What Causes Gear Noise in Cars?
2 Answers
Introduction to the causes of gear noise in cars: 1. Excessive surface roughness of gears. When the gear surface is too rough, the friction area during interaction increases, leading to higher vibration frequency and consequently louder and more frequent noise. 2. Insufficient overlap ratio. Gears undergo varying degrees of deformation when transmitting loads. At the moment of gear meshing and disengagement, meshing impact forces are generated along the gear meshing line direction, causing certain torsional vibration noise in gear transmission. Therefore, an insufficient overlap ratio can result in gear noise. 3. Gear design issues. Improper selection of gear parameters, incorrect or absent gear modification, and unreasonable gearbox structure can all lead to excessive gear noise. 4. Gear precision. Low gear contact precision, inadequate bearing rotation accuracy, and improper clearance can cause excessive gear noise. The precision of gear pitch, tooth profile, and radial runout of the gear ring all affect gear noise to some extent. The higher the precision, the less noise is generated.
I've encountered many gear noise issues in cars, usually caused by daily wear and tear or inadequate maintenance. For example, when the gear tooth surfaces in the transmission become rough, you'll hear a clunking sound when shifting gears; or when the differential bearings fail, it produces a humming noise while driving. Insufficient oil is the most common cause - when transmission fluid ages and loses its lubricating properties, increased gear friction leads to noise. I recommend starting by checking the oil to see if it needs replacement; if that doesn't solve it, have a mechanic diagnose whether the gears themselves are damaged. Untreated problems may worsen into complete failures that are more expensive to repair. Regular checks of fluid levels and gear conditions can prevent issues - don't wait until the abnormal noises become louder to address them.
