It'll pull a trailer fine. But don't expect it to pull a huge trailer, the Jeeps wheel base is just too short to handle heavy loads.
My 2.4 with the 6 speed pulls small trailers just fine.
Remember the 4cyl is rated to pull 1000 lbs, but the 4.0 is rated at 2000. I would say you're safe to pull up to 2000 lbs, the only reason the 4.0 gets a higher rating is because it makes more power, not because it has better brakes or anything.