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Takeuchi Hydraulic Excavator TB175W (S/N 17540001~). WORKSHOP MANUAL - page 18

HYDRAULIC UNITS

SLEW MOTOR

IV-145

TB175W

9. Mount the sun gear (9).

10. Mount the carrier 1 (8).

11. Mount the thrust washer (7), inner race (6), needles

(5), planetary gear A (4), drive gear (3) and thrust
plate (2) on the carrier 1 (8).
• Measure the depth (A) from the case end to the

carrier 1 and select a proper thickness for the
thrust plate by referring to the table.

• The largely-rounded side of the thrust plate

circumference should face the planetary gear.

12. Fit the O-ring (1) to the case.

Slew Motor

1. Unite the hydraulic motor (1) and the reduction

gear (2) and fix them with the cap screws.

Cap screw: 177

10 N·m

Depth (A)

From 5.3 to less
than 5.8 mm

From 5.8 to less
than 6.5 mm

From 6.5 to 7.0

Thrust plate
thickness

2.8

0.14 mm

2.3

0.12 mm

1.8

0.10 mm

K3D627

L3D626

L3D625

L3D642

HYDRAULIC UNITS

SLEW MOTOR

IV-146

TB175W

2. Fit the O-ring to the cover.

3. Fit the anti-rebound valve to the cover and mount

the washer, seal and screws.

Screw: 32.4

2.0 N·m

K3D626

HYDRAULIC UNITS

SLEW MOTOR

IV-147

TB175W

INSPECTION AND ADJUSTMENT

Checking the Parts
Brake Valve

Hydraulic Motor

Parts

Judgement Criteria

Treatment

Check Valve,
Piston

Housing

Relief Valve
Assembly

Spring

• Scratches in sliding portions are deep or roughness is severe.
• The clearance with the body is large.
• Scratches in sliding portions are deep or seating is uneven.

• Scratches in sliding portions are deep or roughness is severe.
• There are scratches where oil leakage occurs.

• The set pressure drops abnormally low.
• The set pressure is unstable and vibration occurs.
• There is a lot of leakage due to faulty seating, etc.

• Damaged or severely deformed.

• Replace
• Replace
• Replace

• Replace
• Replace

• Replace
• Replace
• Replace

• Replace

Parts

Standard

Dimension

Recommended

Replacement

Value

Treatment

Clearance (S) be-
tween piston and
cylinder bore

Clearance (S) be-
tween piston and
shoe

Shaft and needle
bearing rolling sur-
face

Cylinder block
sliding surface (1)

Valve plate sliding
surface (2)

0.02 mm

Replace cylinder
block, swash plate
assembly.

Replace shaft, port
block assembly.

Carry out lap re-
pairs (#1000 Pow-
der) or replace.

Replace

0.04 mm

0.4 mm

Flaking or pitting
in the rolling sur-
face.

Sliding surface is
rough.

0.15 mm

E5D632

S=D-d

E5D633

E5D634

E5D635

HYDRAULIC UNITS

SLEW MOTOR

IV-148

TB175W

Reduction Gears

Parts

Judgement Criteria

Treatment

Drive Gear

Housing,
Internal Gear

Planetary Gear

Needle Bearing,
Planetary Shaft

Carrier, Shaft

Shaft

Thrust Wasyer

Ball Bearing,
Roller Bearing

Collar, Oil Seal,
O-ring

• Gear tooth surfaces are pitted or separating, etc.
• Clearance with motor joint is large due to spline wear.

• Gear tooth surfaces are pitted or separating, etc.

• Gear tooth surfaces are pitted or separating, etc.
• Needle rolling surfaces are pitted or separating, etc.

• Needle and shaft rolling surfaces are pitted or separating, etc.
• Pressure marks, etc. on needle and shaft rolling surfaces.
• Bearing rotation is abnormal (abnormal noise, rotation not smooth,

etc.).

• Clearance with planetary shaft is large.

• Clearance with pinion is large due to spline wear.

• Amount of wear is great.

• Rotation is abnormal (abnormal noise, rotation not smooth, etc.).
• Flaking, separation, etc. on rolling surfaces.
• Pressure marks, etc. on rolling surfaces.

• Scratches, etc. exist which cause leaks.

• Replace
• Replace

• Replace

• Replace
• Replace

• Replace
• Replace
• Replace

• Replace

• Replace
• Replace
• Replace

• Replace

Anti-rebound Valve

Check Valve

• Scratches in sliding portions are deep or roughness is severe.
• The clearance with the body is large.
• Scratches in sliding portions are deep or seating is uneven.

Parts

Judgement Criteria

Treatment

• Scratches in sliding portions are deep or roughness is severe.
• There are scratches where oil leakage occurs.

• Damaged or severely deformed.

Body

Spring, Sleeve

• Replace
• Replace
• Replace

• Replace
• Replace

• Replace

HYDRAULIC UNITS

SLEW MOTOR

IV-149

TB175W

TROUBLESHOOTING

If there is an abnormal increase in noise or heat, this
is an indication that trouble has occurred. When this
type of condition is manifested, stop the machine
immediately and search out the source of the trouble.

The following table shows a number of causes of
general breakdowns that can be seen in the hydraulic
circuits and indicates coutermeasures to take in each
case.

Symptom

How/Where?

Probable Causes

Remedy

Motor does not start.

Motor’s speed won’t
increase.

Oil is leaking.

Motor makes abnor-
mal noise.

(The surface tempera-
ture of the reduction
gears case becomes
high.)

Pressure doesn’t rise at the
motor’s inlet port.

Pressure rises at the motor’s
inlet port.

• Pump’s discharge vol-

ume is insufficient.

• Depends on the motor’s

function.

• Oil is leaking from oil

seals.

• Oil is leaking from mat-

ing surfaces.

• Noise in piping.

• Lubricating oil

• Gear unit

• Relief valve’s set pressure

is low.

• Pump is broken down.

• Control valve is broken

down.

• The load is excessive.
• Hydraulic motor is broken

down.

• Reduction gears are bro-

ken down.

• Pump’s drain amount is

large.

• The motor’s volumetric ca-

pacity is dropping.

• Lip is cut or damaged.

• Bolts are loose.
• O-ring is cut or damaged.
• Mating surface is scratched.

• Piping support is faulty.

• Oil level is low.
• Hydraulic oil is getting in.

• Bearings are damaged.
• Gear surfaces are damaged.

• Set the pressure at the cor-

rect level.

• Repair or replace the

pump.

• Repair or replace the con-

trol valve.

• Lighten the load.
• Repair or replace the hy-

draulic motor.

• Repair or replace the re-

duction gears.

• Repair or replace the

pump.

• Replace the motor.

• Replace the oil seal.

• Tighten the bolts.
• Replace the O-ring.
• Repair the surface with a

grind stone or sand paper.

• Clamp the piping.

• Replenish the oil.
• Replace the reduction gears.

• Replace the reduction gears.
• Replace the reduction gears.

HYDRAULIC UNITS

SLEW MOTOR

IV-150

TB175W

Anit-rebound Valve

The motor does not
rotate or its rota-
tion speed is slow.

Symptom

Probable Causes

Something other than the piston motor, valve
unit or anti-rebound valve is malfunctioning.

Inspect the pressure at the entrance of the
valve. Or, inspect individual units and ser-
vice as necessary.

Remedy

The check valve assembly is not seated prop-
erly.
• Foreign matter is trapped.

• The tightening torque of the anti-rebound

valve mounting bolt exceeds the prescribed
value.