With that much mud, did you spray your cooler off? The tranny cooler is between the AC condensor and the intercooler. If you have the stock cooler, it is low behind the bumper. Don't know if you have a front license plate, but that opening where is/would be is about where it is. You can see it if you look under the rubber shield between the grill and the hood latch. If you got a bunch of mud up in there your cooler may be blocked which, obviously, will keep your temps up.
Worth a look. Good luck!