What Causes Abnormal Noises in the Transmission When Shifting Gears?
1 Answers
Abnormal noises in the transmission when shifting gears may be caused by issues such as a faulty gear shift mechanism, damaged synchronizer rings, worn or abnormal wear of internal transmission bearings, and other related factors. It is recommended to contact a local 4S dealership for inspection and repair to ensure driving safety. Below are detailed explanations of the specific causes: 1. Transmission bearings often operate under high-speed and heavy-load conditions, enduring significant alternating stresses. This can lead to wear, pitting, fatigue spalling, or burning of the bearing balls or cylindrical rollers and raceways, increasing axial and radial clearances and resulting in impact noises. 2. During gear meshing and transmission, sliding friction occurs from the tooth tip to the tooth root, making wear inevitable. As gears wear, the meshing clearance increases, causing impact noises during vehicle operations such as starting or shifting gears. 3. Worn bearings can lead to looseness, shaft deformation, or housing deformation, altering the center distance between meshing gears and causing misalignment of axes. Additionally, wear in sliding keyways on the shaft or internal splines of sliding gears, loose fastening bolts in the control mechanism, and wear or deformation of shift forks can cause gear displacement. 4. Improper driver operations, such as aggressive starting or poor coordination between hand and foot during gear shifting, can generate excessive impact loads in the transmission, leading to gear tooth breakage or fragmentation and resulting in abnormal noises.
