A method and apparatus for adding torsion to a roller tube assembly of a retractable awning which includes a roller tube rotatable about a rod and a torsion spring between the roller tube and the rod. The model number of the roller tube assembly and the required number of turns to obtain the desired torsion is input, by bar code scanner, into a programmable controller. The controller is preprogrammed with data relating to the proper holding assemblies required for various model numbers and boundaries for the data input by the bar code scanner. The controller first verifies that the proper holding fixture is present. The rod is coupled to a drive motor for rotation therewith and the roller tube is secured in the holding assembly to substantially prevent rotation thereof. The rod is coupled and the roller tube is secured solely by longitudinally moving the roller tube assembly into the holding fixture. The drive motor rotates the rod relative to the roller tube for the input number of revolutions to add the desired amount of torsion. The rod is then locked to the roller tube and uncoupled from the drive motor and the roller tube is removed from the holding fixture.