Thanks, Phil. I forgot that one.

The shifter moves because it's engaged with the shift rails, which have the shift forks bolted to them, and the shift forks are engaged in the grooves in the syncro gizmos. With the thrust plate worn, the shaft with the gears and syncros moves fore and aft as the torque is applied to the front and rear of the helical gears, and as the syncro gizmo moves, it moves the fork, rail, and lever.

Not responsible for advice not taken...