What is the reason for sudden failure of all gears in a car?

[BradleyRose]

The reason for sudden failure of all gears in a car is gear lock or incomplete braking when parking. The following are specific solutions for automatic transmission gear failure: 1. Engage first gear: When the car temperature is low, the transmission oil is not fully lubricated. Try to engage first gear without starting the engine. If it engages smoothly, there is no problem. 2. Engage reverse gear: Try to engage reverse gear when the vehicle is stationary. If there is a gear collision sound during the engagement process, it indicates that the clutch separation is not thorough. After repairing the clutch, the fault can be eliminated. 3. Difficulty engaging first gear: If reverse gear engages smoothly but first gear is difficult to engage, go to a specialized repair shop to adjust the gear position and replace the transmission oil.