Manifold

I've got a plan, if all of you have the cast-iron manifolds for it.-Prowl, The Ultimate Doom

Manifolds are piping elements that handle and distribute a flow of fluid. What function or form they have in Transformer bodies is uncertain. Metaphorically speaking, to say that one has durable manifolds is to say that he has strength of character, and cast-iron manifolds imply great strength of character.

Oddly enough, this usage seems analogous to references made by humans to certain parts used in fabrication and transmission of reproductive data. It is unclear whether Transformer manifolds share the vulnerability of these components to a direct impact, and we sure wouldn't let the female Transformers know if they did.

References

From Teletraan I: The Transformers Wiki, a Wikia wiki.