What causes a sudden thud sound when shifting gears in a car?

[MacJulia]

When shifting gears in a car, a sudden thud sound may be caused by loose friction plates on the steel plate or impact noise between the release lever and the window hole. Below is an introduction to car gear shifting: 1. Introduction: It should be referred to as "gear shifting". Gear shifting refers to the transmission, which is used to change the torque and speed of the engine crankshaft. 2. Function: To meet the different requirements of driving wheel traction and speed under various driving conditions such as starting, accelerating, driving, and overcoming road obstacles. 3. Techniques: First, remember the principle of "accelerate before upshifting, decelerate before downshifting" when shifting gears. Before upshifting, "rev" the throttle to increase the speed first, and before downshifting, "release" the throttle to reduce the speed first.