A shipping assembly for a washing machine appliance includes a shipping box that defines a box aperture that is aligned with an aperture defined through a cabinet of the appliance when the appliance is positioned within the shipping box. A bolt assembly is configured for securing the wash tub within the cabinet when the bolt assembly is in an installed position, the bolt assembly including a spacer assembly that spaces apart the wash tub from the cabinet and the cabinet from the shipping box and that includes a retention flange to prevent the spacer assembly from falling into the shipping box. A shipping bolt includes a threaded shaft that passes through the spacer assembly to secure the spacer assembly to the wash tub and a bolt head that is seated against a shoulder of the spacer assembly in the installed position.