rear end issues, tire rubbing on drivers side

Well I just climbed under the car with a flash light and everything seems the same from right to the left side. I checked the leaf springs and they seem fine. Whats weird is I wasn't doing anything when it started, I had just been on the freeway doing 75mph on hwy 280 from San meteo. Not sure why anything would shift at those speeds?
The spacing looks like it's the same on both sides now, but last night when it was rubbing and I stopped to check it you could only get your fingers between the tire and well now there is like an inch?