To make a long story short, I have had several TJ's over the years and this is my first JKU. I bought it with a salvage title due to front end damage. So far, I have replaced the radiator, AC condensor, right side catalytic converter, rebuilt the transmission and added some accessories (i.e. 12000lb winch with cover, front and rear steal bumpers, light bar on front stinger and 33" BFG's). Since the transmission was rebuilt, the jeep seems to not be shifting always when it should and runs hotter than it ever did before. For example, sometimes it will go up to 5k RPM's before it will shift or I have to let off the gas to get it to shift. My mechanic has gone through the entire cooling system since the transmission was put in. I replaced the fan/modular kit because it seemed to be shutting off at higher speeds when I was heading up the mountains. It also runs slightly over the middle on the temp when I am just running around town. What I am trying to figure out is if the transmission rebuild could be causing the jeep to run hotter for some reason and not always shifting the way it should. My mechanic says everything has been checked and it is not the cooling system. He is also the one that put in the tranny so what now?