lift gods! have a question

I recently got a 2 inch BB and 30x950 tires.
looks great ,
after lift i had no vibes in steering, front end, drive shaft, etc. no wobbles.
0-70 drives good. The 4x4 shop didn't even have to align the front it all fell into place so well.
My question is ? when i get to 50 on the highway, i get a quick, hum sound from the back, for just a short second. usually if i'm letting my foot off the pedal at 50. It only happens once in a while and just really quick. then goes away and then may not do it again the next few times.
Is this a vibe problem?
the lift is new and i'm not sure if it will, or all lifts settle after a little while.
and I didn't no if i should take care of (or be concerned about)this hum sound or should i let everything settle ? and for how long? then see if sound still there.
Also no sure what will take care of this? shims, sye? both? cv?
it doesn't seem to be a big problem, didn't no if when the lift settles alittle if the angle might ease up and hum quite.

any info will be a great help! this is my first lift and don't want to drive and ruin anything that i should have fixed easily.
thanks!

I would look for the exaust touching something first.

It's most likely your u-joints yelling at you because they're at bad angles. That's what mine did, but this was every time I'd let off the gas. Check those and then go from there.

It could be anything mentioned above, or a bunch of different things...before you go crazy, just remember one thing.

A lifted vehicle will NOT act or sound the same as a unlifted rig.

Having said that...sounds to me like the rear axle, maybe drain and refill with new fluid. If thats what it is, fluid could be low or have H2O in it. Some axles make a bit of noise their entire lives.

Dont be TOO sensitive about lil noises and such, just because you lifted it a bit, thats all I am saying. You will drive your self NUTS!!!!

Good luck,
CW

I just installed a 2 inch lift with the shackles in the rear and it had a rear end vibration at 40ish mph. It was the exhaust hitting the bigger shackle. Just needed a torch to bend it away..