Why is there a noise when shifting gears in a car?
2 Answers
Car shifting gear noise reasons are as follows: Transmission housing damage: Long-term wear and deformation of the transmission housing and bearing seat holes cause noise, which is loudest when shifting into low gears and gradually decreases when shifting into high gears, with direct gear being the quietest. Gear surface breakage: Impact during meshing caused by breakage of individual gear surfaces. When shifting into this gear, strong impact and vibration occur, leading to resonance in the transmission housing. Improper transmission assembly: Incorrect replacement of gears or needle bearings and bushings in a certain gear of the transmission; abnormal assembly clearance causing poor gear meshing and abnormal noise during transmission in that gear.
I've been repairing cars for many years and have encountered quite a few gear-shifting noise issues. The most common cause is the clutch not being fully depressed, preventing smooth gear engagement and resulting in a clunking sound. Sometimes it's due to worn synchronizers in the transmission, which create friction noise during gear changes. Insufficient or aged transmission fluid can also be a culprit - inadequate lubrication leads to metal-on-metal contact sounds. I recommend car owners first try fully depressing the clutch before shifting. If the noise persists, they should check the fluid level and quality. Regular maintenance is crucial - for instance, changing transmission fluid can prevent such problems. Don't delay when hearing abnormal sounds; get it checked at a professional shop early to avoid minor issues turning into costly major repairs.
