w4 dr rubi auto 08 107 k miles when i am in the the highest gear at about 15-1700 rpm i get this thrumming sound sounds like the death wobble' baby sister as soon as I am on the gas though it goes away it doesn't take a bump to start it . either i crawled under the jeep today the rear drive shaft is fine nice and tight I can't move it front has a little play that seems normal . any idea on what that noise is?

 

Could be a number of different things. Can you figure out what direction it's coming from? Is it speed related? If you haven't isolated direction, have a friend ride with you and see if you can't at least get a quadrant (front left, etc). If problem is seen at slow speeds, also have him stand outside and see what he can determine. I've seen tires, axle U-joints, driveshafts all cause strange noises that are speed/acceleration related.

Unless you really think this is DW-related, I'd avoid bringing that up--it will just confuse the issue because there are many things that will create noise, but they have zero to do with DW, and because while DW can be noisy, that's because the entire Jeep is violently vibrating out of control--all kinds of things are shaking and rattling.