So I have been noticing that my Traverse bottoms out or at least hits the lower spring Insulator (bump stop) when there is weight in the rear and going over a speed bump. I had 4 bags of dirt in an empty car going over a bump at big box, when it hit again - even going slowly. Definitely bottoms out with a 5 people and cargo on a trip. The lower bump stop is actually developing a curve it has hit so much. 42K miles. No leaks in the shocks and i do trailer a boat occasionally. Is this normal wear and tear or seam unusual?