So when I just start moving i can hear i little squeek, then it turns into like rocks tumbling and grinding togeather then the fast i go it just turns into strait grinding, but every now and then, at 60mph and faster it will get realy smooth for a second then go right back to grinding. Just replaced both wheel bearings and it doesent seem like the axle joints have play in them. I have no idea what it is.

 

look at your rotors and see if they have some grooves in them that would indicate the brake pads are dragging. I'm thinking a sticking caliper.

Something to try, the next time you hear it, ease onto the brakes and see if the noise changes. If it doesn't then stab the brake pedal to see if the noise changes, just a quick jab.

Get a video of it so we can hear it.

 

if its grinding - you need to stop driving it because something is wrong and its going to eventually **** up.

spin each rotating part by hand and feel for tightness or roughness. check
wheel bearings
brakes. look for shiny scrapes. also be aware that the "squealers" are built in wear indicators that will begin to drag on an unused section of the caliper when the pads get thin. it will leave a shiny trail, but it squeals, not grinds. collapsed hoses or rusted up calipers can cause dragging.
front drive shaft.
t-case
rear drive shaft, check u-joints.
rear wheels.

a common cause of grinding is a broken snap ring in the t-case rear output shaft. you can probably feel it in the t-case shifter handle.

 

And were the hub nut's torqued correctly after the bearings were replaced