Thanks to a rather nasty Minnesota winter I broke my 108k mile 2007 G35x. The street I live on is rarely plowed and it built up some pretty deep ruts in the snow/ice pack this year. I couldn't drive in the ruts without bottoming out so I tried to drive off-center. The inevitable happened and the car slid into the ruts and I dropped into the rut hard as I slowed for an intersection, kind of knocked the wind out of me.

Immediately after a horrible grinding noise began which is from the rear driver side wheel based on the rust/dust that has built up. It's worse at low speeds and changes sound when I lightly apply the brakes so I had assumed it was a cracked caliper or similar. I've been living with it as I've only been driving once a week for the last two months but am now driving more again. Yesterday I tried backing out of a parking spot and I had to hit the gas pretty hard to get out. The car will no longer go in reverse at all but still drives forward with the grinding.

Doing some reading on the forum it sounds like it might in fact be a bad wheel bearing? It seems weird to me that a bad wheel bearing would cause the rust unless it's really torn up. Does anyone have a better idea? I read that the wheel bearing for the X is not the same as for the RWD and I can't seem to find any writeups for the X. Now that it's nice I plan to pull the caliper off tomorrow but if there's nothing blindingly obvious I'm not sure I can diagnose it.

For a few months before this happened I'd also been getting some abysmal gas mileage (14-16mpg) and I'm hoping they are somehow related.

edit

No comments, but an update for anyone who happens upon this. It appears my wheel bearing might be fine. There is ever-so-slight give with the push-pull test but after pulling the wheel and caliber I discovered that the inner brake pad had come off the backing plate. The pads are relatively new (perhaps 10k miles on them? I'd have to check), all the other pads look brand new and the rotors are in great shape. That pad is now a melted mess of metal and half the thickness of the rotor was gone. This was the result of perhaps 200 miles of driving since the noise began. I'm hoping it actually occurred much earlier and is the source of my bad mileage?