Hi Guys, I have the same 2004 yukon...I have a Howl in the front end. I replaced the unit hubs with Timken's, the old ones were not that bad, but it helped. however this howl is still bad. it is noticable at all speeds but is really noticable when I let off the gas at around 30-40 mph. I think it is the bearings in the front differential. I am probably going to get a wireless microphone system to attach to various locations then drive to see if I can isolate the noise. here are a couple of vids...let me know that you think. or is it front axle ujoints...it has 140k on it.

https://www.youtube.com/watch?v=_1Kn0jvNsxM
https://www.youtube.com/watch?v=MLUX98s4WMI

vids are painfully boring ...

thanks for your help

 

My bosses denali had bad u joints of from driveshaft making noises close to those speeds

 

Just got the Steelman ChassisEar. will hook it up this weekend.