Typical malfunctions of automatic transmission and troubleshooting
March 21, 2021
The transmission, along with the engine, is considered one of the main and important elements of a modern car. In fact, it is a node that transmits the force from the engine to the wheels. When the gearbox malfunctions, the correct operation of the car is impossible. Let’s consider in more detail what malfunctions in the automatic transmission and what to do about them. But if you can not repair the gearbox and along with it the other major components of the car. then such a car is easier to pass for recycling: https://scrapmycarnear.me.
Automatic transmission (automatic transmission) is considered a fairly reliable and stable mechanism. This type of transmission is common and more convenient than the manual, but also subject to breakdowns, due to the conditions of operation in Russian realities. In this article, let’s analyze what happens malfunctions of the automatic transmission.
What is an automatic transmission
The gearbox is one of the main units of the vehicle. The automatic unit (“automatic”) is a type of transport transmission, which is characterized by switching gears without the participation of the driver. Changing speeds does not require constant control from the driver, there is no need to constantly monitor the engine load. The automatic transmission is much more convenient than the manual one, especially when driving in the city.
“Automatic” has the following advantages:
Contributes to the smoothness of movement.
Increases the degree of comfort, the driver is easier to manage and control the car.
Protects the engine from unnecessary load.
How to recognize a malfunction of automatic transmission?
When operating a vehicle, the load on the automatic unit is present in large quantities. “Automatic”, for all its convenience, is considered a very vulnerable place. Modern units have increased strength, increased performance characteristics. The factories declare – a large-scale repair of the mechanism is carried out after 150 thousand kilometers of mileage.
Signs of malfunction are the following symptoms:
The car refuses to move in any direction.
In the process of movement jerks are felt.
Control gear slips. It is expressed in too slow acceleration of the car, there is a feeling of “slipping”. When changing over to a higher gear the power unit works in vain.
Speeds are not shifted, they shift by themselves.
The vehicle continues to move with the gear lever in the “P” position.
An icon not corresponding to the selected speed is displayed on the autopanel.
Oil is leaking out.
While driving, noisy sounds, crunching are heard.
When observing these signs, it is worth not delaying a visit to the car service. As a rule, the damage is not eliminated by itself. They should be localized and eliminated.
The automatic unit is a complex device. To carry out quality repair of automatic transmission under force of experienced qualified specialists. Self-repair work is difficult to do, it all depends on the severity of the defect.
Why does the “automatic machine” break down?
The causes of damage are different factors. Some of them can be eliminated independently:
The vehicle is moving in “P” mode. Most likely, there was a failure in the adjustment of the mechanism for changing speeds. Faulty parts are replaced, adjusted according to the regulations.
Oil is leaking. Happens because of slackening of bolts fastening the aggregate to a crankcase, oil pan. Can be solved by tightening bolt joints. May be leaking due to defects of rings located on shaft outlet or in place of speedometer connection. The problem may be solved by fitting new O-rings.
Noise. Insufficient oil level is to blame. It is necessary to measure the oil level and add the right amount. This case is a factor for an arbitrary, difficult change of speeds.
The cause of the breakdown may be more serious factors. The difficulty of self-diagnosis is the low probability of accurate determination of the breakdown by a non-specialist. For example:
The car refuses to drive regardless of the mode. The reason can be small oil level, dirty filter, damage of torque converter, failure of friction disks, brake tapes. Besides, failure of cuffs, located in friction discs pistons, defect of hydroblock solenoids is also the base of incorrect operation.
Slipping of the unit can be observed when driving uphill, the lowered speed is switched on earlier than it should be. Insufficient oil level, friction clutches defect – the essence should be searched in it.
Slipping, jerking sensation of the car. The cause is a failure of the overrunning clutch.
Sensation of jolts, blows at the moment of gear change. The cause is damage to the clutch discs.
The car continues to move in the position “N”. This is caused by the clutch piston wedge.
KickDown mode does not work correctly. When the gas pedal is pressed hard, it should change to a lower gear. It doesn’t happen if the hydroblock valve is jammed, throttle valve actuator is broken, pressure sensor is broken.