[NumberThree]

I doubt it they didn't do any diagnostic on the truck change what somebody told them but your the second person to mention driveshaft to me.

I'll be the third. Look for any 'play', or 'slop' at all in the drive shaft. In particular, the universal joints at the front and rear of it.
If no play is found there, it could be inside the rear end.

 

[NumberThree]

Ok then ill have a shop put it up on a rack and check it out but what about a loud thump when going from drive to neutral?

As an assembly, any play / anyWHERE in the drive train can cause an audible "thump" when torque is either applied, or released in it. And this includes from the motor/ trans mounts, to the rear main, u-joints, rear end internals, all the way to the leaf spring brackets, then to the axle, then wheel bearings.
Any one link, or part of the entire chain is capable of wearing to the point of inducing play to the rest of the chain which can be heard. So "where it sounds like it's coming from" can really narrow-down the search for the culprit. But you said you checked the mounts, so I assumed that you're now searching from the transmission back at this point?
My previous suggestion was based upon 'where you left-off' in your hunt.