well when I accelerate starting at about 30mph, I get this humming/roaring sound... kind of like 4x4 tires... When I put it in neutral or take my foot off the accelerator, it stops. Also when I put it into gear from park, if I try to shift it down quickly to drive there is a clunking noise and kind of jerks the hummer. It also makes that clunking noise if I take it off cruise control manually accelerate. I actually thought it was the tires at first but when I was driving barefoot, I could feel a slight vibration in the pedal, and when I turned off the radio and the ac, I could really hear it then. There is a very slight light hummingbird type vibration in the steering wheel. I can barely feel it. I took it to a gm dealer, they said whoever serviced it prior to me getting it did a bad job. they used hockey pucks for mounts which I just got underneath and saw it... and they said the differential needs to be overhauled and the transfer case needs to be replaced. I am in no way a mechanic so I have no idea what I am looking at, other than the hockey puck. GGGRRRR... Could it be a u-joint, a bushing... anything else? If it is that... what do you suggest, just replace the whole front end, find used parts.... do it myself or take it for someone to do.
