I have an 08 JKU X and recently have been noticing a high pitched, low whine possibly coming from the drivetrain. I recently changed my front brakes (pads, rotors, and passenger caliper) because the front passenger brake was sticking and causing the rotor to smoke/glow red. I have been hearing this high pitched sound that does not go away when in neutral or when the car is off and costing, but does seem to momentarily go away when going over a bump. I have also noticed a significant decrease in millage but have made no changes to my stock jeep. Never went bellow 16-17 avg. MPG and would refill at about 350 miles. Now its stuck around 15.5 and my gas light comes on around 250-280 miles.

 

check your work , draging?

 

It doesn't seem to be dragging. I replaced the caliper a week after I replaced the pads and rotor because I could still smell the brakes buring. After the caliper replacement, the smell went away.

 

got to hot and burned up bearing in hub?