My Jeep has got 36,500 Miles on it. 34" Terra Grapplers and 16" wheels on at 8,500 Miles. I hit the trails about once a month, drive mostly highway and around town.
So a few weeks ago when the snow and ice was bad up here in Ohio, i would back out of the garage and get an ear piercing screaching from the JK. As the salt ate away at the snow and ice my screaching went away too. The otherday i heard a small grinding sound and figured i should powerwash my brakes and behind the wheels to get all the crap out from there and i'll replace them soon anyway. The very next day the grinding got insanely worse and i was afraid to push the pedal down to hear that nasty sound, like i was trying to stop an old rusted up dump truck. So the dealer wanted $40 just to take a peek and then another $190 to do one end. Luckily my gf's dad does incredible things with cars and trucks and we decided to do it. So i babied my Jeep to autozone to pick up a set of Duralast Cmax Gold ultra quiet ceramic brake pads for the front (bc thats where the grinding was coming from) so $64.04 later we propped up the JK in the garage and removed the front wheels and tires and took off the front pads to find them not too too bad. Bad, but not bad enough to make the terrible grinding. So sure enough we replaced the front pads and i backed out and the grinding was still present though now definately from the back. So i went and got new pads for the rear, $64.04 later the Jeep was up and tires off and her dad pulled these, what used to be brake pads out of the rear:







and the worst one,




So now i've got new brakes all around and they feel great, and have a lifetime warranty and are ultra quiet

 

Yep, the rears normally go first on the JK. Been told it's due to the fact the rears are set to apply more pressure than the front for safety reasons. That along with the differential break lock system, again for safety.
The wifes JK unlimited was purchased in Nov.06 and currently has 25K miles.
As per the last state annual inspection the rears are borderline. Going to install rear rotors and ceramic pads this summer.

 

I don't think you'll need rotors, my rotors were fine except for a little abrassion from the metal on metal grinding on the back. Even with that they're good to go. the fronts were fine as well, but the price on rotors is big bucks, i think one rotor for the front was about $60.00 These new ceramic pads are awesome though, i'm going to need them when i go play in this winter storm later

 

Your right in the fact that the JK has more rear brake bias than similar other vehicles, but the primary reason for the accellerated rear brake pad wear is the ESP system. 90% of its "corrections", i.e. it trying to fix your vehicle direction/yaw, are made from the rear brakes. This combined with the relativley undersized brakes causes the majority of accellerated wear.

 

I had the same experience, replaced my brakes at 48K miles with the same squealing/metal on metal noise. Front brakes were still good (replaced anyway since I had them off), rear brakes literally fell apart in my hand. Completely destroyed. Got them off before they did any damage to the rotors.

 

so the ESP uses the rear brakes to bring down your speed? That totally makes sense now for the rear brake wear.

 

Its not just your speed. If the computer feels you are starting to drift or spin it will also apply the rear brakes independantly to correct you. By applying the rear brake(s) the vehicle yaw center becomes farther back allowing the front end to come into allignment with the projected course. If the front brakes were used by the computer (and they can be when neccassary) the rear will try to do the old end around on you.

 

Ahhh yea. ESP.