2000 Jimmy SLE mystery noise

I have a 2000 SLE Jimmy with 110,000 miles on it. About a month ago it started making this odd rubbing/grinding noise that seems to originate from the front passenger side/front middle. The longer you drive it the worse it seems to get. We replaced the front brakes thinking that that may be the problem. Did not fix it. I have it at the shop now, for inspection. My mechanic says it needs a idler arm, but can't find anyother problems. The noise is kinda stumping him too.

On a side note, last winter the 4x4 drive buttons started sporadically switching from 2/4/4lo, then trying to finally stay in 4lo. It would completely switch into 4 lo if I was coming to a stop. It just quit doing this on it's own and went back to normal.

Are they related? Please help

Might not be your problem, but have your mechanic check the driver's door hinge pins. They can make some really annoying noises when they wear out which is often mistaken for a front end noise. I'd be surprised if yours aren't worn out at 110,000 miles. It's a common problem with these cars.

My grinding noise was a bad catalytic converter. I reached under and banged it with my hand and it rattled.