it has still powertrain warranty. I would ask him straight forward- do you want to fix the problem, or you just waiting, till the 60 month are over? I mean- if he knows and agrees, that there is something wrong- what holds him back to figure it out? and if that means, take the tranny out and open it, well, then you gotta do, what you gotta do. And if they find the issue, report it to the manufacturer and either fix it or change the tranny. easy as pie.
Give him the choice- either give your money back or fix it. I never heard of such, how pansy the dealers are, if it comes to a repair.
I think the biggest problem is, they ain't got nobody who has the skills to do it. I see it every day. believe me. take their repair manual away and they don't even know what a screw driver is.
sorry to hear. hope you have luck with that.