Wheel Bearing?
 

1994, 2.3L, 5 speed

Have this "metal on metal", low grinding sound emanating from the rear end. At first, it was sporadic, but three weeks later it's an everyday occurrence. 1st gear through 3rd, very easily heard; never hear it at highway speeds. Once the noise starts, and I put it in neutral, the grinding will continue as I coast and stops once I am at a complete stop. I drove it around the block a few times, and the passenger-side rear hub was pretty darn hot; all other hubs were cool to the touch.

I think you've found the answer to your problem

It could be a wheel bearing or it could be a rear brake hung up and is now down to metal. I defiantly wouldn't drive it until you have it looked at. I have seen plenty of vehicle catch on fire over a seized up wheel bearing.