Automatic transmission in a modern car is one of the most expensive and time-consuming units to repair, therefore, detailed attention to the preliminary diagnosis of the "automatic" is an extremely important thing.
Instructions
Step 1
When buying a car with an automatic gearbox, it is necessary to conduct a thorough diagnostics of the operation of this most complex automotive unit.
A huge number of high-precision parts that make up the automatic transmission make this system very expensive to repair, so a thorough check of the automatic transmission is the key to reliable and trouble-free operation of the car.
Step 2
A preliminary check of an automatic transmission begins with a visual inspection of the car: there should be no oil smudges or dents in the area where the automatic transmission is located: if the car has been in an accident, hidden damages can affect the operation of the automatic transmission.
Step 3
The next step in diagnosing the box is checking the oil level. During the check, the engine should be idling, the gear lever should be in the “parking” position.
With a cold box, the oil level should be at the minimum mark of the oil dipstick, with a warm box - at the operating level. The inconsistency of the level with these labels is a warning sign.
Visual assessment of oil condition. By dropping oil on a clean sheet of paper, you must make sure that there are no foreign impurities in the liquid: metal particles, flakes, small air bubbles, a burning smell.
The color of the oil can be yellow - this is a sign of good car care; dark brown - if the oil has not been changed for a long time; reddish - in case of a recent replacement.
Step 4
Further check of the automatic transmission takes place in motion. Having squeezed out the brake pedal, it is necessary to smoothly move the automatic transmission lever several times to each of its positions. Switching should take place without knocking, extraneous sounds, sudden jerks and delays; in the neutral position, the box should be turned off.
Before leaving, you need to warm up the car a little, after which you can start diagnosing the operation of the machine during acceleration. Gaining speed up to 60 km / h, two soft shifts should occur - into the second and third gear.
When shifting, such effects as an obvious delay in the response of the gearbox, jolts, extraneous sounds, "slipping" between gears are completely unacceptable.
Step 5
With the permission of the owner of the car, it is worth testing the operation of the machine in kick-down mode, sharply squeezing the accelerator: the "machine" must go into a lower gear.
If the automatic transmission is equipped with an Overdrive button, this mode must also be checked: when the mode is turned off, the gearbox should go into a lower gear, the corresponding yellow icon on the dashboard lights up.
If, when checking the Overdive mode, the “check engine” icon also lights up, the automatic transmission may be faulty.
