What Causes the Clicking Sound When Shifting an Automatic Transmission?

[DeNolan]

Automatic transmission shifting produces a clicking sound due to: 1. Generator gear issues: The symptom is a clicking sound when shifting into D or R gear while pressing the brake, but no sound in N gear, and no abnormal noise while driving. The solution is to replace the generator. 2. Large valve clearance and poor lubrication when the engine is cold: The symptom is a clicking sound during gear shifting between cold and warm engine states, lasting about 3 minutes, which is normal. An automatic transmission eliminates the need for manual gear shifting by the driver, as the vehicle automatically selects the appropriate gear based on speed and traffic conditions. Typically, automatic transmission cars have six gear positions, from top to bottom: P, R, N, D, S, L.