Extreme steering wobble at speeds over 65 mph when hitting bumps on the highway. First time was with about 20,000 miles didnt not know what it was, and it stopped after slowing down. After more times this happened I want to the dealer my warranty was expired and the want to replace the steering stabilizer to start. This problem now happens about every 5 miles on the highway and I fear losing control so I dont drive over 65 mph with this vehicle. What can be done to fix this