According to the working time of the loader, the working environment and the actual technical condition of the loader, the six-level maintenance cycle can also be adjusted appropriately. The maintenance contents at all levels are as follows:
First, daily maintenance
It is done by the driver himself, before driving and after collecting the vehicle every day. Its work includes:

1. Check the oil level of the engine, if it is lower than the marking line of the oil dipstick, refuel should be added. If it is higher than the marking line of the oil dipstick, find out the reason for the increase (dilution) of oil;

⒉. Check the oil level of the fuel tank;

3. Check the tightening and sealing of the engine, torque converter, hydraulic pump and steering gear, and whether there is overheating;

4. Check whether there is oil leakage, water leakage, air leakage, liquid leakage, electric leakage, etc.;

Second, weekly maintenance
Once a week by professional maintenance personnel, in addition to completing the daily maintenance content, also complete:
1. Refuel according to the specified part and the specified grade of oil (grease);
⒉ Clean the oil primary filter, fuel primary filter and air filter element;
3. Check and adjust the tightness of the fan and generator drive belt;
4. Check and add oil in the fuel injection pump;
5. Check the electrolyte level and density of the battery, and the electrolyte level is 10-15mm on the plate, if insufficient, add distilled water.
6. Check and adjust the free stroke of each pedal;
7. Check whether the throttle, parking brake, transmission and other control levers are stuck or inflexible.

3. Monthly maintenance
It is carried out by professional maintenance personnel once a month. In addition to the completion of daily and weekly maintenance operations, it is also necessary to complete:
1. Clean the oil filter and fuel filter element;
2. Check the tire pressure and wear, the pressure is 0.27~0.39MPa (2.8~3.0kgf / cm2), and the lower limit is taken when working on soft ground.
3. Check whether the welding seam of the frame, working device and other parts with large force is de-soldered and whether there is cracking.
Troubleshooting and Routine Maintenance of Wheel Loader Transmissions
The gearbox is one of the important transmission components of the wheel loader. It is responsible for transmitting the speed and torque from the engine to the final drive system, changing the transmission ratio between the engine and the wheels, and realizing the forward and reverse gear operation of the loader. It can realize cutting off the power transmitted to the traveling device when the engine is running, so as to meet the needs of the loader's operation and traveling, and it is convenient to start and stop the engine safely.
However, in the working process of the loader, the failure rate of the gearbox caused by improper use and maintenance has been high, especially if the maintenance procedures are not strictly during use, and the lack of timely inspection and daily maintenance will accelerate the damage of the gearbox. and the formation of failures, and even expand the harmfulness of the consequences of failures.
First, the purpose of preventive maintenance
1. Through the follow-up inspection of the loader operation, stop the machine in a planned way, and make arrangements for the maintenance and repair of the gearbox.
2. Prevent major mechanical failures and related parts damage, and repair them before failures germinate to save a lot of maintenance costs.
3. Make the parts of the whole machine have a long service life, improve the efficiency of the equipment and maintain good working performance.
4. Reduce maintenance difficulty and workload.
Second, common faults and causes of wheel loader gearboxes
1. When the gear is engaged, the gear cannot be entered smoothly. The reasons are:
(1) The pressure of the pressure valve is too low;
(2) The hydraulic pump is not working well and the seal is not good;
(3) The hydraulic pipeline is blocked;
(4) The clutch sealing ring is damaged or leaked;
(5) The gear lever is not in place.
2. When the gearbox is shifting, the gear cannot be disengaged. The reasons are:
(1) The piston ring swells to death;
(2) The clutch friction plate is burnt;
(3) The clutch return spring is invalid or damaged;
(4) The oil return line is blocked.
3. The loader has been in gear, but the loader is weak and cannot even walk. The reasons are:
(1) The friction plate is severely worn and the clearance is too large;
(2) The clutch automatic emptying valve is not tightly sealed, causing the pressure to drop;
(3) The shift control valve pipeline is blocked;
(4) The shut-off valve cannot be returned;
(5) The positioning spring of the shift valve is fatigued or broken, and the steel ball jumps;
(6) The clutch piston ring and sealing ring are severely worn, causing serious leakage.
4. The operating pressure is too low. The reasons are:
(1) The amount of oil in the gearbox oil pan is insufficient;
(2) Oil leakage in the main oil passage;
(3) The transmission filter is blocked;
(4) The steering pump (or hydraulic pump) is damaged, causing serious internal leakage;
(5) Improper adjustment of the pressure of the gearbox pressure regulating valve;
(6) The spring of the gear pressure valve is invalid or broken.
5. The gearbox is automatically out of gear or out of gear. The reasons are:
(1) The positioning device of the shift control valve fails, and the main reason for the failure is the serious wear of the positioning steel ball or the failure of the spring;
(2) Due to the long-term use of the shift lever, the position and length of the lever change, and the ratio of the lever is inaccurate, which makes the operating position deviate, resulting in dislocation.
Third, how to carry out preventive maintenance of the gearbox
1. According to JB/Z194-83, and combined with the actual maintenance, the following regulations should be : (1) Routine maintenance: check the oil level in the low shell;
(2) 50 hours (or weekly): check whether the shift handle is flexible and effective;
(3) 250 hours (only after the first 250 hours of work): clean the transmission oil pan and the transmission oil filter element;
(4) 500 hours: clean the oil pan filter and replace the transmission oil;
(5) 2000 hours: disassemble and inspect the gearbox and torque converter.
2. Hydraulic transmission oil is the energy carrier for the normal operation of the transmission. In the hydraulic transmission system, the pressure, temperature and flow of the working fluid all determine whether the transmission can work normally. Therefore, in the daily maintenance of the transmission, it is necessary to Pay special attention to the inspection and replacement of hydraulic transmission oil.
2. Hydraulic transmission oil is the energy carrier for the normal operation of the transmission. In the hydraulic transmission system, the pressure, temperature and flow of the working fluid all determine whether the transmission can work normally. Therefore, in the daily maintenance of the transmission, it is necessary to Pay special attention to the inspection and replacement of hydraulic transmission oil.
(1) Fixed oil change interval
Oil changes at the correct intervals are the key to maximizing the working life of the components in the transmission. Only by ensuring a reasonable oil change interval can the lubricating and protective properties of lubricating oil be exerted. In general, it should be based on the maintenance cycle recommended by the manufacturer of the whole machine, but this can only be relative and must be combined with the results of oil sample extraction and analysis to know the actual working conditions. For example, the maintenance manual requires that the oil change interval of the gearbox is 50Oh. According to the operating conditions of the loader, we sample and analyze the oil samples every 250h or 100h to decide when to change the oil, but when the lubricating oil is used to 1000h, it should be Replace immediately.

In addition to regular replacement of new oil, in the usual inspection, if the oil is found to be deteriorated or mixed with impurities, it should also be cleaned and inspected, and new oil should be replaced.

(2) Use the correct method of draining and changing oil
When draining the oil, the oil temperature should reach 40~50℃, and the oil flow should be discharged with agitation, and the dirty oil should be drained as thoroughly as possible; when refueling, a tanker with a filter device should be used to add oil.
(3) Use the correct transmission system oil, and the lubricating oil used in the gearbox must meet the specifications. It should be noted that diesel oil cannot be added to the gearbox, because diesel oil will reduce the friction between moving parts such as pistons, and the transmission oil should allow a certain friction between the friction plates when they are combined. , this friction is crucial for the normal operation of the transmission system. Only the correct use of lubricating oil can effectively prolong the working life of the clutch friction plate. At the same time, the correct use of oil can significantly improve the anti-wear performance of gears, eliminate clutch slippage, control the trembling and abnormal noise of the brake, increase the braking force, and provide greater traction. At present, the hydraulic transmission oil most used in the gearbox is 6# and 8# hydraulic transmission oil.
(4) Refer to the filter replacement cycle provided in the maintenance manual, replace the filter in time, clean the filter screen, oil drain magnet screw plug, vent plug, and add lubricating oil according to the standard amount. If the viscosity of the transmission oil is too large, the transmission efficiency of the transmission will be low, the fluidity will be poor, and it will be unfavorable for heat dissipation, and there may be local dry friction between the parts that move relatively at high speeds, which is not conducive to lubrication; if the viscosity of the transmission oil is too small , which can increase the leakage, cause the gearbox control oil pressure to be too low, cause failure, and the oil film strength between the transmission parts with a large load is not enough, resulting in early wear of the transmission parts, which is also unfavorable for lubrication
At the same time, during the normal operation of the gearbox, a small amount of air bubbles will be generated due to the oil churning of the gears. In order to prevent the accumulation of more and more air bubbles, cavitation will occur, which will reduce the thickness of the oil film and affect the operation of the clutch and its control valve inside the gearbox. , the transmission oil must have anti-foaming properties.
Therefore, the use of appropriate transmission oil can not only protect the transmission, prolong the service life of the transmission, reduce the failure rate of the transmission, but also reduce the direct cost of oil change and maintenance of the transmission, and reduce the maintenance labor and maintenance of the transmission. Parking time.
(5) All kinds of lubricating oil must be pure, and after a period of precipitation, meet the specified quality requirements. Oil filling tools, containers and oil filling ports should be cleaned to prevent water and dirt from entering the oil
When checking the fuel level, the vehicle must be level in both longitudinal and lateral directions.
After refueling and changing the oil, be sure to check for oil leakage.
Therefore, it is very necessary to strengthen the failure prevention and daily maintenance of the gearbox in the daily use process, which can not only reduce the inefficiency and delay of working hours caused by downtime and maintenance, but also prevent and avoid larger follow-up failures. occurrence, reduce maintenance costs and improve machine safety.