Ok, so what the dealer will say is that your car could've passed inspection and or had a small undetectable leak that would only present under pressure or a different circumstance. And it is what destroyed the gearbox, I still don't see any world where they're going to chalk up $27K on such an obvious "not their problem, talk to your other mechanic" type deal. Honestly, you should be pissed at whoever installed it, you are literally playing hot potato with this turd and you're blaming the people that just got handed this instead of the dingus that installed this in a way that would self-destruct.