I had to replace outer axle u-joints at 160,000 miles - installed greaseable ball joints from XRF while the wheels were off. The parts seller says they are getting good reviews from oilfield users - which of course is no wheres near as rugged duty as rv work :)
Next maintenance will be a Borgeson intermediate steering shaft. The Dodge is developing the slight cluk cluk in the steering column you can feel in the pedals, like my Buick developed at 80,000 miles, and like my 86 Land Cruiser developed at 312,000 miles...oh wait it doesn't have any injected plastic u-joints... :)