'96...weird noise

I was driving my dad's '96 S-10 today, and heard a strange noise coming from the rear end. It almost sounded like a tire was loose/lopsided, but I checked them all and they all look alright. The truck is still riding pretty much the same as it always has, so I am inclined to believe that it's not the suspension, but I am really not sure. I'm new to this kind of stuff, but I'm learning haha. I was just wondering if anyone has any ideas what it might be.

I was driving my dad's '96 S-10 today, and heard a strange noise coming from the rear end. It almost sounded like a tire was loose/lopsided, but I checked them all and they all look alright. The truck is still riding pretty much the same as it always has, so I am inclined to believe that it's not the suspension, but I am really not sure. I'm new to this kind of stuff, but I'm learning haha. I was just wondering if anyone has any ideas what it might be.
WHEN DO YOU HEAR THE NOISE? DRIVING ON A FLAT ROAD? GOING OVER A BUMP? IS IT A CONSTANT SOUND, OR ONLY ONCE IN A WHILE?
IF ITS ONLY WHEN YOU GO OVER A BUMP, IT COULD BE A BUSTED SHOCK, (HAPPENED TO ME TWICE)

WHEN DO YOU HEAR THE NOISE? DRIVING ON A FLAT ROAD? GOING OVER A BUMP? IS IT A CONSTANT SOUND, OR ONLY ONCE IN A WHILE?
IF ITS ONLY WHEN YOU GO OVER A BUMP, IT COULD BE A BUSTED SHOCK, (HAPPENED TO ME TWICE)

Something with the suspension ran through my mind, but it rides pretty much the same as it did. So I'm guessing it's not that. It's not constant, but it's occuring probably 60% of the time you're driving.

Something with the suspension ran through my mind, but it rides pretty much the same as it did. So I'm guessing it's not that. It's not constant, but it's occuring probably 60% of the time you're driving.
WHAT KIND OF NOISE IS IT?
IS IT LIKE A THUMPING NOISE, OR IS IT LIKE A WHINING NOISE?

Mine makes a thumping noise when it gets on a bind.

Try just crawling underneath, grab the drive shaft and twist it while looking at the u-joint.
Also try wiggling it. Fried u-joints can make weird noises at times

I was on my way home from work tonight, and 5 minutes into the drive I lost 95% of the braking power. Pedal went all the way to the floor. Whether the two cases have anything to do with one another, I don't know yet. I tend to doubt it, so I'm guessing we have some major problems on our hands with the truck.

Look at the back brakes first then the problems might be related

Better check those lugnuts, too!

EDIT: Don't overtighten!!!! 100 lb-ft of torque is the spec. I had 4 studs break off a front wheel due to overtightening while i was turning around at the shop. I woulda drove it, but i noticed them on the ground as i drove back by.....

might give those lugs a quick tighten. ive had lugs be loose but not visibly, tightened em up on a check and thats what it ended up being :o good idea corning.