4transmission system englisg-g9165

Service Manual of RS8160 Road Roller

4 Transmission System

SERVICE MANUAL

Service Manual for G9165 Grader

I

CONTENTS

4 Transmission System ........................................................................................... 4-1

41 Hydraulic Torque Converter-Transmission Box System .................................... 4-1

411 General ......................................................................................................... 4-1

412 Mechanical Principles for Gear Shifting ..................................................... 4-5

413 Transmission Control System...................................................................... 4-5

414 Pressure Test of Transmission Box ............................................................. 4-8

415 Operation and Maintenance of YD13 Power Shifting Transmission Box .. 4-9

416 Disassembly and Assembly of Transmission System ............................... 4-12

417 Precautions ................................................................................................. 4-25

42 Transmission Shaft System ............................................................................... 4-26

421 Overview of Transmission Shaft ............................................................... 4-26

422 Disassembly and Assembly of Transmission Shaft Assembly ................. 4-28

43 Drive Axle System ............................................................................................. 4-30

431 Overview of Drive Axle ............................................................................ 4-30

432 Main Reducer and Differential Assembly ................................................. 4-31

433 Wheel Reducer Assembly ......................................................................... 4-32

434 Balancing Box Assembly .......................................................................... 4-32

435 Disassembly and Assembly of Drive Axle and Balancing Box ................ 4-32

436 Use, Maintenance and Repair of Drive Axle ............................................ 4-36

44 Diagnosis and Solutions for Common Fault of Transmission System ............. 4-38

441 Common Faults of Transmission Box ....................................................... 4-38

442 Common Faults of Drive Axle .................................................................. 4-39


4-1

4 Transmission System

Transmission system of G9165 grader is composed of transmission box, transmission shaft, and

drive axle. The principle diagram of transmission system is shown in Fig. 4-1.

Fig. 4-1 G9165 grader power transmission diagram

1 Engine 2 Hydraulic torque converter + transmission box 3 Balancing box

4 Main drive 5 Transmission shaft 6.Left working pump 7 Right working pump

41 Hydraulic Torque Converter-Transmission Box System

411 General

G9165 grader is equipped with ZFW320 torque converter and YD13 transmission box. Because of

the design, 6 forward gears and 3 reverse gears can be realized to satisfy different working

conditions.

Basic parameters of hydraulic torque converter-transmission box assembly are listed in Table 4-1.


4-2

Table 4-1

Rated input power kw 129

Rated input speed r/min 2200

Hydraulic torque

converter

Model ZFW320

Torque ratio 1.940

MBgo 133.3NM

Inlet pressure of converter (MPa) 0.8~1.0MPa

Outlet pressure of converter (MPa) 0.25~0.4MPa

Transmission box

Shifting gears Forward-6-Reverse-3

Structural style Fixed shaft

Shifting pressure (MPa) 1.3~1.8MPa

Transmission

ratio

Forward I 5.900

Forward II 3.775

Forward III 2.304

Forward IV 1.475

Forward V 0.964

Forward VI 0.617

Reverse I 5.900

Reverse II 2.304

Reverse III 0.964

The torque converter is of single-stage single-phase three-component structure without lockup

clutch (see Fig. 4-2). It is composed of pump impeller, turbine and guide wheel, and a circulating

system is formed by the three components, i.e., the oil circulates in the way of “pump impeller —

turbine — guide wheel”. The mechanical energy outputted by engine is converted into hydraulic

energy by the pump impeller, and then converted into mechanical energy again by the turbine. The

transmission oil pump continuously supplies pressure oil to torque converter, in this way can the

torque converter work to increase engine output torque. Meanwhile, the circulating transmission oil

also absorbs the heat produced by the torque converter, and dissipates it through the radiator for

cooling.

The transmission oil flows into the turbine from the pump impeller, and changes its direction

through the turbine. The outputted torque by turbine depends on the loads. The guide wheel

(reverse-acting component) is installed between the turbine and pump impeller, it can change the

direction of return oil from turbine and send it back to pump impeller, thus, there is reverse-acting

force acted on the guide wheel. The torque ratio of turbine and pump impeller is termed as torque


4-3

ratio of the converter. Generally the torque ratio increases as speed ratio of turbine and pump

impeller deceases. When turbine speed reaches 80% of the pump impeller speed, the torque ratio is

close to 1, which means the turbine torque is equal to pump impeller torque, the torque converter is

a coupler in this case. When speed of turbine is close to zero (zero-speed working condition), the

torque ratio reaches the maximum value, as the output speed increases, the torque ratio will reduce.

Since a torque converter is designed in the system, stepless speed change can be achieved, and

variety of load can be adapted to automatically. In this way, the grader is able to work under all

kinds of conditions, the labor intensity is reduced and service life of grader can be prolonged.

Fig. 4-2 Hydraulic torque converter

The transmission box is of fixed shaft electric hydraulic control (EHC) power shift type, gear

shifting operation can be carried out without cutting off the power by engaging the clutches (with

wet-type friction plates). The transmission box is designed with 6 multi-friction-plate clutches.

When shifting, the pressure oil will push axially to engage the corresponding clutches. Detaching of

clutch is realized by action of return spring force.

YD13 is multi-gear power shift transmission box, it adopts parallel shaft (fixed shaft) transmission,

and all transmission gears are supported by antifriction bearings. Constant mesh transmission is

applied between the transmission gears. Cooled oil is used to lubricate the clutches and bearings.


4-4

1 Oil filter

2 Transmission control valve

3 Measuring port of torque converter

oil temperature

4 Oil outlet From torque converter to

radiator

5 Oil absorption pipe

6 Transmission box housing

7 Nameplate

8 Lifting bolt

9 Auxiliary power takeoff

10 Main power takeoff

11 KVK1 clutch shaft

12 KRK2 clutch shaft

13 K3K4 clutch shaft

14 Parking brake

Fig. 4-3 YD13 transmission box assembly


4-5

412 Mechanical Principles for Gear Shifting

The transmission box is designed with 6 multi-friction-plate clutches, i.e., K1, K2, K3, K4, KV and

KR, and KR is the reverse gear clutch. Each gear requires two engaging clutches, the working

principle diagram of transmission box is illustrated below.

Fig. 4-4 Working principle diagram of transmission box

413 Transmission Control System

YD13 transmission box adopts electro-hydraulic control, a gear selector is installed on the right side

of operator’s seat (see Fig. 4-5). The transmission solenoid valves that connected with the gear

selector are used to control the hydraulic slide valves to carry out gear shifting operation. Gear

shifting operation should be performed orderly, do not skip any gears. The transmission control

pump, which is used to supply oil to torque converter and transmission control valve, is placed

inside transmission box. The pump is directly driven by engine, and its output flow

Q=35L/1000r/min. The pump absorbs oil from oil pan through the oil absorption filter (pre-filter)

and sends it to the fine filter on top of transmission box housing. The filter fineness is 0.025um, and

filter area is 5100cm2. Besides, the filter is designed with a bypass valve for safety protection.


4-6

The control pressure valve (main pressure regulating valve) is used to limit the pressure of oil from

the filter, after being regulated, the oil will flow into transmission control valve through the pressure

control valve. The function of pressure control valve is to adjust pressure rise characteristics of the

clutch oil cylinder in the moment of gear shifting operation. In the moment of gear shifting, the oil

pressure will reduce, the pressure control valve can rebuild the pressure to 1.3~1.8MPa (set value of

control pressure valve) after the shifting process. In this way, impact of shifting is reduced and

shifting quality of transmission box is improved. The pressure oil from transmission control valve

goes directly to the corresponding clutches.

In addition to limit the pressure of transmission control oil, the control pressure valve also sends the

overflowed oil to torque converter and lubricating oil line in the meantime. A safety valve with

opening pressure of 0.8MPa is installed in the oil inlet of torque converter, to avoid oversized oil

pressure from damaging the components inside the torque converter. As we know, according to the

hydraulic transmission principle of torque converter, oil is the medium of energy delivering inside

the converter. Thereby, to prevent cavitation, the torque converter should always be fully filled with

oil, and this is guaranteed by the pressure control valve (counterbalance valve, with opening

pressure of 0.25MPa) installed in the oil outlet of torque converter.

The overflowed oil from torque converter flows directly into oil cooler of the vehicle. If the vehicle

adopts water-cooled engine, the cooler should be installed on the engine cooling water exit end. The

cooler must be designed with bypass valve for protection in case of low temperature or blockage.

The oil from oil cooler flows directly into transmission box lubricating oil line, to provide sufficient

lubricating oil for all lubricating points.

Fig. 4-5 Gear selector

Neutral gear Reverse gears

Forward gears


4-7

The corresponding working condition of transmission solenoid valves and clutches in each gear are

shown in Table 4-2.

Table 4-2

●Solenoid valve is electrically charged Engaged clutches

M1 M2 M3 M4

Forward I ● ● ● KV K1

Forward II ● ● ● K4 K1

Forward III ● ● KV K2

Forward IV ● ● K4 K2

Forward V ● KV K3

Forward VI ● K4 K3

Reverse I ● ● ● ● KR K1

Reverse II ● ● ● KR K2

Reverse III ● ● KR K3

Neutral gear — K3


4-8

Fig. 4-6 Electro-hydraulic control principle of YD13 hydrodynamic transmission box

414 Pressure Test of Transmission Box

ATTENTION

Keep the engine running and make sure the transmission box oil temperature is within

80~95oC when measuring the transmission oil pressure. Standard transmission oil

pressure is 1.3~1.8MPa.


4-9

Fig. 4-7 Fig. 4-8

Pressure measuring points:

3= Inlet oil pressure of torque converter 2= Outlet oil pressure of torque converter

5= K2 clutch oil pressure 6= K1 clutch oil pressure 7= K3 clutch oil pressure

8= Control oil pressure 9= K4 clutch oil pressure 10= KR clutch oil pressure

11= KV clutch oil pressure

Temperature measuring point:

4= Torque converter oil outlet

Flow measuring points:

1= Filter inlet 2 Filter outlet (Min. flow is 50L/min)

Specification of connecting thread of each measuring point:

Table 4-3

Measuring point Specification

3, 5, 6, 7, 8, 9, 10, 11 M10×1

1, 2 M26×1.5

415 Operation and Maintenance of YD13 Power Shifting Transmission

Box

Oil filling

SAE 15W-40 diesel engine oil is applicable to the transmission box, fill approx. 28L for the first

time. The oil filling port and oil dipstick of transmission box is on left-front side of rear frame.


4-10

Fig. 4-9 Fig. 4-10 Transmission box oil dipstick

Check the oil level:

——Park the grader on a flat place.

——Put the gear shifting handle of transmission box in the neutral position "N".

——Make sure the transmission box oil temperature is within normal operating temperature e.

——Run the engine at idle status (about 750r/min).

——Loosen the oil dipstick clockwise and remove the oil dipstick. Clean it.

——Insert the oil dipstick and tighten it. Then take it out to read the oil level (do this at least twice).

——When the oil temperature is 104°F (40°C), oil level should be between bottom scale and

middle scale (ZONE COLD).

——When the oil temperature is 176°F (80°C), oil level should be between highest scale and

middle scale (ZONE HOT).

1. Since the oil in the torque converter, cooler and oil pipes will flow back to the transmission oil

pan when the engine stopped, so when checking oil level, the grader should be stopped in

neutral position and let the engine run at idle status to keep the oil in transmission box stay in

normal working temperature. If the engine is not running when checking the oil level, the oil

level should above the “HOT” scale on oil dipstick (see Fig. 4-10). After the first 100 working

hours of the grader, the oil must be replaced. Since then, replace the oil at least every 500

working hours or every year, and the filter should be replaced at the same time.

2. When checking the oil level of the transmission box, related safety regulations and instructions

must be strictly complied with. For instance, Wedge the tires with wood blocks to prevent

movement, lock the hinged frames with frame locking bar, etc.

3. The gear shifting handle must be in the neutral position before checking oil level.

Transmission box oil dipstick

Transmission box oil filling port


4-11

4. When the oil temperature is 80oC, the oil level should between the middle and the top scale line

of the oil dipstick.

When the oil temperature is 40oC, the oil level should between the middle and the low scale

line of the oil dipstick.

When draining oil, only a part of oil can be discharged from the oil drain holes.

5. When cleaning the oil filter in main oil line, avoid intrusion of oil dirt and impurities. Besides,

installed a cover plate to the brake to prevent oil from dropping into the brake.

6. When installing the filter, avoid exerting external force on the filter and do not tighten it too

tight.

Method to tighten the filter: Coat a thin layer of oil on the seal ring first, screw it into the

mounting hole until contacting with the fitting surface, and then tighten it for another 1/3~1/2

circle by hand or special tool. Pay attention to check the whether bypass valve inside the filter

is in open state.

Driving and shifting gears

When starting the engine, you must confirm that the gear shifting handle is in neutral position. For

safety's sake, before the engine started, the grader must be in the braking state, so the grader won’t

move after the engine started.

After the engine started, remove parking brake state and adjust traveling direction, then shift proper

gear, stamp the accelerator pedal to move to grader. During driving, torque converter supersedes

main clutch. You can shift high gears when the road is clear.

If the grader has stopped moving and the engine is still running, engage a gear at this point, the

engine may not flameout, and on a flat road, the grader may crawl, that’s because tractive force can

be produced by the torque converter when the engine is running at idle status. The right

countermeasure is: put the parking brake in braking state every time you stop the grader. If the

grader needs to stop for a long time, the gear shifting handle must be in neutral position.

When the grader is travelling, the parking brake must be relieved, but what we learned from

experience is that it’s difficult for the operator to immediately find out the parking brake state is not

released, that’s because the large output torque ratio produced by torque converter, which can

overcome braking torque and force the grader to move even under normal operating conditions.

Then the consequence is the torque converter oil temperature rising sharply and overheated brake.

Slow down the machine before turning. Max. running speed during steering should not exceed

10km/h.

Lubricating oil flow rate of transmission box is subject to engine speed, so keep engine speed high

than 1200r/min during driving.


4-12

Pausing and parking

Since there is no rigid connection between engine and torque converter output shaft, so when

parking on a slope (up/down) and the driver intends to leave, in order to prevent slide phenomenon

occurred, we suggest that the grader should not only be braked, but also be wedged with blocks

under the tires.

Towing

The maximum towing speed is 10 km/h, and the maximum towing distance is 10 km. When the

destination is far away, a truck is needed to transport the malfunctioned grader.

416 Disassembly and Assembly of

Transmission System

ATTENTION

Wait until the transmission box is cooled to

do the disassembly.


4-13

In the process of disassembly, the joints of

each pipeline should be bound up to avoid

the sundries entering.

Disassembly of transmission box

1. Wedge the tires with wood blocks properly.

2. Remove the engine hood , cab and platforms.

Refer to 8 Cab & Covering Parts System.

3. Remove the transmission control oil pressure

sensor.

ATTENTION

After removing the pressure sensor, take

measures to protect the exposed oil port and

the pressure sensor should be properly kept.

1

Fig. 4-11

1 Wood block

1 2

Fig. 4-12

1 Engine hood 2 Cab

1

Fig. 4-13

1 Transmission control oil pressure

sensor


4-14

4. Remove the hydraulic oil tank, refer to 9

Working Hydraulic System.

5. Drain transmission box oil.

ATTENTION

In routine maintenance, drain oil from the

specialized oil drain port. When

disassembling the transmission box, you can

drain oil form the oil drain port or remove

the oil filling pipe to drain oil, tighten the

plug timely after draining to prevent

intrusion of foreign matters.

6. Disconnect the transmission box vent pipe.

1

Fig. 4-14

1 Hydraulic oil tank assembly

1

Fig. 4-15

1 Oil drain plug

1

Fig. 4-16

1 Vent pipe


4-15

7. Disconnect the control wire of transmission

control valve.

8. Remove the transmission oil temperature

sensor.

ATTENTION

After removing the temperature sensor, take

measures to protect the exposed oil port and

the pressure sensor should be properly kept.

9. Disconnect the transmission box to radiator oil

pipe.

1 2

Fig. 4-17


2 Control wire

1

Fig. 4-18

1 Oil temperature sensor

1

Fig. 4-19

1 Transmission box to radiator oil pipe


4-16

10. Disconnect the radiator to transmission box oil

pipe.

11. Remove the connecting bolts of transmission

shaft and transmission box.

12. Remove the oil inlet and outlet pipes of

working pump and steering pump.

ATTENTION

Disconnect the oil pipe slowly to prevent oil

splashing. Take measures to protect the

exposed oil ports to prevent intrusion of

1

Fig. 4-20

1 Radiator to transmission box oil pipe

1 2

Fig. 4-21

1 Bolt

2 Transmission shaft assembly


4-17

foreign matters.

13. Remove the parking brake control wire.

14. Remove the cover plate of transmission box.

15. Remove the connecting bolts of torque

converter housing and the connecting plate.

1

Fig. 4-23

1 Parking brake control wire

1 2

Fig. 4-24

1 Cover plate 2 Bolt

1 2

Fig. 4-25

1 Connecting plate 2 Bolt


4-18

16. Remove the connecting bolts of torque

converter housing and engine flywheel

housing.

ATTENTION

Before removing the connecting bolts, you

must support the engine prevent it falling.

17. Remove the fixing bolts of transmission box

support.

18. Lift down the transmission box.

Connect lifting rope to the two lifting eyes on

transmission box, lift it up slowly and pay

attention not to extrude or drag the cables and

pipes.

1

Fig. 4-26

1 Bolt

1

Fig. 4-27

1 Bolt

1 2

Fig. 4-28


4-19

ATTENTION

Lift the transmission box smoothly and do

not tilt to prevent the torque converter

slipping.

Assembly of transmission box

1. Connect the lifting appliance to the

transmission box.

2. Lift the transmission box to the right position.

ATTENTION

Fig. 4-29


4-20

Lift the transmission box smoothly to

prevent the torque converter slipping.

Please be careful during operation and pay

special attention to the cables and hydraulic

hoses on the machine, otherwise, they may

be damaged by clamping or extruding.

3. Install the two upper bolts between the engine

and the transmission box.

4. Install and tighten the connecting bolts

between the engine and the transmission box.

5. Fix the transmission box support on frame

with bolts. Remove the lifting appliance

6. Install the connecting bolts of torque converter

housing and the connecting plate.

1 2 3

Fig. 4-31

1 Transmission box housing

2 Bolt

3 Engine flywheel housing

1

Fig. 4-32

1 Bolt

1 2 3

Fig. 4-33


4-21

7. Install the cover plate of transmission box.

8. Install the radiator to transmission box oil

pipe.

ATTENTION

Before connecting the oil pipe, be sure to

clean the to-be connected oil ports.

9. Install the transmission box to radiator oil

pipe.

1

Fig. 4-36

1 Transmission box to radiator oil pipe

1

Fig. 4-35

1 Radiator to transmission box oil pipe

1 2

Fig. 4-34

1 Bolt 2 Cover plate


4-22

10. Connect the oil inlet and outlet pipes of

working pump and steering pump.

ATTENTION

Before connecting the oil pipes, be sure to

clean the to-be connected oil ports.

11. Connect the transmission shaft to transmission

box.

110~130Nm

Apply 272 thread locking sealant to

the bolts

12. Install the parking brake control wire.

1 2

Fig. 4-37

1 Working pump 2 Oil pipe

1

1 2

Fig. 4-38

1 Bolt



4-23

13. Install the transmission oil temperature sensor.

ATTENTION

When installing the sensor, wrap the thread

end with thread seal tape to prevent

leakage.

14. Connect the control wire of transmission

control valve.

15. Connect the transmission box vent pipe.

1

Fig. 4-42

1 2

Fig. 4-41


2 Control wire

1

Fig. 4-40

1 Oil temperature sensor


4-24

16. Install the hydraulic oil tank.

17. Install the transmission control oil pressure

sensor.

18. Install the engine hood, cab and platforms.

1 2

Fig. 4-45

1

Fig. 4-44

1 Transmission control oil pressure

sensor

1

Fig. 4-43

1 Hydraulic oil tank assembly


4-25

19. Fill in transmission oil.

15W-40 diesel engine oil, about 28L

Run the engine idly and check the oil level

by using the oil dipstick.

417 Precautions

1. Maintenance and overhaul of transmission box should be carried out or guided by professional

staff.

2. Since the torque converter has no axial location, prevent it falling off when lifting.

1

Fig. 4-46

1 Oil filling port


4-26

3. When the grader is travelling, the parking brake must be relieved, but what we learned from

experience is that it’s difficult for the operator to immediately find out the parking brake state is

not released, that’s because the large output torque ratio produced by torque converter, which

can overcome braking torque and force the grader to move even under normal operating

conditions. Then the consequence is the torque converter oil temperature rising sharply and

overheated brake. Parking brake can be used as emergency brake.

4. When the grader has problems and needs welding maintenance, you must disconnect the gear

selector control wires. Otherwise, the impact current during electric welding may burn the

internal wiring.

5. In the case of engine failure and the machine is not able to move, note that the maximum

towing speed is 10 km/h, and the maximum towing distance is 10 km.

6. When draining oil, all oil in transmission box, torque converter and radiator must be discharged

completely to avoid secondary pollution. Use unclean or unqualified oil will cause serious

problem.

42 Transmission Shaft System

421 Overview of Transmission Shaft

1. Structure and function of universal transmission device


4-27

Universal transmission device of the grader is installed between the transmission box and the drive

axle. It usually consists of a universal joint assembly and transmission shaft, etc. (Universal

transmission device is customarily called the transmission shaft assembly). Since the axes of the

grader transmission box output shaft and drive axle input shaft are difficult to be aligned in line;

moreover, during the grader operation process, due to the unfairness road and work place, the

relative position of the two axes changes frequently. So we can’t apply rigid connection between the

output shaft of the transmission box and the input shaft of the drive axle, while we must adopt the

universal transmission device, which is made of two cross universal joints and a drive shaft. The

function of the universal transmission device is to solve the uncoaxiality between the transmission

box and the drive axle, to meet the needs of angle changing between the transmission box and the

drive axle, and pass the power of transmission box to the drive axle.

Rated working torque of the transmission shaft assembly equipped on G9165 grader is 4100Nm, the

axle deviation of the two universal joints is small than 3°, Zl-2 lithium lubricating grease is used for

lubrication, and swing angle of the universal joint is greater than 20°, so the grader is able to work

under all kinds of conditions.

Fig. 4-47 G9165 grader rear transmission shaft assembly

1 Universal joint 2 Hexagon bolt 3 Transmission shaft

2. Universal joint

(1) Structure of universal joint

The universal joint is the most complex part of the universal transmission device. According to its

speed characteristics, it can be divided into ordinary type (unequal angular velocity) universal joint

and equal angular velocity universal joint; according to its rigidity size, it can be divided into rigid

universal joint and flexible universal joint. The universal joint used on the grader universal

transmission device is ordinary cross rigid universal joint.

The ordinary cross rigid universal joint is composed of cross axle, needle bearing, oil seal and oil

cup, etc. In order to reduce the friction loss and improve the transmission efficiency, the joint is

equipped with a needle bearing between the cross axle journal and the sleeve, and the sleeve is fixed


4-28

on the universal joint fork, to prevent the bearing falling off from the universal joint fork under the

action of centrifugal force. In order to lubricate the bearing, the interconnected oil passage is drilled

in the cross axle, and the groove is processed in the end face of the cross axle, so that, the

lubricating grease injected from the oil cup can reach to the working face of the needle bearing.

(2) Transmission characteristics of the cross universal joint

The cross universal joint has the characteristics of the non-constant velocity transmission. The

so-called "non-constant velocity transmission" is that if the driving shaft is rotating in a constant

angular velocity, the revolving speed of driven shaft is sometimes fast and sometimes slow. It

should be noted that so-called "non-constant velocity transmission" is that the angular velocity of

the driven shaft is non-uniform in one circle. But if driving shaft turns a circle, the driven also turns

a circle, the average speed is equal.

The non-constant velocity of the common cross universal joint can cause the driven shaft and its

connected transmission components to generate torsional vibration, thereby generating additional

alternating load, affecting the life of the components. For this reason, a method of "constant

velocity universal transmission" is produced: from the non-constant transmission of a single cross

shaft universal joint, we came up with an idea that if we adopt double cross universal joints

transmission between the two shafts (the output shaft of gearbox and the input shaft of drive axle),

then the non-constant velocity effect of the first cross universal joint is likely to be offset by the

second one, which can achieve constant velocity transmission between the two shafts.

3. Structure and characteristic of transmission shaft

The transmission shaft is an important part of the universal transmission device, usually used for the

connection between the transmission box and drive axle. Generally speaking, the transmission shaft

is composed of pipe sleeve fork assembly, universal joint fork and spline shaft assembly, etc.

During the operation of the grader, the relative position of the transmission box and drive axle

changes constantly, in order to avoid the movement interference, the transmission shaft has sliding

splined connection parts, which consisting of sliding fork and spline shaft, so that, to realize the

change of the length of the transmission shaft. In order to reduce abrasion, the transmission shaft is

equipped with filling grease oil cup, oil seal and spline sheath, etc. Make sure the lubrication of the

spline shaft in the sleeve fork, and prevent water and dust entering into the sliding spline.


Transmission Shaft Assembly

ATTENTION

Transmission shaft should be replaced as a


4-29

whole once unqualified. It is forbidden to

use deformed, scrapped or cracked

transmission shaft assembly.

Pull up the hand brake to engage parking

brake.

Disassembly of transmission shaft assembly



shaft and transmission box.


shaft and drive axle.

ATTENTION

When removing the bolts, you should hold

up the transmission shaft to prevent falling.

Assembly of transmission shaft assembly

1. Connect the transmission shaft to drive axle

with bolts.

110~130Nm


1

Fig. 4-48

1 Wood block

1

Fig. 4-49

1 Bolt

1


4-30

the bolts

2. Connect the transmission shaft to transmission

box with bolts.

110~130Nm


the bolts

ATTENTION

Before assembling the transmission shaft,

you should check whether the universal

joints are normal, whether the transmission

shaft can stretch out and draw back axially.

Replace the transmission shaft immediately

if it is faulty.

43 Drive Axle System

431 Overview of Drive Axle

Drive axle is the key component of the grader transmission system, it is mainly used to enlarge the

torque from engine and allocate it to the left and right drive wheels, it also works as a differential to


4-31

realize differential speed between left side and right side wheels. Moreover, drive axle housing also

plays a role of load-bearing and stress-passing.

G9165 applies three-part rear drive axle, which is specially designed for grader. Main drive axle is

installed with no-spin differential, swing balancing box with swing angle of ±15°, heavy roller

chain transmission, wheel side drum-type brake. Main reduction ratio is 3.7, wheel reduction ratio

is 3.26, balancing box reduction ratio is 1.474, and the total reduction ratio is 17.779. GL-5 85W-90

gear oil is applied as lubricating oil for the drive axle. The joint of balancing box assembly and

wheel reducer, and the balancing box assembly use grease as lubricant.

See Fig. 4-51 for transmission diagram of the drive axle and balancing box.

Fig. 4-51

1 Balancing box assembly 2 Main drive assembly 3 Differential assembly 4 Wheel reducer

The power transmission line:

Transmission shaft

Main reducer

Differential

Left p

inio

n

shaft

Rig

ht p

inio

n

shaft

Left p

lanet

carrierR

igh

t plan

et carrier

Left ch

ain

wh

eel shaft

Rig

ht ch

ain

wheel sh

aft

Left ch

ainR

ight ch

ain

Left d

rive

wheel

Rig

ht d

rive

wheel

432 Main Reducer and Differential Assembly

Main reducer assembly is composed of main drive, differential and input flange. The differential is

of no self-rotation type, also called as no-spin differential. When the vehicle is turning, the outside

wheel spins faster than the inside one, at this point, the outside driven ring separates from the drive


4-32

ring and relative rotation is formed between them. Because of tooth engagement, the middle ring

rotates together with the drive ring, so there is relative rotation between the outside driven ring and

the middle ring too. Hence, the outside driven ring moves upward along the tooth surface until

separated from the middle ring and drive ring, the differential function is in effect When the drive

wheel on one side is on ice or wet road, or off ground, the wheel on the other side can still transmit

100% of original torque to guarantee the machine excellent cross-country ability. The differential

function is done automatically, and no extra operation is need. Compared to common bevel gear

differential, the differential equipped on G9165 grader has better performance.

433 Wheel Reducer Assembly

The wheel reducer assembly adopts cylindrical-gear planetary transmission, power from differential

is transmitted to the sun gear through the axle shaft. The planet carrier is fixed, then power is

transmitted to the chain wheels in balancing box through the gear ring.

434 Balancing Box Assembly

G9165 applies drum-type-brake balancing box, one on each side of rear frame. The balancing box

adopts heavy roller chain transmission, it is supported on rear axle by a copper bush in the middle

of the box, and the lateral positioning is realized by double-row spherical roller bearings. The

balancing box has swing angle of ±15°, hence, not only the cross-country ability of the vehicle is

good, but also the working accuracy is improved. The chain wheel shaft adopts simply supported

beam structure, with strong rigidity and can satisfy all kinds of working conditions of the grader.

In the balancing box, the power is transmitted to the chain wheels through roller chain to realize

forward and backward move of the grader. Tensioning of the roller chain is realized by rotating the

eccentric bearing seat, refer to Section 436 for details.


Drive Axle and Balancing Box

ATTENTION

Park the machine on flat ground before


4-33

disassembling, it’s forbidden to perform

maintenance work on a slope or uneven

ground.

Do not carry out the maintenance work

immediately when the machine is just

stopped, be sure to wait until the drive axle

is cooled.

In the process of disassembling and

assembling, all disconnected oil ports and

pipe joint should be wrapped up properly to

avoid intrusion of foreign matters.

Disassembly of drive axle


2. Disconnect the brake oil pipes on both sides of

the balancing box.

3. Disconnect the breather pipe.

1

Fig. 4-52

1 Wood block

1

Fig. 4-53

1 Brake oil pipe

1


4-34


shaft and drive axle.

5. Use high-torque pneumatic impact wrench to

remove the 8 fixing bolts of drive axle.

6. Connect lifting appliance to the tail of rear

frame, lift the frame up a bit.

7. Remove the wood blocks that used to fix the

rear tires, and push the rear drive axle

1

Fig. 4-55

1 Bolt

1

Fig. 4-56

1 Fixing bolt of drive axle


4-35

assembly together with the tires out rapidly.

8. Use holder to support rear frame.

ATTENTION

Prior to step 6, you should check the

fixation condition of front tires again. Make

sure the front tires are reliably wedged to

prevent the vehicle moving forward when

lifting the rear frame. The lifting appliance

should be reliable.

Assembly drive axle

ATTENTION

When assembling, the mating surfaces

should be properly protected and cleaned,

to avoid intrusion of foreign matters.

The mating surface should be coated with

plane sealant according to related

requirements, the bolts should also be

coated with thread locking seat accordingly.

In the process of assembling, related

standards of tightening torque in this

manual must be strictly followed.

1. Connect lifting appliance to the tail of rear

frame, lift the frame up a bit.

ATTENTION

Before lifting the rear frame, you should

check the fixation condition of front tires.

2. Assemble the drive axle.

Push the drive axle assembly to the bottom of

rear frame, lower the frame slowly, align the

bolts holes, install and tighten the fixing bolts.

1

Fig. 4-58

1 Rear frame


4-36

940~1120Nm

3. Connect the transmission shaft.

110~130Nm

4. Connect the brake oil pipes on both sides of

the balancing box.

5. Connect the breather pipe.

436 Use, Maintenance and Repair of Drive Axle

In normal use, service condition of the components of drive axle is highly related to whether they

are being used, maintained and repaired properly. To keep the machine in good working condition

1 2

Fig. 4-60


2 Bolt

1

Fig. 4-61

1 Brake oil pipe


4-37

and extend its service life, the information, notes and precautions below should be taken as

reference when use, maintaining and repairing the drive axle.

1. Connection of rim and axle

Specification of the rim nut is M22×1.5, the tightening torque is 700~800Nm. The rim nuts should

be tightened symmetrically and equally. In normal use, you should regularly check whether the nuts

are loose and tighten them immediately if so. When ball faced rim nuts are used, you should check

whether the nut ball face and the ball socket are properly fitted, make sure the connection is

reliable.

2. Lubrication

2.1 Lubricating oil type GL-5 85W/90 Gear oil

2.2 Oil filling points and filling quantity

The filling port (an independent oil filling pipe) of main reducer and wheel reducer assembly is

designed on top of the main reducer. The oil level checking hole on both sides of the left and right

balancing box are also used for oil filling, keep the axle horizontal when filling.

Recommended oil filling quantity: filling quantity for main reducer and wheel reducer assembly is

about 28L, filling quantity for each balancing box is 23L.

When filling, a little overflowed oil from the oil level checking hole is allowed, the lower limit is

8mm to the hole bottom edge.

2.3 The joint of balancing box assembly and wheel reducer, and the balancing box assembly use

grease as lubricant. Inject grease into the grease nipples.

3. Use and maintenance

3.1 Clean up the oil dirt, dust and mud regularly. Note that the breather plug should always be

unobstructed. Check the fastening condition of each fastener, especially the connecting bolts of

main reducer, wheel reducer and rim, tighten them immediately if they are loose.

3.2 Periodically check the drive axle for oil leakage, eliminate failure as soon as possible. Check the

lubricating oil level in main reducer, wheel side reducer and balancing box, add if insufficient.

Initial replacement of lubricating oil: In the first month or after the first 100 working hours.

Periodic replacement interval of lubricating oil: Every six month or every 1000 working hours.

3.3 The joint of balancing box assembly and wheel reducer, and the balancing box assembly use

grease as lubricant. Inject grease into the grease nipples every three month.

4. Notes for maintenance

4.1 When overhauling the main reducer, smear test should be performed to check the gear meshing

zone. The meshing zone should be close to the small end in the axial direction, and its size in


4-38

this direction should be ≥1/2 length of the tooth. In the radial direction, the meshing zone

should be in the middle area.

4.2 Wheel side reducer assembly adopts “castellated nut + fastening bolt” locking form.

When assembling, you should apply repair method to adjusting ring to adjust the axial clearance

between the bearing and wheel reducer housing to 0.05~0.15mm, and tighten the castellated

nuts to 500~600Nm, and make sure the chain wheel can rotate freely after that. Then, install and

tighten the fastening bolts to 60~70Nm. The two fastening bolts should be tightened

alternatively and equally. Make sure the fastening bolts have no protrusion to the end face of

chain wheel shaft.

4.3 Use selecting method to assemble the roller pins (in wheel reducer planet gear), diameter

difference between any two roller pins in the same group should be no more than 0.005mm.

Cylindricity of the roller pin should be no greater than 0.003mm. Radial clearance between the

roller pin and pin hole should be 0.015~.030mm.

4.4 When replacing or overhauling the axle shaft, make sure the clearance between adjusting pillar

and the stop block is 1~2mm.

4.5 Rated working pressure of the brake is 10MPa, and the maximum working pressure is 15MPa,

the brake fluid is mineral oil.

4.6 After the first working hours, the transmission trains should be inspected and tensioned when

necessary. Do this maintenance every 500 working hours thereafter.

Refer to Page 1-19 in 1 Repair & Maintenance for inspection and steps to tension the

transmission chain.

4.7 After maintenance, the mating surfaces that were originally coated with sealant should be

cleaned thoroughly, and should be recoated with a layer (1mm) of 598 plane sealant after being

dried. The bolts should be cleaned and dried too, and coat 262 thread locking sealant to the

bolts, and then tighten the bolts according to related requirements.

4.8 All seals and sealing gaskets should not be reused once removed.

4.9 Check the thickness of the friction plates through the observation hole, the brake shoe must be

replaced if the friction plate is worn to 3mm.

44 Diagnosis and Solutions for Common Fault of Transmission System

441 Common Faults of Transmission Box


4-39

Fault phenomenon Possible cause Elimination method

1. Low

transmission

oil pressure

1) Oil level in transmission box is

low

1) Add transmission oil to

specified level

2) Oil filter is blocked 2) Replace the filter

3) Control valve pressure valve

element is in seizure

3) Clean the valve element and

replace it if necessary

4) Transmission oil pump is faulty 4) Replace the pump

2. Transmission

oil pressure of

a certain gear

is low

1) The gear valve element is in

seizure

1) Clean the valve element and

replace it if necessary

2) The clutch has internal leakage

problem 2) Replace the clutch

3) Oil seal is damaged 3) Replace the seal

3. Unable to

engage a gear


low


specified level

2) The transmission oil pump has

severe internal leakage problem,

low efficiency

2) Replace the pump

3) Wire of gear valve is loose or

broken 3) Fasten or replace the wire

4. Overheating

of torque

converter and

transmission

box

1) The radiator is clogged or

damaged

1) Unchoke the radiator or

replace it


low


specified level

3) Long-time driving at high gear

or low gear

3) Change the habit, select

different gears when driving

4) The safety valve of torque

converter is faulty 4) Replace the valve

5) The transmission oil has gone

bad 5) Replace the oil

6) Slipping of clutch 6) Overhaul the clutch

5. Disordered

gears

1) The electric control signal is

incorrect

1) Check according to Table

4-2

2) The solenoid valve is in open

circuit or burnt 2) Check and replace the valve

3) The gear valve is in seizure 3) Overhaul and clean the valve

4) The gear clutch is sintered 4) Overhaul and replace the

valve

442 Common Faults of Drive Axle

Fault phenomenon Possible cause Elimination method


4-40

1. The balancing

box produces

severe

abnormal

noise

1) Tensioning of the transmission

chain is inappropriate 1) Adjust

2) The transmission chain is faulty 2) Replace the chain

2. Overheating

of drive axle

1) Oil in drive axle is insufficient or

the oil has gone bad 1) Add or replace the oil

2) Main drive clearance is

undersized 2) Adjust the clearance

3. The drive axle

produces

abnormal

noise

1) Main drive clearance is

oversized 1) Adjust the clearance

4transmission system englisg-g9165

Documents

transmission shaft system

yd13 transmission box

transmission control

overview of transmission

drive axle system

balancing box assembly

assembly of drive axle

overview of drive axle