Damn look at the gear marks on the Diff housing!!!!!! Ive never seen that before!
4wheel Parts only covers their install, not the locker. You have to call ARB for that (which is better because 4WP will tell them that you are running big tires with that little diff). They will make you send them the old one and make the determination based off of what they see. Same with the gears. With those gear marks scored into the housing, my guess is that they will probably not warranty it - but its worth a try.
FYI, there was a thread on JKO last year where ARB was NOT honoring warranties on their air lockers if the tires were bigger than stock. Here is a link to their warranty:
http://www.arbusa.com/Contact/Warranty.aspxIts such a detail oriented install, that even the best installer gets one wrong every now and them. Thats why I go to a shop that backs up their work to have gears done. I have had several sets of gears redone after bad installs when the excessive noise didn't go away after break-in, and was glad that I used shops that took care of the problem, no questions asked. And, a reputable shop will always help handle parts warranties because they don't want to cover the costs of lockers/gears/axles due to a bad install. Point is, if you had this done at 4Wheel Parts, they would be covering the gears, locker, and install and you would never have to call ARB. So doing gears yourself often ends up costing more in the end.