The change of 1st jumps when you traction Hyundaih1

Hi, I think the problem is with the gear lock spring. The three shift rods each have a bolt, a spring, and a metal pulley that holds the gears in place. All these bolts are on the outside of the gearbox. There are three of them on the central body of the gearbox, almost at the end. After that comes a funnel-shaped tail section where the driveshaft fits. There are three of them together. Check the springs and replace them (the springs are stiff; if you can squeeze them with your fingers, they're worn out). The gearbox is made up of three parts: the central body, the tail section, and the tail section.
I hope there's still time. Bye.

Friends, I have the same problem. I took the box apart and there's no apparent damage...what do you think it could be?

Thanks and regards.