What is the cause of gearbox failure?

It is best not to continue driving, because the gearbox is expensive, it is not cheap to repair, and there will be safety failures. The main reason of gearbox failure is that the valve body is too dirty, which will destroy the quality and friction characteristics of gearbox oil. Increase friction and wear, at the same time, sludge will also be produced in the gearbox, which will cause the valve body and pipeline to be blocked and the oil pressure cannot be adjusted in sequence, thus causing gearbox failure.

When the car is in use, the gear light on the instrument is on or the information desk prompts that the gearbox is faulty, and at the same time, the car will have a shift impact, indicating that the gearbox is faulty. The system is in emergency mode, so it needs inspection and maintenance.

Extended data

Automatic transmission cannot be upshifted.

When the car is driving, the automatic transmission can't be put into second gear or high gear; When driving, the automatic transmission can shift to second gear, but it cannot shift to third gear or overdrive gear.

Troubleshooting:

The throttle cable or throttle position sensor is incorrect; The speed sensor is faulty; Corresponding brake or clutch failure; The shift valve is stuck; Gear switch failure

Automatic transmission upshift failure is too late.

When the car is driving, the upshift speed is obviously higher than the standard value, and the engine speed is higher before the upshift. It is necessary to use the accelerator pedal to shift up in advance (that is, release the accelerator pedal for a few seconds and then press it) to make the automatic transmission shift to high speed or high gear.

Troubleshooting:

The throttle cable or throttle position sensor is incorrect; The throttle position sensor is damaged; The oil pressure of main oil circuit or throttle valve is too high; Forced downshift, switch short circuit; Computer or sensor failure.