I recently purchased an 05 GC 5.7L from an out of state dealer. As we were 2 hours away from the stealership the transmission started to act up. While the cruise was on the transmission would drop to 4th, 3rd, 2nd then 1st gear. We turned the cruise off and it did the same thing while driving 65 miles an hour!! We have had it less than 3 hours and the this started!!! We would turn it off and wait awhile and then it would drive great for about 10 min then start dropping gears again!! We bought it "as is" so the jokes on us!!! Does anyone know what the problem might be???