The invention relates to a transmission drive unit (10) and to a method for producing the same, especially for adjusting a mobile part (58) in the motor vehicle. Said drive unit comprises a drive wheel (18) which can be driven by a drive assembly (42) and which is received on a spindle (16), the drive wheel (18) being rotatably received in a support tube (14). A receiving module (90) can be secured to the support tube (14) and comprises a seat (88) for a fastening device (44) to be provided on the motor vehicle (99) or the element (58) to be adjusted. Said receiving module (90) can be retrofitted and separately installed.