A drive assembly is disclosed, including a housing cylinder having a cap end and an attachment end including a first attachment surface, with gear teeth being disposed around an inner circumference forming at least one ring gear. The housing cylinder encloses a planetary gear set including at least one sun gear and at least one set of planet gears. An output interface includes an interface body having an annular attachment lip including a second attachment surface. The first attachment surface contacts, and is connected, as by welding, to the second attachment surface, whereby rotational power may be transmitted from the planetary gear set to the output interface via the gear teeth and the contact between the attachment surfaces.