Maintenance technology of automatic transmission


The automatic transmission of the equipment is mainly four structural types, which are hydraulic automatic transmission (AT), mechanical stepless automatic transmission (CVT), electronically controlled mechanical automatic transmission (AMT), dual clutch automatic transmission (DUALCLUTCHTRANSMISSION-DCT) . The automatic transmission is mainly composed of a hydraulic mesh or dual clutch, a planetary gear or an external gear shifting mechanism (tape), a hydraulic manipulation system, an electronic control system. The maintenance of the automatic transmission mainly has a technical examination, replacing lubricant, and the like.

(1) Project and method for routine examination

1. Check the height of the automatic transmission oil surface

Before doing any automatic transmission or fault diagnosis, first check the height of the transmission oil surface, the vehicle should be checked for 10,000 km per car.

A few minutes in the vehicle, so that the transmission reaches the normal operating temperature (70 ° C ~ 80 ° C), park the vehicle in the flat pavement, tighten the parking brake, keep the engine idle operation, press the driving brake pedal, and convert the transform bar Hou in each gear by the P file and stays more than 30s over each gear, and finally hang into the P file, then observe the kale sign of the automatic transmission. At the normal operating temperature, the oil surface should be in the HOT, such as low, indicating that the same model transmission oil is required.

2. Check the quality of automatic transmission oil

The oil should be cleaned. If the oil is black, dark red or dark brown, the lubricant should be replaced; if there is a flavor flavor in the oil, there is a brine in the oil, or the oil contains a glue, the spin should be decomposed in-depth examination.

3. Check if the hydraulic system oil leaks

The various joints of the hydraulic system have oil seals and seals. These parts are places where they have leaked. Oil leakage will cause a drop in oil pressure, causing a variety of faults, so if there is oil, it should be excluded in time. Common oil spills have an O-seal of a vehicle speed sensor, the O-seal of the speed sensor, the O-seal of the electromagnetic coil wiring, the O-seal of the oil ruler, the Test plug of the pressure line and O-shaped Sealed rings, direct frames, tachometer oil seals, oil pump oil seals, hydraulic oil cooler pipe joints, repleased back pressure test stresses and O-shaped seals, oil sides, and transmission combination, should be examined one by one, no leak items .

4. Check and adjust the throttle lasson

Improper length of throttle can cause abnormal oil pressure to abnormally, the normal operation of the automatic transmission is very affected. Under normal circumstances, the throttle cable length should ensure that the throttle is closed after the engine is turned off, and when the accelerator pedal is stepped on, the throttle is open. Adjustment method: Stepping accelerator pedal, check if the tester is fully opened, such as the end, adjust the accelerator pedal link; if it is invalid, adjust the pull-up adjustment nut on one side of the throttle, so that the rubber sleeve and wire stop block The distance is 0 ~ 1mm, tighten the adjustment nut, reintegrate until the technical requirements are met.

5. Check and adjust the replacement rod position

The shift lever is changed from the n to other gear position, the shift lever should be smooth, accurately enter the change gear, the shifting indicator can correct the gear position, if the indicator does not match the gear position, should be adjusted It is the method to loosen the positioning nut on the shift lever, push the control axial to the end, then refund two gaps to the n gear, turn the shifting rod in the n gear, tighten the shift lever Positioning nut. Start the engine, start the start test, when the D-Dynamics, the vehicle forwards, when the R is, the vehicle is fell.

6. Check and Adjust the Nelet Start Switch

Checking the engine can only be started when the shift rod is in the n-gear or P file, and in other gear points cannot be started, otherwise, adjustments should be adjusted in the following order:

(1) Loosen the neutral switching bolt and set the shift lever in the n gear.

(2) Align the idle reference line with the groove.

(3) Keep this position, tighten the bolts, torque is 13 N · m.

7. Check the engine idle speed

The idle speed of the engine also affects the normal operation of the automatic transmission. If the idle speed is too high, from N to P or to D, R, 2, 3, the vehicle can cause vibration; if the idle speed is too low, from N to P, the engine is turned off or stepped on the brake during the driving process. When the engine is easy to shut down. In the case where the sedan is in the n-gear, the air conditioner switch is closed, the idle speed range is at 750 r / min, such as that does not meet the requirements, should be adjusted.

(2) Replacement of automatic transmission hydraulic oil

Generally equipped with automatic transmission vehicles 40,000km per normal and must be changed once. In addition, each of the automatic transmission 20000km or 6 months, the height of the oil surface height and hydraulic oil should be checked. When the oil quality is deteriorated, it should be changed immediately. The oil change method of the automatic transmission is as follows:

(1) Traveling the vehicle to prevent the automatic transmission to the normal operating temperature (oil temperature 70 ° C ~ 80 ° C) is stopped.

(2) Remove the automatic transmission oil bottom shell and put the oil rush, and clean the hydraulic oil in the oil casing. Some models of automatic transmission oil housings do not put the oil rush, should remove the entire oil casing, then put oil. When the oil housing should be removed, the rear half oil bottom shell screw should be removed, loose the front oil bottom shell screw, and then the rear half oil housing is thrown away from the transmission housing, discharge some hydraulic oil, and finally The oil housing is removed.

(3) Remove the oil bottom shell and clean the oil casing. Some automatic transmissions of the oil bottom shell are magnetically filled, and some automatic transmission dedicated to a magnet in the oil housing to adsorb the ferrupers. When cleaning, you must pay attention to cleaning the iron filings on the magnet.

(4) Remove the automatic transmission hydraulic oil radiator tubing joint, blow the residual hydraulic oil in the heat sink with compressed air, and then install the tubing joint.

(5) Install the oil housing and the oil absorbing.

(6) Add a prescribed grade hydraulic oil from the automatic transmission tube. The amount of oil in the automatic transmission oil housing is around 4L.

(7) Start the engine and check the height of the automatic transmission oil. It should be noted that since the newly added oil temperature is low, the height of the oil surface should be near the lower limit of the oil scale. If the oil surface is too low, it should continue to refuel to the height of the prescribed oil surface.

(8) Let the car drive to the engine and the automatic transmission to reach the normal operating temperature, check whether the height of the oil surface is near the upper limit of the oil measurement. If it is too low, it should continue to refuel until the specified requirements are met. If you accidentally add too much hydraulic oil, so that the oil is higher than the specified height, and the oil should be removed.

After regular inspection, such as automatic transmission still failures, there is a need for further professional examination to automatic transmission.

(3) Precautions in use

In general, the gear position of the automatic transmission is divided into P, R, N, D, 2, 1 or L, etc.

P (parking): Used as a parking, it is to lock the rotating portion of the car using the mechanical device to make the car cannot move. When the car needs to stay in a fixed position, it will pull the hand brake and pull the lever into the "P" position before leaving the cab after stopping the cab. It should be noted that the vehicle must use the P file when it is completely stopped, otherwise, the automatic transmission mechanical portion will be damaged. In addition, the automatic transmission is equipped with a space start switch to enable the car to start the engine on the "P" or "N" file to avoid errors in other gear. Therefore, it is necessary to confirm whether the shift lever is in "P" or "N" before starting the engine.


R (Reverse): In reverse, the vehicle is reversed. You can usually press the insurance button on the lower chart to move the lever to the "R" file. It should be noted that when the vehicle has not been fully stable, it is absolutely not forced to go to the "R" file, otherwise the transmission will be seriously damaged.

N (neutral): Needle. Place the lever on the "N" file, the power between the engine and the transmission has been cut. For a short stay, the lever can be placed in this file and tighten the parking brake, and the right foot can be taken away from the brake pedal to rest.

D (DRIVE): The forward file is used in the general road. Place the lever on the "D" file, the driver controls the speed of the speed of the speed, just control the accelerator pedal.

2 (SecondGear): 2 gear is forwarded, but the transmission can only be converted between 1 file, 2 files, and will not jump to 3 gears and 4 files. Place the lever in 2 gear, the car will start from 1 gear and 2 files automatically increase when the speed is increased. 2 files can be used as the use of the upper and lower slopes. The advantage of this segment is when uplink or downhill, the vehicle will remain stably in 1 gear or 2 position, and does not turn to convert the gear by the unbalanced transmission of the load or the unbalanced speed of the speed. In the downhill, the resistance to the engine low speed is made, and the faster the vehicle is not allowed.

1 (FIRSTGEAR): 1 gear is also moving, but the transmission can only work within 1 file and cannot be transformed to other gear. It uses the situation and the slope when severe traffic jam and the slope is played.

Each gear should be noted when using:

(1) When the mount lever is placed in the P, N position, the engine can start the engine, and if the ignition switch is opened, if you want to remove the two gear position, you must first step on the brake pedal, press the handle button at the same time. The gear rod can be moved into other gear.

(2) The P file can be used as a hand-made auxiliary brake, but it is not alternative to the brake.

(3) When the vehicle is traged, the gear rod must be placed in N position, and the speed of the vehicle can not exceed 50km / h at the traction. The traction distance cannot exceed 50km. If the distance is taken, the drive wheel will be driven away from the ground.

(4) If the control unit of the automatic transmission causes it to enter the emergency state due to the electrical failure, only 3, 1, and the R file can work, do not think that there is a gear position, if it does not repair, it should be found in time to identify the fault and Exclude, otherwise it will damage the plurality of clutches in the automatic transmission.

(5) The vehicle equipped with the automatic transmission cannot be launched by a method of traction or pushing the start, as the ATF oil pump does not work, and the automatic transmission cannot establish a normal working oil pressure.

(6) In the cold winter, start the engine preheating before 1 minute before driving.

(7) It is not possible to hang N-gear sliding when driving or downhill. Some drivers think that hanging n-gear slides at high speed or downhill can save fuel, in fact this is very wrong and dangerous. The automatic transmission is higher in the output shaft speed at the time of the car, and if the engine is transferred into the idle state (when the N-Dynamic), the transmission will have insufficient oil supply, especially for multiple clutches, and it is easier because of the lack of lubrication. Cooling and burning.