4Transmission System ENGLISG-G9180

Service Manual of RS8160 Road Roller

SERVICE MANUAL

4 Transmission System

Service Manual for G9180 Grader

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

I

Service Manual for G9180 Grader

4 Transmission System Transmission system of G9180 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 G9180 grader power transmission diagram 1 Engine

2 Hydraulic torque converter + transmission box

3 Balancing box

4 Differential

5 Transmission shaft

7 Right working pump

6.Left working pump

41 Hydraulic Torque Converter-Transmission Box System 411 General G9180 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.

4-1

Service Manual for G9180 Grader Table 4-1

Hydraulic converter

torque

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

Shifting gears

Forward-6-Reverse-3

Structural style

Fixed shaft

Shifting pressure (MPa)

1.3~1.8MPa

Transmission box Transmission ratio

Forward I

5.986

Forward II

3.42

Forward III

2.594

Forward IV

1.48

Forward V

1.178

Forward VI

0.672

Reverse I

5.986

Reverse II

2.594

Reverse III

1.178

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 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 4-2

Service Manual for G9180 Grader 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.

4-3

Service Manual for G9180 Grader

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

4-4

Service Manual for G9180 Grader

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. 4-5

Service Manual for G9180 Grader 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.

Reverse gears

Neutral gear

Forward gears

Fig. 4-5 Gear selector

4-6

Service Manual for G9180 Grader 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 Forward I Forward II

●

M2

M3

M4

●

●

●

KV

K1

●

K4

K1

●

KV

K2

●

K4

K2

KV

K3

K4

K3

● ●

Forward III Forward IV

● ●

Forward V Forward VI

●

Reverse I

●

Reverse II Reverse III

●

●

●

KR

K1

●

●

●

KR

K2

●

●

KR

K3

—

K3

Neutral gear

4-7

Service Manual for G9180 Grader

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.

4-8

Service Manual for G9180 Grader

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 3, 5, 6, 7, 8, 9, 10, 11 1, 2

Specification M10×1 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. 4-9

Service Manual for G9180 Grader

Transmission box oil filling port

Transmission box oil dipstick

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. 4-10

Service Manual for G9180 Grader 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. 4-11

Service Manual for G9180 Grader 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. 4-12

Service Manual for G9180 Grader 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.

1 Fig. 4-11 1 Wood block

Refer to 8 Cab & Covering Parts System.

1 Fig. 4-12 1 Engine hood

2 2 Cab

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. 4-13

1 Fig. 4-13 1 Transmission control oil pressure

Service Manual for G9180 Grader

4.

Remove the hydraulic oil tank, refer to 9 Working Hydraulic System.

1 Fig. 4-14 1 Hydraulic oil tank assembly 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

1 Fig. 4-15 1 Oil drain plug

intrusion of foreign matters.

6.

4-14

1 Fig. 4-16

Disconnect the transmission box vent pipe.

Service Manual for G9180 Grader

7.

Disconnect the control wire of transmission control valve.

1 2 Fig. 4-17 1 Transmission control valve 2 Control wire

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. 1 Fig. 4-18 1 Oil temperature sensor

9.

Disconnect the transmission box to radiator oil pipe.

4-15

1 Fig. 4-19 1 Transmission box to radiator oil pipe

Service Manual for G9180 Grader

10. Disconnect the radiator to transmission box oil pipe.

1 Fig. 4-20 1 Radiator to transmission box oil pipe 11. Remove the connecting bolts of transmission shaft and transmission box.

1 2 Fig. 4-21 1 Bolt 2 Transmission shaft assembly

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 4-16

Service Manual for G9180 Grader foreign matters.

13. Remove the parking brake control wire.

1 Fig. 4-23 1 Parking brake control wire 14. Remove the cover plate of transmission box.

1

2

Fig. 4-24 1 Cover plate

2 Bolt

15. Remove the connecting bolts of torque converter housing and the connecting plate.

4-17

1 Fig. 4-25

2

Service Manual for G9180 Grader

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.

1 Fig. 4-26 1 Bolt 17. Remove the fixing bolts of transmission box support.

1 Fig. 4-27 1 Bolt

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. 4-18

1

2

Service Manual for G9180 Grader

ATTENTION Lift the transmission box smoothly and do not tilt to prevent the torque converter slipping.

Fig. 4-29

Assembly of transmission box 1.

Connect

the

lifting

appliance

to

the

transmission box. 2.

Lift the transmission box to the right position.

ATTENTION 4-19

Service Manual for G9180 Grader 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.

1 2 3 Fig. 4-31 1 Transmission box housing 2 Bolt 3 Engine flywheel housing 5.

Fix the transmission box support on frame with bolts. Remove the lifting appliance

1 Fig. 4-32 1 Bolt 6.

Install the connecting bolts of torque converter housing and the connecting plate.

4-20

1 Fig. 4-33

2

3

Service Manual for G9180 Grader

1 Fig. 4-34 1 Bolt

7.

Install the cover plate of transmission box.

8.

Install the radiator to transmission box oil

2 2 Cover plate

pipe.

ATTENTION Before connecting the oil pipe, be sure to clean the to-be connected oil ports.

1 Fig. 4-35 1 Radiator to transmission box oil pipe

9.

Install the transmission box to radiator oil pipe.

4-21

1 Fig. 4-36

Service Manual for G9180 Grader

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.

1 Fig. 4-37 1 Working pump

2 2 Oil pipe 11. Connect the transmission shaft to transmission box. 110~130Nm Apply 272 thread locking sealant to the bolts

1 2 Fig. 4-38 1 Bolt 2 Transmission shaft assembly 12. Install the parking brake control wire.

4-22

Service Manual for G9180 Grader

13. Install the transmission oil temperature sensor.

ATTENTION When installing the sensor, wrap the thread end with thread seal tape to prevent leakage.

1 Fig. 4-40 1 Oil temperature sensor

14. Connect the control wire of transmission control valve.

1

2

Fig. 4-41 1 Transmission control valve 2 Control wire

15. Connect the transmission box vent pipe.

4-23

1

Service Manual for G9180 Grader

16. Install the hydraulic oil tank.

1 Fig. 4-43 1 Hydraulic oil tank assembly 17. Install the transmission control oil pressure sensor.

1 Fig. 4-44 1 Transmission control oil pressure sensor

18. Install the engine hood, cab and platforms.

4-24

1

2

Service Manual for G9180 Grader

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.

1 Fig. 4-46 1 Oil filling port

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. 4-25

Service Manual for G9180 Grader 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 4-26

Service Manual for G9180 Grader 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 G9180 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 G9180 grader rear transmission shaft assembly 1 Universal joint 2.

2 Hexagon bolt

3 Transmission shaft

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 4-27

Service Manual for G9180 Grader 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.

422 Disassembly and Assembly of Transmission Shaft Assembly ATTENTION Transmission shaft should be replaced as a 4-28

Service Manual for G9180 Grader 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 1.

Wedge the tires with wood blocks properly.

2.

Remove the connecting bolts of transmission

1 Fig. 4-48 1 Wood block

shaft and transmission box. 3.

Remove the connecting bolts of transmission shaft and drive axle.

ATTENTION When removing the bolts, you should hold up the transmission shaft to prevent falling. 1 Fig. 4-49 1 Bolt

Assembly of transmission shaft assembly 1.

Connect the transmission shaft to drive axle with bolts. 110~130Nm Apply 272 thread locking sealant to

4-29

Service Manual for G9180 Grader the bolts 2.

Connect the transmission shaft to transmission box with bolts. 110~130Nm Apply 272 thread locking sealant to 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 4-30

Service Manual for G9180 Grader realize differential speed between left side and right side wheels. Moreover, drive axle housing also plays a role of load-bearing and stress-passing. G9180 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: Left planet carrier

Left chain wheel shaft

Left chain

Left drive wheel

Right planet carrier

Right chain wheel shaft

Right chain

Right drive wheel

Left pinion shaft

Transmission shaft Main reducer

Right pinion shaft

Differential

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 4-31

Service Manual for G9180 Grader 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 G9180 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 G9180 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.

435 Disassembly and Assembly of Drive Axle and Balancing Box ATTENTION Park the machine on flat ground before 4-32

Service Manual for G9180 Grader 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 1.

Wedge the tires with wood blocks properly.

2.

Disconnect the brake oil pipes on both sides of

1 Fig. 4-52 1 Wood block

the balancing box.

1 Fig. 4-53 1 Brake oil pipe

3.

4-33

Disconnect the breather pipe.

Service Manual for G9180 Grader

4.

Remove the connecting bolts of transmission shaft and drive axle.

1 Fig. 4-55 1 Bolt

5.

Use high-torque pneumatic impact wrench to remove the 8 fixing bolts of drive axle.

1 Fig. 4-56 1 Fixing bolt 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

4-34

Service Manual for G9180 Grader 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. 1 Fig. 4-58 1 Rear frame 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.

4-35

Service Manual for G9180 Grader 940~1120Nm

3.

Connect the transmission shaft. 110~130Nm

1 2 Fig. 4-60 1 Transmission shaft assembly 2 Bolt 4.

Connect the brake oil pipes on both sides of the balancing box.

5.

Connect the breather pipe.

1 Fig. 4-61 1 Brake oil 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 4-36

Service Manual for G9180 Grader 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 4-37

Service Manual for G9180 Grader 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 4-38

Service Manual for G9180 Grader Fault phenomenon

1.

2.

3.

4.

5.

Low transmission oil pressure

Transmission oil pressure of a certain gear is low

Unable to engage a gear

Overheating of torque converter and transmission box

Disordered gears

Possible cause

Elimination method

1) Oil level in transmission box is low

1) Add transmission 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

1) The gear valve element is in seizure 2) The clutch has internal leakage problem

1) Clean the valve element and replace it if necessary

3) Oil seal is damaged

3) Replace the seal

1) Oil level in transmission box is low 2) The transmission oil pump has severe internal leakage problem, low efficiency 3) Wire of gear valve is loose or broken 1) The radiator is clogged or damaged 2) Oil level in transmission box is low 3) Long-time driving at high gear or low gear 4) The safety valve of torque converter is faulty 5) The transmission oil has gone bad

1) Add transmission specified level

6) Slipping of clutch

6) Overhaul the clutch

1) The electric control signal is incorrect 2) The solenoid valve is in open circuit or burnt

1) Check according to Table 4-2

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

Possible cause

oil

to

2) Replace the pump 3) Fasten or replace the wire 1) Unchoke the radiator or replace it 2) Add transmission oil to specified level 3) Change the habit, select different gears when driving 4) Replace the valve 5) Replace the oil

2) Check and replace the valve

Elimination method 4-39

to

2) Replace the clutch

442 Common Faults of Drive Axle Fault phenomenon

oil

Service Manual for G9180 Grader 1.

2.

3.

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

Overheating of drive axle

1) Oil in drive axle is insufficient or the oil has gone bad 2) Main drive clearance is undersized

The drive axle produces abnormal noise

1) Main drive oversized

clearance

4-40

is

1) Add or replace the oil 2) Adjust the clearance

1) Adjust the clearance