What is the reason for frequent gear collision during gear shifting?

[LaDallas]

When shifting gears, if the gear cannot be engaged smoothly and there is often a gear collision sound, the reason is incomplete clutch disengagement. The following is a related introduction about shifting faults: The reasons for incomplete clutch disengagement: Excessive free travel of the clutch pedal; bending or deformation of the release lever, loose support, or detachment of the support pin, making it difficult to adjust the height of the inner end of the release lever; fatigue, insufficient height, or breakage of individual release springs; warping of the driven plate steel sheet, cracking of the friction plate, or loose rivets; oil leakage, air presence, or insufficient oil in the clutch hydraulic control mechanism; wear or damage to the engine support, causing misalignment between the engine crankshaft and the transmission input shaft. For fault diagnosis and elimination, check the free travel of the car's clutch pedal, and adjust it if the free travel is too large; for the hydraulic control mechanism, check whether the fluid reservoir has insufficient oil or if there is air in the pipeline and perform necessary elimination; check the height of the inner end of the release lever, and adjust it if the release lever is too low or not on the same plane. Fault diagnosis and elimination: First, determine whether the clutch can disengage or if the disengagement is complete. After confirming that the clutch is working normally, start the engine and perform gear shifting tests during car starting and road testing: shift sequentially from low gear to high gear, and then from high gear to low gear. If a certain gear cannot be engaged or is barely engaged and then difficult to disengage, or if there is a gear collision sound during the shifting process, it indicates difficulty in shifting that gear. When the transmission has difficulty shifting gears, the fault can be diagnosed and eliminated using the following method.