Under normal/smart wheeling the CV's should hold up fine up to 35's, even w/a locker. However if you abuse them by jumping the truck, hitting obstacles at speed and/or w/the steering at full lock, etc., they will break. I have been running a true-trac in my '91 for 3yrs now and haven't had any issues, and a buddy just ran the Rubicon in his '98 runner with an ARB(using it often) and the CV's held up fine. How long they will last is anyone's guess, their no different then any other item on a trail rig, and is why you should carry spares.
