I have a 95 honda civic dx. When im going about 65-70 it begins vibrating/shaking real bad like I have a flat tire in the back. If i slow down to aroun d 50-55 it stops. Also if im on freeway and hit a bump, it will start again randomly. It squeeks in the back whenever i go over bumps in the road. Im thinking its a bad ball joint in the back? Also a new tire just got worn to the threads if that makes any difference. Just wanted some second opinions on what problem might be before i buy another joint/spend the time replacing it. Thanks 