Made it 451 miles in our brand new Grand Design Solitude 380FL and noticed it looked crooked and smoke started coming from the drivers side while going 70 mph down I24 in TN. Pulled over and had a torn tire on both sides, axle was coming off due to missing a U bolt and the leaf spring had come apart. Fortunately we were paying attention and caught this as the 16,000 lb trailer would have flipped taking our vehicle and us with it. Mechanic came out, noticed locking bolts were not used on U bolts that were still in place, he was unable to fix it. Grand Design sent a mechanic down the next evening to put the axle back on so we could take it to the dealership. Took to dealership, they were supposed to make it