What Causes the Noise When Shifting Gears?
2 Answers
Possible reasons for noise when shifting gears are as follows: 1. Transmission failure: Damage to the transmission housing or long-term wear and deformation of the transmission housing and bearing seat holes. This type of noise is most pronounced when shifting into low gears and gradually decreases as higher gears are engaged, being the least noticeable in direct drive. 2. Gear failure: Fracture of individual gear surfaces causes impact during meshing. When shifting into the affected gear, strong impacts and vibrations occur, leading to resonance in the transmission housing. 3. Drivetrain failure: Poor technical condition of the drivetrain components outside the transmission (clutch, drive shaft) can cause impacts and vibrations during use, leading to transmission resonance and resulting in irregular noise. This noise often occurs unpredictably within a certain RPM range.
I've been driving for over twenty years and have encountered gear-shifting noises several times. The most common scenario is when you rush to shift gears without fully depressing the clutch, causing the transmission gears to make terrifying clunking sounds. Last time I went for repairs, the mechanic said dirty transmission fluid could also cause this—when there are too many impurities in the oil, the gears wear severely. Another time, there was a loud clunk when shifting into reverse, and it turned out to be worn synchronizers. In my opinion, if you press the clutch more slowly when shifting and regularly check the transmission fluid, you can avoid most of these issues. It's especially important to pay attention during cold starts in winter—let the car warm up for a few minutes before driving, as metal components are most prone to abnormal noises when not properly lubricated.