Hyundai Excavator R450LC-7. Service and repair manual - page 31

8-73-23

31

Apply loctite to the tapped holes of the
ring gear(11) and then mount swing motor
onto the ring gear(11).
Don't fail to coincide the gauge bar(33)
hole.

Tighten socket bolts(31) around the swing
motor assembly.

·

Tightening torque : 25

±

2.5kgf

·

m 

(181

±

18lbf

·

ft)

29
30

30

1

33
32

(14)

※

(15)

Assemble plugs(29, 30), gauge bar(33)
and gauge pipe(32).

(16)

Turn the swing motor assembly upside
down and assemble cover plate(34) by
tightening the hexagon socket bolts(35).
Install spacer(3) and pinion gear(13) to
the drive shaft(2).
Assemble lock plate(36) on the pinion
gear(13).
Assemble 2 lock washers(25) on the lock
plate(36) with their 2 hole coincided
individually to the tapped holes of drive
shaft(2).
Tighten hexagon socket bolts(37) to the
drive shaft(2) and then fold all the lock
washer(25) corners over the hexagon
bolts(37).

·

Tightening torque : 25

±

2.5kgf

·

m

(181

±

18lbf

·

ft)

Inject oil into the reduction gear.

25 37

36

13

3

35

34

2

(17)

(18)

21078SR027

21078SR028

21078SR029

8-74

1.  REMOVAL AND INSTALL

REMOVAL

Swing the work equipment 90

。

and lower

it completely to the ground.

Operate the control levers and pedals
several times to release the remaining
pressure in the hydraulic piping.

Loosen the breather slowly to release the
pressure inside the hydraulic tank.
E

E

scaping  fluid  under  pressure  can

penetrate  the  skin  causing  serious
injury.
When pipes and hoses are disconnected,
the oil inside the piping will flow out, so
catch it in oil pan.

Remove the track shoe assembly.
For details, see removal  of  track  shoe
assembly.

Remove the cover.

Remove the hose.
Fit blind plugs to the disconnected hoses.

Remove the bolts and the sprocket.

Sling travel device assembly(1).

Remove the mounting bolts(2), then
remove the travel device assembly.

·

Weight : 360kg(790lb)

INSTALL

Carry out installation in the reverse order
to removal.

Bleed the air from the travel motor.

Remove the air vent plug.
Pour in hydraulic oil until it overflows from
the port.
Tighten plug lightly.
Start the engine, run at low idling, and
check oil come out from plug.
Tighten plug fully.

Confirm the hydraulic oil level and check
the hydraulic oil leak or not.

GROUP  6  TRAVEL DEVICE

1)

2)

(1)

(2)

(3)

※

(4)

(5)

(6)

※

(7)

(8)

(9)

(1)

(2)

①
②

③
④

⑤

(3)

45078TM01

13031GE18

8-75

2. TRAVEL MOTOR(1/2)

STRUCTURE

1)

1

Rotary group 

2

Hyd section rotary

3

Cylinder

4

Control lens

5

Center pin

6

Piston

7

Steel ring

8

Adjustment shim

9

Pressure spring

10

Retainer plate

11

Screw

12

Drive shaft

13

Shim

14

Back up plate

15

Retainer ring

16

Roller bearing

17

Roller bearing

18

Housing

19

Retainer ring

20

Shaft seal ring

21

Back up plate

22

O-ring

23

Locking screw

24

O-ring

25

Threaded pin

26

Seal lock nut

27

O-ring

4

3

11

10

9

7

6

5

8

15

14

17

13

16

12

19

20

21

2

23

26

25

1

22

A

18

A

14

25

450A8TO02

8-76

TRAVEL MOTOR(2/2)

·

·

Control part 

18

O-ring

19

Throttle pin

20

Valve

21

Poppet valve

22

Pressure spring

23

Seat poppet

24

Poppet valve

25

Pressure spring

26

Locking screw

27

O-ring

28

Locking screw

29

Valve screw

30

Bushing

31

Socket screw

32

Socket screw

33

Cylinder pin

34

Locking screw

1

Port plate

2

Position piston

3

Position turnnion

4

Control bushing

5

Control piston

6

Pressure spring

7

Locking screw

8

Throttle screw

9

Throttle screw

10

Brake valve

11

Brake piston

12

Locking screw

13

Pressure spring

14

Washer

15

Throttle screw

16

Throttle screw

17

Throttle pin

35

Locking screw

36

O-ring

37

O-ring

38

Brake off pin

39

Ball

40

Locking screw

41

Brake off pin

42

Locking screw

43

Pressure control valve

44

Locking screw

45

Control piston

46

Control bushing

47

Pressure spring

48

O-ring

49

Shim

50

Relief pressure valve

51

Cap

17

22

12

12

42

21

23

30

7

50

46

28

8

19

9

35

39

29

35

22

23

24

25

27

26

18

13

14

16

17

15

11

37

6

5

4

18

13

14

16

15

21

24

25

27

26

36

2

31

34

40

312

3

33

10

10

20

45

47

49

48

44

1

38

51

41

450A8TO03

8-78

DISASSEMBLY

General precautions

Before disassembling the motor, check the items to be inspected and, for remedy against trouble,
closely examine the nature of the trouble, so that the motor can be disassembled effectively.
To disassemble the motor, use the disassembling procedures described in section 2) and select a
clean place.
Place a rubber or vinyl sheet or other such protective materials on your working bench to protect
the surface of the motor to be serviced.
During disassembly, give a match mark to the mating surfaces of each part.
Arrange removed parts in order so that they will not become damaged or missing during
disassembly.
Once seals have been disassembled, they should be replaced even if damage is not observed.
Have replacement seals ready on hand before starting your disassembling job.

3)

(1)

①

②

③

④
⑤

⑥

Seal kit and component groups

Attention
Observe the following notices when
carrying out repair work at hydraulic
aggregates!

Close all ports of the hydraulic
aggregates.

8-79

(2)

①

②

Replace all seals.
Use only original spare parts.

③

Check all seal and sliding surfaces for
wear.
Rework of sealing area for example with
abrasive paper can damage surface.

④

8-81(1) 450-3

2.TIF (450-3)

3.TIF (450-3)

4.TIF (450-3)

8-80

Fill up hydraulic aggregates with
hydraulic oil before start-up.

Seal kit for drive shaft.

⑤

⑥

External seal kit.

⑦

Housing.

⑧

450A8TO08

6.TIF (450-3)

450A8TO05

450A8TO06

8-81

Complete rotary group.

Port plate with control piston and
counter-balance valve.

⑨

⑩

Relief valve/Make up check valve 

⑪

Replace seal nut.
First measure and record setting height. 

⑫

450A8TO07

450A8TO08

450A8TO09

450A8TO10

8-82

★

When tightening, counterhold setting

screw, then check setting height. 

Sealing the drive shaft

Protecting the drive shaft.
Remove retaining ring and shim.

⑬

①

Screw in sheet metal screw into the
holes fitted with rubber.
Pull out seal with pliers.

②

Press in shaft seal and shim with bush to
stop.
Pay attention to pressing depth!

★

Mark for pressing depth.

Assemble retaining ring.

③

※

(

(

3)

450A8TO11

450A8TO12

450A8TO13

450A8TO14

8-83

Sealing of the relief valve

Remove relief valve.

(5)

①

Sealing of the control parts

HZ-Controller
O-ring, O-ring groove, housing.

(4)

①
※

Inspect 
O-ring.

②

450A8TO15

450A8TO16

450A8TO17

Disassembly of the port plate

Note dimension x.
Remove Q

min

-screw.

8-84

(6)

①

Q

min

-screw

For disassembly of the port plate, swivel
always rotary group to zero position.
Piston rings to hang out of the cylinder
boring.
Swivel rotary group to zero position with
screw Q

max

.

②

450A8TO18

450A8TO19

8-85

Port plate
Mark position. Loosen screws.
Removal.

Check O-ring. 
Stick new O-ring with some grease. Do
not swivel rotary group. Piston rings to
hang out from the cylinder boring.

③

④
※

450A8TO20

450A8TO21

8-86

Remove rotary group

Screw in threaded pin into center pin.
Fix the cylinder with disc and lock nut.
Size : M8

×

105mm

Press out rotary group!
If the bearings are used again do not hit
on the drive shaft. 

(

(

7)

①

②
※

Exchanging of the rotary group

Remove fixing screw(cylinder).
Remove cylinder. 

Disassemble retaining plate.
Screws are glued. Use Torx-tools.

(8)

①

②
※

450A8TO22

450A8TO23

450A8TO24

450A8TO25

Inspection notes

Free of corrosion, erosion or fretting; no
damage to splines or keyways.

8-87

1

2

Pistons
No scoring and no pittings.

①

②

Center pin
No scoring and no pittings.

Retaining plate
No scoring and no evidence of wear.

③

④

(

(

9)

450A8TO26

450A8TO27

450A8TO28

450A8TO29

8-88

a

a

b

b

Cylinder block / control lens
a : Bores free of scoring, no evidence of    

wear.

b : Faces smooth and even, free of 

cracks and scoring.

Control housing 
Sliding surface and side guides free of
scoring and no wear. 

Visual check : Bearing areas free of
scoring and no evidence of wear. 

⑤

⑥

⑦

450A8TO30

450A8TO31

450A8TO32