What Causes the Transmission to Make Noise When the Throttle is Released?
2 Answers
There are several reasons why the transmission makes noise when the throttle is released: 1. Bearing wear: Wear and damage to bearings can cause increased clearance and reduced fitting accuracy. When bearings are damaged, they cannot operate normally, leading to abnormal noises and even damage to transmission components, exacerbating the issue. 2. Transmission component wear: Wear of transmission components or the use of low-precision replacement parts, such as gears with excessive clearance between new and original gears. 3. Insufficient lubrication: Inadequate or overly viscous lubrication can lead to poor lubrication. The corresponding lubricant (grease) should be replaced; otherwise, it will accelerate transmission wear and shorten its lifespan. 4. Loose bolts: Bolts on the transmission housing (end cover) may become loose due to vibration during use. Regular inspections should be conducted to prevent this.
I've been driving for almost 30 years and have encountered several instances where the transmission makes noise as soon as the accelerator is released. There are actually quite a few reasons for this. The most common one is wear and tear on the internal bearings or gears of the transmission, leading to increased clearance, which causes a clattering sound when the engine speed drops rapidly. Additionally, insufficient or dirty transmission fluid, resulting in inadequate lubrication, can also lead to friction noises. For automatic transmission vehicles, it might be an issue with the valve body or control unit. Ignoring this noise for a long time can accelerate damage to transmission components and even affect driving safety. I recommend regularly checking the fluid level—normal fluid should be clear with a slight red tint. If it turns black or contains impurities, replace it promptly, generally every two years or 40,000 kilometers. At home, you can simply start the car and have a friend help identify the source of the noise, but it's best to have a professional repair shop conduct a thorough inspection with diagnostic equipment to avoid costly major repairs down the line.
