What Causes the Abnormal Noise When Shifting Gears in an Automatic Transmission?

[LeviDella]

Automatic transmission shifting produces abnormal noise due to the following reasons: 1. The release bearing lacks lubricant, causing dry friction or bearing damage. 2. There is no clearance between the release bearing and the inner end of the release lever. 3. Severe oil contamination or dust accumulation between the release bearing sleeve and the guide tube, or fatigue, breakage, or detachment of the release bearing return spring and pedal return spring, resulting in poor return of the release bearing. 4. Loose fit between the spline hole of the driven plate and its spline shaft. 5. Annealing, fatigue, or breakage of the driven plate damping springs. 6. Loose rivets or exposed rivet heads on the driven plate friction disc. 7. Wear and looseness of the drive pins of the double-disc clutch and the pin holes in the intermediate pressure plate and pressure plate.