Haha, that's a big shocker, huh? So did Rampage never need to go to the CR tank/chamber. Because I was watching Deep Metal, and when he takes the stick, log, whatever you want to call it, out of his chest we see that he is healed instantly. So ever time he was blown up then, did he just heal automatically? And why didn't he just automatically repair himself when Depth Charge took the energon blade to him? He is indestructible, right? Am I just confusing myself? Does anyone understand what I'm TRYING to say? lol
He seemed to need the CR tank after Silverbolt knocked him down the hill and then Megatron removes half of his spark (he didn't even seem to be able to heal from his initial fall since Megatron found him splayed on the ground later on).
After that, though, my guess is that he never needed a CR tank again. I don't remember seeing him in any again.
And I don't think he was indestructible. Those who made him tried to make him indestructible, but apparently they failed.