My '00 GC, 145,000 mi, has developed a whine from 35 mph and up. It's only under steady speed or acceleration, and changes tone over bumps- leading me to believe it was u joints or suspension related. I replaced rear u joints, no change (they were a little stiff). Then I have noticed that on certain road surfaces, the noise is gone! I understand it could be transfer case, front or rear diffs, ect, but now I'm thinking it could be tire noise. I have Dunlop A/T Radial Rovers 245/70 16's with about 60% tread left. All tires look good, and have GREAT traction in the snow. Any ideas?
Thanks for your help, Mark the fireman

 

You probably just started driving with the windows down, haven't you. I'd bet it's tire noise. I have General Grabber AT2s on my WJ and they make noise with the windows down. I hadn't noticed it in the winter. I'm in upstate NY and we just started getting some really nice weather.

 

No, I actually noticed it last fall/winter and just got back here and started driving it again and realized I needed to find out what's wrong! Thanks for your thoughts tho...