GROUP 4 DISASSEMBLY AND ASSEMBLY

1. PRIORITY VALVE
1) STRUCTURE

1 2 4 3 9 5 2 6

7405S 5-6

1 Plug 4 Housing 8 Drive screw

2 O-ring 5 Spring 9 Orifice
3 Spool 6 Plug

2) TOOLS
・Torque wrench(5kgf・m)
・Hex socket wrench(1")
・Hex socket wrench(7/8")
・Hex wrench (7/32")
・Pincette
・Grease

5-27
3) DISASSEMBLY
※ Cleanliness is the primary means of
assuring satisfactory the priority valve life.
Select clean place.
Before removing the piping, clean the
surrounding area of valve ports.

(1) Fix the housing(4) in a vise with copper or

lead sheets.
P EF

Do not over tighten jaws.

(2) Loosen plug(6) for LS port.

7405S PV01

(3) Remove spring (5).

P EF

7405S PV02

(4) Remove Plug(1) and separate O-ring(2)

P EF
individually.

7405S PV03

5-28
(5) Remove the spool(3).
※ Can't remove the orifice(9) from spool(3), P EF

because the orifice was locked at the

spool.

7405S PV04

(6) The priority valve is now dismantled.

7405S PV05

5-29
4) ASSEMBLY
※ Clean all metal parts in clean solvent and
blow dry with air and correct any damage,
burrs and rust.
※ Do not wipe dry with cloth or paper towel.
※ Replace seals such as O-ring with new
ones as a rule and coat with grease.

Fix the housing(4) in a vise.

(1)
※ Do not over tighten jaws. P EF

Insert the spool(3) in the housing(4).

(2)
※ Secure the spool(3) remain in their correct
direction as the illustration.
※ Secure the spool(3) to move smoothly by
finger.

7405S PV06

(3) Install the O-ring(2) onto plug(1) and istall

P EF
the plug(1) into the housing(4).
・Tighten torque : 6.1kgf・m(44.3lb・ft)

7405S PV07

(4) Insert the spring(5) into the housing(4).

P EF

7405S PV08

5-30
(5) Install the O-ring(2) on plug(6) and install
the plug(6) into the housing(4). P EF

・Tighten torque : 6.1kgf・m(44.3lb・ft)

This completes assembly.

7405S PV09

5-31
5) TROUBLESHOOTING
Problem Cause Remedy

Steering wheel 1. Relief valve of steering unit is clogged Disassembly, clean and reassembly.
is heavy with dirt.
2. Spool is stuck. Disassembly, clean and reassembly or
replace.
3. Orifice of plug and spool is clogged. Disassembly, clean and reassembly.
(Steering wheel a. Pump is faulty. Check pump.
is heavy at
engine low idle)

(Steering speed b. Control pressure is low. Reset control pressure.

is not high at
c. Piping is faulty. Replace piping.
engine high idle)
d. Pump is faulty. Check pump.

Abnormal noise 1. Relief valve of steering unit is clogged Disassembly, clean and reassembly.
with dirt.
2. Spool is stuck. Disassembly, clean and reassembly or
replace.

Leakage 1. Loosen the plug. Retighten the specified torque.

2. O-ring is damaged. Replace.

5-32
2. STEERING UNIT
1) STRUCTURE

21

VALVE BLOCK
2 5
38 31
37 6
36
35 33
34 7

8
39 2
34
35 10
39 36
38 9
37 11
12
13
14

13
15
19
13
16
17

18

7407SE11

1 Dust seal ring 11 O-ring 21 Complete relief valve without seat

2 Housing, spool, sleeve 12 Intermediate plate 31 Set of o-rings
3 Ball 13 O-ring 33 Rolled pin
4 Thread bushing 14 Distributor plate 34 Screw
5 Roto glyd ring 15 Gearwheel set 35 Shock valve
6 Bearing assembly 16 End cover 36 Spring
7 Ring 17 Washer 37 O-ring
8 Cross pin 18 Screw with pin 38 Plug
9 Set of spring 19 Screw 39 Housing, check valve
10 Cardan shaft

5-33
2) TOOLS
(1) Holding tool.

7405S STVLV38(1)

(2) Assembly tool for O-ring and kin-ring.

7405S STVLV38(2)

(3) Assembly tool for dust seal.

7405S STVLV38(3)

(4) Torque wrench 0-7.1kgf m(0-51.6lb ft).

13mm socket spanner
12mm screwdriver
6mm screwdriver
2mm screwdriver
Plastic hammer
Ratchet spanner

7405S STVLV38(4)

5-34
3) DISASSEMBLY
(1) Disassemble steering column from
steering unit and place the steering unit in
the holding tool. Screw out the screws in
the end cover(7-off-one rolled pin).

7405S STVLV39(1)

(2) Remove the end cover, sideways.

7405S STVLV39(2)

(3) Lift the gearwheel set with spacer

bushing(and spacer if fitted) off the unit.
Take out the two O-rings.

7405S STVLV39(3)

(4) Remove spacer bushing and spacer(if

fitted) from the gearwheel.

7405S STVLV39(4)

5-35
(5) Remove cardan shaft.

7405S STVLV40(1)

(6) Remove distributor plate.

7405S STVLV40(2)

(7) Remove O-ring.

7405S STVLV40(3)

(8) Lift off intermediate plate.

7405S STVLV40(4)

5-36
(9) Remove O-ring.

7405S STVLV41(1)

(10) Screw out the threaded bushing.

7405S STVLV41(2)

(11) Remove cross pin.

7405S STVLV41(3)

(12) Shake out the ball(Ø8.5mm).

7405S STVLV41(4)

5-37
(13) Pull sleeve and spool out of the housing.

7405S STVLV42(1)

(14) Take ring, bearing races and needle

bearing from sleeve and spool. The
outer(thin) bearing race can sometimes
"stick" in the housing, therefore check that
it has come out.

7405S STVLV42(2)

(15) Carefully pull the spool out of the sleeve.

7405S STVLV42(3)

(16) Press the neutral position springs out of

their slots in the spool.

7405S STVLV42(4)

5-38
(17) Remove dust seal and O-ring.

7405S STVLV43(1)

(18) The steering unit is now completely

disassembled.

7405S STVLV43(2)

Cleaning
Clamp all parts carefully in Shellsol K or the
like.
Inspection an replacement
Replace all seals and washer. Check all
parts carefully and make any replacements
necessary.
Lubrication
Before assembly, lubricate all parts with
hydraulic oil.

5-39
4) ASSEMBLY
(1) Assemble spool and sleeve.
※ The sleeve and spool are correctly B A
assembled when
① The slots-in sleeve and spool-for the
neutral position springs are opposite
each other and
② One of the 3 T-shaped grooves(A) in the
spool is opposite one of the sets(B) of
7405S STVLV44(1)
small holes in the sleeve.

(2) Place the two flat neutral position springs

in the slot.

7405S STVLV44(2)

(3) Place the curved springs between the flat

ones and press them into place.

7405S STVLV44(3)

(4) Line up the spring set.

7405S STVLV44(4)

5-40
(5) Guide the spool into the sleeve.

7405S STVLV45(1)

(6) Press the springs together and push the

neutral position springs into place in the
sleeve.

7405S STVLV45(2)

(7) Line up the springs and center them.

7405S STVLV45(3)

(8) Guide the ring down over the sleeve.

※ The ring should be able to rotate-free of
the springs.

7405S STVLV45(4)

5-41
(9) Fit the cross pin into the spool/sleeve.

7405S STVLV46(1)

(10) Fit bearing races and needle bearing as

shown on below drawing.

7405S STVLV46(2)

1 Outer bearing race

1
2 Needle bearing
2
3 Inner bearing race
3
4 Spool
5 Sleeve *
* Inside chamfer on inner bearing race 4
must face inner spool.
5
7405S STVLV46(3)

(11) Grease O-ring and kin-ring with hydraulic

oil and place them on the tool. See next
page.

7405S STVLV46(4)

5-42
 7405S STVLV47(1)

(12) Put the steering unit in the holding tool

keeping the bore vertical. Guide the outer
part of the assembly tool into the bore.
Guide the inner part of the tool right to the
bottom.

7405S STVLV47(2)

(13) Press and turn the O-ring into position in

the housing. Draw the inner and outer
parts of the assembly tool out of the
steering unit bore, leaving the guide in the
bore.

7405S STVLV47(3)

(14) Take the steering unit out of the holding

tool and place it horizontally. With a light
turning movement, guide the spool and
sleeve into the bore.

7405S STVLV47(4)

5-43
(15) The spool set will push out the assembly
tool guide. The O-ring is now in position.

7405S STVLV48(1)

(16) Put the steering unit back into the holding

tool keeping the bore vertical. Place the
cross pin in the spool/sleeve so that it is
parallel to the port flange.

7405S STVLV48(2)

(17) Put the ball into the hole indicated by the

arrow.

7405S STVLV48(3)

(18) Screw the threaded bushing lightly into the

bore. The top of the bushing must lie just
below the surface of the housing.

7405S STVLV48(4)

5-44
(19) Grease the O-ring with mineral oil
approximate viscosity 500 cSt at 20 °C
and place it in the groove.

7405S STVLV49(1)

(20) Place the intermediate plate so that the

channel holes match the holes in the
housing.

7405S STVLV49(2)

(21) Grease the O-ring with mineral oil

approximate viscosity 500 cSt at 20 °C
and place it in the groove.

7405S STVLV49(3)

(22) Place the distributor plate so that the

channel holes match the holes in the
intermediate plate and the housing.

7405S STVLV49(4)

5-45
(23) Guide the cardan shaft down into the bore
so that the slot is parallel with the
connection flange.

7405S STVLV50(1)

(24) Place the gear wheel(Rotor) so that the

cross pin from item 33 is positioned in
relation to two tooth bases - as the screw
driver indicates.

7405S STVLV50(2)

(25) Grease the two O-rings with mineral oil

approximate viscosity 500 cSt at 20 °C
and place them in the two grooves in the
gear rim. Fit the gear rim so that the seven
through holes match the holes in the
distributor plate.
※ Turn the gear rim so that the smaller
diameter of the holes face the distributor
plate.
7405S STVLV50(3)

(26) Orientate the holes with a single screw.

7405S STVLV50(4)

5-46
(27) Place the end cover in position.

7405S STVLV51(3)

(28) Place the washers over the holes and the

rolled pin in the hole shown.

7405S STVLV51(4)

(29) Fit the other six screws. Cross - tighten all

the screws and the rolled pin with a torque
of 3±0.6kgf m(22±4.4lb ft). Steering unit
can now be function tested.

7405S STVLV52(1)

(30) Turn the steering unit 180°and place the

dust seal ring in the housing.

7405S STVLV52(2)

5-47
(31) Fit the dust seal ring in the housing using
special tool and a plastic hammer.

7405S STVLV52(3)

(32) Press the plastic plugs into the connection

ports. Do not use a hammer.

7405S STVLV52(4)

5-48
3. VALVE BLOCK
1) STRUCTURE

31

33
38
37
36
35

39

34
35
39 36
37
38

P,T,L,R port PF 1/2

Shock valves 270-290 bar

7407SE12

31 Set of springs 36 Spring

33 Rolled pin 37 O-ring
34 Screw 38 Plug
35 Shock valve 39 Housing and check valve

5-49
2) TOOLS
(1) Hexagon socket spanner, 8mm.

7405S OVLOAD63(1)

(2) Torque wrench, 0~7.1kgf m(0~51lb ft)

with 8mm hexagon socket spanner.

7405S OVLOAD63(2)

(3) Adjustable wrench.

7405S OVLOAD63(3)

5-50
3) DISASSEMBLY
(1) Remove the rolled pin.

7405S OVLOAD64(1)

(2) Remove the plug(38) and O-ring(37).

8
38
7
37

7405S OVLOAD64(2)

(3) Remove the spring(36) and shock

valve(35). 6
36

5
35

7405S OVLOAD64(3)

(4) Remove the O-ring set(31).

1,2
31

7405S OVLOAD64(4)

5-51
(5) Remove the check valve(39).
39
9

7405S OVLOAD65(1)

(6) The overload valve is now disassembled.

7405S OVLOAD65(2)

5-52
4) ASSEMBLY
Cleaning
Clean all parts carefully in Shellsol K or the
like.
Inspection an replacement
Replace all seals and washers. Check all
parts carefully and make any replacements
necessary.
Lubrication
Before assembly, lubricate all parts with
hydraulic oil.

(1) Fit check valve(39).

39
9

7405S OVLOAD66(1)

(2) Fit the shock valve(35) and spring(36).

36
6

35
5

7405S OVLOAD66(2)

(3) Fit the O-ring(37) and screw the plug(38).

38
8
37
7

7405S OVLOAD66(3)

5-53
(4) Fit the rolled pin.

7405S OVLOAD66(4)

(5) The overload valve is now assembled. It

can be checked for leakage separately or
when mounted on a steering unit.

7405S OVLOAD67(1)

(6) Locate the four O-rings between overload

valve and steering unit and fit these
components together.

7405S OVLOAD67(2)

(7) Tighten the hexagon socket screws with a

torque of 6.6+0.5
0 kgf m(47.7+3.6
0 lb ft).

7405S OVLOAD67(3)

5-54
(8) Press the plastic plugs into the connection
ports. The overload valve is now
assembled.

7405S OVLOAD67(4)

5) TROUBLESHOOTING

Problem Cause Remedy

Steering wheel 1. Over tighten mounting torque. Retighten as specified torque.

is heavy
2. Over load valve seat side is clogged Disassembly, clean, reassembly.
with dirt.

Steering cylinder 1. Overload valve seat side is clogged Disassembly, clean, reassembly.
reaction is bad with dirt.
2. Anti cavitation check valve seat is Disassembly, clean, reassembly.
clogged with dirt.
3. Damage of O-ring for adjusting. Replace.

Abnormal noise 1. Overload valve seat side clogged Disassembly, clean, reassembly.
with dirt.

Leakage 1. Loosen 2 mounting bolt. Retighten as specified torque.

2. Damage of O-ring. Replace.
3. Leakage through plug. Apply seal tape to thread and retighten
as specified torque.

5-55
4. STEERING CYLINDER
1) STRUCTURE

3 9,8 12 6,5 7 11,10 4 2 1 13 14 15 16 17 25 24

22,23

19,20,21 18

7407SE07

1 Tube assy 10 O-ring 18 Pipe assy

2 Rod assy 11 Back up ring 19 U-bolt
3 Gland 12 O-ring 20 Hexagon nut
4 Du bushing 13 Piston 21 Washer spring
5 Rod seal 14 O-ring 22 Bushing
6 Back up ring 15 Piston seal 23 Dust seal
7 Buffer ring 16 Wear ring 24 Spherical bearing
8 Dust wiper 17 Nylon nut 25 Retaining ring
9 Snap ring

5-56
2) TOOLS AND TIGHTENING TORQUE
(1) Tools

Tool name Remark

17 B
Spanner 32
41
Steel bar For gland
(-) Driver Small and large sizes
Torque wrench Capable of tightening with the specified torques

(2) Tightening torque

Torque
Part name Item Size
kgf・m lbf・ft
Gland 3 M70 × 2.0 70 ± 7 506 ± 51
Nylon nut 17 M27 × 2.0 75 ± 8 542 ± 58
Nut(Pipe assy) 18 M22 × 1.5 30 ± 3 217 ±21.7
Nut 20 M10 × 1.5 3.2 ± 0.3 23.1± 2.2

5-57
3) DISASSEMBLY
(1) Remove cylinder head and piston rod
① Hold the clevis section of the tube in a
vise.
※ Use mouth pieces so as not to damage
the machined surface of the cylinder
tube. Do not make use of the outside
piping as a locking means.

② Pull out piston rod(2) about 200mm

(7.1in). Because the piston rod is
rather heavy, finish extending it with air m
0m
20
pressure after the oil draining operation.

7405S 5-65(1)

③ Loosen and remove the gland(3).

※ Cover the extracted piston rod(2) with Wrench
rag to prevent it from being accidentally
damaged during operation.

3
2
7405S 5-65(2)

④ Draw out gland(3) and piston rod (2)

assembly together from cylinder tube(1).
Lift
※ Since the piston rod assembly is heavy
in this case, lift the tip of the piston rod(2)
with a crane or some means and draw it
out. However, when piston rod(2) has
been drawn out to approximately two
thirds of its length, lift it in its center to Full straight Oil pan
draw it completely. sideways
7405S 5-65(3)

5-58
※ Note that the plated surface of piston
rod(2) is to be lifted. For this reason, do
not use a wire sling and others that may
damage it, but use a strong cloth belt or a
rope.

⑤ Place the removed piston rod assembly

on a wooden V-block that is set level.
※ Cover a V-block with soft rag. Piston assy

Wooden block
7405S 5-66(1)

(2) Remove piston and gland assembly

① Remove the nylon nut(17). 14 15 16 13 17
② Remove piston assembly(13), and O-
ring(14).

7405S 5-66(2)

④ Remove the gland(3) assembly from

piston rod(2). Lift with a crane
※ If it is too heavy to move, move it by Plastic 8,9 5,6
hammer
striking the flanged part of gland(3) with 7 4
a plastic hammer.
Full straight
※ Pull it straight with cylinder head
assembly lifted with a crane.
Exercise care so as not to damage the lip
of rod bushing(4) and packing (5,6,7,8,9)
by the threads of piston rod(2). 3 2
7405S 5-66(3)

5-59
(3) Disassemble the piston assembly
① Remove wear ring(16) and piston seal 15 16
(15).
※ Exercise care in this operation not to
damage the grooves.

7405S 5-67(1)

(4) Disassemble gland assembly

① Remove back up ring(11), and O-ring 8,9 12 5,6 7 10,11 4
(10).
② Remove O-ring(12).
③ Remove snap ring(9) and dust wiper(8).
④ Remove back up ring(6), rod seal(5).
⑤ Remove buffer ring(7).
※ Exercise care in this operation not to
damage the grooves.
7405S 5-67(2)
※ Do not remove seal and ring, if does not
damaged.

5-60
4) ASSEMBLY
(1) Assemble gland assembly
※ Check for scratches or rough surfaces if
found smooth with an oil stone.
① Coat the inner face of gland(3) with
hydraulic oil.
3

7405S 5-68(1)

② Coat dust wiper(8) with grease and fit Press here

dust wiper(8) to the bottom of the hole of (Straight down)
dust wiper. Metal
At this time, press a pad metal to the 8
metal ring of dust seal.
③ Fit snap ring(9) to the stop face.

7405S 5-68(2)

④ Fit back up ring(6) and rod seal(5) to

corresponding grooves, in that order.
⑤ Fit buffer ring(7).
※ Coat each packing with hydraulic oil Wrong Right
before fitting it.
※ Insert the backup ring until onside of it is
inserted into groove.

7405S 5-68(3)

※ Rod seal(5) has its own fitting direction.

Therefore, confirm it before fitting them. Push bar
※ Fitting rod seal(5) and buffer ring(7) up
side down may damage its lip. Therefore
check the correct direction that is shown
in fig. 7
5,6

7405S 5-68(4)

5-61
⑥ Fit back up ring(11) to gland (3).
※ Put the backup ring in the warm water of
30~50°C . 4
⑦ Fit O-ring(10) to gland(3). 10
⑧ Fit O-ring(12) to gland(3). 11
3
12

7405S 5-69(1)

(2) Assemble piston assembly

※ Check for scratches or rough surfaces.
If found smooth with an oil stone.
① Coat the outer face of piston(13) with
hydraulic oil.

7405S 5-69(2)

② Fit piston seal(15) to piston

※ Put the piston seal in the warm water of
60~100°C for more than 5 minutes. 15
※ After assembling the piston seal, press
its outer diameter to fit in.

7405S 5-69(3)

③ Fit wear ring(16) to piston(13).

④ Fit O-ring(14) to piston(13). 14 15 16 13

7405S 5-69(4)

5-62
(3) Install piston and gland assembly
① Fix the piston rod assembly to the work Gland assembly Piston rod
bench.
② Apply hydraulic oil to the outer surface of
piston rod(2), the inner surface of piston
and gland.
③ Insert gland assembly to piston rod(2).

7405S 5-70(1)

④ Fit piston assembly to piston rod.

・Tightening torque : 50±5kgf・m Piston assembly
(362±36lbf・ft) Piston rod

7405S 5-70(2)

⑤ Tighten nylon nut(17) to piston rod(2).

・Tightening torque : 75±8kgf・m 2 17
(542±58lbf・ft)

7405S 5-70(3)

5-63
(4) Overall assemble Fix with a bar
① Place a V-block on a rigid work bench.
Mount the cylinder tube assembly(1) on it Lift
and fix the assembly by passing a bar
through the clevis pin hole to lock the
assembly.
Straight
② Insert the piston rod assembly in to the
cylinder tube assembly, while lifting and
moving the piston rod assembly with a Apply liquid packing
7405S 5-71(1)
crane.
※ Be careful not to damage piston seal by
thread of cylinder tube.
③ Match the bolts holes in the cylinder
head flange to the tapped holes in the Tube
cylinder tube assembly and tighten
socket bolts to a specified torque. Piston rod
※ Refer to the table of tightening torque.
Wrench

Gland
7405S 5-71(2)

5-64
5. CENTER PIVOT PIN
1) CONSTRUCTION
Figure shows the construction of the center pivot pin assembly. This assembly serves to connect
the front frame with the rear frame; two sets of assemblies are provided, one each for the upper and
lower parts. The numbers in parentheses following the parts name denote the item numbers
shown in the figure in the disassembly and assembly procedures.

14,15 7 6 21

9
13 12

18
2
1
14,15 3,4 20

20
19
1
3,4
9 8

16,17

21 10 18 14,15

UPPER LOWER

7707SE13

1 Bearing 9 Plate 16 Shim(0.1T)

2 Retainer 10 Pin 17 Shim(0.5T)
3 Shim(0.1T) 12 Seal 18 Bushing
4 Shim(0.5T) 13 Seal 19 Retainer
6 Pin 14 Hexagon bolt 20 Front frame
7 Collar 15 Hardened washer 21 Rear frame
8 Collar

5-65
2) DISASSEMBLY
After supporting the front frame and the
rear frame as horizontally as possible using
wood blocks and jacks, disassemble as
follows: In order to facilitate the
disassembly/assembly of the center pivot
pins, remove the drive shaft, hydraulic line
and steering cylinder first.
(1) Maintain the horizontal level of front
frame(20) and rear frame(21), and then
14
remove hexagon bolt(14) and plate(9). 9

(2) Take out upper pin(10) to the downside

using a metal punch.
20

21

10
7707SE14

(3) Maintain the front frame horizontal level,

remove hexagon bolts(14) and then 21
6
remove the plate(9) and shims(16,17).
(4) Take out lower pin(6) to the upside using
a metal punch carefully.
20
(5) Jack up or lifting the front frame(20) 8
slightly, the collar(8) protrudes over the
rear frame. 9
Remove the collar(8). 16,17
14
(6) Lift the frame by passing the slinging wire 7707SE15
rope at four positions of front frame, in
order to separate it from the rear frame.
(7) Support the front frame safely.

5-66
 (8) Remove bolt(14) and then take out
retainer(2) and shims(3,4). 14 13 2

(9) Take out dust seal(13) from the retainer (2). 3,4

(10) Remove the bearing(1), and dust

seal(13).
1

13
7707SE16

(11) Remove bolt(14) and then take out 12 7

retainer(19) and shims(3,4).
1
(12) Take out the dust seal(12) from the
retainer(19).
(13) Remove the bearing(1), collar(7) and dust
seal(12). 3,4

19 12 14
7707SE17

3) INSPECTION
(1) Check the bearing sliding surface for excessive wear, scorching or scratches; replace if
necessary.
(2) Replace all dust seals(12,13) with new ones.
(3) Grind any pins(6, 10) dented with an oilstone or replace any pins abrasive excessively.
(4) Check inside retainer(2, 19) and collar(7, 8) for dents or scratches; if any damage is found, correct
with a grinder or replace.
(5) The serviceable limit of pins and bushings is shown in the table below.
Unit : mm

Std Serviceable limit

Item No. Name dimension Remedy
Outer dia Inner dia Clearance
6, 10 Pin 64.5 -
1 Tapered roller bearing 65 - 65.5 0.8 Replace
7, 8 Collar - 65.5
12, 13 Dust seal When removed Replace

5-67
4) ASSEMBLY
Assemble the center pivot group by reversing the order of disassembly while paying close attention
to the following.
(1) Put the dust seal(12,13) into retainer(2, 19) and front frame(20).
※ Apply grease to the lip of the dust seal. Insert the dust seal so that the dust seal lip faces out and
punch four places on the outer circumference of the seal to lock it.
(2) Lower the temperature of the lower bearing cup to -75 5°C (-103 9°F ) and install it to front
frame until it contacts the bottom of the frame.
(3) Coat lightly with oil and install lower bearing in bore in front frame. Coat lightly with oil and install
upper bearing in bore in upper front frame.
(4) Position the upper retainer(2) and hold in place with bolt(14). At this time, adjust shims(3,4) to
press the shoulder of bearing(1) against retainer.
Shim thickness : 0.1mm, 0.5mm
(5) Apply grease to lower collar(8) and insert it to the lower of roller bearing.
(6) After setting the bearing so that its upper surface is horizontal, tighten the bolt.
After tightening, confirm that tapered roller bearing moves lightly ; if does not move smoothly, add
shims(3,4).
Tightening Torque : 9.8~15.8kgf m(70.9~114lbf ft)
(7) Move the front frame and join it to the rear frame so that match the pin hole at the center.
(8) Apply grease to pin(10), bushing(18) and insert it into tapered roller bearing(1).
(9) Apply grease to lower collar(8) and insert it to the lower of roller bearing through rear frame(21).
(10) Apply grease to pin(6) and insert it into tapered roller bearing(1).
(11) Position the plate(9) and hold in place with bolt(14).
Tightening Torque : 9.8~15.8kgf m(70.9~114lbf ft)
Apply locktite #243.
(12) Before tightening bolt(14), adjust shims(16,17) in order to control the clearance between the
plate(9) and rear frame(21).
Shim thickness : 0.1mm, 0.5mm
Tightening Torque : 9.8~15.8kgf m(70.9~114lbf ft)
Apply Locktite #243.

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5) TROUBLESHOOTING

Trouble Probable cause Remedy

Shock is felt when steering Capscrew for fixing steering valve is loose Retighten
Faulty center pivot pin mounting bolts Retighten
Center pivot pins have worn out Readjust or replace
Faulty hydraulic system See hydraulic system
Shock is felt when moving Fault fixing of connecting capscrews Retighten
backward or forward
Center pins have worn out Readjust or replace
Bearings of support unit have worn out Retighten
Drive shaft damaged See drive system
Faulty transmission See transmission system

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