Jeep Repair: 2002 Grand Cherokee, cherokee 4x4, vacuum leak

Question
Hello Nathan, I have a '02 Grand Cherokee 4X4 w/ 83K miles, 4.7L. Recently the car feels like it can't decide whether to downshift or not upon excelleration. Especially going up hill. It runs alittle rough at idle too, but when your going about 55-65mph cruising it feels like the tranny doesn't know when to shift. I was towing a small camper this weekend and when I excellerated to get on the interstate it really seemed to lose power and the engine light started to flash. After I slowed down it stopped flashing. This maybe no relation to this problem, but the other day we thought we heard a hissing sound, like a vacuum leak, coming from under the car. Haven't heard it since and we didn't hear it the day on the interstate. Also-I want to up grade my rear shocks, I do tow about 3000# often, what do you suggest? Thanks very much!

Answer
I would really have to test drive this one to tell you much.  At first thought I would recommend checking the transmission fluid, could be low or burnt.  I would also check the engine and transmission for codes.  If you do a lot of towing your transmission may be getting hot.  A Jeep is not really made for heavy towing, but I would recommend an aftermarket transmission cooler.  They are fairly easy to install and help temperatures greatly.  Hope I could help!