Driving home tonight I noticed a noise, well sort of a hum coming from what seemed to in front of the shifter. I was not driving in 4 wheel. I applied the brakes to see if it slowed with the vehicle but didn't seem to. I plan to crawl under the Jeep tomorrow before work to see if I can see anything obvious. Is there any specific problem areas I should look at? I am new to Jeeps so this set up is pretty new to me. I have a 1999 Cherokee Sport with an auto trans. Thank for any and all help.

 

it could be your front driveshaft humming a little, this is normal and it will be hard to distinguish at moderate speeds by slowing down slightly. Does it sound electrical or mechanical?

 

Try pulling (lightly) on the t-case shifter when you hear the humming to see if it goes away.