>>70727955First of all, Transformers, in most depictions, aren't actually robots. They're Star Trek-style pure energy beings that just use robot bodies to better perceive, move through, and interact with their environments.
Transformer population replenishment varies depending on which depiction you're looking at, and some series have multiple methods of making new Transformers. Actual sexual reproduction is very rare in the franchise, only really being alluded to in two series: Rattrap makes several sexual innuendos in Beast Wars, and the manga for the Japanese Victory series has Decepticon offspring being hidden away out of the warzone.
Non-sexual population replenishment has included:
- liquid metal budding
- artificial cloning
- life infusion via robo-divine conduit
- literally just build a new guy
As for fanfic/fanart fucking, they just got metal dicks and puss. Touch sensors and shit.