10/02/2023
🔴1. Transmission oil leakage
There is oil leakage from the gearbox casing or oil pan. One reason is that the seal is aging and the seal is not good. The other reason is that the casing has trachoma due to poor manufacturing process.
🔴2. When the gearbox is in gear, the engine stalls, there is no response, and there is an impact
The standard for testing gear entry is to start the engine, idle, step on the brakes, and shift into gear. Normally, there is a feeling of shifting into gear within 1-1.2 seconds and the brake pedal is released. The vehicle will slow down without stepping on the accelerator pedal. Start slowly and gradually extract the vehicle speed of 10-20 km/h. This is a normal standard for entering gears. If it is delayed for more than 2 seconds after entering the gear, it needs to be repaired immediately; A strong impact feeling is the impact of positioning into the gear. It should be noted that any automatic transmission has a certain degree of impact feeling when entering the gear. Acceptable, the problem caused by it is very complicated, including many aspects other than the gearbox; the situation of stalling in the gear is that the engine will stall when the gear is in the gear. This problem is more obvious when the car is cold, and the problem is caused by the gearbox. The problem also has problems with other body systems
🔴3. The transmission is mounted in D or R and the engine is turned off
This kind of failure may be caused by the damage of the lock-up solenoid valve or the lock-up control valve, which causes the D or R gear to be shifted, and then the vehicle does not move after the brake is released. Or the car can travel for a short distance after the cold car is started, but the car cannot travel when the car is hot. This situation is mostly caused by damage to the input shaft or reverse gear clutch, or damage to the D/R brake. It may also be that the automatic gearbox has serious oil leakage and severe oil shortage; the connecting rod or cable between the shift lever and the rocker arm of the manual valve is loose, and the manual valve remains in the neutral or parking position;
🔴4. The oil inlet filter of the gearbox is clogged, and the oil circuit is seriously leaking: the oil pump is damaged, and the shock and rush of the vehicle during the driving process are also common fault phenomena of the automatic gearbox. This may be caused by the dirty gearbox oil. Caused by valve body stuck.
🔴5. The gearbox slips and the acceleration is weak; the gearbox is flooded. When the car is driving, there is the sound of the engine idling when the accelerator is accelerated. The speed of the car does not increase, and the whole car feels weak. This phenomenon is mostly due to the burning of the clutch plate. cause. The gearbox is caused by water ingress due to external reasons, which leads to abnormal operation of the gearbox. This may be due to oil leakage in the water tank, or water entering from the gearbox vent cap.
🔴6. Abnormal sound of gearbox
① It is the abnormal noise of the bearing. Generally, the abnormal noise of the bearing is closely related to the speed. The higher the speed, the more the squealing sound. , because the meshing surfaces of the gears are not divided, generally the sound is obvious when refueling, and the sound is obviously weakened when the accelerator is released.
③ It is the abnormal sound of the hydraulic system such as the oil pump. This sound is closely related to the speed but has nothing to do with the speed of the vehicle. When the speed is high, the oil pump is blocked and causes screams. It should be noted that the transmission system works together with the alarm, chassis and other components, and it is not easy to identify many sounds mixed together.
🔴7. There is a peculiar smell in the gearbox box
The gearbox body works by hydraulic oil. When the oil temperature is too high, there will be some burning, and these peculiar smells will come out, which means that some executive parts in the gearbox body are not working properly.
🔴8. Automatic shift time is too long or too short
Generally, automatic transmissions have specific shift speeds and vehicle speeds. If you find that the shift time is suddenly too long or too short, it means that the transmission ratio of the gearbox is out of proportion. At the same time, you will feel that the engine speed is too high. What's more, the gearbox does not shift gears, which indicates that there is a problem with the gearbox
🔴9. The engine speed is high during driving
This problem includes two situations: the speed is always high during steady driving and the speed is during the speed-up process: the speed is high during the smooth process, and it is easier to test. It often takes 3000 revolutions or more to reach 100 kilometers, which indicates this fault. Generally, this fault is caused by the failure of the high-speed gear of the gearbox or the failure of the internal lock-up clutch of the shifter. The gearbox needs to be repaired immediately. The speed is too high during the acceleration process. This fault test is a bit complicated, because the increase in the engine speed is closely related to the accelerator pedal during the speed up process. The vehicle can be accelerated up to 2500 rpm, but the alarm will be raised to 5500-6000 rpm under full throttle. Such a huge contrast is due to the fuzzy logic control of the electronic control system of the gearbox, so this standard requires certain Professional standard to complete
🔴10. Engine idling
Engine idling generally occurs in two situations. One is that the engine idling suddenly occurs when the vehicle is stable, and it returns to normal when the vehicle speed slows down. This situation generally indicates that the gearbox suddenly drops from high gear to high gear in a short period of time. In the low gear, the problem may be in the control system or the cooling system, but the gearbox itself has no problem. The second is that there is a short-term slipping and idling phenomenon during the acceleration process or during the gear shifting process. The intuitive feeling is that the latter is not as severe as the former. In fact, it is exactly the opposite. Most of the latter's problems lie in the gearbox. In the clutch and other related links, the gearbox needs to be completely dismantled and overhauled, and the time and cost consumption is much more than the former.
The above is the full introduction of the solution to the common faults of the car gearbox by the editor of the car maintenance network. For the common faults of the car gearbox
