An internal spur gear drive has a mounting base including one or more sets of motor mounting lugs extending therefrom, for attaching a corresponding number of drive motors thereto. A drive shaft housing containing a rotary drive shaft extends from the mounting base. A drive bell is affixed to the drive shaft distal end, and rotates therewith. The opposite end of the drive bell has an internally toothed ring gear extending therefrom. Each motor drives a pinion gear which engages the internal teeth of the drive bell ring gear to rotate the drive bell and thus rotate the drive shaft as well. The motor mounting lugs are slotted, allowing the motors to be adjusted radially relative to the drive shaft and drive bell ring gear. This provides adjustment for gear lash, as well as permitting different sizes of pinion gears to be installed on the motors for different gear ratios.