"The principal diamond deposits are located in a region called the Andes Mountains in South America along the border of the countries Peru and Brazil. The area is pretty secluded and if we are lucky, we might be able to do the work undetected." Answers Wheeljax.
"As for Optimus Prime... As you know, he was hurt pretty badly. His circutry is much more complex and advanced than you or I thanks to the rebuilding and upgrades that Alpha Trion added to him when he was originally known as Orion Pax. Ratchet can fix him, but the damage is extensive and covers many of those upgrades. We're going to have to use some of the Ark's equipment to repair Optimus... but if we do that, the Ark will never be able to fly again.
"I'm sure that Impact's generous contribution will help greatly in getting Optimus functional again. But, it looks like it might come down to the Ark or Prime. On the one hand, if we can get the Ark repaired, we can return to Cybertron where we could easily repair Optimus, but then, we'd be without his leadership. On the other, we'd get Optimus back, but possibly never be able to return to Cybertron. As Second in command, Jackknife, what do you say?"