Hyundai Excavator R450LC-7. Service and repair manual - page 32

8-89

ASSEMBLY 

General precautions

Reassemble in a work area that is clean and free from dust and grit.
Handle parts with bare hands to keep them free of linty contaminates.
Repair or replace the damaged parts.
Each parts must be free of burrs its corners.
Do not reuse O-rings, oil seal and floating seal that were removed in disassembly.
Provide the new parts.
Wash all parts thoroughly in a suitable solvent.
Dry thoroughly with compressed air.
Do not use the cloths.
When reassembling oil motor components of motor, be sure to coat the sliding parts of the motor
and valve with fresh hydraulic oil. (NAS class 9 or above)
Use a torque wrench to tighten bolts and plugs, to the torque specified as follows.

4)

(1)

①
②
③

④

⑤

⑥

⑦

Rotary group assembly

Rotary group completely assembled
ready for assembly.

Place assembly sleeve. 

Warm up housing to 80

。

C.

8-90

(2)

①

②

③

80

。

C

450A8TO33

450A8TO34

450A8TO35

8-91

Insert rotary group into housing to seat
position. 

Fix zero position of cylinder with Q

max

-

screw.
a.  Disassemble cylinder fixing screw. 
b.  Insert O-ring. 

④

⑤

b

a

450A8TO36

450A8TO37

8-92

Rotary group adjustment

Determine cylinder swivel range to max
angle with screw. 

*Disc

Place centering disc.

Mount measuring device.

(3)

①

②

③

④

450A8TO38

450A8TO39

450A8TO40

450A8TO41

Check dimension X.

Assembly of the port plate

Stick centrol lens in sliding surface with
grease.  Assembly in reversal order.
Mount port plate. 

Assembly port plate. 
Take care of assembly design!  Tighten
fixing screws with torque.
a.  Set Q

min

-screw to dimension*.

b.  Assemble plug. 
c.  Remove assembly sleeve. 

8-93

①
※

(4)

※

⑤

*

450A8TO42

450A8TO43

450A8TO44

8-94

Assemble shaft seal, disc and safety ring.
Press-in with assembly sleeve. 
Take care of press-in depth. 

②

※

450A8TO45

8-95

21

11

13

12

1

2

4

14

5

7

10

8

9

6

3

35

34

36

33

22

18

19

15

16

17

24

25

26

27

28

29

30

20

31

32

23

1

Washer 

2

Breather plug

3

Screw

4

Cover set

5

O-ring

6

Pad

7

Sun gear

8

Reduction assy(1st)

9

Sun gear

10

Reduction assy(2nd)

11

Screw

12

Reduction assy(3rd)

13 Bushing
14

Sun gear

15

Housing

16

Lifetime seal 

17

Hub

18

Spacer

19

Brake shaft

20

O-ring

21

Brake disc

22

Steel ring

23

Back up ring

24

O-ring

25

O-ring

26

Spiral ring

27

Piston

28

Spring

29

Spacer

30

Circlip

31

Flange

32

O-ring

33

Screw

34

Plug

35

Screw

36

O-ring

3. REDUCTION GEAR 

STRUCTURE

1)

450A8TR01

DISASSEMBLING
Initial inspection of the gears and the travel
motor, can be made without disassembling
the track and the gearmotor from the
machine. 
Prior to disassembling make sure that the
oil is discharged, unscrew and remove the
2 screws(33), and remove the travel motor
and the O-ring(32). 

Unscrew the 8 socket head screws (3)
and remove the motor flange from the
flanged hub(17).

Remove the O-ring (20) from its grove in
the motor flange(31).

Remove the O-ring(36) from its grove in
the flanged hub(17).

8-96

(1)

(2)

(3)

2)

450A8TR04

450A8TR05

450A8TR06

8-97

After having places the disc on the spring
retainer(29), fix the pusher on the flanged
hub(17) as shown in the scheme by
screwing the threaded bar, push the disc
on the retainer, thus removing the force of
the springs(28) on the circlip(30) and
allowing its disassembling.

Using pliers remove the circlip(30) from its
grove in the flanged hub(17).

Disassemble the equipment from the
flanged hub(17) and remove the
circlip(30).

Remove the springs retainer(29).

(4)

(5)

(6)

(7)

450A8TR07

450A8TR08

450A8TR09

450A8TR10

8-98

Remove the springs(28) from their groves. 

Using pliers remove the brake piston(27).
To get it easier, pumping compressed air
into the brake port hole. 

Remove the brake shaft(19).

Remove brake discs pack(21, 22).

(8)

(9)

※

(10)

(11)

450A8TR11

450A8TR12

450A8TR13

450A8TR14

8-99

Remove the O-rings(24,25) and the
backup rings(23, 26) from their groves in
the flanged hub(17).

Turn the gearbox around, unscrew and
remove the 2 plugs(2) and the 2 washers
(1) from the end cover(4). 

(12)

(13)

Unscrew and remove the 16 socket head
screws(3).

By means of a puller remove the end
cover(4). 

(14)

(15)

450A8TR15

450A8TR16

450A8TR17

450A8TR18

8-100

Remove the O-ring(5) from its grove in the
end cover(4). 

Remove the 1st stage sun gear(7).

(16)

(17)

Remove the 1st reduction assembly(8). 

Remove the 2nd stage sun gear(9).

(18)

(19)

450A8TR19

450A8TR20

450A8TR21

450A8TR22

8-101

Remove the 2nd reduction assembly(10).

Remove the 3rd stage sun gear(14).

(20)

(21)

Unscrew the 4 socket head screws(11),
fixing the 3rd reduction assembly(12) to
the flanged hub(17). 

Remove the 4 screws(11).

(22)

(23)

450A8TR23

450A8TR24

450A8TR25

450A8TR26

8-102

Using a press and a metal stopper,
remove the flanged hub(17) from the
gearbox housing(14), paying attention to
the eventual falling down of the main
bearing's balls.

Remove the 3rd reduction assembly(12)
from the flanged hub(17).

(24)

(25)

Using the equipment, remove bushes(13)
from the flanged hub(17). 
It is possible that the planet assemblies

(

see reassembly(11)

)

)

remain assembled

to the planet-carrier. In this case it is
sufficient to push on them by means of a
rubber pad or a press. 
In case the planet assemblies remain
assembled to the flanged hub, it is better
to use the fixture(for this operation).

(26)

※

450A8TR27

450A8TR28

450A8TR29

REASSEMBLY

For the correct assemble of gearbox
please follow these basic instructions:
In case of damaged gears, for example a
planetary, replace all the reduction
assembly and not only the damaged gear.
Before reassembling the O-ring, gaskets
and the oil seals:
Concerned should be removed. 
Clean with care all the housing of the seal
and put some grease on the gasket before
mounting.
Never change only one part of the lifetime
seal, always the two rings together. 

8-103

3)

※

※

※

By means of an extractor, remove the
inner race of the bearing and spacer kept
on the flanged hub(17).

Withdraw both the half-seals(16) from the
flanged hub(17) and from the gearbox
housing(15).
L

L

ifetime seal check

In case of oil leakages, it should be
necessary to check and eventually replace
the lifetime seal(16), which means both
the metal rings parts and the O-rings. In
this case it is necessary to disassemble
the gearbox from the machine.
The gearbox disassembly ends with the
above operation: All items are now
available for the necessary checks. 

(27)

(28)

※

※

450A8TR30

450A8TR31

8-104

Fit the half seals(16) on the tool.

Fit the half seals(16) inside the gearbox
housing(15).

Clean carefully the metallic face of the
half-seal.  

Assemble, by using the same tool, the half
seal(16) on the flanged hub(17).

(1)

(2)

(3)

(4)

450A8TR32

450A8TR33

450A8TR34

450A8TR35