is my rearend going or loose u joints if when im cruisin along at about 50 km/h and gun it then a 1/2 second later theres a clunk in the rear somewhere.
it happens in 2 or 4wd

 

Could be a number of items in the driveline. U joints maybe - do you hear any howling? Could be a little slip yoke thump - what happens when you shift from Park to Drive - any lurching? Could also be some slop in the rear gear - again any noise, like a howl or groan, at cruise or coasting?

 

no howl or groan yet, no lurch/clunk putting into gear, just seems like slopiness looseness in rear drivetrain somewhere and only present when yu add hard acceleration to cruisin speed