Happened once while helping a just haul old mining equipment out of a 12k+ elevation mine. We realized it was there on the dirt road where we were transferring gear from one flatbed truck to another and used a pry bar to remove it no problem. Have not had it happen on my truck but we don't get into 4wd rocky roads much. I taught a class at the Overland Expo on matching trucks and campers and one couple told me they had had a number of occurrences in their experience well off road. The only time they had damage was when they didn't notice it in time. My take away there is that the key is in early detection so stop and look of you are driving in suspect terrain (not the book by John Macphee about ophiolite sequences etc!). To me it is clearly an issue to be aware of but not an issue that means duallies do not have an appropriate place carrying heavy loads off road.