Duka, in old Pali language, is reference to the off-centre square axel hole in the wheel, meaning bad wheel that causes a bumpy, uncomfortable ride, while Suka is the opposite, the well centered and thus balanced wheel providing good, comfortable ride.
Thus, the monk(s), who later added the four noble truths to the first sutra which is attributed to Siddhartha Gautama Buddha, either knew the original 'duka/suka' metaphor from Siddhartha or used it to describe the Buddhist concepts contained in it, which is likely the case.
Nice and simple, however when it comes to the mainstream interpretations of the first sutra, never mind the rest of it, which is quite a bit,; it gets convoluted broken telephone very fast. For example, in Wikipedia it mentions not the actual Dukkha meaning of uncentred wheel as a metaphor for the ego, the sense of self, uncentred from the soul residing in the spiritual centre, therefore causing suffering and confusion, and that uncentred state of being is what results in karma of potentially endless samsara.
"Dukkha - "incapable of satisfying," "the unsatisfactory nature and the general insecurity of all conditioned phenomena"; "painful." Dukkha is most commonly translated as "suffering". According to Khantipalo, this is an incorrect translation, since it refers to the ultimately unsatisfactory nature of temporary states and things, including pleasant but temporary experiences.[39] According to Emmanuel, Dukkha is the opposite of sukha, "pleasure," and it is better translated as "pain.""
