Mdmetalman,
i believe i would make them give you a copy of what that 90 day warranty covers. In most cases it would cover the power train and engine as most usually do.

As far as this "rental ready" thing they speak of? Well rental trucks have to run and be in good shape too... just because its a rental truck doesn't give them the option to sell or rent a truck that leaks or has in bad condition. Sounds to me like they have already spent more on it than they wanted and they are trying to weasel out of the support they promised. Not to mention they obviously did not check the truck out well enough (or they knew what was going on and dumped it on you all well knowing what was wrong with the truck.)

If the warranty is still valid i would make them do it because if the deny it they are in void of THEIR contract and you can burn em a new one if you know what i mean ;o)

20yrs of business down the drain? that seems strange they would let that go.