Why does the car make a thud sound when the transmission overheats?

[VonAdelyn]

It could be due to wear and tear of transmission bearings or gears, or bearing spots. When accelerating and shifting gears, abnormal noises from the transmission may indicate the presence of metal powder in the transmission oil, suggesting excessive wear of components such as brake bands and clutches inside the transmission. Solutions: The transmission consists of numerous parts, and the causes of noise are relatively complex. When analyzing and diagnosing, pay attention to the following: whether the noise is related to specific speeds, as some planetary gears may produce noticeable noises around 50Km/h. Whether the noise is related to certain gears, which is crucial for diagnosing transmission issues. If noise occurs in a specific gear, it is certainly related to the components affecting that gear's transmission; if noise occurs in all gears, it is often due to faults in the constant-mesh gear shaft or insufficient transmission oil. Whether the noise is related to specific actions, such as shifting gears, starting, rapid acceleration, rapid deceleration, or turning, all of which are effective means for diagnosing abnormal noises. Among these, changing speed and direction are particularly important for determining rear axle faults.