Im get this weird sound in the rear it's not the posi its kinda like a whump whump whump only on the right could it be a axle seal or something i really don't know what it is any help?

 

It's hard to say, whump isnt very descriptive. Is there any vibration or squealing durring this? A bad brake shoe could cause this. If your set on the diff being the problem theres a few possible causes, The pinion gear could be hitting the carrier housing via a bad pinion nut allowing the gear to back off, a bearing could be shot, catching a rough spot and even spinning the race, even a bad ujoint could cause a problem.
I cant give you any advice as to what the problem is, I just know a rear end isnt something to take lightly so its best to get it checked if you cannot determine the problem.

 

Sounds like a bad axle, brinnelled where the bearing rides on it... take it apart and look

 

Make sure your backing plates are tightened all the way, I had that same problem and I found they were loose, which was allowing my calipers to move back and forth.
-Mark