Might be possible that your pinion nut has backed off, I have heard of this happening before. If you try to fix it yourself Dodge may not honor your warranty. As for the taller tires, that shouldn't have anything to do with it but you will have to check with Dodge about that.
I too have the Pinion seal leak, and now a growl, but I also just put some new 35 inch Nittos tires on it and I had thought the growl was that, but the noise dissapears when I make long right turns at speed. What can i do to head off a disaster? what is loose? I have rebuild a diff before but no on my daily driver. Will Dodge still honor the lifetime warranty with taller tires on it? I have 122K on it. Any help would be appreciated.