We have 16k on our 2006 Xterra and no issues yet. Of course only minimal wheeling. I've heard of some issues with the clutch and the diffs, front and rear. I'm sure it has happened and there may be some weakness. Seems like the new spider gears have helped with the rear diff. But I also feel that a lot of it has to do with driving style. Especially with the front diff. I think the key is to minimize wheel spin when the wheels are turned at full lock and to watch out for spinning tires coming down hard on the rocks. Keep the tires on the ground and use an smooth steady throttle. I also remember people complaining that the Toyota 100 series cruisers has a weak front diff but you still see tons of them on the trail. Just my opinion. Now watch me bust a diff on the way to work tomorrow!!:xxrotflma