Axle weight is often overlooked. I used to work at a cider factory that had its weigh bridge open to the public. They had a few contracts with some companies to weight their vehicles. You'd be surprised at how many vans are back end heavy (over weight for rear axle but still within their gross weight limit. Adding a badly loaded trailer is another issue people can overlook. I never weighted a camper but can see how easy it may be to over load the rear. Bung it all on the bed out the way.