My suburban makes odd noises when I accelerate and also vibrates,it sounds like its coming from the rear end what could it be?

It might just be a U joint but were never that lucky. To check block tires. Put in nuetral slide under and try to wiggle shaft off center line if it mo0ves then bad u joint. (make sure there are no dents in drivshaft they may cause vibration also) look at u joints if rusty dust coming out from under the caps it may be going bad. If it has carrier bearing in middle of drive shaft make sure its still has rubber in between bearing and mounting strap. Also while at rear of drive shaft push up and down to make sure pinion bearing in rear axle is not out. The yoke the ujoint sits in will move up and down and oil will more likely be leaking around the seal. I you still find nothing rotate shaft both directions if rotates more that 1/4 turn from stop to stop gears or bearings are worn out. Once these are done if still find nothing. U need to jack up both rear tires and use a bar under tires and pick up and down if one side clunks or moves without whole axle moving you have bad wheel bearings. If you havent seen any issues yet unbolt cover on rear end and drain the gear oil should be a magnent in bottom of housing if have alot of metal shavings something inside is bad!