As long as I've had my '86 190d 2.5 5spd, the front suspension has bottomed out when I hit big bumps in the road. I recently had the tires balanced, and was told that my front tires had smacked the fender well so many times that they were out of round. They also told me I needed two new lower ball joints. Will replacing the lower ball joints alone help keep the front from bottoming out, or do I need new springs as well?