Rear End Buzzing

I read a thread today that made me think of my own funny noise. I have OME 919 for weight reasons with the Overland Gear and Roof Tent. When I am not all loaded down, I am low on fuel, or coasting down a hill (clue is weight on the rear end) there is a high frequency buzzing sound and some resistance until I accelerate, similar to an exhaust brake. I wonder if it has anything to do with the angle of the driveline U Joint.

Any ideas. It doesn't seem to effect the VX in any noticeable way other than the noise.

Used the ol' search function and found this, I believe we share a similar issue. I will try to add more grease.

http://www.vehicross.info/forums/sho...ght=rear+joint