Stuttering coming from the back end

I just bought a 2004 explorer and it seemed
to run fine until I drove it all day and now I'm
getting some stuttering coming from the
back end when I let my foot off the gas to
decelerate for a light. It's almost as if the
back tires are catching on something and
suddenly the car will pull to the left for no
reason. It seems to shift fine and I don't
smell hit tranny fluid but I can't think of
anything other than maybe a bad drive shaft.
Please help