.0 ± 6.0 kgm}

[*4]
3 Mounting bolt (14):
382.2 ± 44.1 Nm {39.0 ± 4.5 kgm}
3 Mounting bolt (15):
274.4 ± 34.3 Nm {26.0 ± 3.5 kgm}

[*4]
a Install the brake band with the pin position
facing the body.

• Refilling with oil (steering, transmission

case)
a Tighten the drain plug on the steering case,
refill with the engine oil to the specified level,
and run the engine to circulate the oil through
the system. Then check the oil level again.
5 Steering, transmission case: 149 l

• Alignment
a See "Alignment of brake pedal stroke" of
Testing and adjusting for alignment of a brake
pedal stroke.

D155C-1 30-147
Disassembly and assembly Brake booster

Disassembly and assembly of

brake booster assembly
Disassembly
1. Remove brake booster assembly (1).

2. Remove the following parts from valve body (2):

1) Remove snap ring (3), and remove retainer
(4) and spring (5).
k If the snap ring is removed carelessly,
the retainer and spring jump out by the
tension of the spring, so remove the
spring while holding the retainer.
a Spring installation load: 98 N {10 kg}
2) Remove piston (6) and spool (7).

Assembly
1. Install the following parts to valve body (2):
1) Build in spool (7) and piston (6).
a Install the spool with the taper seal sur-
face facing the piston.
2) Build in spring (5) and retainer (4), and fix
them with snap ring (3).

2. Install the O-ring, and install brake booster

assembly (1).

30-148 D155C-1
Disassembly and assembly Steering relief valve

Disassembly and assembly of

steering relief valve assembly
Disassembly

1. Remove snap ring (1), then remove stopper (2).

2. Remove spring (3), valve (4), and piston (5).

Assembly
1. Build piston (5), valve (4), and spring (3) in the
valve body.

2. Install the O-ring, and install stopper (2) and fix it

with snap ring (1).
a Check that the snap ring is surely engaged to
the ring groove.

D155C-1 30-149
Disassembly and assembly Steering clutch

Disassembly and assembly of

steering clutch assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

791-465-5001 Compressor 1
790-101-1102 Pump 1
D
Puller
790-101-2102 1
(294 kN {30 ton})

Disassembly
1. Remove brake band (1).

2. Using eyebolt [1], remove brake drum (2).

3. Set clutch assembly (3) on tool D.

4. Extend the puller and remove bolts (4).

5. Push in the puller and remove pressure plate

(5).

6. Remove disc (6) and plate (7).

a Store removed discs and plates on a flat
place so that they do not bend.

7. Remove clutch drum (8).

8. Remove springs (9) and (10) and sleeve (11).

a Installation load
Spring (9): 2,372 N {242 kg}
Spring (10): 1,352 N {138 kg}

9. Remove clutch piston (12) from tool D.

30-150 D155C-1
Disassembly and assembly Steering clutch

Assembly
1. Install the seal ring on clutch piston (12) and set
the clutch piston on tool D.

2. Install the guide bolt to the clutch piston, and

install sleeve (11) and springs (10) and (9).

3. Install clutch drum (8) and tighten it with tempo-

rary mounting bolts.

4. Build in disc (6) and plate (7).

5. Install pressure plate (5).

6. Extend the puller and remove the guide bolt,

then tighten the pressure plate with bolts (4).

7. Using eyebolt [1], build in brake drum (2) with

the plate and disc in a free state, then push in
the puller.
a Align external teeth of the disc to inner teeth
of the drum and gradually build in the disc.

8. Remove the brake drum and clutch assembly

from tool D.

9. Install the brake band (1).

D155C-1 30-151
Disassembly and assembly Bevel gear shaft

Disassembly and assembly of

bevel gear shaft assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

1 791-475-6000 Remover & installer 1

791-480-3001 Remover D 1
790-101-1102 Pump 1
2
Puller
790-101-3800 1
E (490 kN {50 ton})
790-480-4001 Installer C 1
790-101-1102 Pump 1
3
Puller
790-101-3800 1
(490 kN {50 ton})

Disassembly
1. Steering clutch assembly
See "Removal of steering clutch assembly" for
removal of left and right steering clutch assem-
blies.

2. Valve assembly linked to steering brake

Remove the valve assembly linked to the steer-
ing brake.

3. Valve seat, tube

1) Remove the valve seat.
2) Remove tube (1).

4. Nut
Fix the bevel gear through bolt holes on the hub,
then remove nut (2).

5. Hub nut
Remove the lock plate, fix the hub with plate [1],
and use tool E1 to remove left and right hub nuts
(3).

6. Packings
Remove left and right packings (4).

7. Hub
Set tool E2, then remove left and right hubs (5).

30-152 D155C-1
Disassembly and assembly Bevel gear shaft

8. Bearing
1) Temporarily raise the bevel gear shaft as-
sembly and remove mounting bolts, then
use extraction bolts [2] to remove left and
right bearing cages (6).
a Check the number and thickness of
shims assembled in the bearing cage
before storing them.
2) Remove outer races (7) from left and right
bearing cages.

9. Shaft assembly
1) Gently strike the bevel gear to pull out the
faucet joint portion of the shaft, then remove
shaft assembly (8).
a Take out the shaft assembly from the
right clutch housing.
4 Bevel gear shaft assembly : 40 kg
2) Using puller [3], remove left and right bear-
ings (9).

10. Bevel gear

Remove bevel gear (10).
4 Bevel gear assembly: 35 kg

D155C-1 30-153
Disassembly and assembly Bevel gear shaft

Assembly
1. Bevel gear
Set bevel gear (10) in the case.

2. Shaft assembly
1) Using push tool [4], press-fit left and right
bearings (9).
2) Build shaft assembly (8) in the bevel gear.
a Insert the shaft assembly from the right
clutch housing.
3) Temporarily tighten hub nuts on both ends
of the shaft, then raise the shaft to align the
bevel gear to the faucet joint portion of the
shaft.
4) Install the bevel gear mounting bolts, build
the lock plate in, and temporarily tighten the
nut.

3. Bearing cages
1) Using push tool [5], press-fit outer race (7).

2) Temporarily raise the bevel gear shaft to

build in shims and install left and right bear-
ing cages (6).
a Build in the same number and thickness
of shims stored at disassembly.
a Standard shim thickness: 2.5 mm

30-154 D155C-1
Disassembly and assembly Bevel gear shaft

4. Nuts
Temporarily assemble the hub, install the locks
in bolt holes on the hub, and tighten nuts (21),
then fix the hub with the lock plate.
3 Nut: 230 – 309 Nm {23.5 – 31.5 kgm}

5. Adjusting preload
a When adjusting the preload, remove the
transmission. For details, see Removal of
transmission assembly.
a Revolve the bevel gear shaft by 2 – 3 turns
to fit the bearing, then adjust the preload on
the bearing according to the following proce-
dure.
1) Apply push-pull scale (6) to the outside
tooth tip of the bevel gear shaft assembly
and measure the running torque of the bevel
gear shaft assembly.
• Turning force: 19.6 – 58.8 Nm {2 – 6 kgm}
2) If the turning force is higher or lower than
the standard value, increase or decrease
the shims in 3.

6. Adjusting backlash, tooth contact

a When adjusting the backlash and tooth con-
tact, install the transmission. For details, see
Installation of transmission assembly.
1) Adjusting backlash
i) Put probe of dial gauge (7) in contact
with tooth face at tip of bevel gear.
ii) Fix bevel pinion in position, and read
scale when bevel gear is moved back-
ward and forward (in direction of rota-
tion).
• Standard value of backlash:
0.25 – 0.33 mm
a Measure at 3 places on diametrically op-
posite sides.

iii) If the result of the measurement shows

that the backlash is not correct, adjust
as follows.
a When adjusting the shim thickness, add
or remove shims on the left or right
sides. However, to prevent the preload
of the bearing from changing, always
keep the same total thickness of shims
on the left and right. (Adjust by moving
shims from one side to the opposite
side.)

D155C-1 30-155
Disassembly and assembly Bevel gear shaft

• When backlash is too small:

Reduce the shim thickness on the right
side of the chassis and add the same
shim thickness to the left side. (Move
the bevel gear in direction A.)

• When backlash is too large:

Reduce the shim thickness on the left
side of the chassis and add the same
shim thickness to the right side. (Move
the bevel gear in direction B.)

2) Adjusting tooth contact

Testing
i) Coat the tooth face of the bevel pinion
lightly with red lead (minium), then
rotate the bevel gear forward and back-
ward and inspect the tooth contact pat-
tern left on the bevel gear teeth.
ii) The standard value for the tooth contact
is as follows
(from tip of bevel pinion tooth)
a. Center of tooth contact: 35 – 55 % of
tooth width (from small end )
b. Width of tooth contact: 45 – 65 % of
tooth width
c. Center of tooth contact: 35 – 65 % of
tooth height (from root of tooth)
d. Width of tooth contact : 60 – 80 % of
tooth height
In addition, check that there is no
strong contact at the tip or root of
the teeth or at the big and small
ends.
a If the gears are adjusted to this pattern,
the tooth contact will be correct when
load is applied.

30-156 D155C-1
Disassembly and assembly Bevel gear shaft

Adjusting
If the result of the inspection shows that the
correct tooth contact is not being obtained,
adjust again as follows.
a For adjustment of the shims on the bevel
pinion side, see Assembly of TORQ-
FLOW transmission assembly.
i) When bevel pinion is too far from center
line of bevel gear:
Contact is at the small end of the con-
vex tooth face of the bevel gear and at
the big end of the concave tooth face.
• Adjust the shim thickness at the bevel
pinion end and move the bevel pinion in
direction A.
Or, adjust the shim thickness and move
the bevel gear in direction B.
After adjusting, check the tooth contact
pattern and backlash again.
ii) When bevel pinion is too close to center
line of bevel gear:
Contact is at the big end of the convex
tooth face of the bevel gear and the
small end of the concave tooth face.
• Correct as follows:
Adjust the shim thickness at the bevel
pinion end and move the bevel pinion in
direction A.
Or adjust the shim thickness and move
the bevel gear in direction B.
After adjusting, check the tooth contact
pattern and backlash again.

7. Hubs
1) Install the seal ring and align left and right
hubs to the taper serration part to build them
in the bevel gear shaft.
2) Using tool E3, press-fit left and right hubs
(6).
a Press-fitting part: Lubricant containing
molybdenum disulfide (LM-P)
a Press-fitting force: 294 kN {30 ton}
a After press-fitting the hubs, measure di-
mension a between the level difference
on the bevel gear shaft and surface of
the hub.
a Dimension a: 5 to 6.5 mm

D155C-1 30-157
Disassembly and assembly Bevel gear shaft

8. Packing
Build in left and right packings (4).

9. Hub nuts
Fix the hub with plate [1], then use tool E1 to
tighten left and right hub nuts (3) and fix the hub
with the lock plate.
3 Hub nut: 686 ± 49 Nm {70 ± 5 kgm}
a When aligning lock holes of hub nuts, do not
turn any hub nut to the loosening direction
even within the specified torque.

10. Tube, valve seat

1) Install tube (1).
2) Install the valve seat.

11. Valve assembly linked to steering, brake

Install the valve assembly linked to the steering
and brake.

12. Steering clutch assembly

See "Installation of steering clutch assembly" for
installation of left and right steering clutch as-
semblies.

30-158 D155C-1
Disassembly and assembly First pinion

Disassembly and assembly of

first pinion assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

Remover and
1 791-475-6000 1
installer
791-480-3001 Remover D 1
790-101-1102 Pump 1
2
Puller
G 790-101-3800 1
(490 kN {50 ton})
791-480-4001 Installer C 1
790-101-1102 Pump 1
3
Puller
790-101-3800 1
(490 kN {50 ton})

Disassembly
1. See "Removal of steering clutch assembly" for
removal of the steering clutch assembly.

2. Remove the lock washer and use tool G1 to

remove nut (1).

3. Remove spacer (2).

4. Using tool G2, remove flange (3).

5. Using forcing screw [1], remove bearing cage

assembly (4).

6. Fine disassembly of bearing cage assembly

1) Remove oil seal (5).
2) Remove bearing (6).

D155C-1 30-159
Disassembly and assembly First pinion

7. Remove first pinion assembly (7).

8. Fine disassembly of first pinion assembly

Remove inner race (8).
Remove inner race (9).

30-160 D155C-1
Disassembly and assembly First pinion

Assembly
1. Fine assembly of first pinion assembly
1) Using a push tool, press-fit inner race (9).
2) Using a push tool, press-fit inner race (8).

2. Install first pinion assembly (7).

3. Fine assembly of bearing cage assembly

1) Using a push tool, press-fit bearing (6).
2) Using a push tool, press-fit oil seal (5).

4. Install bearing cage assembly (4).

2 Mounting bolt: Liquid adhesive (LT-2)
3 Mounting bolt:
276.85 ± 31.85 Nm {28.25 ± 3.25 kgm}
2 Oil seal lip surface: Grease (G2-LI)

5. Using tool G3, press-fit flange (3).

2 Spline: Lubricant containing molyb-
denum disulfide (LM-P)
a Press-fitting force:
294 kN to 392 kN (30 to 40 t)
a Check dimension a between the surface of
the flange and different level surface of the
pinion shaft.
• Dimension a: 0 +0.5–1.0 mm
a Set dial gauge [2] on hub (10) and measure
facial runout and radial runout of flange (3).
(Carry out measurement while turning left
and right track shoes by using a jack.)
• Facial runout, radial runout:
0.4 mm or less
a Check the dimension between flange (3) and
hub (10).
• Dimension between flange and hub:
218.5 mm
a Using dial gauge [2], measure the end play
of the bearing.
• Bearing end play: 0.7 to 1.4 mm

6. Remove spacer (2).

7. Using tool G1, tighten nut (1) and fix it with a

lock washer.
3 Nut: 686 ± 49 Nm {70 ± 5 kgm}
a When aligning lock holes of nuts, do not turn
any nut to the loosening direction even within
the specified torque.

8. See "Installation of steering clutch assembly" for

installation of the steering clutch assembly.

D155C-1 30-161
Disassembly and assembly Final drive

Disassembly and assembly of

final drive assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

1 791-575-1301 Box 1
791-575-1400 Wrench 1
2 791-108-1370 Guide 1
791-420-6130 Handle 1
791-576-1003 Remover A 1
791-101-1102 Pump 1
3
Cylinder
791-101-1600 1
(686 kN {70 ton})
791-575-2003 Installer A 1
791-101-1102 Pump 1
4
Cylinder
791-101-1600 1
(686 kN {70 ton})
5 791-575-1520 Installer 1
6 791-580-1510 Installer 1
791-575-3003 Remover 1
790-101-1102 Pump 1
7
F Cylinder
790-101-1600 1
(686 kN {70 ton})
791-575-4003 Installer 1
790-101-1102 Pump 1
8
Puller
790-101-2102 1
(294 kN {30 ton})
9 791-551-1300 Wrench 1
791-575-5500 Remover B 1
790-101-1102 Pump 1
10
Cylinder
790-101-1600 1
(686 kN {70 ton})
791-575-6110 Plug 1
or
791-575-6501 Installer 1
11
790-101-1102 Pump 1
Cylinder
790-101-1160 1
(686 kN {70 ton})
12 790-401-1800 Lifting tool 1

Disassembly
1. Track frame assembly
See "Removal of track frame assembly" for re-
moval of the track frame assembly.

2. Drainage of oil
Remove the drain plug and drain oil in the final
drive case and steering case.
6 Steering, transmission case: 149 l
6 Final drive case: 55 l (1 side)

3. Cover
Remove cover (1).

30-162 D155C-1
Disassembly and assembly Final drive

4. Nut
Remove lock plate (2) and use tool F1 to re-
move nut (3).

5. Support
1) Remove washer (4).
2) Remove support (5).
a Store floating seals in a pair.
3) Fine disassembly of support.
Remove bushing (6).

6. Collar, key
1) Remove collar (7).
2) Remove key (8).

7. Sprocket nut
1) Remove lock (9).
2) Using tool F2, remove sprocket nut (10).

8. Retainer
Remove retainer (11).

D155C-1 30-163
Disassembly and assembly Final drive

9. Sprocket assembly
1) Using tool F3, pull out the press-fitted part of
the sprocket assembly and remove sprocket
boss assembly (12)
a Store floating seals in a pair.
4 Sprocket boss assembly: 350 kg

2) Fine disassembly of sprocket assembly

Remove the following parts from boss (13):
i) Remove cover (14).
ii) Remove teeth (15).

10. Final gear case assembly

1) Using tool F12 and an forcing screw, re-
move final gear case assembly (16).
4 Final gear case assembly: 300 kg

2) Fine disassembly of gear case assembly

Remove the following parts from gear case
(17).
i) Remove cover (18).
ii) Remove bearing (19).

30-164 D155C-1
Disassembly and assembly Final drive

11. Second gear hub assembly

1) Set tool F7, pull out the press-fitted part of
the second gear hub assembly, and remove
second gear hub assembly (20).
4 Second gear hub assembly: 340 kg

2) Fine disassembly of second gear hub as-

sembly
Remove the following parts from gear (21):
i) Remove hub assembly (22)
ii) Remove snap ring (23), then remove
bearing (24).
iii) Remove bearing (25).

3) Remove spacer (26).

12. First gear, second pinion assembly

1) Remove first gear and second pinion as-
sembly (28).
4 First gear, second pinion assembly:
120 kg

D155C-1 30-165
Disassembly and assembly Final drive

2) Fine disassembly of first gear and second

pinion assembly
Remove the following parts from second
pinion (29):
i) Remove plate (30).
ii) Remove inner race (31).
iii) Remove spacer (32).
iv) Remove first gear (33), then remove
key (34).
v) Remove plate (35).
vi) Remove inner race (36).
3) Remove bearing (37).

13. Nut
1) Remove snap ring (38), then remove pin
(39).
2) Using tool F9, loosen nut (40).

14. Sprocket shaft

Using tool F10, remove sprocket shaft (41)
4 Sprocket shaft: 140 kg

30-166 D155C-1
Disassembly and assembly Final drive

Assembly
1. Sprocket shaft
Using tool F11, press-fit sprocket shaft (41).
2 Press-fitting part: Lubricant contain-
ing molybdenum disulfide (LM-P)
a Press-fit the shaft with the key groove facing
up.
a Build the nut and snap ring in the shaft during
press-fitting.
a Press-fitting force:
147 to 529.2 kN (15 to 54 t)

2. Nut
1) Using tool F9, tighten nut (40).
a Align the pin hole of the shaft to that of
the nut.
2) Install pin (39) and fix it with snap ring (38).

3. First gear, second pinion assembly

1) Using a push tool, press-fit bearing (37).
2) Assembly of first gear, second pinion as-
sembly
Install the following parts to second pinion
(29):
i) Using a push tool, press-fit inner race
(36).
ii) Install plate (35).
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}
iii) Install key (34), then install first gear
(33).
iv) Install spacer (32).
v) Using a push tool, press-fit inner race
(31).
vi) Install plate (30).
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}
3) Install first gear and second pinion gear as-
sembly (28).

D155C-1 30-167
Disassembly and assembly Final drive

4. Second gear, hub assembly

1) Install spacer (26).
a Install the spacer with the inside cham-
fered surface facing the body.

2) Fine assembly of second gear, hub assem-

bly
Install the following parts to gear (21):
i) Using a push tool, press-fit bearing (25).
ii) Using a push tool, press-fit bearing (24)
and fix it with snap ring (23).
iii) Mount hub assembly (22).
3 Mounting bolt:
686 ± 49 Nm {70 ± 5 kgm}

3) Build the second gear and hub assembly in

the sprocket shaft, then use tool F8 to
press-fit second gear and hub assembly
(20).

4) Measurement of backlashes
Measure backlashes of first pinion (42), first
gear (43), second pinion (44), and second
gear (45).
a Standard values of backlashes
1st pinion and 1st gear: 0.27 to 0.68 mm
2nd pinion and 2nd gear:
0.31 to 0.82 mm

30-168 D155C-1
Disassembly and assembly Final drive

5. Gear case assembly

1) Fine assembly of gear case assembly
Install the following parts to gear case (17):
i) Using a push tool, press-fit bearing (19).
ii) Install cover (18).
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

2) Using tool F12, install the gasket, then in-

stall gear case assembly (16).
2 Gasket: Liquid gasket (LG-1)
2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
548.8 ± 58.8 Nm {56 ± 6 kgm}

6. Sprocket assembly
1) Fine assembly of sprocket assembly
Install the following parts to boss (13):
i) Install teeth (15).
2 Mounting bolt:
Liquid adhesive (LT-2)
3 Mounting bolt:
1,176 ± 98 Nm {120 ± 10 kgm}
ii) Install cover (14).
3 Mounting bolt:
110.25 ± 12.25 Nm {11.25 ± 1.25 kgm}

2) Using tool F6, build floating seals in the gear

case and sprocket.
a Apply oil thinly on surfaces of seals after
building them in.

D155C-1 30-169
Disassembly and assembly Final drive

3) Build the sprocket assembly in the sprocket

shaft, then use tool F4 to press-fit sprocket
assembly (12).
a Press-fitting part:
Lubricant containing molybdenum
disulfide (LM-P)
a Press-fitting force:
686 to 784 kN (70 to 80 t)

a Press-fit the sprocket assembly with the

specified pressure and specify clear-
ance a to the reference press-fit size.
• Clearance a: 3.3 to 5.3 mm

7. Retainer
Install retainer (11).
3 Mounting bolt:
176.4 ± 19.6 Nm {18 ± 2 kgm}

8. Sprocket nut
1) Install the O-ring to the sprocket, then use
tool F2 to tighten sprocket nut (10).
2) Install lock (9).

9. Collar, key
1) Install key (8).
2) Install collar (7).
a Install the collar with the larger outer di-
ameter facing the body.

30-170 D155C-1
Disassembly and assembly Final drive

10. Support
1) Fine assembly of support
Using a push tool, press-fit bushing (6).
2) Using tool F5, build floating seals in the
sprocket and support.
a Apply oil thinly on surfaces of seals after
building them in.

3) Install support (5).

4) Install washer (4).
a When installing the support, align the
notch of dowel pin (46) to that of the sup-
port.

11. Nut
1) Using tool F1, tighten nut (3) and fix it with
lock plate (2).
3 Nut:
1,715 ± 245 Nm {175 ± 25 kgm}

2) Tighten the nut with the specified torque,

then measure dimension b between the
sprocket nut and support.
a Dimension b: 2.2 to 4.6 mm

D155C-1 30-171
Disassembly and assembly Final drive

12. Cover
Install cover (1).
3 Mounting bolt:
276.85 ± 31.85 Nm {28.25 ± 3.25 kgm}

13. Refilling with oil

Tighten the drain plug and refill the final drive
case and steering case with oil to the specified
levels.
5 Steering, transmission case: 149 l
5 Final drive case: 55 l (1 side)
a Run the engine to circulate the oil through
the systems. Then check the oil levels again.

14. Track frame assembly

See "Installation of track frame assembly" for in-
stallation of the track frame assembly.

30-172 D155C-1
Disassembly and assembly Track

Removal and installation of

track assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

791-681-5000 Remover & installer t 1

790-101-1102 Pump t 1
N
Cylinder
790-101-4300 t 1
(1,471 kN {150 ton})

Removal
1. Boom-and-frame assembly (on the left side)
See Removal of boom-and-frame assembly.

2. Counterweight-and-frame assembly (on the

right side)
See Removal of counterweight-and-frame as-
sembly.

3. Positioning machine
Position machine so that there is enough room
for track to be fully separated. Move machine
back and forth until master link of track is be-
tween idler and carrier roller.

4. Relieving track tension

Open inspection cover (1) and loosen plug (2) to
relieve track tension by allowing grease under
pressure to escape.
a If grease does not flow away smoothly, move
the machine backward and forward.
k Plug (2) and lubricator (3) are under inspec-
tion cover (1). Be careful not to confuse
plug (2) with lubricator (3).
a Both plug (2) and lubricator (3) are equipped
with stopper (4) to prevent them from spring-
ing up when loosened. For maximum safety,
however, do not stand in front of inspection
window during work and do not loosen plug
more than one turn.

5. Master pin
Set special tools N on machine and remove
master pin (9).

D155C-1 30-173
Disassembly and assembly Track

6. Temporary pin
Remove special tools and insert temporary pin
(5) in master pin hole. Move machine forward
until master link comes near ground. Wedge
block [1] approximately 150 mm high under the
grouser beneath temporary pin and set machine
on it. Pull out temporary pin.
a Setting track on block is to relieve track ten-
sion at temporary pin area.

7. Separating track
Pull out temporary pin and disconnect track. In-
sert bar [2] into hole of last link and sling the bar
from crane. Back machine slowly, allowing track
(6) to ride over carrier rollers and off the sprock-
et.
k To assure safety during track separa-
tion work, be sure to make proper sig-
nals between persons in cooperation
with each other.

Installation

1. Installing track
As machine is moved slowly forward, put bar [2]
into the last link and guide track (6) over sprock-
et, carrier rollers and idler.
k To assure safety during track installa-
tion work, be sure to make proper sig-
nals between persons in cooperation
with each other.

2. Spacer and washer

1) Position track by wedging block [1] in place.
2) Install spacers and washers inside link (7).
Move machine forward and connect link (7)
to link (8).
k After connecting links together, apply
parking brake.

3. Temporary pin
Align holes and install temporary pin (5).

30-174 D155C-1
Disassembly and assembly Track

4. Positioning machine
Back machine until temporary pin is located to
the middle position between idler and carrier
roller.

5. Master pin
Using special tool N, press-fit master pin (4).
a Install master pin so that each end of pin pro-
trudes equally from links.

6. Adjusting track tension

Open cover (1) and tighten plug (2). Apply
grease to lubricator (3) until proper track tension
is obtained.
3 Plug: 49.0 ± 2.5 Nm {5 ± 0.25 kgm}
a Use GLT2-LI grease.
a Place a straightedge over idler and carrier
roller. Adjust track tension until 20 to 30 mm
of clearance is obtained between straight-
edge and grouser at the middle position be-
tween idler and carrier roller.

7. Counterweight-and-frame assembly (on the

right side)
See Removal and installation of counterweight-
and-frame assembly.

8. Boom-and-frame assembly (on the left side)

See Removal and installation of boom-and-
frame assembly.

D155C-1 30-175
Disassembly and assembly Carrier roller

Removal and installation of

carrier roller assembly
Removal

1. Relieving track tension

Open inspection cover (1) and loosen plug (2) to
relieve track tension by allowing grease under
pressure to escape.
a If grease does not flow away smoothly, move
the machine backward and forward.
k Plug (2) and lubricator (3) are under inspec-
tion cover (1). Be careful not to confuse
plug (2) with lubricator (3).
a Both plug (2) and lubricator (3) are equipped
with stopper (4) to prevent them from spring-
ing up when loosened. For maximum safety,
however, do not stand in front of inspection
window during work and do not loosen plug
more than one turn.

2. Jacking up track
Using jack [1] placed on track frame rear cover,
raise track (5) enough to provide 350 mm or
more of clearance between carrier roller support
and track link.

3. Carrier roller assembly

1) Sling carrier roller and remove support
mounting bolts (6).
a Leave only from bolt (7) installed loosely.
2) With carrier roller slung, turn roller toward
you.
Remove bolt (7) and take out carrier roller
assembly (8).
4 Carrier roller-and-support assembly:
65 kg

30-176 D155C-1
Disassembly and assembly Carrier roller

Installation

1. Jacking up track
Using jack [1] placed on track frame rear cover,
raise track (5).
a Jack up track enough to provide approx. 350
mm of clearance between carrier roller sup-
port mounting face and track link.

2. Carrier roller assembly

1) Lift carrier roller assembly (8) into position
and install support mounting bolt (7) tempo-
rarily.
2) Turn carrier roller assembly, while sling rope
is slackened as necessary, until match mark
on support comes into alignment with that
on track frame. Install all mounting bolts
and tighten them to the specified torque.
2 Mounting bolt:
Adhesive compound (LT-2)
3 Mounting bolt:
549 ± 58 Nm {56 ± 6 kgm}
3) Remove sling wire and jack [1].

3. Adjusting track tension

Open inspection cover (1) and tighten plug (2).
Apply grease to lubricator (3) until proper track
tension is obtained.
a Use GLT2-LI grease.
3 Plug: 49.0 ± 2.5 Nm {5 ± 0.25 kgm}
a Place a straightedge over idler and carrier
roller. Adjust track tension until 20 to 30 mm
of clearance is obtained between straight-
edge and grouser at the middle position be-
tween idler and carrier roller.
a If grease cannot be applied to lubricator
smoothly, try moving machine backward and
forward.

D155C-1 30-177
Disassembly and assembly Track roller

Removal and installation of

track roller assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

790-401-1700 Lifting tool t 1

H
790-401-1760 Adapter t 1

Removal

1. Relieving track tension

Open inspection cover (1) and loosen plug (2) to
relieve track tension by allowing grease under
pressure to escape.
a If grease does not flow out smoothly, move
the machine backwards and forwards.
k Plug (2) and lubricator (3) are under inspec-
tion cover (1). Be careful not to confuse
plug (2) with lubricator (3).
a Both plug (2) and lubricator (3) are equipped
with stopper (4) to prevent them from spring-
ing up when loosened. For maximum safety,
however, do not stand in front of inspection
window during work and do not loosen plug
more than one turn.

2. Track roller mounting bolt

Remove track roller mounting bolts (5).
a When removing No. 4, 5 or 6 track roller, de-
tach the inside and outside track roller
guards.

3. Raising machine
To remove any of rear rollers, place block [1] ap-
proximately 300 mm high behind track. Drive
the machine backwards allowing track to climb
up on block just enough to lift roller (6) off track.
k Set parking brake securely. To remove any
of front rollers, drive the machine onto a
block placed ahead of idler.

4. Track roller assembly

Insert special tools H under track roller assem-
bly (6) and pull out assembly.
4 Track roller assembly: 110 kg (Single)
120 kg (Double)

30-178 D155C-1
Disassembly and assembly Track roller

Installation

1. Track roller assembly

Using special tools H, set track roller assembly
(6) with its lubricating plug facing out onto track
link.

2. Track roller mounting bolt

1) Lift up roller with special tools H and tighten
mounting bolts temporarily.
2) Lower machine slowly from block [1]. Re-
tighten roller mounting bolts (5).
2 Mounting bolt:
Adhesive compound (LT-2)
3 Track roller mounting bolt:
1323.9 ± 147.1 Nm {135 ± 15 kgm}
a When No. 4, 5 or 6 track roller has been
replaced, install the inside and outside
track roller guards.
2 Mounting bolt:
Adhesive compound (LT-2)
3 Guard mounting bolt:
927 ± 98 Nm {94.5 ± 10 kgm}

3. Adjusting track tension

Open inspection cover (1) and, after making
sure of tightness of plug (2), apply grease to lu-
bricator (3) until proper track tension is obtained.
a Place a straightedge over idler and front car-
rier roller. Adjust track tension until 20 to 30
mm of clearance is obtained between
straightedge and grouser at the middle posi-
tion between idler and carrier roller.

D155C-1 30-179
Disassembly and assembly Recoil spring

Disassembly and assembly of

recoil spring assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

1 791-685-8000 Compressor t 1
Cylinder
J 2 790-101-1300 t 1
(981 kN {100 ton})
3 790-101-1102 Pump t 1

Disassembly
1. Set recoil spring assembly (1) on tool J.
k Because the installation load of the spring is
large, surely set the spring to avoid danger.
a Spring installation load:
216,580 kN {22,100 kg}

2. Slowly apply oil pressure to compress the spring

and release lock (2) to remove nut (3).

3. Gradually depressurize the oil to ease the spring

tension.

4. Remove rear pilot (5), shaft (6), bolt (7), and

pilot (8) from spring (4).

30-180 D155C-1
Disassembly and assembly Recoil spring

Assembly
1. Build pilot (8), bolt (7), shaft (6), and rear pilot
(5) in spring (4), then set the spring on tool H.
k Because the installation load of the spring is
large, surely set the parts to avoid danger.

2. Gradually pressurize the oil to compress the

spring and set the spring so that its installation
length conforms to the standard value.
a Spring installation length a: 770 mm

3. Install nut (3), then install lock (2).

4. Gradually depressurize the oil to ease the spring

tension, then remove recoil spring assembly (1)
from tool J.

D155C-1 30-181
Disassembly and assembly Track frame

Removal and installation of

track frame assembly
Removal

1. Separating track
See Removal of track assembly.

2. Raising machine
1) Raise the rear end of machine by slinging
the rear end of right and left track frames
and placing block [1] (approximately 90 mm
high) under right and left sides of steering
case.

2) Sling the front end of right and left track

frames to raise the front end of machine.
Support machine on a block [2] (approxi-
mately 90 mm high) placed under the ma-
chine center frame.
k After raising machine, make sure that
machine is supported stably on blocks.

3. Track frame cover

Remove front and rear track frame covers (1).

4. Sprocket cover
1) Remove sprocket cover (2).
2) Remove cover (3).

30-182 D155C-1
Disassembly and assembly Track frame

5. Track frame assembly

1) Sling track frame assembly (4) at its front
and rear ends.
k Wedge a block under track frame on the
opposite side to prevent machine from
tilting to that side when track frame is
lifted out.

2) Remove mounting bolts (5) from front end of

track frame.
3) Remove mounting bolts (6) from rear end of
track frame.

4) Remove cap (7).

5) Lift out track frame assembly (4) by pulling it

outward gradually.
4 Track frame assembly: 3,600 kg

D155C-1 30-183
Disassembly and assembly Track frame

Installation

1. Track frame assembly

1) Sling track frame assembly (4) at its front
end and rear end.
Lift it gradually into position on frame and
final drive support.
2 Joint faces between support and
track frame:
Anti-friction compound (LM-P)
2) Install the respective mounting bolts tempo-
rarily.

3) Install cap (7), bringing its dowel pin into

alignment with pin hole in support.
2 Joint faces between can and sup-
port:
Anti-friction compound (LM-P)
3 Mounting bolt:
1716.2 ± 196.1 Nm {175 ± 20 kgm}

4) Retighten mounting bolts (6) at rear end of

track frame.
5) Retighten mounting bolts (5) at front end of
track frame.
2 Mounting bolt threads:
Adhesive compound (LT-2)
3 Mounting bolt:
1716.2 ± 196.1 Nm {175 ± 20 kgm}

2. Sprocket cover
1) Install cover (3).
2) Install sprocket cover (2).
2 Mounting bolt threads:
Adhesive compound (LT-2)
3 Mounting bolt:
274.6 ± 29.4 Nm {28 ± 3 kgm}

30-184 D155C-1
Disassembly and assembly Track frame

3. Track frame cover

Install front and rear track frame covers (1).
2 Mounting bolt threads:
Adhesive compound (LT-2)
3 Mounting bolt:
274.6 ± 29.4 Nm (28 ± 3 kgm)

4. Lowering machine
1) Sling machine at front end of right and left
track frames. Remove block [2] and lower
front end of machine.

2) Sling machine at rear end of right and left

track frames. Remove block [1] and lower
rear end of machine.

5. Track assembly
See Removal and installation of track assembly.

D155C-1 30-185
Disassembly and assembly Idler

Removal and installation of

idler assembly
Removal
1. Remove the blade assembly.
See "Removal of blade assembly" for details.

2. Remove the track shoe.

See "Removal of blade assembly" for details.

3. Remove the cover.

4. Remove yoke mounting bolt (1).

5. Loosen mounting bolts (3) and remove shim (2).

[*1]

6. Loosen seat support bolt (4).

7. Run a wire rope through hanging holes on the

idler to raise the idler assembly and slide it along
the upper end of the track frame to pull out idler
assembly (5) forward. [*2]
4 Idler assembly: 500 kg

8. Remove spring seat (6), spring (7), and seat (8).

a The above parts are built in between the sup-
port and track frame.

Installation
• Carry out installation in the reverse order to re-
moval.

[*1]
a Standard shim thickness: 6 mm
3 Mounting bolt:
744.8 ± 83.3 Nm {76 ± 8.5 kgm}

[*2]
a Set the idler assembly in the center of the
track frame and align clearance a between
the track frame and guide plate.
a Standard clearance a: 0.5 to 1.0 mm

30-186 D155C-1
Disassembly and assembly Winch control valve

Removal and installation of

winch control valve assembly
Removal

1. Detach clamp of wire (1).

2. Disconnect lever (2).

a Put a match mark on lever and shaft before
disconnection.

3. Detach control rods (3) and (4).

4. Sling winch control assembly and remove

mounting bolts (5).

5. Move control valve assembly (6) outward, dis-

connect it from sleeve (7), and take it out.
4 Winch control valve assembly: 65 kg

Installation

1. Sling winch control valve assembly (6), connect

it to sleeve (7), and position it in place on
bracket (8).

2. Tighten mounting bolts (5).

3. Attach control rods (3) and (4) with spacers fitted

to both ends of each rod.

4. Connect lever (2).

a Attach lever so that match marks fall in line
with that on shaft as before dismounting.

5. Attach clamp of wire (1).

D155C-1 30-187
Disassembly and assembly Winch control valve

Disassembly and assembly of

winch control valve assembly
Disassembly

• Remove bolts (1) and separate valve assembly

(2) from camshaft assembly (3).

• Valve assembly
1) Remove plug (4) and take out spring (5).
2) Pull out valve (6) and shaft assembly (7)
from the valve body.
3) Remove piston (8) from valve (6).

4) When disassembling shaft assembly, pry

snap ring (9) off and remove collar (10),
guide (11), spring (12), retainer (13), spring
(14) and retainer (15) in that order from
shaft (16).

• Camshaft assembly
1) Separate yoke (17) and rod (18) from cam-
shaft and remove lever assembly (19).
2) Remove lever (20).
a Put a match mark on camshaft and lever
before removing lever.

30-188 D155C-1
Disassembly and assembly Winch control valve

3) Remove right and left plates (21).

a Mark right and left plates before removal
to prevent confusion between them.
4) Pull out right and left camshafts (22) from
case (23).
a Mark right and left camshafts before re-
moval to prevent confusion between
them.

5) When disassembling each camshaft assem-

bly, use the following procedure:
i) Pry snap ring (24) off and pull out cam-
shaft (25).
ii) Pry snap ring (26) and remove bearing
(27).
iii) Remove oil seal (28) from cage (29).

6) Remove notch (30) and spring (31).

7) Remove bolts fastening gland assembly
(32) to case (23). Remove gland assembly
by using jack bolts (10 mm, P=1.5).

8) When disassembling gland assembly, use

the following procedure:
i) Remove plug (33) and pull out spool
(34).
ii) Remove seal (36) from gland (35).

D155C-1 30-189
Disassembly and assembly Winch control valve

Assembly

a Coat sliding surfaces of disassembled parts with

engine oil and make sure that they are free from
dust, scratches and other defects.

• Camshaft assembly
1) Reassemble gland assembly using the fol-
lowing procedure:
i) Fit O-ring to gland (35) and install seal
(36).
ii) Install spool (34).
iii) Attach on O-ring and install plug (33).
3 Plug: 68.7 ± 9.8 Nm {7 ± 1 kgm}

2) Attach O-ring and fit gland assembly (32) on

case (23).
3) Install spring (31) and notch (30).

4) Reassemble camshaft assembly using the

following procedure:
i) Using push tool (42 mm O.D.), press-fit
oil seal (28) into cage (29).
a Fill 40 to 60% of seal lip vacancy
with grease (GLT2-LI).
ii) Using push tool (25 mm I.D.), press-fit
bearing (27) onto camshaft (25) and
lock with snap ring (26).
iii) Press-fit cage into bearing outer race
and lock with snap ring (24).

30-190 D155C-1
Disassembly and assembly Winch control valve

5) Attach O-rings and insert right and left cam-

shaft assemblies (22) in case (23).
a Be careful not to confuse the right and
left camshaft assemblies with each oth-
er.
6) Install right and left plates (21).

7) Attach lever (20) so that match marks fall in

line with each other as before disassembly.
8) Install lever assembly (19). Connect rod
(18) and yoke (17).
a Be sure to bend cotter pin securely.
9) After completion of assembly, check for
proper action of shaft locking mechanism.
(Cam should act at LOW and HI positions,
but should not at N position.)

• Valve assembly
1) Reassemble shaft assembly as follows:
Install retainer (15), spring (14), retainer
(13), spring (12), guide (11) and collar (10)
in that order to shaft (16). Then, lock with
snap ring (9).

2) Install shaft assembly (7) to the body.

3) Insert piston (8) into valve (6) and then in-
stall valve to the body.
4) Install spring (5).
5) Attach on O-ring and install plug (4).
3 Plug:
107.9 ± 14.7 Nm {11 ± 1.5 kgm}

D155C-1 30-191
Disassembly and assembly Winch control valve

• After coating mating surfaces with liquid gasket,

fit camshaft assembly (3) to valve assembly (2)
with mounting bolts (1).
2 Mating surfaces: Liquid gasket (LG-4)

30-192 D155C-1
Disassembly and assembly High/low speed selector valve

Removal and installation of

high/low speed selector valve
assembly
Removal

1. Detach intermediate clamp and disconnect tube

(1) leading to cooler.

2. Remove flow divider (2).

3. Disconnect yoke (3) from spool.

4. Remove bolts (4) fastening valve assembly (6)

to sleeve (5), and take out valve assembly.

Installation

1. Attach O-ring and fit valve assembly (6) to

sleeve (5) with bolts (4).

2. Connect yoke (3).

a Be sure to bend cotter pin.

3. Attach O-ring and install pipe (7).

4. Attach O-ring and install flow divider (2).

3 Mounting bolts:
30.4 ± 2.9 Nm {3.1 ± 0.3 kgm}
5. Attach O-ring and connect tube (1) leading to
cooler.

6. Attach intermediate clamp of tube.

D155C-1 30-193
Disassembly and assembly High/low speed selector valve

Disassembly and assembly of

high/low speed selector valve
assembly
Disassembly

• Remove bolts (1) and separate relief valve as-

sembly (2) from spool assembly (3).

• Disassembly of Relief valve assembly

1. When disassembling the lubrication valve

assembly, use the following procedure:
1) Remove plugs (4) and (5).
2) Pull out valve (6) from body. Take out piston
(7), spring (8) and washers (9).
a Check and record the number of wash-
ers removed.

2. When disassembling the cooler bypass valve

assembly, use the following procedure:
1) Remove plugs (10) and (11).
2) Pull out valve (12) from body. Take out
spring (13), washers (14) and piston (15).
a Check and record the number of wash-
ers removed.

3. When disassembling the pressure control valve

assembly, use the following procedure:
1) Remove plugs (16) and (17).
2) Pull out valve (18). Take out piton (19),
spring (20) and washers (21).
a Check and record the number of wash-
ers removed.

30-194 D155C-1
Disassembly and assembly High/low speed selector valve

• Disassembly of Spool assembly

1) Remove plug (22).

2) Remove ball (23).
3) remove nut (24) and screw (25). Take out
spring (26) and ball (27).
a Unless it is necessary, screw (25) should
not be removed to maintain proper set-
ting of operating force, If removal of
screw is necessary, check and record
protrusion of screw from nut end face
before removing nut.
4) Remove detent (28) and then case (29).
5) Remove plug (30).
a Be sure to leave spool installed to the
body when loosening plug. (This is nec-
essary to prevent spool from bending.)
6) Remove retainer (31), spring (32), retainer
(33) and spacer (34).
7) Pull out spool (35) from body (36).
8) Remove plate (37) and take out U-packing
(38).
9) Remove U-packing (39).

D155C-1 30-195
Disassembly and assembly High/low speed selector valve

Assembly

a Coat sliding surfaces of disassembled prates

with engine oil and make sure that they are free
from dust, scratches and other defects.

• Assembly of Spool assembly

1) Install U-packings (39) and (38) to body.
Attach O-ring and install plate (37).
2) Inset spool (35) into body (36).
3) Install spacer (34), retainer (33), spring (32)
and retainer (31) in that order and install
plug (30).
3 Plug: 34.3 ± 4.9 Nm{35 ± 0.5 kgm}
a Be sure to install spool to body before
tightening. (This is necessary to prevent
spool from bending.)
4) Install case (29) and detent (28).
5) Insert ball (27) and spring (26) into plug.
Turn in screw (25) to the same depth as be-
fore disassembly and lock with nut (24).
3 Nut: 24.5 ± 4.9 Nm {2.5 ± 0.5 kgm}
6) Install ball (23).
7) Install plug (22).
3 Plug: 73.6 ± 9.8 Nm {7.5 ± 1 kgm}

30-196 D155C-1
Disassembly and assembly High/low speed selector valve

• Assembly of Relief valve assembly

1. Reassemble pressure control valve assembly

using the following procedure:
1) Install piston (19) in valve (18).
a Insert end of piston with the larger space
between grooves into valve.
2) Install washer (21) and spring (20). Insert
valve (18) into body.
3) Attach O-ring and install plugs (17) and (16).
3 Plug: 68.6 ± 9.8 Nm {7 ± 1 kgm}

2. Reassemble cooler bypass valve assembly

using the following procedure:
1) Install piston (15) in valve (12).
a Insert end of piston with the larger space
between groove into valve.
2) Insert the same number of washers (14) into
valve as before disassembly.
3) Insert spring (13) into valve. Install valve
(12) to body, attach O-ring, and install plugs
(11) and (10).
3 Plug: 68.6 ± 9.8 Nm{7 ± 1 kgm}

3. Reassemble the lubrication valve assembly

using the following procedure:
1) Install piston (7) in valve (6).
a Insert end of piston with the larger space
between grooves into valve.
2) Insert the same number of washers (9) into
valve as before disassembly.
3) Insert spring (8) into valve. Install valve (6)
to body, attach O-ring, and install plugs (5)
and (4).
3 Plug: 68.6 ± 9.8 Nm{7 ± 1kgm}

• Attach seat (40) and O-ring to spool assembly

(3), set relief valve assembly (2) in place, and
tighten bolts (1).
3 Mounting bolt:
30.4 ± 2.9 Nm {3.1 ± 0.3 kgm}
a Tighten mounting bolts in diagonal se-
quence.

D155C-1 30-197
Disassembly and assembly Towing winch pump

Removal and installation of

towing winch pump assembly
Removal

1. Remove drain plug (1) and loosen plug (2) to

drain oil from towing winch case.
6 Towing winch case oil: Approx. 100 l

2. Remove mounting bolts and detach towing

winch pump assembly (3).
4 Pump assembly: 25 kg

Installation

1. Attach O-ring and install towing winch pump

assembly (3).

2. Install drain plug (2) and plug (1) securely.

Refill case with engine oil through oil filler (4) up
to specified oil level.
5 Towing winch case oil: Approx. 100 l

30-198 D155C-1
Disassembly and assembly Counterweight pump

Removal and installation of

counterweight pump assembly
Removal

k Be sure to keep counterweight lowered com-

pletely.
k Loosen oil filler cap gradually to release the in-
ner pressure from hydraulic tank.
1. Remove drain plug (1) to drain oil from hydraulic
tank.
6 Hydraulic tank: Approx. 28 l

2. Remove floor plate.

3. Detach intermediate hose (2) from counter-

weight cylinder piping.

4. Detach starting engine rod (3) and remove

bracket (4).

5. Detach pump inlet tube (5) and disconnect outlet

tube (6).

6. Life off counterweight pump assembly (7).

4 Counterweight pump assembly:
25 kg

Installation

1. Attach O-ring to housing. Lift counterweight

pump assembly (7) into position so that its
spline meshes with that of housing.

2. Attach O-ring to housing. Connect outlet tube

(6), and install inlet tube (5).

3. Install bracket (4) and connect starting engine

rod (3).
a Be sure to bend cotter pin securely.

4. Attach O-ring and connect intermediate hose (2)

to counterweight cylinder piping.

5. Install floor plate.

6. Install drain plug (1) and refill hydraulic tank with

oil through oil filler (8) up to specified level.
5 Hydraulic tank: Approx. 28 l
a Recheck oil level after running the engine to
allow oil to circulate in piping.

D155C-1 30-199
Disassembly and assembly Counterweight cylinder

Removal and installation of

counterweight cylinder
assembly
Removal

k Lower counterweight completely and stop en-

gine. Move cylinder control lever two or three
times to release the residual pressure from pip-
ing.

1. Disconnect inlet and outlet hoses (1) and (2)

from the cylinder.

2. Sling counterweight cylinder assembly (3).

3. Remove lock plates and pull pin (4) until piston

rod can be detached from frame.
a Bind piston rod to cylinder with wire to pre-
vent rod from slipping off cylinder after de-
tachment.

4. Remove lock plates and pull out joint pin (5) at

the bottom of the cylinder.
Lift off counterweight cylinder assembly (3).
4 Cylinder assembly: 70 kg

Installation

1. Lift counterweight cylinder assembly (3) into

position. Align pin hole in the bottom of cylinder
with that in frame. Insert pin (5), and install lock
plates.

2. Align pin hole in piston rod with that in frame,

drive in pin (4), and install lock plates.

3. Attach O-rings and connect inlet and outlet

hoses (2) and (1).

4. Start engine to allow oil to circulate in cylinder.

Then, refill tank with engine oil through oil filler
(6) up to specified oil level.

30-200 D155C-1
Disassembly and assembly Counterweight cylinder

Disassembly and assembly of

counterweight cylinder
assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

1 790-102-3000 Repair stand t 1

K
2 790-102-1200 Power wrench t 1

Disassembly
• Disassembly of piston rod and head assem-
bly

1. Piping
Detach tube (1) and remove elbow (2).

2. Piston rod and head assembly

Remove bolts (3). Take out piston rod and head
assembly (4) from cylinder (5) and set the as-
sembly in special tool K1.

3. Nut
Using special tool K2, remove nut (6).
a Width across flats of nut;

4. Piston assembly
Detach piston assembly (7) from piston rod.

5. Head assembly
Detach head assembly (8) from piston rod.

• Disassembly of piston assembly

6. When disassembling the piston assembly,

use the following procedure:
1) Remove retainer (9) and take out U-packing
(10).
2) Pry snap ring (11) off.
3) Remove retainer (12) and take out U-pack-
ing (13).
4) Remove wear ring (14) from piston (15).

D155C-1 30-201
Disassembly and assembly Counterweight cylinder

• Disassembly of head assembly

7. When disassembling the head assembly, use

the following procedure:
1) Unscrew mounting bolts (16) and remove
gland assembly (17).
2) Pry ring (19) off and take out dust seal (20)
from gland (18).
3) Remove bushing (21) from gland.
4) Remove nylon heel (23), U-packing (24), O-
ring (25) and back-up ring (26) from head
(22).
5) Remove bushing (27) from head.

30-202 D155C-1
Disassembly and assembly Counterweight cylinder

Assembly
a Coat sliding surfaces of disassembled parts with
engine oil and make sure that they are free from
dust, scratches, and other defects.

• Assembly of head assembly

1. Reassemble the head assembly using the

following procedure:
1) Using push tool (55 mm O.D.), press-fit bush-
ing (27) into head (22).
a Be careful not to deform bushing.
2) Install back-up ring (26), O-ring (25), U-
packing (24) and nylon heel (23) in that or-
der into head.
3) Using push tool (55 mm O.D.), press-fit bush-
ing (21) into gland (18).
a Be careful not to deform bushing.
4) Install dust seal (20) in gland and lock it with
ring (19).
5) Install gland assembly (17) in head with
mounting bolts (16).

• Assembly of piston assembly

2. Reassemble piston assembly using the fol-

lowing procedure:
1) Fit wear ring (14) to piston (15).
2) Install U-packing (13) and retainer (12) on
the piston and lock with snap ring (11).
3) Fit U-packing (10) to piston and install re-
tainer (9).

D155C-1 30-203
Disassembly and assembly Counterweight cylinder

• Assembly of piston rod and head assembly

3. Head assembly
Set piston rod in special tool K1 and install head
assembly (8).

4. Piston assembly
Install piston rod assembly (7) on piston rod.

5. Nut
Install nut (6) with special tool K2.
3 Nut: 1.77 ± 0.18 kNm {180 ± 18.0 kgm}

6. Piston rod and head assembly

Detach piston rod and head assembly (4) from
special tool. Fit the assembly to cylinder (5) with
mounting bolts (3).
3 Mounting bolt:
981 ± 98.0 Nm {100 ± 10.0 kgm}

7. Piping
1) Attach O-ring and install elbow (2).
2) Attach O-ring and install tube (1).

30-204 D155C-1
Disassembly and assembly Counterweight control valve

Removal and installation of

counterweight control valve
assembly
Removal

k Lower counterweight completely and stop en-

gine. After moving control lever two or three
times, loosen oil filler plug (1) to release the in-
ner pressure of tank.

1. Remove drain plug (2) and drain oil from

hydraulic tank.
6 Hydraulic tank: Approx. 28 l

2. Remove hydraulic tank cover (3).

3. Detach tube (4).

4. Disconnect yoke (5) from spool.

5. Remove plate (6) and disconnect control valve

inlet and outlet tubes (7), (8) and (9).

6. Remove mounting bolts (10) and detach coun-

terweight control valve assembly (11).
4 Control valve assembly: 25 kg

Installation

1. Attach O-ring. Using guide bolts (1 mm, P = 1.5),

position counterweight control valve assembly
(11) on tank and install the assembly at that
position with mounting bolts (10).

2. Attach O-rings and connect control valve inlet

and outlet tubes (9), (8) and (7).

3. Install plate (6).

4. Connect yoke (5).

a Be sure to bend cotter pin securely.

5. Install tube (4).

6. Attach gasket and install tank cover (3).

7. Install drain plug (2).

Refill hydraulic tank with engine oil through oil
filler (1) up to specified oil level.

5 Hydraulic tank: Approx. 28 l

a Start engine to allow oil to circulate in piping
and, then, recheck oil level.

D155C-1 30-205
Disassembly and assembly Counterweight control valve

Disassembly and assembly of

counterweight control valve
assembly
Disassembly

30-206 D155C-1
Disassembly and assembly Counterweight control valve

• Disassembly of Suction valve assembly

1. Remove mounting bolts (1) and detach suction

valve assembly (2).
2. Remove plate (3) and take out spring (4) and
valve (5).
3. Remove plate (6). Apply compressed air
(approx. 0.39 MPa {4 kg/cm 2 } in pressure) to
port until valve assembly spring (9) and valve
(10) from collar (7).

• Disassembly of Main relief valve

4. Remove mounting bolts (11) and detach main

relief valve assembly (12).
5. Remove valve (14), spring (15), seat (16), pop-
pet (17), spring (18) and valve body (19) from
housing (13).
a Before removing adjustment plug (20), mea-
sure and record length a.
a Do not remove adjustment plug unless nec-
essary.

• Disassembly of Check valve

6. Remove plate (21).

7. Turn in jack bolt [1] (8 mm, P = 1.25) to the tap

hole in check valve seat (22) and pull out the
seat with pliers.

8. Take out spring (23) and check valve (24).

• Disassembly Spool assembly

9. Remove plug (25). Take out spring (26), guide

(27) and detent ball (28) from case (29).

10. Remove case (29).

11. Pull out spool assembly (30) from body (31).

12. Remove bolt (32). Remove detent (33), collar

(34), spring (35) and collar (36) from spool (37).

D155C-1 30-207
Disassembly and assembly Counterweight control valve

Assembly

a Coat sliding surfaces of disassembled parts with

engine oil and make sure that they are free from
dust, etc.

• Assembly of Spool assembly

1. Install collar (36), spring (35), collar (34) and

detent (33) in that order on spool (37).
Install and tighten bolt (32).

2. Install spool assembly (30) to body (31).

3. Fit case (29) to body. Insert ball (28), guide (27)

and spring (26) in that order into case. Install
plug (25).
3 Plug: 83.4 ± 14.7 Nm {8.5 ± 5 kgm}

30-208 D155C-1
Disassembly and assembly Counterweight control valve

• Assembly of Check valve

4. Install check valve (24) and spring (23) to body.

Attach O-ring and fit check valve seat (22) to
body.

5. Install plate (21).

• Assembly of Main relief valve assembly

6. Insert spring (18) and poppet (17) into valve

body (19). Install seat (16), to which O-ring is
attached, to valve body.

7. Install valve (14) in housing. Then install spring

(15) in housing.

8. Put valve body and housing together to form

main relief valve assembly (12). Attach O-ring to
the assembly and position the assembly on
body.

9. Install and tighten mounting bolts (11).

3 Mounting bolt:
98 ± 9.8 Nm {10 ± 1 kgm}
a If readjustment of plug (20) is necessary, set
it to the same length a as before disassembly
and lock it to that position with but (38).
a Standard of length a is 12 mm.
a Oil pressure varies for each turn of plug.
a For details of oil pressure adjustment, see
Adjustment of main relief valve in Testing
and adjusting section.

• Assembly of Suction valve assembly

10. Install valve (10), spring (9) and spring seat (8)
in that order into collar (7). Install collar, on
which O-ring is fitted, to housing (39).

11. Install plate (6).

12. Install valve (5) and spring (4) to body. Attach O-

ring to plate (3) and install plate to body.

13. Attach O-rings to suction valve assembly (2) and

install the assembly to body (31) with mounting
bolts (1).
3 Mounting bolt:
66.2 ± 7.4 Nm{6.75 ± 0.75 kgm}

D155C-1 30-209
Disassembly and assembly Gate frame

Removal and installation of

gate frame assembly
Removal

1. Boom/frame
See Removal and installation of boom/frame.

2. Counterweight/frame
See Removal and installation of counterweight/
frame.

3. Towing winch assembly

See Removal and installation of towing winch
assembly.

4. Cover and plate

1) Remove right and left engine side covers.
2) Remove plates (1), (2), (3) and (4).

5. Piping
Disconnect hoses (5) and (6) between block and
counterweight cylinder from their respective
tubes.

6. Clamp
1) Remove hose clamps (7) and (8).
2) Detach heater hose clamp on the bottom of
gate frame.

30-210 D155C-1
Disassembly and assembly Gate frame

7. Support
Remove oil filler clamp and detach support (9).

8. Bracket
Remove cover (10) and detach winch control
rod bracket (11) from frame.

9. Gate frame assembly

Sling gate frame assembly (12) and remove the
right and left mounting bolts.
a Lift off gate frame assembly gradually, taking
care not to cause a collison with the sur-
roundings.
4 Gate frame assembly: 920 kg

Installation

1. Gate frame assembly

1) Lift gate frame assembly (12) into position
on the frame.
a Lower gate frame assembly gradually,
taking care not to cause a collison with
the surroundings.
2) Install collars and mounting bolts.
2 Bolt thread: Bonding agent (LT-2)

2. Bracket
Attach winch control rod bracket (11) to frame
and install cover (10).

3. Support
Install support (9) and attach oil filler clamp.

D155C-1 30-211
Disassembly and assembly Gate frame

4. Clamp
1) Attach heater hose clamp on the bottom of
gate frame.
2) Attach clamp (8) for hose between control
valve and pump. Attach clamp (7) for hose
between control valve and block.

5. Piping
Attach O-rings and install hoses (6) and (5) to
connect counterweight cylinder to block.

6. Cover and plate

1) Install plates (4), (3), (2) and (1).
2) Install right and left engine side covers.

7. Towing winch assembly

See Removal and installation of towing winch
assembly.

8. Counterweight /frame
See Removal and installation of Counterweight /
frame.

9. Boom/frame
See Removal and installation of boom/frame.

30-212 D155C-1
Disassembly and assembly Counterweight/frame

Removal and installation of

counterweight/frame
Removal

k Counterweight/frame removal work requires the

utmost care because it involves the handling of
heavy weight under unstable condition.

1. Counterweight
Raise counterweight assembly fully. Remove
plates and bolts and lift off the right and lift coun-
terweight (1).
4 Counterweight (one piece): 1600 kg

2. Bracket
1) Sling bracket (2)
2) Pull joint pins (3) until the right and left cylin-
der piston rods can be detached. Set the
right and left cylinder assembly (4) to winch.
3) Pull out joint pins (3) fully to disconnect the
right and lift links (5) from bracket.

4) Sling bracket and support links (6) on block

[1].
5) Pull out joint pins and lift off bracket (2).
4 Bracket: 2150 kg

3. Link
Sling right or left link (5), pull out joint pin, and lift
off the link. Remove the opposite link in the
same way.
4 Link: 80 kg

D155C-1 30-213
Disassembly and assembly Counterweight/frame

4. Cylinder assembly
k Move control lever two or three times to ex-
pel the remaining pressure from piping.
1) Disconnect cylinder inlet and outlet pipes (7)
and (8).
2) Sling cylinder assembly (4), pull out joint
pin, and lift off cylinder assembly. Remove
the opposite cylinder assembly in the same
way.
4 Cylinder assembly: 62 kg

5. Link
Sling right or left link (6), pull out joint pin, and lift
off the link. Remove the opposite link in the
same way.
4 Link: 700 kg
a Identify the right and left links to prevent con-
fusion.

6. Frame
1) Sling frame (9).
2) Remove upper and lower mounting bolts (1)
and lift off frame.
4 Frame: 590 kg

30-214 D155C-1
Disassembly and assembly Counterweight/frame

Installation

k Counterweight/frame installation work requires

the utmost care because it involves the handling
of heavy weight under unstable condition.
2 Joint pin:
Fill each joint pin with grease (GLT2-Ll)

1. Frame
1) Lift frame (9) into position on track frame
and gate frame.
2) Tighten upper and lower mounting bolts
(10).

2. Link
1) Lift link (6) into position to connect it to
frame. Insert the joint pin and install plate to
prevent pin from coming loose.
2) Place link on block [1].

3. Cylinder assembly
1) Lift cylinder assembly (4) into position to
connect it to frame. Insert joint pin and in-
stall plate to prevent pin from coming loose.
2) Attach O-rings and connect cylinder inlet
and outlet hose (7) and (8). Leave cylinder
assembly positioned on winch side.

D155C-1 30-215
Disassembly and assembly Counterweight/frame

4. Link
Lift link (5) into position to connect it to frame. In-
sert joint pin and install plate to prevent pin from
coming loose.

5. Bracket
1) Lift bracket (2) into position to connect it to
link (6). Insert joint pin and install plate to
prevent pin from coming loose.

2) Lift bracket (2) into position to connect it to

link (5). Drive in joint pin (3) halfway.
3) Align pin hole in piston rod of cylinder (4)
with joint pin (3) and drive in joint pin com-
pletely. Install plate to prevent pin from com-
ing loose.

6. Counterweight
1) Start engine and raise bracket to the end of
its stroke.
2) Lift counterweight (1) into position on brack-
et.
3) Install bolts and plates.

30-216 D155C-1
Disassembly and assembly Boom/frame

Removal and installation of

boom/frame
Removal

1. Lower boom (1) to ground.

2. Disconnect wire rope from sheave. Start engine

and operate winch control lever to wind the wire
rope onto winch.

3. Remove electric cable (2) from the connector.

4. Sling boom (1), pull out joint pin (3), and lift off
boom.
4 Boom: 1850 kg (7.3 m-Boom)

5. Sling frame (4), remove upper and lower mount-

ing bolts (5), and lift off frame.
4 Frame: 590 kg

Installation

1. Attach shims to gate frame.

a Standard shim thickness: 5 mm

2. Lift frame (5) into position on track frame and

gate frame.
Tighten mounting bolts (4).

3. Lift boom (1) into position. Connect boom to

frame with joint pin (3). Install plate.

4. Connect electric cable (2) to connector.

5. Unwind wire rope from winch and wind it onto

sheave.
a Take care to prevent twisting of wire rope
when winding.
a Make sure that end of wire rope is tied to
sheave securely.

6. After mounting, apply grease (GLT2-LI) to all

pins.

D155C-1 30-217
Disassembly and assembly Towing winch

Removal and installation of

towing winch assembly
Special tool

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

L 790-102-1100 Wrench t 1

Removal

Preparation work
• Lower the counterweight completely.
• Wind off wire rope from winch drum.

1. Rod
Detach control rod (1) from towing winch.

2. Piping
1) Remove intermediate clamp (2).
2) Disconnect tubes (3) and (4) leading to cool-
er.

3. Guard
Remove guard (5).

4. Plate
Remove plate (6) and take out shims.
a Check and record the number and thickness
of shims.

30-218 D155C-1
Disassembly and assembly Towing winch

5. Universal joint
1) Remove universal joint under cover.
2) Remove universal joint (7).

6. Towing winch assembly

1) Using special tool L, remove mounting bolts
(8).
kSet special tool L (multiplier wrench)
securely and operate it carefully.
a Width across flats of bolt: 60 mm

2) Lift off towing winch assembly (9).

4 Towing winch assembly: 3200 kg

D155C-1 30-219
Disassembly and assembly Towing winch

Installation

1. Towing winch assembly

1) Lift towing winch assembly (9) into position
on gate frame.

2) Install bolts (8) and tighten them using spe-

cial tool L.
k Set special tool L securely and operate
it carefully.
a Width across flats of bolt: 60 mm
3 Mounting bolt:
3285.2 ± 343.2 Nm {335 ± 35 kgm}

2. Universal joint
1) Position universal joint (7) on coupling and
tighten mounting bolts.
3 Mounting bolt:
107.9 ± 14.7 Nm {11 ± 1.5 kgm}
2) Install universal joint under cover.

3. Plate
Attach shims and install plate (6).
a Standard shim thickness: 4.6 mm

4. Guard
Install guard (5).

30-220 D155C-1
Disassembly and assembly Towing winch

5. Piping
1) Attach O-rings and connect tubes (4) and
(3) leading to winch control valve from cool-
er.
2) Attach intermediate clamp (2) and fix tubes.

6. Rod
Attach spacer to each end of winch control rod
(1) and install rod.

7. Wire rope
Wind up wire rope onto towing winch.
a Fit the front end of wire rope to winch drum
and sheave securely.
a Be careful not to twist or slacken wire rope
when winding.

D155C-1 30-221
Disassembly and assembly Towing winch

Disassembly and assembly of

towing winch assembly
Special tools

New/remodel
Necessity
Symbol

Sketch
Q'ty
Part No. Part Name

1 791-780-1400 Wrench t 1
2 791-781-1330 Wrench t 1
3 791-781-1310 Wrench t 1
4 791-781-1320 Wrench t 1
5 791-781-1000 Compressor t 1

M 791-100-2200 Installer t 1
790-101-1102 Pump t 1
6
Puller
790-101-2102 t 1
(294kN {30ton})
790-101-1102 Pump t 1
7 Puller
790-101-2102 t 1
(294kN {30ton})

Disassembly (1/2)

k When turning an assembly upside down, rope

the assembly securely and take special care to
prevent accidents.

1. Draining oil
Drain oil from towing winch case.
6 Towing winch oil: Approx. 100 l

2. Limit switch assembly

1) Sling limit switch assembly (1).
2) Remove mounting bolts and detach limit
switch assembly and shims.
a Check and record the number and thick-
ness of shims removed.

3. Bracket and sheave assembly

1) Remove lock plate from shaft.
2) Sling bracket and sheave assembly (2).
3) Drive out shaft (3) and remove bracket and
sheave assembly.
4 Bracket and sheave assembly:
140 kg
4 Shaft: 30 kg

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4. Filter
Remove filter assembly (4).

5. Selector valve assembly

1) Detach flow divider and remove selector
valve assembly (6).
2) Remove bracket (7).

6. Winch control valve assembly

1) Sling winch control valve assembly (8).
2) Remove 8 mounting bolts (9) and lift off
winch control valve assembly.
4 Control valve assembly: 100 kg

7. Winch pump assembly

Remove winch pump assembly (10).

8. Cover
Remove covers (11), (12), (13), (14), (15), (16),
(17) and (18).

9. Seat
Turn in guide bolts [1] (10 mm, P = 5), remove
mounting bolts, and take out seats (19) and (20).

D155C-1 30-223
Disassembly and assembly Towing winch

10. Collar
Remove collars (21), (22) and (23).

11. Cover
1) Remove covers (24) and (25).
2) Remove level gauge guide (26).

12. Nut
Using special tool M1, loosen right and lift nuts
(27) on drum shaft.
a Temporarily loosening these nuts at this
stage is necessary to facilitate disassembly
work.

13. Case
1) Lift towing winch assembly into position on
blocks (250 mm high) so that winch control
valve faces downward.
k Set blocks stably to prevent winch as-
sembly from overturning.

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2) Using special tool M2, remove brake shaft

nut (28).

3) Remove drum shaft nut (29), washer and

holder (30).
4) Pull out cage (31) using jack bolts (12 mm, P
= 1.75, l = 100 mm) and remove shims (32).
a Check and record the number and thick-
ness of shims removed.

5) Remove case mounting bolts.

6) Sling case using two eyebolts [2] (10 mm, P
= 1.5) and one eyebolt [3] (12 mm, P = 2.0).
7) Put puller [4] against brake shaft and install
jack bolts [5] (16 mm, P = 2.0). Turn in jack
bolts and apply pressure to puller alternately
until case (33) comes off brake shaft.
4 Case: 260 kg

14. Pipe
Remove pipe (34).

15. Pinion and gear assembly

Remove pinion and gear assembly.
4 Pinion and gear assembly: 50 kg

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Disassembly and assembly Towing winch

16. Brake assembly (for boom)

1) Remove collar (36) and take out gear (37).
2) Remove collar (38).

3) Remove mounting bolts.

4) Fit eyebolts [6] (12 mm, P = 1.75) and lift off
brake assembly (39).
4 Brake assembly: 70 kg
5) Remove inner drum (40), retainer (41) and
collar (42) from shaft.

17. Gear assembly

1) Remove mounting bolts (43).
2) Sling gear assembly (44) and turn in jack
bolts [7] (20 mm, P = 2.5, l = 200 mm) until
the assembly comes off shaft.
4 Gear assembly: 100 kg

18. Intermediate case

Fit eyebolts [8] (16 mm, P = 2.0) and lift off inter-
mediate case (45).
4 Intermediate case: 220 kg

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19. Boom drum

1) Wind wire rope around drum and lift off
boom drum (46).
4 Boom drum: 150 kg
2) Remove collar (47).

20. Strainer
Remove strainer (48).

21. Cover
Remove covers (49), (50) and (51). Remove
drain plug assembly (52).

22. Seat
Remove seat (53).

23. Case
1) Sling towing winch and turn it upside down
so winch control valve faces upward.
k Support case and drum stably on
blocks to prevent winch from overturn-
ing.

D155C-1 30-227
Disassembly and assembly Towing winch

2) Using special tool M2, remove brake shaft

nut (54).

3) Remove drum shaft nut (55), washer and

holder (56).
4) pull out cage (57) using jack bolts (12 mm, P
= 1.75, l = 100 mm.)

5) Remove case mounting bolts.

6) Sling case using two eyebolts [3] (12 mm, P =
1.75) and one eyebolts [2] (10 mm, P = 1.5).
7) Put puller [4] against brake shaft and install
jack bolts [5] (16 mm, P = 2.0). Turn in jack
bolts and apply pressure to pulley alternate-
ly until case (58) comes off brake shaft.
4 Case: 300 kg

24. Pipe
Remove pipe (59) and lubrication pipe (60).

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25. Pinion and gear assembly

Remove pinion and gear assembly
4 Pinion and gear assembly: 50 kg

26. Brake shaft gear

Remove collar (62) and take out gears (63) and
(64).

27. Input shaft gear

1) Pry snap ring (65) off.
2) Using puller [7], pull out gear (66), collar
(67) and bearing (68) from input shaft.

3) Remove collar (69).

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Disassembly and assembly Towing winch

28. LOW clutch assembly

1) Using special tool M3, remove nut (70).
2) Using puller [7], pull out gear outer drum
(71), collar (72) and bearing (73).

3) Remove inner race (74) and retainer (75).

4) Remove clutch assembly (76).

29. Bracket
Remove bracket (77).

30. Brake assembly (for boom)

1) Remove mounting bolts.
2) Lift off brake assembly (78) using eyebolts
[3] (12 mm, P = 1.75).
4 Brake assembly: 70 kg

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Disassembly and assembly Towing winch

3) Remove collar (79).

4) Remove inner drum (80) and retainer (81).
5) Remove shaft (82).

31. Gear assembly

1) Remove mounting bolts (83).
2) Remove gear assembly (84) using jack bolts
(20 mm, P = 2.5, l = 200 mm).
4 Gear assembly: 100 kg

32. Case and clutch assembly

Lift off case and clutch assembly (85) using eye-
bolts [7] (16 mm, P = 2.0)

33. Hook drum

Wind wire rope around drum and lift off hook
drum (86).
4 Hook drum: 170 kg

34. Drum shaft

Remove drum shaft (87).

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Disassembly and assembly Towing winch

35. Brake shaft

1) Place case and clutch assembly on blocks
(250 mm high).
k Set blocks stably to prevent the assem-
bly from falling down.
2) Remove guide (88).
3) Sling shaft (89).
4) Drive out shaft, remove gear (90) and collar
(91), and take out bearing inner race.

36. Input shaft

1) Remove coupling and take out oil seal cage
(92).
2) Pry snap ring (93) off.

3) Using puller [4], pull out input shaft (94). Re-

move gear (95) and collar (96).

37. Clutch assembly

1) Using special tools M3, and M4, remove
clutch nuts (97), (98) and (99).

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2) Sling HI clutch assembly (100) and put a

pipe (55 mm I.D.) against it.
3) Pull out shaft using puller [4] and lift off
clutch assembly.

4) Similarly, remove boom up/hook up clutch

assembly (101) and boom down/hook down
clutch assembly (102).

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Disassembly (2/2)

• Disassembly of Brake assembly

1) Set brake assembly in a press, put plate [1]
(210 mm O.D.) on brake cover, and expand
press ram to apply pressure to plate.
2) Remove mounting bolts (1). Retract press
ram gradually to loosen spring tension.
3) Remove cover (2).

4) Take out 24 springs (3) and (4).

5) Remove piston (5).
a Put match marks on piston and drum be-
fore removal.

6) Turn brake assembly upside down. Remove

cover (6).
7) Remove plates (7) and discs (8).

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• Disassembly of Clutch assembly (for boom

down/hook down)

1. Remove boom side clutch assembly using

the following procedure:
1) Remove gear (9).

2) Remove outer drum (10).

3) Remove inner race (11) and plate (12).

4) Remove clutch assembly (13).

2. Remove hook side clutch assembly using

the following procedure:
1) Set HOOK DOWN clutch and shaft assem-
bly in a press.
2) Remove nut (14).
3) Pull out shaft (15). Remove bearing (16)
and collar (17).
4) Remove outer drum (18).
5) Detach inner race and plate and remove
clutch assembly (19).

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Disassembly and assembly Towing winch

3. Disassemble clutch assembly using the following

procedure:

1) Set clutch assembly (19) in a press. While

plate (20) is kept pressed by press ram, re-
move bolts (21).
2) Retract press ram gradually to loosen spring
tension. Remove plate (20).
3) Remove discs (22) and plates (23).
4) Take out springs (24).
5) Remove inner drum (25).
6) Remove plate (26).
7) Remove collar (27).
8) Detach piston (28) from drum (29).

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Assembly (1/2)

• Assembly of Clutch assembly (for boom and

hook)

a Coat sliding surfaces of disassembled parts and

make sure that they are free from dust, scratch-
es, and other defects.

1. Reassemble clutch assembly using the fol-

lowing procedure:

1) Attach O-ring and install piton (28) in drum

(29).
2) Install collar (27).
3) Install plate (26).
4) Install inner drum (25).
5) Install springs (24).
6) Install discs (22) and plates (23) alternately.
7) Set the assembled unit in a press.
8) Set the plate (20) in place.
a Use two guide bolts (10 mm, P = 1.5) to
set the plate.
9) Press the plate gradually to compress
springs.
Install and tighten mounting bolts (21).
3Mounting bolt:
65.7 ± 6.9 Nm {6.7 ± 0.7 kgm}

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Disassembly and assembly Towing winch

2. Reassemble hook side clutch assembly

using the following procedure:

1) Attach an O-ring to shaft (15).

2) Install clutch assembly (19) to shaft.
a Install clutch assembly so that the lubri-
cation hole in the inner drum is posi-
tioned 90° ± 19° away from the
lubrication hole in shaft.
3) Install plate (30) and inner race (31). Install
outer drum so that its teeth come into align-
ment with external teeth of clutch plates.
a Install inner race so that its lubrication
hole is positioned 90° ± 19° away from
lubrication hole in the shaft.
a Before installing outer drum, align all of
the notches in the periphery of clutch
plates with each other.
4) Install collar (17). Press-fit bearing (16) us-
ing push tool (70 mm I.D.).
a Predetermine the protrusion of shaft
from the press-fitted bearing.
5) Fasten nut (14).
3 Nut: 137.3 ± 19.6 Nm{14 ± 2 kgm}
a Be sure to bend lock plates securely.

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3. Reassemble boom side clutch assembly

using the following procedure:
1) Attach O-ring to shaft.
2) Install clutch assembly (13) to shaft.
a Install clutch assembly so that the lubri-
cation hole in the inner drum is posi-
tioned 90° ± 19° away from the
lubrication hole in shaft.
3) Install plate (12) and inner race (11).
a Install inner race so that its lubrication
hole is positioned 90° ± 19° away from
the lubrication hole in shaft.
4) Install outer drum (10).
a Install outer drum after aligning all of the
notches in the periphery of clutch plates
with each other.
5) Install gear (9).

• Assembly of Brake assembly

a Coat sliding surfaces of disassembled parts with

engine oil.

1) Install seal ring. Install piston (5) in outer

drum (32).
a Align match marks with each other to in-
stall piston in the same condition as be-
fore disassembly.
2) Set outer drum in special tool M5.
3) Install 24 springs (4) and (3).
a Make sure that each spring is seated
properly.
4) Set cover (2) in place
a Make sure that top of each spring is
seated properly to cover.
5) Fix cover at that position using guide bolts
[2] (12 mm, P = 1.75).
6) Using special tool M7, compress springs
and install mounting bolts (1).
7) Turn outer drum upside down and install
special tool M7.

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Disassembly and assembly Towing winch

8) Install inner drum (33).

a Install inner drum together with a plain
spacer (10 mm) inserted between piston
and inner drum.
a Set inner drum so that clearance be-
tween inner drum and outer drum is uni-
form.

9) Install plates and discs (7) alternately.

a Install plates so that all of the notches in
the periphery of plates come in align-
ment with each other.
a After installing plates and discs, check
again for uniformity of clearance be-
tween inner drum and outer drum.
10) Tighten nut of special tool M5 to fix inner
drum.

11) Install plate (7).

3 Mounting bolt:
65.7 ± 6.9Nm {6.7 ± 0.7 kgm}
12) Remove nut of special tool M5 by loosening
it gradually. Take out brake assembly from
special tool.
13) Remove inner drum and spacer from brake
assembly.

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Assembly (2/2)

k When turning an assembly upside down, rope

the assembly securely and take special care to
prevent accidents.

a Coat sliding surfaces of disassembled parts with

engine oil.

1. Bearings and oil seal

1) Using a push tool, press-fit bearings (104),
(105), (106), (107), (108) and (109) into
case.
2) Using a push tool (220 mm O.D.), press-fit
oil seal (110) into case.

3) Turn case upside down and place it on

blocks.
k Set blocks stably to prevent case from
falling down.

2. Clutch assembly
1) Sling BOOM DOWN/HOOK DOWN clutch
assembly (102) and keep it horizontal by us-
ing a pipe (55 mm I.D.). Set the assembly to
bearing.
a When inserting clutch assembly into
case, be careful not to allow drum teeth
to get out of alignment with disc teeth.

D155C-1 30-241
Disassembly and assembly Towing winch

2) Put puller [4] against bearing inner race to

prevent it from coming out of case.
3) Keeping clutch assembly horizontal, press-
fit its shaft into bearing with puller [8] and
special tool M7.

4) Similarly, install BOOM UP/HOOK UP clutch

assembly (101) and HI clutch assembly
(100).

5) Install lock plates and tighten nuts (99), (98)

and (97) temporarily.
a These nuts are retightened later.

3. Input shaft
1) Install gear (95) in case.
2) Install collar (96) to shaft (94).
3) Align shaft spline with gear spline and install
shaft in bearing.

30-242 D155C-1
Disassembly and assembly Towing winch

4) Put puller [4] against bearing inner race to

prevent it from coming out of place.
5) Keeping shaft horizontal, press-fit input
shaft (94) into bearing using puller [8] and
special tool M7.

6) Install snap ring (93).

7) Attach on O-ring and install oil seal case
(92).
2 Oil seal lip: Grease (GLT2-LI)
Fill 40 to 60% of
vacancy.
8) Install coupling.

4. Brake shaft
1) Install bearing inner race (111) in bearing.

2) Install gear (90).

3) Sling shaft (89) and install collar (91).
4) Engage shaft spline with gear spline and in-
stall shaft in bearing inner race.
5) Supporting bearing inner race to prevent it
from coming out of place, press fit brake
shaft (89).

D155C-1 30-243
Disassembly and assembly Towing winch

6) Attach O-ring and install guide (88).

7) Attach gasket and install cover (112).

5. Drum shaft
Fit collar (114) to shaft (113). Install bearing in-
ner race (115), seal collar (116) and bearing in-
ner race (117) in that order.

6. Hook drum
1) Press-fit bearing (118) into drum and install
snap ring (119).
2) Press-fit oil seal (120).

3) Fix drum shaft (87).

4) Wind wire rope around hook drum (86),
sling drum, and install it on drum shaft.
2 Drum interior: Fill 60% of drum
interior with
grease (GTLT2-LI)
2 Oil seal lip: Fill 40 to 60% of
vacancy with
grease (GLT2-LI)

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7. Case and clutch assembly

1) Turn case and clutch assembly (85) upside
down. Lift the assembly using eyebolts [7]
(16 mm, P = 2.0), bring it close against hook
drum, and place it on a block [8] (700 mm
high).
2 Oil seal lip: Fill 40 to 60% of
vacancy with
grease (GLT2-LI)
k Set the block stably to prevent the as-
sembly from falling down.

2) After setting case and clutch assembly, ad-

just drum height with jack [10].
3) Sling drum shaft and adjust its height. Sup-
port the shaft bottom on a block to keep the
height adjusted.

8. Gear assembly
1) Using push tool (215 mm O.D.), press-fit
bearing (121) into gear (122).
2) Using push tool (180 mm O.D.), press-fit oil
seal (123) into gear (122).
2Oil seal lip: Fill 40 to 60% of
vacancy with
grease (GLT2-LI)

3) Attach O-ring to hook drum.

4) Lift gear assembly (84) into position in line
with drum shaft by aligning dowel pins with
their mating hose.
5) Using special tool M6, press-fit the gear as-
sembly.

D155C-1 30-245
Disassembly and assembly Towing winch

6) Install mounting bolts (83).

a Be sure to bend lock plates securely.

9. Brake assembly (for hook)

1) Press-fit bearing inner race (125) onto shaft
(124) and install holder (126).
a Be sure to bend lock plates securely.
2) Install shaft (82) in case.
3) Install retainer (81) and inner drum (80) to
shaft.
a Install drum so that lubrication hole in
gear is positioned 90° ± 17° away from
the lubrication hole in shaft.

4) Install collar (79) to shaft.

a Install collar so that its notch faces up-
ward.
5) Using eyebolts [3] (12 mm, P = 1.75), lift
brake assembly (78) into position so that
shaft spline comes into engagement with in-
ner gear spline.
6) Install mounting bolts.

10. Bracket
Install bracket (77).

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11. LOW clutch assembly

1) Reassemble LOW clutch assembly.
a Before installing drum, align all of the
notches in the periphery of clutch plates
with each other.
2) Attach O-ring to shaft.
3) Install LOW clutch assembly (127) on shaft
by fitting its splines.
a Be careful to prevent loosening of the
joint between drum and plates during in-
stallation.
a Position lubrication holes in shaft, drum
and inner race 90° ± 19° away from each
other.
4) Install collar (72).
5) Using push tool (70 mm, I.D.), press-fit
bearing (73).
6) Using special tool M3, tighten nut (70).
3 Nut: 137.3 ± 19.6 Nm{14 ± 2kgm}
a Be sure to bend lock plates securely.

7) Install pinion and gear assembly (61).

12. Pipe
Attach O-rings and install pipe (59) and lubrica-
tion pipe (60).

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Disassembly and assembly Towing winch

13. Case
1) Coat fitting surface of case with liquid gas-
ket. Lift case (59) into position using two
eyebolts [33] (12 mm P = 1.75) and one
eyebolt [2] (10 mm, P = 1.5).
2 Fitting surface of case:
Liquid gasket (LG-4)
a Be careful not to damage bearing during
installation.
2) Install mounting bolts.

3) Using puller [4] and special tool M7, press-fit

bearing (135).
4) Using special tool M2, tighten nut (54).
3 137.3 ± 19.6 Nm {14 ± 2 kgm}
a Be sure to bend lock plate securely.

5) Attach O-ring to drum shaft.

6) Attach O-ring and install cage (57), using
guide bolts [11] (12 mm, P = 1.75) and align
dowel pins with pin holes.
7) Install holder (56) and washer. Temporarily
install nut (55).
a Leaving the nut installed temporarily is
necessary to facilitate assembly work.
The nut is to be retightened later.

14. Nut
1) Turn case assembly upside down so that
winch control valve side is placed on a block
(250 mm high).
k Be sure to set the block stably to pre-
vent case assembly from falling down.
2) Using special tools M3 and M4 tighten nuts
(136), (137) and (138).
3 Nut: 137.3 ± 19.6 Nm {14 ± 2 kgm}
a Be sure to bend lock plates securely.

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15. Seat
Attach O-ring and install seat (53).

16. Cover
1) Install seal ring to each shaft
a To facilitate installation of cover, tighten
seal ring with clamp [12].
2) Attach O-rings and install covers (51), (50)
and (49).
a Install covers by hand. Never hammer
them, as it may damage the O-rings.
3) Attach O-ring and install drain plug assem-
bly (52).

17. Strainer
Attach O-ring and install strainer (48).

18. Boom drum

1) Press-fit bearing (139) into drum and lock
with snap ring (140).
2) Press-fit oil seal (141).

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Disassembly and assembly Towing winch

3) Install collar (47) to shaft.

4) Wind wire rope around boom drum (46) and
lift the drum into position on shaft.
2 Drum interior: Fill 60% of drum
interior with
grease (GLT2-LI)
2 Oil seal lip: Fill 40 to 60% of
vacancy with
grease (GLT2-LI)
a Insert a spacer (9 to 10 mm) between
boom drum and hook drum.

19. Intermediate case

1) Using a push tool (220 mm O.D.), press-fit
oil seal (142) into case.
2) Using a push tool (170 mm O.D.), press-fit
bearing (143) into case.

3) Attach O-ring. Sling intermediate case (45)

horizontally using eyebolts [7] (16 mm, P =
2.0) and position the case on boom drum.
2 Oil seal lip: Fill 40 to 60% of
vacancy with
grease (GLT2-LI)
4) Install mounting bolts.

20. Gear assembly

1) Using push tool (215 mm O.D.), press-fit
bearing (145) into gear (146).
2) Using push tool (180 mm O.D.), press-fit oil
seal (147) into gear (146).
2 Oil seal lip: Fill 40 to 60% of
vacancy with
grease (GLT2-LI)

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Disassembly and assembly Towing winch

3) Attach O-ring to boom drum.

4) Lift gear assembly (44) into position on
drum shaft so that dowel pins come into
alignment with pin holes.
5) Using special tool M6, press-fit the gear as-
sembly.

6) Install mounting bolts (43).

a Be sure to bend lock plates securely.

21. Brake assembly (for boom)

1) Install collar (42), retainer (41) and inner
drum (40) in that order to shaft.
a Install drum so that the lubrication hole in
gear is positioned 19° ± 17° away from
the lubrication hole in shaft.
2) Using eyebolts [6] (12 mm, P = 1.75), lift
brake assembly (39) into position so that
shaft spline fits in with inner gear spline.
3) Install mounting bolts.

4) Install collar (38).

a Install collar so that its notch faces up-
ward.
5) Install gear (37) and collar (36).

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22. Pinion and gear assembly

1) Drive key (149) in pinion (148).
2) Press-fit gear (150) to pinion.
3) Using push tool (95 mm I.D.), press-fit bear-
ing (151) and lock it with snap ring (152).
4) Using a push tool (1.75 mm I. D.), press-fit
bearing (153) and lock it with snap ring
(154).
5) Install pinion and gear assembly (35).

23. Pipe
Attach O-ring and connect lubrication pipe (34).

24. Case
1) Coat fitting surface of case with liquid gas-
ket. Sling case (33) horizontally using two
eyebolts [2] (10 mm, P = 1.5) and one eye-
bolt [3] (12 mm, P = 1.75). Lift the case into
position.
2 Fitting surface of case:
Liquid gasket (LG-4)
a Be careful not to damage bearing during
installation.
2) Install mounting bolts.

3) Using puller [4] and special tool M7, press-fit

bearing (155).
4) Using special tool M2, tighten nut (28).
3 Nut: 137.3 ± 19.6 Nm {14 ± 2 kgm}
a Be sure to bend lock prates securely.

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5) Attach O-ring to drum shaft.

6) Install a set of shims (32) having the same
thickness as before disassembly.
a Standard shim thickness: 1.5 mm
7) Attach O-ring and install cage (31) to shaft.
8) Install holder (30) and washer. Temporarily
tighten nut (29).
a To facilitate assembly work, leave the
nut tightened temporarily until retighten-
ing of it becomes necessary.

25. Nut
1) Turn towing winch upside down and place it
on a block (250 mm high).
k Set the block stably to prevent towing
winch from falling down.

2) Using special tool M1, tighten nuts (27).

3 Nut: 686.5 ± 98.1 Nm {70 ± 10 kgm}
a Tighten hook drum side nut first and,
then tighten boom drum side nut.
a Be sure to bend lock plates securely.

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26.
1) Attach O-ring and install oil level gauge
guide (26).
2) Install seal ring to brake shaft, attach O-ring,
and fit cover (25).
3) Attach O-ring and install cover (24).

27. Seal ring

Install seal rings to shafts (156), (157), (158) and
(159).
a To facilite installation of covers, tighten
each seal ring with a hose clamp.

28. Collar
Attach O-rings and install collars (23), (22) and
(21).

29. Seat
1) Screw in guide bolts [1] (10 mm, P = 1.5) to
case.
2) Attach O-ring to seats (20) and (19).

30-254 D155C-1
Disassembly and assembly Towing winch

30. Cover
Attach O-rings and install collars (18), (17),(16),
(15),(14), (13),(12) and (11).
a Install covers (11), (13), (15) and (16) by
hand. Never hammer them as it may dam-
age O-rings.

31. Winch pump

Attach O-ring and install winch pump (10).

32. Winch control valve assembly

1) Attach O-ring to valve seat.
2) Lift winch control valve assembly (8) into po-
sition on valve seat and install 8 mounting
bolts.(9).

33. Selector valve assembly

1) Attach O-ring to valve seat.
2) Install bracket (7) and fit selector valve (6) to
bracket.
3) Attach O-ring and install flow divider (5).
3 Mounting bolt:
29.4 ± 2 Nm {3 ± 0.2 kgm}

34. Filter
Attach O-ring and install filter (4).

35. Bracket and sheave assembly

1) Lift bracket and sheave assembly (2) into
hole in winch case.
2) Drive shaft (3) in.
3) Install shaft lock plate.
4) Fill with grease (GLT2-LI)

D155C-1 30-255
Disassembly and assembly Towing winch

36. Limit switch assembly

Lift limit switch assembly (1) into position on
bracket and pulley block assembly using a pack
of shims having the same thickness as before
disassembly.

37. Lubrication
Refill towing winch with engine oil through oil fill-
er (160) up to the specified level.
5 Towing winch oil: Approx. 100 l

30-256 D155C-1
Disassembly and assembly Heater

Removal and installation of

heater assembly
–50°C specification

Removal
1. Remove right side covers (1) and (2).

2. Close heater fuel valve (3).

3. Disconnect heater hose (4).

4. Disconnect fuel hoses (5) and (6).

5. Remove heater cover (7).

6. Disconnect main wire (8).

7. Disconnect ground wire (9).

8. Remove 6 heater assembly mounting bolts (10)

(3 pieces on each side) and heater assembly
(11).

–50°C specification
Installation

a Carry out installation in the reverse order to re-

moval.

D155C-1 30-257
 40 Maintenance standard

Engine mount................................................. 40- 2

PTO ............................................................... 40- 3
TORQFLOW transmission............................. 40- 4
(1) Torque converter................................... 40- 4
(2) Relief valve and regulator valve............ 40- 6
Transmission ................................................. 40- 8
Transmission control valve ............................ 40- 10
Transmission pump ....................................... 40- 12
Bevel gear shaft and steering clutch.............. 40- 14
Steering brake ............................................... 40- 18
Steering control valve .................................... 40- 20
Steering pump ............................................... 40- 22
Final drive ...................................................... 40- 24
Track frame.................................................... 40- 28
Recoil spring .................................................. 40- 29
Track .............................................................. 40- 30
Idler................................................................ 40- 32
Track roller..................................................... 40- 34
Carrier roller................................................... 40- 36
Suspension .................................................... 40- 38
Winch pump................................................... 40- 39
Counterweight pump...................................... 40- 40
Hi-Lo valve..................................................... 40- 41
PPC valve ...................................................... 40- 42
Flow divider valve .......................................... 40- 43
Winch............................................................. 40- 44
Lower clutch................................................... 40- 46
Raise clutch ................................................... 40- 48
Winch brake................................................... 40- 50
Control valve (for counterweight)................... 40- 52
Counterweight cylinder .................................. 40- 54
Slow return valve ........................................... 40- 55
Counterweight................................................ 40- 56
Boom ............................................................. 40- 58

D155C-1 40-1
Maintenance standard Engine mount

Engine mount

40-2 D155C-1
Maintenance standard PTO

PTO

Unit: mm

No. Check item Criteria Remedy

Standard clearance Clearance limit

1 Backlash of each gear
0.18 – 0.45 1.0
Replace
Backlash between planetary
2 0.19 – 0.50 1.0
gear and driven gear
Press fitting force of main
3 11.8 – 58.8 kN {1.2 – 6 ton} Adjust
shaft

D155C-1 40-3
Maintenance standard TORQFLOW transmission

TORQFLOW transmission
(1) Torque converter

40-4 D155C-1
Maintenance standard TORQFLOW transmission

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

1 Outside diameter of pilot
78 77.075

Seal seat outside diameter on

2 100 99.9 High chrome
seal contact surface
plating repair
Gear outside diameter on seal or replace
3 150 150.3
ring contact surface
Outside diameter of stator
4 shaft on seal ring contact 65 65.5
surface
Width 4.5 3.0
5 Stator shaft seal ring
Thickness 5.5 5.0
Width 2.5 2.0
6 Turbine shaft seal ring
Thickness 2.5 2.2
107.187
7 Wear of drive gear teeth 106.80
(displacement over 12 teeth)
Replace
Backlash of scavenging pump
8 0.16 – 0.43 0.5
drive gear
Side clearance of scavenging
9 0.13 0.25
pump
Top clearance of scavenging
10 0.15 0.30
pump
Tightening torque of pump-to-
11 49 ± 4.9 Nm{5.0 ± 0.5 kgm}
drive case mounting bolts
Tightening torque of stator
12 66.2 ± 7.4 Nm{6.75 ± 0.75 kgm}
mounting bolts
Tightening torque of stator
13 110.3 ± 12.3 Nm{11.25 ± 1.25 kgm}
shaft mounting bolts
Tightening toruque of pump
14 17.2 ± 2.5 Nm{1.75 ± 0.25 kgm}
drain plug
Retighten
Tightening torque of drive
15 case-to-drive gear mounting 110.3 ± 12.3 Nm{11.25 ± 1.25 kgm}
bolts
Tightening torque of reamer
16 bolts for stator shaft holder 95.6 ± 2.5 Nm{9.75 ± 0.25 kgm}
mounting
0°C 1660 ± 60 rpm
RPM at time of torque
17 20°C 1635 ± 60 rpm
converter stalling
40°C 1635 ± 60 rpm

D155C-1 40-5
Maintenance standard TORQFLOW transmission

(2) Relief valve and regulator valve

Relief valve Regulator valve

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between valve size Shaft Hole Clearance limit
1
body and spool
–0.050 +0.025 0.050 –
32 0.20
–0.066 +0.025 0.091

Standard size Repair limit

Free length Installed Installed Installed

Relief valve spring Free length
× O.D. length load load
2 622.7 N 567.8 N
137.7 × 24 98.0 134.2
{63.5 kg} {57.9 kg}

+0.03 Oil temperature:

Relief valve setting pressure 0.85 ± +0.03 MPa {8.7 +0.3 2
+0.03 kg/cm } Replace
70 – 80°C
Standard size Repair limit
Free length Installed Installed Installed
Free length
Regulator valve spring × O.D. length load load
126.6 × 205 N 137.3 N
106.5 120
23.5 {20.9 kg} {14.0 kg}
3
0.44 ± 0.1 MPa
{2.5 ± 1.0 kg/cm2} at 50 l/min.
Regulator valve setting 0.34 ± 0.05 MPa Oil temperature:
pressure {3.5 ± 0.5 kg/cm2} at 100 l/min. 70 – 80°C
0.44 ± 0.05 MPa
{4.5 ± 0.5 kg/cm2} at 250 l/min.

40-6 D155C-1
Maintenance standard Transmission

Transmission

Unit: mm

No. Check item Criteria Remedy

Backlash between No. 1, 3, 4

1 0.13 – 0.38
sun gear and planetary gear
Backlash between No. 2 sun
2 gear and planetary gear, 0.12 – 0.34
and No. 2 planetary gears Replace
Backlash between eachring
3 0.15 – 0.41
gear and planetary gear
Backlash between transfer
4 0.18 – 0.55
drive gear and driven gear

40-8 D155C-1
Maintenance standard Transmission

Unit: mm

No. Check item Criteria Remedy

Thickness of a disc for No. 1 – Standard size Tolerance Repair limit

5
4 clutches 5.4 ±0.15 4.9

Thickness of plate for No. 1 –

6 7.0 ±0.1 6.3
4 clutches
Thickness of a disc for No. 5
7 5.4 ±0.1 4.9
clutch
Thickness of a plate for No. 5
8 5.0 ±0.1 4.5
clutch
Overall thickness of four discs
9 and three plates for No. 1 42.6 ±0.26 40.5
clutch Replace
Overall thickness of four discs
10 and three plates for No. 2 42.6 ±0.26 40.5
clutch
Overall thickness of three
11 discs and two plates for No. 3 30.2 ±0.22 28.6
clutch
Overall thickness of two discs
12 17.8 ±0.17 16.7
and one plate for No. 4 clutch
Overall thickness of five discs
13 and four plates for No. 5 47.0 ±0.3 44.3
clutch
High chrome
Outside diameter of oil seal
–0.087 plating
14 contact surface on input 110.0 109.8
–0.087 Repair or
coupling
replace
Standard size Repair limit
Installed Installed
Free length Free length Load
15 No. 1 clutch spring length load
117 N 99 N
66.0 57.6 62.0
{11.9 kg} {10.1 kg}
130 N 111 N
16 No. 2 clutch spring 66.0 56.6 62.0
{13.3 kg} {11.3 kg} Replace
126 N 107 N
17 No. 3 clutch spring 59.0 46.2 55.5
{12.8 kg} {10.9 kg}
149 N 127 N
18 No. 4 clutch spring 59.0 43.8 55.5
{15.2 kg} {12.9 kg}
1.96 kN 1.77 kN
19 No. 5 clutch spring 8.7 7.5
{200 kg} {180 kg}
Thickness of shims for cage
20 1.6
mounting part
Adjust
Thickness of shims for cover
21 0.5
mounting part

D155C-1 40-9
Maintenance standard Transmission control valve

Transmission control valve

40-10 D155C-1
Maintenance standard Transmission control valve

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between modulating size Shaft Hole clearance limit
1
valve sleeve and valve body
–0.035 +0.016 0.035 –
35 0.081
–0.045 +0.013 0.061
Clearance between modulating
–0.035 +0.013 0.035 –
2 valve sleeve and modulating 25 0.078
–0.045 +0.013 0.058
valve spool
Clearance between modulating –0.020 +0.018 0.020 –
3 15 0.068
valve spool and piston –0.030 +0.021 0.048
Clearnace between quick
+0.015 +0.025 –0.015 –
4 return valve sleeve and 44 0.055
–0.010 +0.011 0.035
valve body
Clearnce between quick
–0.035 +0.011 0.035 –
5 return valve sleeve and 12 0.076
–0.045 +0.011 0.056
valve body
Clearance between reducing –0.035 +0.013 0.035 –
6 28 0.078
valve and valve body –0.045 +0.013 0.058
Replace
Clearance between reducing –0.020 +0.018 0.020 –
7 15 0.068
valve and piston –0.030 +0.018 0.048
Clearance between F-R valve –0.035 +0.013 0.035 –
8 28 0.078
and valve body –0.045 +0.013 0.058
Clearance between speed –0.035 +0.013 0.035 –
9 28 0.078
valve spool and valve body –0.045 +0.013 0.058
Standard size Repair limit
Installed Installed Installed
Modulating valve sleeve Free length Free length
10 length load load
spring
83.9 N 79.7 N
53.0 35.0 51.4
{8.56 kg} {8.13 kg}
Modulating valve spool spring 65.1 N 61.9 N
11 41.5 36.9 40.3
(small) {6.64 kg} {6.31 kg}
Modulateing valve spool 65.1 N 61.9 N
12 42.4 39.6 41.1
spring (large) {6.64 kg} {6.31 kg}
140 N 133 N
13 Reducing valve spring 52.0 43.7 50.4
{14.3 kg} {13.59 kg}

D155C-1 40-11
Maintenance standard Transmission pump

Transmission pump
FAL045

Unit: mm

No. Check item Criteria Remedy

Standard clearance Clearance limit

1 Side clearance
0.075 – 0.085 0.115 Replace
Clearance between plain
2 0.055 – 0.079 0.14
bearing and gear shaft
Revolving Discharge Standard
Discharge Discharge limit
speed pressure discharge
— Oil: EO10W-CD (l/min) —
(rpm) (MPa {kg/cm2}) (l/min)
Oil temperature: 45 – 55°C
2,300 2.9 {30} 82 78

40-12 D155C-1
Maintenance standard Bevel gear shaft and steering clutch

Bevel gear shaft and steering clutch

40-14 D155C-1
Maintenance standard Bevel gear shaft and steering clutch

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Thickness of drive plate Replace
2.9 2.0
1
Tolerance Repair limit Correct or
Strain of drive plate
Less than 0.2 0.3 replace

Standard size Repair limit

Thickness of driven plate Replace
4.7 3.7
2
Tolerance Repair limit Correct or
Strain of driven plate
Less than 0.2 0.3 replace

Total assembled thickness of Standard size Repair limit

3
drive plate and driven plate 88.3 81.6

Backlash between drive plate Standard clearance Repair limit

4 Replace
and clutch drum (inner) 0.3 – 0.4 1.0
Backlash between driven
5 0.3 – 0.4 1.0
plate and brake drum (outer)

Backlash between bevel gear Standard clearance Clearance limit Adjust or

6
and pinion 0.25 – 0.33 0.75 replace

Clutch drum (inner drum) Standard size Repair limit

7 inside diameter on seal ring
contact surface 245 245.5

Clearance between piston Standard clearance Repair limit

8
seal ring groove and seal ring 0.07 – 0.18 0.4
Inner diameter of bevel gear Standard size Repair limit Replace
9 shaft flange on seal ring
contact surface 145 145.3

Seal ring width 4.5 4.0

10 Width of bevel gear shaft seal Standard clearance Clearance limit
ring groove 4.5 5

Outside diameter of brake Standard size Repair limit Correct or

11
drum (outer drum) 450 445 replace

D155C-1 40-15
Maintenance standard Bevel gear shaft and steering clutch

40-16 D155C-1
Maintenance standard Bevel gear shaft and steering clutch

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Free length Installed Installed Installed
Free length
12 Clutch spring (large) × O.D. length load load
2491.8 N 2246.7 N Replace
145.15 × 104 141
{254.1 kg} {229.1 kg}
1431.8 N 1294.5 N
13 Clutch spring (small) 137.83 × 104 134.5
{146 kg} {132 kg}
Tolerance Repair limit
14 Squareness of brake drum Correct or
Less than 0.3 0.5
replace
15 Eccentricity of brake drum Less than 0.15 0.3

Standard Tolerance Standard Clearance

size Shaft Hole clearance limit
16 Bevel gear reamer bolt fitting Replace
–0.018 +0.027
16 0 – 0.045
–0.018 +0.027
Correct or
Repair limit: 0.05
17 Bevel gear back deflection replace as an
(To be measured after installation on the bevel gear shaft)
assembly
Standard revolving torque: 3.9 – 11.8 Nm {0.4 – 1.2 kgm}
Preload on bevel gear shaft
18 (to be measured 18.61 – 58.4 Nm {2 – 6 kgm} at bevel gear top in Adjust
taper roller bearing
mesh with bevel pinion)
Bevel gear shaft hub press-fit
19 294.2 kN {30 ton}
force

Dimension after press-fit of Standard size Repair limit

20
bevel gear shaft hub 6 ± 0.5 mm +0.5
Replace
Squareness of bevel gear shaft
21 Repair limit: 0.15 mm
hub
Concentricity of bevel gear
22 Repair limit: 0.15 mm
shaft hub

D155C-1 40-17
Maintenance standard Steering brake

Steering brake

40-18 D155C-1
Maintenance standard Steering brake

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

1 Thickness of brake lining
15.5 11.5

Standard Tolerance Standard Clearance

Clearance between booster size Shaft Hole clearance limit
2
piston and booster housing
–0.030 +0.030 0.030 –
70 0.1
–0.049 +0.027 0.079
Clearance between booster –0.005 +0.064 0.039 –
3 25 0.1
spool and sleeve –0.010 +0.034 0.074
Replace
Standard size Repair limit
Free length Installed Installed
Free length Load
4 Booster spool return spring × O.D. length load
98.1 N
89.0 × 58.0
{10.0 kg}
196.1 N 156.9 N
5 Brake band return spring 78.3 x 23.2 97.0 82.0
{20.0 kg} {16.0 kg}
44.5 N 35.3 N
6 Brake band relief spring 42.4 x 18.3 47.4 43.4
{4.54 kg} {3.6 kg}

D155C-1 40-19
Maintenance standard Steering control valve

Steering control valve

40-20 D155C-1
Maintenance standard Steering control valve

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between modulating size Shaft Hole clearance limit
1
valve and free piston
–0.02 +0.018 0.020 –
15 0.08
–0.03 –0.017 0.048
Clearance between spool and –0.034 +0.013 0.034 –
2 30 0.1
housing –0.043 +0.021 0.056
Clearance between modulating –0.034 +0.013 0.034 –
3 30 0.1
valve and housing –0.043 +0.021 0.056
Clearance between main –0.014 +0.013 0.014 –
4 28 0.08
relief valve and housing –0.025 +0.030 0.038
Clearance between main –0.02 +0.018 0.020 –
5 15 0.08
relief valve and free piston –0.03 +0.043 0.048
Clearance between free –0.020 +0.07 0.020 –
6 31 0.1
piston and housing –0.041 +0.07 0.048
Clearance between brake –0.016 +0.017 0.016 –
7 31 0.1
free piston and housing –0.026 +0.017 0.043
Clearance between brake
–0.065 +0.021 0.065 –
8 relief valve sleeve and 21 0.15
–0.098 +0.021 0.119 Replace
plunger
Clearance between nut and –0.016 +0.027 0.016 –
9 14 0.1
plunger –0.034 +0.027 0.061
Clearance between lever –0.020 +0.108 0.022 –
10 20
shaft and bush –0.053 –0.075 0.128
Standard size Repair limit
Free lingth Installed Installed
Free length Load
11 Modulating valve spring × O.D. length load
59.2 N
45.9 × 26.9 40
{6.04 kg}
28.3 N
12 Modulating valve spring 106 × 26.8 46
{2.89 kg}
78.5 N
13 Spool return spring 96.8 x 18 60
{8 kg}
122.6 N
14 Main relief valve spring 46.5 x 18.9 40
{12.5 kg}
115.7 N 104 N
15 Brake relief valve spring 82.4 x 19.6 63 80.4
{11.8 kg} {10.6 kg}

D155C-1 40-21
Maintenance standard Steering pump

Steering pump
FAR100

Unit: mm

No. Check item Criteria Remedy

Standard clearance Clearance limit

1 Side clearance
0.065 – 0.090 0.150
Replace
Clearance between plain
2 0.090 – 0.100 0.125
bearing and gear shaft
Revolving Discharge Standard
Discharge Discharge limit
speed pressure discharge
— Oil: EO10W-CD (l/min) —
(rpm) (MPa {kg/cm2}) (l/min)
Oil temperature: 45 – 55°C
2,000 2.9 {30} 180 170

40-22 D155C-1
Maintenance standard Final drive

Final drive
(1/2)

40-24 D155C-1
Maintenance standard Final drive

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between sprocket size Shaft Hole clearance limit
1
shaft and steering case Replace
–0.036 +0.054 0.036 –
100 0.5 bushing
–0.071 +0.054 0.125
Clearance between support –0.145 +0.080 0.105 –
2 140 0.5
shaft collar and bushing –0.208 –0.040 0.288

Backlash between No. 1 Standard clearance Repair limit

3
pinion and No. 1 gear 0.27 – 0.68 1.5
Replace
Backlash between No. 2
4 0.31 – 0.82 1.5
pinion and No. 2 gear
Face runout of final drive Face runout of pinion flange in reference to bevel gear shaft flange
5
flange shall be within 0.4 mm
Radial runout of final drive Radial runout of pinion flange in reference to bevel gear shaft
6
flange flange shall be within 0.4 mm
Final drive flange and No. 1
7 294.2 – 392.3 kN {30 – 40 ton}
pinion press-fit force
Dimension after press-fit of Clearance between flange bottom surface and shaft shoulder:
8
final drive flange 0 ± 0.5
Radial runout of final drive
9 0.3
case
Final drive No. 1 pinion shaft
10 0.7 – 1.4
side clearance
Adjust
Final drive 2nd pinion shaft
11 1.0 – 1.6
side clearance
12 Sprocket press-fit force 686.5 – 784.5 kN {70 – 80 ton}
Dimension from sprocket hub
13 40 ± 1
end to sprocket boss end
Clearance of floating seal
14 3.3 – 5.3
guard
Clearance between sprocket
15 2.2 – 4.6
nut and support
16 Sprocket shaft press-fit force 147.1 – 529.6 kN {15 – 54 ton}
Dimension from sprocket shaft
17 —
to steering case
18 Bend of sprocket shaft Repair limit: Less than 1.0 Replace

D155C-1 40-25
Maintenance standard Final drive

(2/2)

40-26 D155C-1
Maintenance standard Final drive

Unit: mm

No. Check item Criteria Remedy

Wear of sprocket teeth (top) Standard size Tolerance Repair limit

19
diameter 1,011
Wear of sprocket teeth
20 912.15
(bottom) diameter Rebuild or
Standard size Repair limit replace
Wear of sprocket teeth (top)
21
width 83
Wear of sprocket teeth
22 103 95
(bottom) width

D155C-1 40-27
Maintenance standard Track frame

Track frame

Unit: mm

No. Check item Criteria Remedy

Item Repair limit

Curve 7 (per level length of 100)
1 Deformation of track frame Torsion 3 (per level length of 300)
Opening at idler 5 Repair or
Mounting yoke end replace
Standard size Repair limit
Center distance between left
2 Difference in front and rear less
and right track frames 2,380
than 15

40-28 D155C-1
Maintenance standard Recoil spring

Recoil spring

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Free length Installation Installation
Free lingth Load limit
1 Recoil spring (large) × O.D. length load
216.7 kN 196.3 kN
1008 × 304 770 985
{22,100 kg} {20,000 kg}
68.7 kN 61.4 kN Replace
2 Recoil spring (small) 693.5 × 172 565 675
{7,000 kg} {6,260 kg}

Standard Tolerance Standard Clearance

Clearance between adjustment size Shaft Hole clearance limit
3
cylinder and bushing
–0.036 +0.070 0.036 –
130 0.5
–0.090 +0.063 0.160
4 Idler yoke press fit force 392.3 kN {40 ton}
Clearance between rear pilot Adjust
5 10
and nut

D155C-1 40-29
Maintenance standard Track

Track

40-30 D155C-1
Maintenance standard Track

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Turn or
1 Link pitch Nominal Measure Impact loading Normal loading
replace
228.6 228.85 231.85 233.85
Lug welding,
Grouser height rebuild
2 80 30
(STD single shoe) grouser or
replace
Rebuild or
3 Link height 138 125
replace
Standard size Repair limit
Turn or
4 Outside diameter of bushing Impact loading Normal loading
79.0 replace
76 74.0

Standard Tolerance Standard

Repair limit
Clearance between master size Shaft Hole interference
5
pin and bushing
–0.055 +0.78
48.5 0.43 – 1.03 —
–0.025 +0.38
Clearance between regular +0.434 +1.164
6 48.5 0.23 – 0.83 —
pin and bushing +0.334 +0.664
Interference between link and +0.344 +0.074 0.230 –
7 77 0.100
bushing +0.304 +0.074 0.344
Replace
Interference between link and +0.434 +0.062 0.272 –
8 48.5 0.140
regular pin +0.334 +0.074 0.434
Interference between link and +0.230 +0.062 0.138 – Correct or
9 48.5 0.080
master pin +0.200 +0.074 0.230 replace
Standard clearance Standard clearance
Clearance at link fitting Repair limit
10 (one side) (both side)
surface Replace
0 – 1.4 0 – 2.8 8
11 Bushing press-fit force 120.6 – 179.5 kN {12.3 – 18.3 ton}
Correct or
12 Master pin press-fit force 209.9 – 362.8 kN {21.4 – 37.0 ton}
replace
13 Regular pin press-fit force 209.9 – 362.8 kN {21.4 – 37.0 ton} Replace
14 Shoe bolt tightening torque 980.7 – 1176.8 Nm {100 – 120 kgm} Retighten

D155C-1 40-31
Maintenance standard Idler

Idler

40-32 D155C-1
Maintenance standard Idler

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

1 Outside diameter of flange
850
2 Outside diameter of tread 800 781 Rebuild or
3 Width of flange 120 replace

4 Width of tead 60 69
5 Total width 245
6 Shaft collar width 20 19

Standard Tolerance Standard Clearance

Clearance between shaft and size Shaft Hole clearance limit
7
bushing
–0.210 +0.255
85 0.43 – 0.51 1.5
–0.260 +0.220 Replace
Interference between idler +0.130 +0.10
8 135 0.02 – 0.180 –0.30
and outer bushing +0.080 –0.05
Standard clearance Clearance limit
9 Shaft play in axial direction
0.51 – 0.74 1.5
Clearance between guide Rebuild or
10 2.0
plate and support replace
Clearance between guide Adjust or
11 0.5 – 1.0 3
plate and side plate replace
Thickness guide plate
12 6.0
standard shim Adjust
13 Filler plug tightening torque 206 ± 49 Nm {21 ± 5 kgm}

D155C-1 40-33
Maintenance standard Track roller

Track roller

40-34 D155C-1
Maintenance standard Track roller

Unit: mm

No. Check item Criteria Remedy

Outside diameter of outer Standard size Repair limit

1
flange 298
Outside diameter of inner
2 282
flange
3 Outside diameter of tread 255 230
4 Total width 292
5 Width of tread (single flange) 65 74 Rebuild or
replace
6 Width of tread (double flange) 62 80
7 Width of flange (single flange) 24 15
Width of flange
8 24 15
(double flange, outer)
Width of flange
9 22 13
(double flange, inner)
10 Shaft collar width 20 19

Standard Tolerance Standard Clearance

Clearance between shaft and size Shaft Hole clearance limit
11
bushing
–0.210 +0.255 0.43 –
85 1.5
–0.260 +0.220 0.515
Replace
Interference between roller +0.130 +0.063 0.017 –
12 135 0.30
and outer bushing +0.080 +0.037 0.130
Standard clearance Clearance limit
13 Shaft play in axial direction
0.50 – 0.76 1.5
Track roller mounting bolt
14 922 ± 98 Nm {94 ± 10 kgm}
tightening torque Adjust
15 Oil filler plug tightening torque 206 ± 49 Nm {21 ± 5 kgm}

D155C-1 40-35
Maintenance standard Carrier roller

Carrier roller

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

1 Outside diameter of flange
220
Rebuild or
2 Outside diameter of tread 190 171
replace
3 Width of flange 21 14
4 Width of tread 64 72
Standard clearance Clearance limit Nut adjustment
5 Shaft play in axial direction or bearing
0.10 – 0.13 0.20 change
Support mounting bolt
6 549 ± 59 Nm {56 ± 6 kgm}
tightening torque Adjust
7 Filler plug tightening torque 206 ± 49 Nm {21 ± 5 kgm}
8 Oiling quantity 630 – 720 cc (GO140B)

40-36 D155C-1
Maintenance standard Suspension

Suspension

40-38 D155C-1
Maintenance standard Winch pump

Winch pump
FAL100

Unit: mm

No. Check item Criteria Remedy

Standard clearance Clearance limit

1 Side clearance
0.14 – 0.24 —
Replace
Clearance between gear shaft
2 0.065 – 0.142 0.15
and plain bearing
Revolving Discharge Standard
Discharge Discharge limit
speed pressure discharge
— Oil: EO10W-CD (l/min) —
(rpm) (MPa {kg/cm2}) (l/min)
Oil temperature: 45 – 55°C
2,000 2.9 {30} 180 —

D155C-1 40-39
Maintenance standard Counterweight pump

Counterweight pump
PAL063

Unit: mm

No. Check item Criteria Remedy

Standard clearance Clearance limit

1 Side clearance
0.10 – 0.15 0.19
Replace
Clearance between plain
2 0.025 – 0.051 0.080
bearing and gear shaft
Revolving Discharge Standard
Discharge Discharge limit
speed pressure discharge
— Oil: EO10W-CD (l/min) —
(rpm) (MPa {kg/cm2}) (l/min)
Oil temperature: 45 – 55°C
2,500 13.7 {140} 152 139

40-40 D155C-1
Maintenance standard Hi-Lo valve

Hi-Lo valve

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between valve size Shaft Hole clearance limit
1
body and spool
0.020 –
12 — — —
0.030
Clearance between valve 0.020 –
2 22 — — —
body and spool 0.030
Clearance between valve 0.025 –
3 19 — — —
body and Hi-Lo selector spool 0.045
Standard size Repair limit
Installed Installed Installed
Free length Free length Replace
4 Selector valve spring length load load
158.8 N 127.0 N
— 36.0 —
{16.2 kg} {12.96 kg}
63.3 N 50.67 N
5 Detent spring — 11.5 —
{6.46 kg} {5.17 kg}
118.6 N 94.86 N
6 Relief valve spring — 54.0 —
{12.1 kg} {9.68 kg}
73.5 N
7 Cooler bypass spring — 49.0 — —
{7.5 kg}
39.2 N 31.36 N
8 Lubrication valve spring — 49.0 —
{4.0 kg} {3.20 kg}

D155C-1 40-41
Maintenance standard PPC valve

PPC valve

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Installed Installed Installed
Free length Free length
1 Spring (For clutch) length load load
20.78 N
48.7 27.05 — —
{2.12 kg}
40.38 N
2 Spring (For clutch) 30.2 29.25 — —
{4.12 kg} Replace
40.38 N
3 Spring (For clutch) 44.5 23.16 — —
{4.12 kg}
19.11 N
4 Spring (For brake) 48.7 28.85 — —
{1.95 kg}
42.34 N
5 Spring (For brake) 30.2 29.20 — —
{4.32 kg}

40-42 D155C-1
Maintenance standard Flow divider valve

Flow divider valve

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between valve size Shaft Hole clearance limit
1 Replace
body and flow divider spool
–0.020 +0.017 0.020 –
31 0.06
–0.041 +0.017 0.058

D155C-1 40-43
Maintenance standard Winch

Winch

40-44 D155C-1
Maintenance standard Winch

Unit: mm

No. Check item Criteria Remedy

Backlash between Lo clutch Standard clearance Clearance limit

1 gear and winch input shaft
idler gear 0.20 – 0.70 —

Backlash between Hi clutch

2 gear and boom LOWER 0.23 – 0.78 —
clutch gear
Backlash between boom
3 LOWER clutch gear and 0.23 – 0.78 —
RAISE clutch gear
Backlash between boom
4 RAISE clutch gear and hook 0.20 – 0.78 — Replace
brake gear
Backlash between boom
5 0.22 – 0.75 —
brake gear and idler gear
Backlash between idler gear
6 0.24 – 0.79 —
and boom drum gear
Backlash between Hi clutch
7 gear and winch input shaft 0.21 – 0.74 —
idler gear
End play of winch case and
8 0.88 – 1.47 —
bearing outer race
Quantity of grease in hook
9 5 – 6 kg
drum
Add
Quantity of grease in boom
10 2.5 – 3 kg
drum

D155C-1 40-45
Maintenance standard Lower clutch

Lower clutch

40-46 D155C-1
Maintenance standard Lower clutch

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Clutch disc thickness Replace
3.8 3.3
1
Tolerance Repair limit Repair or
Distortion of disc
Within 0.2 0.3 replace

Standard size Repair limit

Clutch plate thickness Replace
3.1 2.6
2
Tolerance Repair limit Repair or
Distortion of plate
Within 0.1 0.3 replace

Thickness of assembled Tolerance Repair limit

3
plates and discs 52.1 47.8

Backlash between disc and Standard clearance Clearance limit

4
inner drrum 0.34 – 0.67 0.1
Backlash between plate and
5 0.33 – 0.74 1.0
outer drum

I.D. of O-ring contacting Tolerance Repair limit

6 Replace
surface of inner drum (large) 190 19.3
I.D. of O-ring contacting
7 135 134.7
surface of inner drum (small)
Standard size Repair limit
Installed Installed Installed
Free length Free length
8 Clutch spring length load load
230.5 N 216.7 N
107.2 80 102
{23.5 kg} {22.1 kg}

D155C-1 40-47
Maintenance standard Raise clutch

Raise clutch

40-48 D155C-1
Maintenance standard Raise clutch

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Clutch disc thickness Replace
3.8 3.3
1
Tolerance Repair limit Repair or
Distortion of disc
Within 0.2 0.3 replace

Standard size Repair limit

Clutch plate thickness Replace
3.1 2.6
2
Tolerance Repair limit Repair or
Distortion of plate
Within 0.1 0.3 replace

Thickness of assembled Standard size Clearance limit

3
plates and discs 52.1 47.8

Backlash between disc and Standard clearance Clearance limit

4
inner drum 0.34 – 0.67 1.0
Backlash between disc and
5 0.33 – 0.74 1.0
inner drum

I.D. of O-ring contacting Standard size Clearance limit

6 Replace
surface of inner drum (large) 190 190.3
I.D. of O-ring contacting
7 135 134.7
surface of inner drum (small)
Standard size Repair limit
Installed Installed Installed
Free length Free length
8 Clutch spring length load load
230.5 N 216.7 N
107.2 80 102
{23.5 kg} {22.1 kg}

D155C-1 40-49
Maintenance standard Winch brake

Winch brake

40-50 D155C-1
Maintenance standard Winch brake

Unit: mm

No. Check item Criteria Remedy

Standard size Repair limit

Brake disc thickness Replace
3.8 3.3
1
Tolerance Repair limit Repair or
Distortion of disc
Within 0.2 0.3 replace

Standard size Repair limit

Brake plate thickness Replace
3.1 2.6
2
Tolerance Repair limit Repair or
Distortion of plate
Within 0.1 0.3 replace

Thickness of assembled Standard size Clearance limit

3
plates and discs 92.8 85

Backlash between disc and Standard clearance Clearance limit

4
inner drum 0.34 – 0.74 1.0
Backlash between plate and
5 0.33 – 0.74 1.0
inner drum

I.D. of seal contacting surface Standard size Clearance limit

6
of piston drum (large) 270 270.3
I.D. of seal contacting surface
7 230 230.3
of piston drum (small)
Standard size Repair limit Replace

Installed Installed Installed

Free length Free length
8 Brake spring (large) length load load
1005.2 N 944.4 N
134.5 105 128
{102.5 kg} {96.3 kg}
377.6 N 355 N
9 Brake spring (small) 103 56 98
{38.5kg} {36.2 kg}

Clearance between retainer Standard clearance Repair limit

10
seal ring groove and seal ring 0.1 – 0.2 0.4

I.D. of seal ring contacting Standard size Repair limit

11
surface of retainer 160 160.3

D155C-1 40-51
Maintenance standard Control valve (for counterweight)

Control valve (for counterweight)

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between spool and size Shaft Hole clearance limit
1
valve body
+0.010 0.012 –
30 0.045
+0.010 0.020
Standard size Repair limit Replace

Free lingth Installed Installed Installed

Free length
2 Spool return springs × O.D. lingth load load
97.1 N 77.5 N
128 × 65 115
{9.9 kg} {7.9 kg}

40-52 D155C-1
Maintenance standard Control valve (for counterweight)

Main relief valve

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between relief size Shaft Hole clearance limit
1
valve and valve body
0.020 –
25 0.07
0.030
Standard size Repair limit
Replace
Installed Installed Installed
Free length Free length
2 Main relief valve spring length load load
55.9 N 50 N
55 34
{5.7 kg} {5.1 kg}
268.7 N 242.2 N
3 Control valve spring 37.5 30.4
{27.4 kg} {24.7 kg}

D155C-1 40-53
Maintenance standard Counterweight cylinder

Counterweight cylinder

Unit: mm

No. Check item Criteria Remedy

Standard Tolerance Standard Clearance

Clearance between piston rod size Shaft Hole clearance limit
1 Replace
and bushing
–0.080 +0.164
50 0.606
–0.142 +0.007
Clearance between piston rod +0.174
2 60 1.0
support shaft and bushing +0.100
Replace pin
Clearance between cylinder and bushing
+0.174
3 bottom support shaft and 60 1.0
+0.100
bushing

40-54 D155C-1
Maintenance standard Slow return valve

Slow return valve

Unit: mm

No. Check item Criteria Remedy

Clearance between slow Standard clearance Clearance limit

1
return valve and body 0.010 – 0.020 —
Installed Installed Installed
Free length Free length
length load load
2 Spring 700-61-43170
6.96 N Replace
30.0 — —
{0.71 kg}
2.55 N
3 Spring 700-61-43140 12.0 — —
{0.26 kg}
6.91 N
4 Spring 700-61-43230 25.5 — —
{0.75 kg}

D155C-1 40-55
Maintenance standard Counterweight

Counterweight

40-56 D155C-1
Maintenance standard Counterweight

Unit: mm

No. Check item Criteria Remedy

Clearance between lower pin Standard size Standard clearance

1
of large link and bushing 65 0.350 – 0.454
Clearance between upper pin
2 60 0.350 – 0.454
of small link and bushing
Free length of spring (large)
3 139 [136 kg]
[Installed load]
Clearance between lower pin
4 60 0.350 – 0.454
of small link and bushing
Clearance between cylinder
5 60 0.290 – 0.410
bottom pin and bushing
Clearance between upper pin
6 65 0.350 – 0.454
of large link and bushing

D155C-1 40-57
Maintenance standard Boom

Boom

40-58 D155C-1
Maintenance standard Boom

Unit: mm

No. Check item Criteria Remedy

Standard size Standard clearance

1 Clearance of foot pin
80 0.32 – 0.446
2 Clearance of sheave pin 70 0 – 1.8
3 Clearance of sheave pin 55 0 – 1.5
4 Clearance of bearing pin 90 0.008 – 0.034
5 Clearance of bearing pin 90 0.008 – 0.034

D155C-1 40-59
 90 Others

Electric circuit diagram (STD) .......................................................................................................................90- 3

Electric circuit diagram (–50°C spec.)...........................................................................................................90- 5
Cab electric circuit diagram...........................................................................................................................90- 7

D155C-1 90-1
Others Electric circuit diagram (STD)

Electric circuit diagram (STD)

D155C-1 90-3
Others Electric circuit diagram (–50°C spec.)

Electric circuit diagram (–50°C spec.)

D155C-1 90-5
Others Cab electric circuit diagram

Cab electric circuit diagram

D155C-1 90-7