Toyota Repair: Noise in rear of 97 4Runner, axle bearings, metal particles

Question
I just purchased a '97 4runner. As I drove it home on the highway I noticed that as I lifted my foot off the accelerator I would hear what sounds like the tires getting louder in the rear(as if the road was wet). I can't hear it as I accelerate so I don't think its the tires.

Answer
Possibly a differential problem, first check the oil level, if it's ok I would recommend draining the oil to see what it looks like, check for any metal particles on the magnetic drain plug and in the oil itself, if the differential doesn't seem to be the problem there may be a problem with one of the rear axle bearings, maybe both.