This morning my wife took my 2004 Ram 1500 4X4 with 245K miles to work. About half a mile from home she said the truck made a metalic sound and came to a stop. I drove to the truck, started the truck and made a U turn and drove it back home. When I started driving it it seemed to drive fine but about a block the truck developed a grumble, it seemed in the front right, and came to almost a complete stop. I didn't notice much of a pull to either side. I drove it the rest of the way to my house with a strong drag in the front, sounded like metal on metal. I took my wife using her car. When I came back home I put the truck up on jack stands and could not find any thing making noise, nothing seemed loose. I took the truck down and drove it up and down the road tracing the path my wife drove this morning, no problem. I drove up and down the road a couple of miles and no problem. I did turn it left to go down a road and I made a noise similar to this morning but not as loud. I drove it back home and again put it up on stands. I can't find anything. I do get a metalic clanging noise from the middle of the front driveshaft between the transfer case and front axle when I spin it by hand. I also replaced the front left CV axle last week.

 

I would be thinking RF wheel bearing (hub assembly)

 

I agree.

 

Given you are in the rust belt, its not going to be fun getting that steel hub out of that aluminum housing. Buy some penetrating oil to help get it separated, and some anti-seize for when you reassemble. Most people use the power steering system as a hydraulic press to get the hub out.

 

I thought it would be the bearing but it spins quietly. I replaced the bearings on both sides maybe five years ago, maybe longer. At that time the bearing was growling like crazy.

 

When I had the 1500, I was driving home one evening and suddenly it sounded like I had a rock stuck between my caliper and rotor. I pulled over, looked under - nothing. It was loud, but it didn't cause the truck to stop rolling. Drove it the rest of the way home, and the next day it was quiet again.

 

+1, I had a similiar thought.

 

Jack the truck up and with the wheel still on, try to wiggle (<---fancy technical term) the top and bottom of the wheel. If there's any play, you need a wheel bearing.

 

Just for what its worth...I discovered wiggle test isnt 100 % accurate all the time.
A couple yrs ago wife slid off icy back road into ditch. Little damage but resulting wheel bearing noise. RR wheel bearing got tweaked and became noisey. Nothing found in wiggle test.
Same car recently developed horrendous noise in LF. Again no play found in wheel bearing...until I removed brake caliper, pads and axle nut...then I found wiggle. Lol.
Back to OP post. Drove my 03 Ram about 90 mins on highway. No bearing noise. Stopped for 5 mins in gravel park lot at racetrack. Went to move and RF wheel kept locking up in gravel....again no signs or noises beforehand. Ended up doing repair at racetrack before drive home. just fyi

 

It's true that sometimes when you check things by hand, the bearings won't make any noise. Mine didn't when spun, nor did the wheel rock when I grabbed the top and bottom. The bearings were dry as chip once I replaced them though. Oh and don't replace just one side. That said, wheel bearings make a whooooo sound... low level like plane taking off, increasing with speed.