What is the metallic grinding/popping sound?

My first thought would be a bad CV joint. Have you looked under your vehicle yet? Check the rubber boots. They like to split open and sling all of the grease out. They then become dry and start making noise. Also take off your front tire and inspect your front brake pads. You may have the drag bars hitting against your rotor if your pads are worn down. Should be something simple if the vehicle only has 45K.

Reeline68: Thanks for your reply, I had looked at the boots and they seemed to be okay (no grease etc.). This problem just occurred in the last 24 hrs so I haven’t had the time to do much more about it. The brakes are definitely a possibility, but they don’t make a noise when braking, maybe there’s a pebble jammed in around the caliper somewhere (I drive on gravel roads often). I’ll get it checked out…thanks.

I had this happen on a 2003 Avalanche. It turned out to be the emergency brake shoes that had worn and were catching on their respective drums. The dealer initially said it was the transfer case.