i see this in all the forums. i can understand if you don't know, you don't know. people, these shocks are rebuildable for a reason, bacause they need to be rebuilt. if you don't have rebuildable shocks in you sled, buy them. the ride is way better. if you ride 600-700 miles a year at a minimum, in somewhat rough terrain you need to get them rebuilt once a year. you won't believe the difference in newly rebuilt shocks. those things take a pounding. when the nitrogen gets mixed in with the oil, as they all will, the shock performance will go bad, and ride performance is affected. i want to see the oil that comes out of these shocks with 1000 plus miles on them. it is the equivelant of never chaging the oil in you car or truck, except your ride performance and butt blows not your motor. once a year guys!!