Ok, I'm more of a DIY kinda guy, a loud humming is happening, now this occurred when I put on my open country m/t, I know what it sounds like when the tires start talkin, it's not that, sounds like a bearing is going out so I checked the front an rear diff, no metal shavings in either of them and bearings seem good by the looks of them, I know my front drive shaft needs to be replaced for the boot is gone and it is stock with a 3 1/2" RC lift on my 07JKUX. Could this cause the humming?? It's not consistent either it's only when I am pushing down on the gas pedal when I let off it stops,

 

it could very well be the CV joint on the driveshaft going out. I'd pull the shaft and drive around to narrow it down.

 

Check for missing weights on the driveshafts maybe?

 

Sounds to me like a bad unit bearing. Jack one front tire just off the ground and grasp the tire with your hands at the 12 and six position. Try wiggling the tire. You should have virtually no movement. If you do change it out.

 

I'm having the exact same problem. Going to pull my front ds this week to verify that is what is causing mine. Post up what you find out on yours.

 

Checked for missing weights I'm not missing any

Checked tires no movement but I rotated my front driver side tire an my front DS moves and it sounds aweful it's not smooth at all so I'm assuming that's my problem my DS can I drive without my front DS??

 

Yes with no problems

 

I had the same humming/vibration in my steering wheel, shifter, and floorboards after my lift.
Shop only installed 2 of the 4 axle flange bolts.
I installed and torqued all four. Rides nice and smooth now. Should definitely be a driveshaft issue.

 

My front driveshaft is hosed, but it turned out not to be my problem. The bar attaching to the cross-member that goes over the exhaust cross-over pipe was bent up and in contact with the exhaust. Pulled it out and beat it back somewhat straight this morning and now my vibration is gone.

 

Would you mind taking a pic of the bar? Can't visually place which it is and curious if I have the same issue.