A few of the motors wound spin bearings around 40K miles, but that is well past it. The only major issue is the 3.8 motor burns oil, some only a few ounces per 5000 miles, others (rare) almost 2 quarts.
Considering my "german engineered" BMW I-6 specs 1gt of consuption in 7K in the owners manual and they make an emboidered pouch to keep the quart of oil in i would say a qt every 5-6K on a jeep isn't really that bad, lol