service repair manual

1. 950106-00268E Shop Manual
Copyright 2011 DOOSAN
DOOSAN reserves the right to improve our products in a continuing process to provide the best possible
product to the market place. These improvements can be implemented at any time with no obligation to
change materials on previously sold products. It is recommended that consumers periodically contact their
distributors for recent documentation on purchased equipment.
This documentation may include attachments and optional equipment that is not available in your
machine's package. Please call your distributor for additional items that you may require.
Illustrations used throughout this manual are used only as a representation of the actual piece of
equipment, and may vary from the actual item.
Shop Manual
950106-00268E
Serial Number 5001 and Up
DX340LCA

2. Table of Contents
Page I
1Table of Contents
Safety
Track Excavator Safety......................................................................... SP002025
Specifications
Specification for DX340LCA ................................................................. SP002320
General Maintenance
General Maintenance Procedures........................................................ SP000016
Standard Torques................................................................................. SP000813
Upper Structure
Cabin .................................................................................................... SP001737
Counterweight....................................................................................... SP001738
Fuel Tank.............................................................................................. SP002321
Fuel Transfer Pump (Opt)..................................................................... SP000021
Swing Bearing....................................................................................... SP001856
Swing Reduction Gear.......................................................................... SP001740
Lower Structure and Chassis
Track Assembly .................................................................................... SP001741
Engine and Drive Train
Drive Coupling (Main Pump)................................................................. SP000026
Hydraulics
Hydraulic System Troubleshooting, Testing and Adjustment ............... SP002451
Accumulator.......................................................................................... SP000028
Center Joint (Swivel)............................................................................. SP000181
Cylinders............................................................................................... SP000030

3. Table of Contents
Page II
Swing Motor.......................................................................................... SP000261
Travel Motor.......................................................................................... SP000253
Main Pump............................................................................................ SP000186
Gear Pump ........................................................................................... SP000260
Main Control Valve ............................................................................... SP000034
Remote Control Valve (Work Lever / Joystick)..................................... SP000069
Travel Control Valve (With Damper)..................................................... SP001743
Solenoid Valve Assembly ..................................................................... SP001622
Breaker EPPR Valve (Opt) ................................................................... SP000192
Hydraulic Schematic DX300LC/DX300LCA/DX340LCA ...................... SP001752
Electrical System
Electrical System .................................................................................. SP002453
Electrical Schematic DX300LCA / DX340LCA ..................................... SP002031
Attachments
Boom and Arm...................................................................................... SP001851
Bucket................................................................................................... SP001852

4. SP002025
Page 1
Track Excavator Safety
SP002025
TRACK EXCAVATOR SAFETYSP002025
Track
Excavator
Safety
Edition 1

5. SP002025
Page 5
Track Excavator Safety
SAFETY PRECAUTIONS
APPLICABLE MODELS
The contents of this section apply to the following models and
serial number ranges.
CAUTION
Follow all safety recommendations and safe shop practices
outlined in the front of this manual or those contained
within this section.
Always use tools and equipment that are in good working
order.
Use lifting and hoisting equipment capable of safely
handling load.
Remember, that ultimately safety is your own personal
responsibility.
MODEL SERIAL NUMBER RANGE
DX300LCA 5001 and Up
DX340LCA 5001 and Up

6. SP002025Track Excavator Safety
Page 6
TO THE OPERATOR OF A
DOOSAN EXCAVATOR
Please respect the importance of taking responsibility for your
own safety, and that of other people who may be affected by
your actions.
The safety information on the following pages is organized into
the following sections:
1. “General Safety Essentials” on page-9
2. “Location of Safety Labels” on page-10
3. “Summary of Safety Precautions for Lifting in Digging
Mode” on page-11
4. “Unauthorized Modifications” on page-12
5. “General Hazard Information” on page-12
6. “Before Starting Engine” on page-21
7. “Machine Operation” on page-24
8. “Maintenance” on page-31
9. “Battery” on page-39
10. “Towing” on page-41
11. “Shipping and Transportation” on page-42
12. “Lifting With Sling” on page-42
DANGER
Unsafe use of the excavator could lead to serious injury or
death. Operating procedures, maintenance and equipment
practices or traveling or shipping methods that do not
follow the safety guidelines on the following pages could
cause serious, potentially fatal injuries or extensive
damage to the machine or nearby property.

7. SP002025
Page 7
Track Excavator Safety
WARNING
Improper operation and maintenance of this machine can
be hazardous and could result in serious injury or death.
Operator and maintenance personnel should read this
manual thoroughly before beginning operation or
maintenance.
Keep this manual in the storage compartment to the rear of
the operator's seat, and have all personnel involved in
working on the machine read the manual periodically.
Some actions involved in operation and maintenance of the
machine can cause a serious accident, if they are not done
in a manner described in this manual.
The procedures and precautions given in this manual apply
only to intended uses of the machine.
If you use your machine for any unintended uses that are
not specifically prohibited, you must be sure that it is safe
for any others. In no event should you or others engage in
prohibited uses or actions as described in this manual.
DOOSAN delivers machines that comply with all applicable
regulations and standards of the country to which it has
been sent. If this machine has been purchased in another
country or purchased from someone in another country, it
may lack certain safety devices and specifications that are
necessary for use in your country. If there is any question
about whether your product complies with the applicable
standards and regulations of your country, consult
DOOSAN or your DOOSAN distributor before operating the
machine.
SAFETY ALERT SYMBOL
Be Prepared - Get to Know All Operating and Safety
Instructions.
This is the Safety Alert Symbol. Wherever it appears in this
manual or on safety signs on the machine you should be
alert to the potential for personal injury or accidents.
Always observe safety precautions and follow
recommended procedures.

8. SP002025Track Excavator Safety
Page 8
Learn Signal Words Used with Safety Alert
Symbol
The words "CAUTION," "WARNING," and "DANGER" used
throughout this manual and on decals on the machine indicate
degree of risk of hazards or unsafe practices. All three degrees
of risk indicate that safety is involved. Observe precautions
indicated whenever you see the Safety Alert "Triangle," no
matter which signal word appears next to the "Exclamation
Point" symbol.
Safety precautions are described in SAFETY from Operation
and Maintenance Manual on page 1-4.
DOOSAN cannot predict every circumstance that might involve
a potential hazard in operation and maintenance. Therefore the
safety messages in this manual and on the machine may not
include all possible safety precautions. If any procedures or
actions not specifically recommended or allowed in this manual
are used, you must be sure that you and others can do such
procedures and actions safely and without damaging the
machine. If you are unsure about the safety of any procedures,
contact a DOOSAN distributor.
CAUTION
This word is used on safety messages and safety labels and
indicates potential of a hazardous situation that, if not
avoided, could result in minor or moderate injury. It may
also be used to alert against a generally unsafe practice.
WARNING
This word is used on safety messages and safety labels and
indicates potential threat of a hazardous situation that, if not
avoided, could result in serious injury or death. It may also
be used to alert against highly unsafe practice.
DANGER
This word is used on safety messages and safety labels and
indicates an imminent hazard of a situation that, if not
avoided, is very likely to cause death or extremely serious
injury. It may also be used to alert against equipment that
may detonate or explode if handled or treated carelessly.

9. SP002025
Page 9
Track Excavator Safety
GENERAL SAFETY ESSENTIALS
Accessory Applications
The excavator has been primarily designed for moving earth
with a bucket. For use as a grapple or for other object handling,
contact DOOSAN for proper installation and application. Lifting-
work applications (unless restricted or prohibited by local
regulations) are permitted in approved lift configuration, to rated
capacity only, with no side-loading. DO NOT use the machine
for activities for which it was not intended. DO NOT use the
bucket for lifting work, unless lift slings are used in the approved
configuration.
Use of an accessory hydraulic hammer (breaker), work in rough
terrain, demolition applications or other hazardous operation
may require installation of additional protective structures to
safeguard the operator.
Lifting Capacity Rating Configuration
Lifting capacity ratings that are printed at the end of this safety
section are based on the machine being level, on a firm
supporting surface, with hooks and slings attached in approved
configuration. Loads must be balanced and supported evenly.
Use tag lines to keep the load steady if wind conditions and
large surface area are a problem. Work crew hand signals,
individual tasks and safe procedures should all be universally
understood before the lift is made.
IMPORTANT
Before using the excavator to make lifts check municipal
and regional regulations or statutes that could apply.
Governing ordinances may require that all heavy lifting be
done with single purpose equipment specifically designed
for making lifts, or other local restrictions may apply.
Making heavy lifts with a general purpose excavator that
can be used for digging, loading, grading or other work may
be expressly forbidden by a regional injunction or other
legal prohibition. Always follow all of the other instructions,
guidelines and restrictions for Safe Lifting in the Operation
and Maintenance Manuals.

10. SP001740
Page 1
Swing Reduction Gear
SP001740
SWING REDUCTION GEARSP001740
Swing
Reduction Gear
Edition 1

11. SP001740
Page 5
Swing Reduction Gear
SAFETY PRECAUTIONS
APPLICABLE MODELS
The contents of this section apply to the following models and
serial number ranges.
CAUTION
Follow all safety recommendations and safe shop practices
outlined in the front of this manual or those contained
within this section.
Always use tools and equipment that are in good working
order.
Use lifting and hoisting equipment capable of safely
handling load.
Remember, that ultimately safety is your own personal
responsibility.
MODEL SERIAL NUMBER RANGE
DX340LC 5980 and Up
DX340LCA 5001 and Up
DX350LC 5980 and Up
DX420LC 5327 and Up

12. SP001740Swing Reduction Gear
Page 6
GENERAL DESCRIPTION
Theory of Operation
The swing reduction gearbox is a two-step planetary gearbox
with three planet gears, one sun gear and 2-step output
reduction. The planetary gear engages with the ring gear. The
pinion gear is connected with the output shaft and spline.
The gearbox reduces swing motor rpm to increase swing motor
output torque. The available maximum swing speed provides a
fast turning rate for efficient, rapid work cycling with more than
adequate power for good acceleration.
Parts List
Figure 1

13. SP001740Swing Reduction Gear
Page 10
REMOVAL
1. Park on firm and level ground.
2. Lower front attachment (bucket) to ground.
3. Shut down engine.
4. Set safety lever on "RELEASED" position.
5. Turn starter switch to "I" (ON) position.
6. Fully stroke work levers (joysticks) in all directions to
relieve any pressure from accumulators.
7. Set safety lever on "LOCK" position.
8. Turn key to "O" (OFF) position and remove from starter
switch.
9. Hang a maintenance warning tag on controls.
10. Disconnect negative (-) battery cable leading to frame from
battery.
11. Tag and disconnect hoses from swing motor (1, Figure 3).
Plug and cap hoses and ports to prevent contamination
from entering hydraulic system or component.
12. Disconnect tube (2) from drain cock (3) and hose fitting (7)
from fill hole.
13. Remove twelve bolts and washers (4, Figure 3) holding
swing reduction gearbox (5) to frame.
14. Using a suitable lifting device, sling swing motor (1, Figure
3) and remove swing motor and reduction gearbox (5) as
an assembly from unit.
NOTE: A drain cock (3, Figure 3) and tube are on side
of gearbox. Be careful not to damage valve or
tube.
NOTE: There are two alignment pins (6, Figure 3), one
on each side of reduction gearbox flange.
O I
FG014348
DO NOT OPERATE
when performing inspection
WARNING
190-00695A
or maintenance
Figure 2
WARNING
If engine must be running while performing
maintenance, always use extreme caution. Always
have one person in cab at all times. Never leave cab
with engine running.
Figure 3

14. SP001740
Page 11
Swing Reduction Gear
DISASSEMBLY
NOTE: Clean all exterior surfaces of the gearbox before
beginning disassembly.
1. Remove the drain plugs and allow all oil to drain from the
gearbox.
2. Remove the socket cap screws that hold the cover to the
gearbox housing. Remove the cover from the housing.
3. Remove the sun gear.
4. Thread an eye bolt into each of the three shafts that
support the 1st level planetary gears. Loop lifting straps
through the eye bolts and lift the planetary gears and the
first planetary mounting plate out of the gearbox.
5. Slide sun gear off the shaft and out of the gearbox.
6. Thread an eye bolt into each of the three shafts that
support the planetary gears. Loop lifting straps through the
eye bolts and lift the gear housing assembly out of the
gearbox.
Figure 4
IMPORTANT
Use a clean, dry container (with at least 11 liters, or 2.9
gallons capacity) to catch gear oil. A clean container
allows an evaluation to be made of the used oil. The
presence or relative lack of metal wear shavings in the
used oil or obvious deterioration or contamination of
the oil can provide a useful indicator of the motor’s
general condition.
Figure 5
Figure 6

15. SP001740Swing Reduction Gear
Page 12
7. Use a flat tipped punch to drive the spring pin back into the
shaft, so that the shaft can be pulled out of the gear
housing. Drive back the spring pins on the other two shafts.
8. Hold the planetary gear and thrust plate with one hand and
slide the gear shaft out of the housing. Use this method to
remove the two remaining gear shafts, gears, and thrust
plates.
Use the punch to drive the spring pins out of the shafts.
Use new spring pins when assembling the gearbox.
9. Sealant has been applied to the joint where the ring gear
and the gear case meet. It will be necessary to pry the ring
gear from the gear case, to separate the two parts.
10. Use a screwdriver to pry the snap ring from the output side
of the gear case.
Figure 7
Figure 8
Figure 9
Figure 10

16. SP001740
Page 13
Swing Reduction Gear
11. Insert the gear case into a hydraulic press. Position the
gear case so that the input end of the shaft is facing up.
Insert a metal spacer into the bore of the shaft. Press down
on the shaft until the shaft, with the spacer, plate, and roller
bearing attached, is pressed out of the gear case.
12. Reach into the gear case and remove the roller bearing.
13. Use a hammer and a screwdriver to drive the seal out of
the gear case.
NOTE: It is only necessary to disassemble the shaft
when one of the shaft components is damaged
(bearing, spacer, etc.) and needs replacement.
Figure 11
Figure 12
Figure 13

17. SP001740Swing Reduction Gear
Page 14
14. Set the shaft down into a metal pipe that has an inside
diameter of 145 mm. The pipe should contact the bearing
inner race only. Place a metal spacer on top of the shaft.
Use a hydraulic press to press down on the spacer until the
bearing is free of the shaft. Slide the shaft spacer, plate,
bearing and bearing spacer off the shaft.
15. Use a nonflammable, nontoxic solvent to clean all gearbox
parts. Dry the parts with compressed air. Inspect all parts
before assembly. Replace any parts that show damage or
obvious signs of wear.
Figure 14

18. SP001740
Page 15
Swing Reduction Gear
ASSEMBLY
Shaft and S/R Bearing Shrinkage Fitting
1. Washing of the shaft
Remove liquid like anti-corrosion liquid on the shaft and
then use an air gun to remove all of remaining foreign
substance.
2. Insert the spacer in the prepared shaft as shown in the
figure below and put and heat the bearing on the specified
heater.
Figure 15
Figure 16

19. SP001740Swing Reduction Gear
Page 16
3. Lift the bearing when the temperature of the heater
reaches 90° - 100°C (194° - 212°F) and put it into the shaft
with both hands holding it horizontally. To do so, insert it
slowly about 4 to 5 mm that the bearing takes its seat by
itself and then push it with force that it sticks to the spacer
assembled into the shaft.
Figure 17
Figure 18

20. SP001740
Page 17
Swing Reduction Gear
4. After completing the assembly of the bearing, allow the
bearing to air dry for one to two hours.
Assembly of the Carrier Subassembly
Washing of the Carrier
Use a dipping washer to wash the carrier which was got rid of
burr through a corner end finishing (shaping) process, check
again if foreign substance is removed completely, and put it on
the assembly die.
Washing of Planet Gears
Check if planet gears are washed well and have any dent and
put them on the assembly die.
Figure 19
Figure 20

21. SP001740Swing Reduction Gear
Page 18
Assembly of the Carrier Subassembly 1
1. Put the carrier No.1 on the assembly jig as shown in the
figure below.
2. Put the pin assembly No.1 on the pin hole correctly and
insert it with a press.
Figure 21
Figure 22
Figure 23

22. SP001740
Page 19
Swing Reduction Gear
3. After its pressure insert, check its state visually.
4. Insert the pin assembly 1 in the 3 remaining parts with a
pressure in the same way.
5. Turn over the carrier in which the pin is inserted and put
the thrust washer No.1 on 4 pins as shown in the figure
below.
Figure 24
Figure 25
Figure 26

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24. SP001740Swing Reduction Gear
Page 20
6. Assemble the planetary gear No.1.
7. Put thrust washer No.3 as shown in the figure below.
Figure 27
Figure 28
Figure 29

25. SP001740
Page 21
Swing Reduction Gear
8. Engage the snap ring (for φ 40 axis) to each thread of the
pin 1 and turn the gear to check if it rotates smooth.
Assembly of the Carrier Subassembly 2
1. Put the carrier No.2 on the assembly die as shown in the
figure below.
Figure 30
Figure 31
Figure 32

26. SP001740Swing Reduction Gear
Page 22
2. Insert the bush No.2 in the planetary gear No.2 and put the
thrust washer No.2 on it.
3. Hold the gear with both hands and the thrust washer facing
downward, insert it in the carrier, and arrange both gauges
of the carrier and the bush.
Figure 33
Figure 34
Figure 35
Figure 36