I just put new 4 new tires on my 90 z24 and on the way home from the tire shop, I developed a real bad wobble in the front end like the tire was coming off. I tapped the brakes and it went away, went a few miles then it happened again. I checked all the lugs and they were tight, it doesn't do it all the time and it doesn't have to hit a bump to start the wobble. Any help with what this could be? Thanks