Last week I pulled a load to the dump in my 12' bumper-pull dump trailer. Gross weight was around 20,000# like every other day. After dumping I noticed a wobble in the steering wheel, like it was in four wheel drive on dry pavement, or like a wheel is loose, only at low speeds turning corners. I put it on the lift, rotated tires, checked pressure, changed oil, looked the front end over, no paint chipped or cracked that I found, made sure it wasn't stuck in four wheel drive too. Didn't notice the wobble the rest of the week until today after the dump, same thing only worse. This happens loaded or unloaded. Only turning corners at low speed. I have heavier duty coils in the front (for the snow plow) and added a leaf in the rear. Any ideas? Thanks and sorry for the long post.