rearend help please

[dppowrstroke]

so the other day i was driving to work when all the sudden a little pop and then some vibrating and humming with a slight tick. i thought my rear end went. i pulled the rear diff cover off and i couldnt see anything wrong. i just did the u joints like a month ago and they are still good. i am just wonder what to look for in the rear. when your driving it sounds like it is coming from the rear. and it is a different noise then a u joint or a wheel bearing. the truck is a 2000 f250 4x4

[ABKTM]

Park brake come apart in the drum?