Sooner or later had to have something go wrong since she's the daily driver, so I guess I'm due. 
Today I leave work to head home for lunch, and notice a "shhh-shhh-shhh " sound coming from the left rear axle area when backing up. When I straighten up and at speed, I don't hear it.
Any clues on what it could be, and what I'm looking at to fix it? I've done nothing to either axle to date, except change the diffs out on both when I first got it.

Today I leave work to head home for lunch, and notice a "shhh-shhh-shhh " sound coming from the left rear axle area when backing up. When I straighten up and at speed, I don't hear it.
Any clues on what it could be, and what I'm looking at to fix it? I've done nothing to either axle to date, except change the diffs out on both when I first got it.