Help me diagnose bearing noise- Video

Hey guys, this is my first time post here. I have a 1996 Jeep Cherokee 4 door. 4.0/AX15 4x4. It has 3.07 gears, rear axle is 8.25. I traded a Snapper Riding mower, which I paid $75, for the Jeep so I have little invested in it.

There is a loud hum accompanied by a wine. I think it is all coming from the rear end. I made a short video of the noise. Please note that the loud hum is not the engine, it is the bearing noise. It is so loud that I have to raise my voice so passengers can hear me.

At low speed, under 5mph, the rear makes a scraping noise which then turns into a hum and wine with speed.

There does not seem to be any play on the pinion shaft.

Link: http://youtu.be/1Pz41M3cMy0

Any help will be greatly appreciated!

A litte update. I removed the rear drive shaft and put the transfer case in 4 high and drove around the block. The noise is completely gone. I replaced the ujoints in the driveshaft and reinstalled it. The noise is back. I don't if this can help anyone pin point what exactly is wrong with my rear axle. Pinion bearing, ring and pinion, etc. I think I can rule out the wheel bearings.

same noise on accel and decel points to carrier or outer wheel bearings. usually with a pinion bearing as a load is put on it during acceleration it gets much louder and quiets down when you let off the gas. does the noise change at all when going around a corner? since the noise went away with the driveshaft removed I would say it's not the outer wheel bearings either, there is no difference in the load on those bearings.

pop the plug on the cover and stick your finger in the hole down into the gear oil, then look at it in the sun to see if you can see metal dust in the oil. if so, it's time to tear it apart.

If you decide to tackle this yourself be forewarned that the 8.25 axle has adjuster rings to set the meshing of the ring gear to the pinion, if the carrier comes out it has to be re set up you can't just pop it back in.

I appreciate the help. I'm glad you mentioned the fact that the 8.25 has to be reset. Bummer... I dont have the knowledge or tools to do that. I think I will be on the hunt for a used axle and hope that it doesnt have the same issues.

Kinda sounds like gear whine.