What's wrong with the first gear of the car?

Vehicle gearbox has the fault phenomenon of uneven gear. Common fault points are:

It may be caused by the internal 1 gear wear of the gearbox.

It may be caused by the damage of the fifth gear synchronizer inside the gearbox.

The gear 1 in the gear lever assembly may be damaged.

It may be that the shift mechanism of the manual gearbox is out of order.

It may be that the three-piece sleeve in the clutch system is invalid, the release bearing is worn, the clutch plate is worn to the limit, and the pressure plate is damaged.

The above are common fault points, and the specific fault points are recommended to be determined after inspection.