I just bought the truck and havent pulled the Jimmy yet. I am just getting everything ready before I test her out. The truck came with the heavy duty trailering package, power steering cooler, oil cooler and automatic transmission cooler with it, but I do not know the history of the transmission, I do not know if it has had regular service done to the tranny, it has 188,000 miles, should I leave things be with it (seems to run fine right now), or should I service it?