What Causes Abnormal Noise During Gear Shifting in the Transmission?

[Hayden]

Here are the main reasons for abnormal noise during gear shifting in the transmission: 1. Transmission bearings often operate under high-speed and heavy-load conditions, enduring significant alternating loads. As a result, the rolling balls or cylindrical rollers and raceways of the bearings may experience wear, spots, fatigue spalling, or burning, leading to increased axial and radial clearance, which causes impact noise. 2. During gear meshing transmission, sliding friction exists from the tooth top to the tooth root, making wear inevitable. Due to gear wear, the meshing clearance increases, resulting in impact noise during vehicle operations such as starting or shifting gears. 3. After bearing wear causes looseness, shaft deformation or housing deformation alters the center distance between meshing gears and causes misalignment of axes; wear in the sliding keyways on the shaft and internal spline grooves of sliding gears; loose fastening bolts in the control mechanism and wear or deformation of the shift fork can lead to gear displacement. 4. Improper driver operation, such as aggressive starting or poor hand-foot coordination during gear shifting, can cause significant impact loads in the transmission, leading to broken or shattered gear teeth and abnormal noise.