A twin drum cable helical gear worm drive garage door opener which provides positive drive in either direction and ensures positive cable take-up and supply spool synchronization and ensures positive position relationship between the trolley and the operator head and has pre-assembled anchored cable ends which allow easy assembly and disassembly. The cable is oriented in the vertical plane which allows the point of cable latch to be in the same load/force plane and minimizes bowing of the support shaft under severe load conditions. The integral motor worm reels and support shaft results in a compact light weight unit and cable tensioning means are provided for allowing easy and simple adjustment of the unit when it is installed.
