After the automatic transmission is flooded, if it is not repaired in time, a series of problems may be induced for a long time, such as oil leakage, abnormal sound, "running into the car" and so on, or if the automatic transmission oil is not changed for a long time, the automatic transmission oil will become thicker. If it loses its efficacy because of long-term use, the components will directly rub without a protective layer, thus aggravating the wear of mechanical parts, and seriously damaging automatic wave planetary carrier, differential and other components.

Low-quality or counterfeit gearbox oil has poor temperature resistance, and is prone to oxidation, resulting in sludge and oil residue, blocking the filter screen and lubricating oil passage of automatic gearbox, resulting in increased friction of internal components of automatic gearbox, which may lead to abnormal noise of vehicles. When the car is idling, the noise disappears after stepping on the clutch, which means that the noise source is caused by the failure of the gearbox.

Solution

1. When the car is idling or driving, it hears abnormal noise in the transmission part

The transmission oil is short or the oil is deteriorated; The transmission bearing is worn, loose or damaged; Bending of transmission shaft; The normal meshing clearance of gear meshing is too large or too large; Metal peeling off the gear tooth surface, tooth fracture or repair and assembly dislocation; The groove between the shift lever and the shift fork is loose. There is a dry metal friction sound when the car is driving, and it feels hot when touching the transmission housing with your hands. This noise is caused by lack of lubricating oil or deterioration of lubricating oil. You should refuel or check the oil quality and replace it if necessary.

2. Abnormal noise of the gearbox in neutral

Abnormal noise occurs in neutral, and the noise is eliminated after stepping on the clutch pedal. Generally, the front and rear bearings of the transmission shaft are worn, loose or the gears are frequently engaged. If it rings when shifting into any gear, it is the rear bearing of the second shaft. If the bearing is seriously loose or damaged, it should be repaired or replaced.

3. Abnormal noise of the gearbox when the vehicle is traveling at high speed

The rhythmic "honk, honk, honk" noise appears when the vehicle is traveling at high speed, but it becomes a messy gear collision sound and gears are engaged, which may be caused by the good meshing of gears in the transmission. If the noise is slight and even, it can be used continuously. If it is serious and even, it should be disassembled for inspection and readjusted or replaced if necessary.

4. Abnormal noise of the gearbox when the engine is idling

When the engine is idling, it makes a rhythmic noise of "honk, honk, honk". When the throttle is increased, the noise is more serious and the transmission is vibrated. Generally, it is caused by tooth surface peeling or broken teeth. If the gear center is misaligned during repair and assembly, it will also make this noise. In this case, it should be disassembled for inspection and replaced with a new one if necessary.

5. Abnormal sound without rhythm in the gearbox

When a certain gear is driving, there is an rhythmic and dull noise, and the noise disappears when the gear lever is held by hand, which may be caused by the wear of the gear fork groove or the working face at the gear lever end, so it should be disassembled, inspected, repaired or replaced.

6. Abnormal noise when the gearbox is shifted into a certain gear

When shifting into a certain gear while driving, the noise is obviously that the gear of that gear is excessively worn and makes a noise. If it makes a periodic noise, it will make a sudden impact sound when individual gear teeth are damaged and the gear teeth may be broken. Take apart the transmission in time for inspection and repair or replacement.